The idea that dinosaurs never ventured into aquatic niches is perhaps one of the most frequent ways in that media distinguishes dinosaurs from marine reptiles like ichthyosaurs. It is not without merit; the only dinosaurs that produced marine forms were ornithurine birds, and within these only Hesperornithes, penguins and plotopterids became recognisable as cetacean-like animals (smaller, flightless seabirds like the Great Auk and the Flightless Cormorant are usually nested within clades of capable flyers).
However, we now know that dinosaurs did in fact venture into aquatic niches. Much like the Cenozoic saw several clades of placental mammals venture into freshwater ecosystems, the lakes, rivers and swamps of the Mesozoic were equally filled with several semi-aquatic dinosaurs, either hunting underwater like modern cormorants or seeking refuge from predators like modern swamphen. While a fully aquatic non-avian dinosaur most likely never existed, dinosaurs most certainly swam.
Ornithischians as a whole don’t seem to have ventured much into aquatic niches, nor did sauropods (ironically enough). One possible explanation is the absence of aquatic angiosperms through most of the Mesozoic, thus giving herbivores less reasons to take aquatic niches. Some primitive ceratopsians and hadrosaurs have been interpreted as semi-aquatic; while these opinions are usually considered delusional ramblings, several north american ceratopsid and hadrosaur taxa might have engaged in semi-aquatic behaviour, specially species found in the vicinity of the Western Interior Seaway. Both Laramidia’s and Appalachia’s shores were dominated by wetlands, which would have encouraged such behaviour.
One of the most logical candidates for aquatic ornithopods is Lurdusaurus arenatus, a large iguanodont (possibly a close relative of hadrosaurs) from the Aptian of North Africa. This ornithopod is noted as having a low, robust torso, similar to that of an hippo, and limbs that are short and robust, being poorly adapted for running, and also unusually dense, like those of modern diving birds. The short, slightly spreading metatarsus is backed by an enlarged foot pad, in keeping with the massive, spreading hand, a possible adaptation to move in soft substrates. The ecosystem it lived in, dominated by tropical swamps, would have certainly encouraged a semi-aquatic lifestyle, if only as means from protection from predators like carcharodontosaurs.
Thescelosaurids like Thescelosaurus itself have also been suggested as being semi-aquatic, having short, robust legs that are poorly suited for running and having lived in what appears to have been a wetland ecosystem. In these animals, like in modern hippos, capybaras and tapirs, terrestrial foraging was likely the main source of food, with semi-aquatic behaviour being mostly for protection, either directly evading predators or sleeping in the water/islands away from shore like in modern aquatic birds.
Evidence for aquatic behaviour in basal theropods is mostly composed of aquatic trackways made by an animal while swimming. Said trackways are usually attributed to a coelophysid, probably an animal similar to Megapnosaurus. It is possible that said trackways might have been made an animal that was swimming casually, not really being specialised to an aquatic lifestyle. However, coelophysids, with their long rostrums and stork-like necks and legs, might have lived like modern day wetland birds such as herons, wading in the shallows in search of prey.
Dilophosaurs are sometimes assumed to have been dedicated piscivores, though so far this has only been inferred from interpretations of their dental apparatus, which, while unusual, can also be interpreted as apropriate for flesh slicing.
Ceratosaurus is considered by Robert Bakker to be a specialised predator of aquatic prey. It’s tail is described as “alligator like”, making it a good swimmer, while the dentition is supposedly apropriate to capture aquatic prey like fish and crocodiles. It’s inferred lifestyle is overall similar to that of spinosaurs (see below), being a semi-aquatic predator that actually chased prey underwater like an otter or a cormorant, rather than just wading. However, given how frequent it’s teeth are found on terrestrial dinosaurs, this lifestyle is not taken seriously anymore (as 70% of Bakker’s work anyway).
Abelisaurs have been inferred occasionally as aquatic animals, based on their robust limbs. Now that we know that many were actually fast predators like modern cheetahs, or sauropod specialists, an aquatic lifestyle is considered unlikely.
However, a close relative of abelisaurs, Masiakasaurus, is thought to have been a piscivorous animal, thanks to it’s bizarre dentition. Compare to other noasaurs, it’s body is also more robust, though nowhere as near as in spinosaurs, suggesting that this animal was transitioning from a wader like coelophysids to a diver, meaning it probably hunted more often in the shallows.
Spinosaurids were the apex of aquatic behaviour in non-avian dinosaurs. With robust skeletons, gharial like jaws (I’m sick of folks who say they had crocodile like jaws; spinosaur jaws were long and thin, like those of gharials and ornithocheirid pterosaurs, not wide like those of crocodiles; likewise, their bite force was also considerably weak, comparable to that of gharials, unlike the tremendous bite force of crocodiles), nostrils high up the jaws and limbs more adapted for swimming than running after prey, spinosaurids were essencially the closest dinosaurs came to seals and archaeocete whales, being diving predators.
Oxygen isotope ratio studies famously indicated that, rather than just wading like herons, spinosaurs actually swam after prey, spending most of their lives on water. Even the supposedly least aquatic spinosaur, Spinosaurus itself, had it’s isotope ratios much closer to those of modern crocodiles than to those of other theropod dinosaurs, indicating that, rather than a terrestrial carnivore or a “bear analogue”, this animal was living like modern day gharials and similar crocodyllians, spending most of it’s time swimming, coming ashore only to bask, to lay eggs and, occasionally, to sleep (which it could also do on the water, of course). Indeed, spinosaurids appearently outcompeted pholidosaurids, a lineage of gharial like crocodyllians. On other words, spinosaurs were more efficient aquatic predators than crocodyllians themselves! (of course, as indicated behaviour, terrestrial niches were a different matter entirely)
Spinosaurids were not above hunting terrestrial prey; one pterosaur fossil shows evidence of being attacked by a spinosaurid, while an iguanodont juvenile bears similar tooth marks. Modern gharials still do ambush terrestrial prey from time to time, however, so it is possible that such incidents happened on unlucky land animals being near the water. Indeed, such incidents appear to not have been common place; Spinosaurus itself has no evidence of having predated land animals, but there are many fossils that indicate a predator/prey relationship between Spinosaurus and several contemporary fish, such as Onchopristis.
The demise of spinosaurids is similarly fitting for aquatic animals; they were hit very hard by the Cretaceous Thermal Maximum, of which most tetrapod victims were aquatic (such as nearly all marine sauropsid clades with the exception of two plesiosaur clades and mosasaurs). Mid-Santonian remains in China indicate that spinosaurids did survive the CTM, but they appearently never returned to their original splendor, perhaps coinciding with the success of champsosaurs.
Aside from Avialae, aquatic lifestyles are not known in Maniraptora except for one clade.
Unenlagiines were as a whole stork like critters, with long legs and long rostrums, being adapted to hunt small prey. Much like modern wading birds, their legs appear to be less suited for running when compared to those of other deinonychosaurs like troodontids, indicating that they presumably spent most of their time wading on the shallows, safe from terrestrial predators. Likewise, competition with the most defenitely terrestrial azhdarchid pterosaurs would have also encouraged a piscivorous lifestyle (though azhdarchids do appear to have replaced unenlagiines in parts of South America).
One particular genus stands out among unenlagiines. The largest member of this clade, Austroraptor, appears to have occupied a similar niche to spinosaurids; it is far more robust than it’s relatives, and it became much larger, indicating that it too dived after prey instead of just wading. Unlike spinosaurids, it had small arms, indicating that it probably engaged in cormorant style swimming. Considering that unenlagiines used their arms as wings, having small arms is presumably indicative of it being analogous to the modern Flightless Cormorant, having given up flight for an aquatic lifestyle.
There is indirect evidence that a glaciation event existed during the late Aptian-early Cenomanian [approximately 100 MA]. Here in eastern Nebraska the event is recorded by a large-scale, unconformity-bounded sequence of the lower Woodbury Member of the Dakota Sandstone [aka "Muddy-Mowry Seaway" or "Muddy sandstone"]. An eustatic sea-level mechanism lowered worldwide sea-levels by more than 25 m and that this sea-level fall occurred in a rather short period of geologic time. A glacioeustatic component is most likely to account for the observed sea-level changes during the mid-Cretaceous “greenhouse” world. I'm not aware of the existence of large-scale continental ice sheets. But, a Southern Hemisphere polar ice sheet with limited extent and volume compared to “icehouse” continental ice sheets, and global alpine glaciers that were fed by wet climate cycles [a local condition which is well documented during Dakota sedimentation] could account for sea-level fluctuations that resulted in valley incision and subsequent filling.
Alley, N.F., and Frakes, L.A. 2003. First known Cretaceous Glaciation: Livingston Tillite Member of the Cadna-owie Formation, South Australia. Australian Journal of Earth Science. v. 50, p. 139-144.
Bornemann, Norris, Friedrich, Beckmann, Schouten, Sinninghe Damsté, Vogel, Hofmann and Wagner.2008. "Isotopic Evidence for Glaciation During the Cretaceous Supergreenhouse" Science Vol. 319 no. 5860 pp. 189-192
Gale, A.S., Hardenbol, J., Hathaway, B., Kennedy, W.J., Young, J.R., and Phansalker, V. 2002. Global correlation of Cenomanian (Upper Cretaceous)sequences: Evidence for Milankovitch control on sea level. Geology. v. 30, p. 291-294.
Haq, B.U., Hardenbol, J., and Vail, P.R. 1987. Chronology of Fluctuating Sea Levels since the Triassic. Science. V. 235, n. 4793, p. 1156-1167.
Immenhauser, A. 2005. High-rate sea-level change during the Mesozoic: New approaches to an old problem. Sedimentary Geology, Vol. 175, p. 277-296.
Ludvigson, G.A., Gonzalez, L.A., Metzger, R.A., Witzke, B.J., Brenner, R.L., Murillo, A.P., White, T.S. 1998. Meteoric sphaerosiderite lines and their use for paleohydrology and paleoclimatology. Geology, v. 26, n. 11, p. 1039-1042.
Miller, K.G., Sugarman, P.J., Browning, J.B., Kominz, M.A., Hernandez, J.C., Olsson, R.K., Wright, J.D., Feigenson, M.D., and Van Sickel, W. 2003. Late Cretaceous chronology of large, rapid sea-level changes: Glacioeustasy during the greenhouse world. Geology. v. 31, no. 7 (July), p. 585-588.
Sahagian, D., Pinous, O., Olferiev, A., and Zakharov, V. 1996. Eustatic Curve for the Middle Jurassic-Cretaceous Based on Russian Platform and Siberian Stratigraphy: Zonal Resolution. AAPG Bulletin. v. 80, no. 9. p. 1433-1458
Stoll, H.M., and Schrag, D.P. 1996. Evidence for glacial control of rapid sea-level changes in the Early Cretaceous. Science. v. 272, p. 1771-1774.
The Pentagram is a powerful symbol, and without doubt has a place as one of the most prevalent Indo-European signs. From Pythagorean Perfection to the wounds of Christ, the Pentagram is involved with nearly all esoteric traditions in Europe and Asia, and it’s easy to see it’s appeal. Five is a good number for magic, after all.
Most notoriously, the Pentagram has it’s place as a symbol of elemental magick. In nearly all post-Levi systems, it is tradition to have the four classical elements aligned with each of the pentagram’s points, often as a twist of the cardinal directions. Air and Water are paired as the upper pair, left and right respectively (Air is associated with the East and Water with the West), while Earth and Fire are the bottom pair, also right and left respectively (Earth is associated with the North, Fire with the South), and the uppermost point belongs to the loosely defined “Spirit”.
However, this system might not be accurate, as older sources disagree with this notion.
Basics and alchemical views
There are at least three interrelated systems connected with the Pentagram: the classical planets (Saturn, Jupiter, Mars, Mercury, Venus the Sun and the Moon), the classical elements and the four directions. To complicate matters, the pentagram can either be aproached circularly, around the outside, and/or as linearly, tracing the triangles that compose it. Progress, thus is either in 12345 or as 13524.
Alchemical systems have provided multiple alternatives to the arrangement seen in the top picture of the article. Such arrangements include (once again, clockwise from the topmost point) Spirit/Quintessence-Fire-Earth-Water-Air and Spirit/Quintessence-Air-Water-Earth-Fire. Planetary systems include Mercury-Jupiter-Saturn-Venus-Mars, Mercury-Saturn-Jupiter-Mars-Venus and Mercury-Venus-Jupiter-Saturn-Mars; the Sun and the Moon are never excluded, being placed aside, representing, respectively, the active and passive processes.
Agrippa shows a rather unorthodox system, being Fire-Air-Water-Mixtum-Earth. The planetary associations are seen in the image above.
The pentagram first appeared as a sumerian pictographic sign for the word “UB” meaning “corner, angle, nook, cavity”. It quickly adquired associations with heavenly bodies, and became a distinct symbol for directions. Ancient babylonians believed that Heaven was ruled in four quartets (a belief still seen in christian esoterism, associating specific heavenly houses with the archangels), with a fifth point indicating rulership over these quartets and domain over their owners. The heavenly quartets were Jupiter, Mars, Mercury and Saturn, with Venus, represented by the goddess Ishtar, on the top, but otherwise there’s no connection to the specific points of the pentagram.
While Babylonia probably did not have an extensive view of elemental alignments or even a general elemental theory, it is clear that there was a system of four realms identifiable with classical elements: Anu (“Luminous Heaven”), Enlil (“Sky”), Marduk (“Earth”), Ea (“Watery Abyss”). Unfortunately, so far we can only associate Marduk with Jupiter.
The elemental system, clearly invocatory of a ladder of realms (from the more divine to the more physical), has a crucial difference in regards to the greek system, in that Water in the Babylonian system is below Earth, while the opposite happens in the greek system. Plato’s system in particular is of enormous relevance to alchemy.
Egyptian theology had even less evidence for an elemental theory than the babylonian one, although by hellenic times greek influence obviously was present:
In addition, the Sun is associated with Osiris and the Moon with Isis, even though neither had anything to do with those celestial bodies.
Another system is offered by the Ogdoad of Hermopolis, which possibly might actually describe the original system of the egyptians without hellenic corruption. It is displayed as deity couples:
Nun and Naunet: Abyss
Huh and Hauket: Expansiveness
Kuk and Kauket: Darkness
Amun and Amaunet: Hidden
All of these are aspects of Thoth, analogous to the greek Hermes and thus to the planet Mercury, which takes place as the “dominant planet” in this system, much like Venus/Ishtar in the babylonian one.
Ptolemy’s Tetrabiblos provides a system more based on the four elemental qualities rather than the elements themselves. These qualities are based on the dualities Hot/Cold and Dry/Wet, on which the elements themselves are based (Fire is Dry/Hot, Earth is Dry/Cold, Air is Wet/Hot and Water is Wet/Cold). These qualities also take place as a natural order, as an organic system:
Wet, Child, Spring, Moon’s 1st quarter and West
Hot, Youth, Summer, Moon’s 2nd quarter and South
Dry, Middle Age, Autumm, Moon’s 3rd quarter and East
Cold, Old Age/Death, Winter, Moon’s 4th quarter and North
The Cold/Wet transition is rendered as of immense importance; it symbolises the darkness on the Moon’s face, the Vernal Equinox and reincarnation. The directional associations are made by the winds and the anemoi associated with them (Boreas for North, Notus for South, Eurus for East and Zephyrus for West).
There’s also a physical order, using the degree of density; naturally, it’s Earth-Water-Air-Fire, with Earth and Fire being extremes while Water and Air are “mediators”/”means”. The corresponding order is Dry/Cold/Wet/Hot/Dry. Being another cycle, this system has made it into alchemical thought, and also corresponds to natural transitions (the Vernal Equinox, for instance, is the Cold-Wet transition).
Like in the Babylonian system, this one also corresponds to divine ascension, very important to shamanic travelling, although as noted before Water comes before Earth in the Babylonian arrangement, creating a ladder from Abysssal Depths to Celestial Fire.
Ptolemy’s planetary arrangement is more complex:
Mercury: Dry/Wet (alternating)
Venus: Wet, Hot, Air and Water
Mars: Dry, Hot, Fire
Jupiter: Hot, Wet, Air
Saturn: Cold, Dry, Earth
From this, a more elaborate table of correspondences can be made:
With all of this said and done, now to assign the elements. There are several options, but the most logical one is this:
This arrangement is brought about by the nature of linear progress (13524); a more detailed explanation can be seen in the following paragraph, by Biblioteca Arcana:
“First observe that this Pentagram embodies the Physical Order of the Elements; if we stay on the Mundane level we have EWAF, and we can make it a cycle counterclockwise (as in the Alchemical Circulation) by returning from F to E across the horizontal beam of the Pentagram. Likewise, the Pentagram includes the Extended Physical Order (the Metaphysical Order), which includes the ascent to Spirit: EWAFS by a counterclockwise circuit. Of course we get the descent SFAWE by going clockwise. Also, the Organic Order WAFE = spring/summer/fall/winter is still embodied in the lower trapezoid, though the Organic Transition Point (Water) is the left leg of the Pentagram, an undistinguished position. Notice, too, how Spirit, with its four descending lines, surrounds the Cross of Opposition with its Form. (In my previous post I described how the Four Elements etc. are circumferentially bounded by Form or Spirit.)”
According to Ptolemy, Venus/Water and Jupiter/Air are “benevolent” while Mars/Fire and Saturn/Earth are “evil”; likewise, Saturn/Venus are nocturnal, while Jupiter/Mars are diurnal; to compliment the system, the Moon is located outside the pentagram on the left and the Sun is on the right:
The implication is obvious: the Left and Hand paths are represented here, each leading to a shamanic way. The Left path goes through the Earth into the watery abyss, while the Right path goes through the air into the celestial fire. In spite of what idiots like Madame Blavatsky say, neither are inherently good or evil; both represent valid ways to practise magick.
Pterosaurs have gone through an epic renaissance in the beginning of the 21th century, unfortunately only very recently noticed by the public. In 2000, we knew they were elegant, endothermic flyers not unlike birds or bats, but we thought these animals were restricted to aquatic biomes, occupying the niches of modern aerial seabirds (how nobody questioned the absurdity of such a gigantic number of species occupying the same niche remains unanswered), the exceptions being the tiny insectivorous anurognathids (because frankly, even then you’d be called an idiot for suggesting small, bat like flyers were seagull analogues), and the terrestrial, mollusc eating dsungaripterids (which were still connected to aquatic environs). We also had no idea how they reproduced, and even less about many other details about their anatomy. We weren’t even sure of how they flew.
By 2007, our knowledge had radically changed. We know knew pterosaurs were lizard like in terms of reproductive habits, laying soft shelled eggs that hatched juveniles already capable of flight. We learned that their wings were not mere leather, but the most complex membranes amidst tetrapods, with tens of millimetre (or even half-millimetre) thick layers of muscle and collagen fibers. We learned several details of their internal organ anatomy, such as a complex air sac pulmonary system akin to that of birds, that even extended into the wings. We even learned how they flew, and how they took off.
Most importantly, we also learned that pterosaurs weren’t just giant, weird seagulls. Pterosaurs were most definitely not restricted to aquatic environs, taking forms as diverse as the marten like Dimorphodon, the stork like azhdarchids, the antelopine tapejarids, the kite/vulture like istiodactylids and even the boar/bear like dsungaripterids. Pterosaurs didn’t occupy many niches birds colonised, but they branched off in ways that birds never did; in fact, pterosaurs might have been fierce competitors with non-avian dinosaurs, and many forms resemble modern mammals in terms of ecological roles.
The Ecological Bias
In the end though, the newly discovered ecological niches that pterosaurs occupied were not sufficient to dispell the public idea that most pterosaurs were aquatic, that there was an ecological bias towards waterbird/seabird like niches. When new pterosaurs are discovered, more often than not the bias is mentioned, comparing the new terrestrial taxon to the “seabird like majority”.
In the end, no matter how chaotic nature is, there are still patterns, and nothing better indicates this than ecological biases towards certain ecological niches. All bovids are herbivores, but the vast majority are still “antelopes”, with only a few select clades producing bizarre mountain forms, robust beasts or horse and deer mimics. Carnivorans include such bizarre forms as the short skulled felines, the marine pinnipedes and the cursorial dogs and hyenas, but the vast majority still gravitates towards mustelid and viverrid like niches. Gruiformes include stork like cranes, grouse like bustards, loon like sungrebes, and, according to recent genetic studies, the extremely passerine like cuckoos (!), but they still are mostly rail like forms. Pseudosuchians included theropod like macropredators, ostrich like omnivores, armadillo like omnivores, dolphin like piscivores, duck billed omnivores, whale like filter feeders and even various types of herbivores, but a bias towards the iconic amphibious lifestyle was already occuring in the Triassic (although, through most of the Mesozoic and well into the Cenozoic, the basal monitor like terrestrial forms were equally common).
As obvious, the more speciose and diverse a clade is, the smaller is the presence of a bias. You can pinpoint the niches that individual placental clades gravitate towards, but you can’t accurately pinpoint the ecological trends of the entirity of Eutheria.
Pterosaur Niche Trends
Pterosaurs, being a clade of specialised aerial tetrapods, were highly diverse in terms of lifestyles, producing forms ranging from the small insectivorous anurognathids to massive terrestrial macropredators like azhdarchids and dsungaripterids to the bizarre filter feeding ctenochasmatoids and boreopterids. They were more diverse than modern chiropteran mammals, and while nowhere as speciose as birds, they were just as diverse in terms of body plans and ecological niches, and in fact branched in ways birds never did (although birds also colonised niches likely never occupied by pterosaurs). All in all, they weren’t degenerate specialists, but a lineage that competed fiercely with their dinosaurian relatives, and simply had the misfortune of not being able to cope with the KT event (and neither did most birds; 90% of all Cretaceous avian taxa was gone alongside the pterosaurs, thus discrediting any inherent “superiority”).
That said, volant vertebrates, while inherently extremely adaptable, are indeed limited by their aerial evolutionary path. Modern bats, while the second most speciose mammal lineage, are after all almost entirely comprised of aerial insectivores, with a few specialised forms. Neornithes, although a doubtlessly titanic clade of over 12000 species (and those are just the ones that weren’t wiped out due to anthropogenic influence), still follows follows ecological trends; most “generic” neornithes are forms similar to Charadriiformes, being mostly terrestrial or semi-aquatic omnivores. Within Neoaves, however, passerine like forms are also prevalent.
Pterosaurs, for the most part, seem also to follow a distinct ecological bias. However, contrary to what the media claims, or to what we subconsciously gravitate towards due to our upbringing, this bias is not towards aquatic, seabird like forms; within Pterosauria, only three lineages became specialised in piscivorous niches, said lineages being Campylognathoidea, Rhamphorhynchidae (note that, while often classified as rhamphorhynchids, scaphognathines may not belong within that clade, and in any case they appearently weren’t strictly if at all piscivorous, being terrestrial predators) and Euornithocheiroidea; Ctenochasmatoidea was comprised of aquatic forms, but they resembled more closely modern waterfowl in habits, rather than seabirds.
After Mark Witton’s gift to the world in showing that azhdarchids were terrestrial predators, the public seems to have taken this to the extreme and claimed that pterosaurs in general were terrestrial predators. And indeed the ecological bias pterosaurs followed seems to have been that one: most pterosaurs were, in fact, terrestrial predators.
Within non-pterodactyloid pterosaurs, dimorphodontids, scaphognathines and wukongopterids are all thought to have been predatory animals; their jaws exhibit teeth designed to pierce like those of their piscivorous cousins, but they considerably more robust, less designed to hold slippery prey and more to crush through bones. Likewise, their inland habitats make a piscivorous lifestyle suspicious at best, and both dimorphodontids and some scaphognathines show a decrease in their flight capacities, having become more specialised to stalk prey on the ground.
In pterodactyloids, the development of better adaptations for terrestriality without sacrificing flight capacities allowed this type of lifestyle to become rampant. The most basal ornithocheiroids, isitodactylids, had short, serrated teeth, like those of a shark, indicating that they fed on flesh, presumably being scavengers like modern kites and vultures. “Generic pterodactyloids”, like Pterodactylus itself and basal dsungaripteroids, are pretty much crow/seagull like animals, being small sized generalistic carnivores that foraged on the ground (or, in Pterodactylus‘ case, also in the water) in search of small tetrapods, invertebrates or carrion. Azhdarchoids became even more specialised in hunting small prey on the ground, having developed long necks and toothless beaks, while the limbs also elongated and in fact developed similar proportions to those of modern ungulate mammals, indicating their ability to run efficiently. Their wings also became shorter, as they became further specialised to hunt on the ground.
Derived dsungaripteroids, however, took this lifestyle to it’s logical extreme. Their skeletons became more robust, to the point that their flight capacities were barely superior to those of modern Galliformes. Their jaws, meanwhile, became progressively more robust, and developed a sharp rhamphoteca at the tips, with the lower jaw consistently bending upwards in a hook (in Dsungaripterus itself, the upper jaw also forms an upwards oriented hook); generally, this was interpreted as specialisations towards molluscivory, but the inland habitat of these pterosaurs casts doubt about this. Most likely they were generalistic carnivores, feeding on not only mussels, but also carrion and living vertebrates, up to the size of small dinosaurs. The poor flight capacities, alongside the robust, upwards bent jaws (remaniscent to some extent of the jaws of the pseudosuchian aetosaurs), would have meant a lifestyle probably not too dissimilar to that of modern boars and small bears, or even that of small to medium sized terror birds.
With each new discovery, the idea that pterosaurs were seabird analogues becomes further an artifact of ignorance. Some pterosaurs were indeed piscivores, but in the context of the clade as a whole, these were aberrant forms, as their relatives occupied inland biomes.
Julio Lacerda deserves special credit, because he was the inspiration for this post.I plan to use his pterosaur pics for a greater purpose than this post, and I greatly thank him for his permission on the matter. Go check his blog:
Appearently, through dubious research, the animal that most represents me is the swan, both as a totem and as a daemon (read His Dark Materials, scum). I must say I’ve always felt drawn towards large, white waterbirds, but it is still something of a shock.
Regardless, swans, I think, are very interesting for mutiple reasons. They seem like nature’s experiment at creating something that should not exist: from an ancient small, bipedal theropod came a being that is fautlessly angelic, with a serpentiforme neck, a soft, platypus like beak (Anseriformes are notable amidst modern birds for barely having a true rhamphoteca, restricted to the very tip of their jaws as that iconic “tooth”; the rest of the beak is covered by a very thin and soft keratin covering, almost like colourful leather), and angelic wings capable of breaking human bones. They are what I like to call an “angelic abomination”*; by themselves, they’re beautiful, but their anatomy seems like an abominable distortion when compared to even other birds.
*Yes, I do realise how redundant that is. If you don’t know why, then you don’t know how judeo-christian angels look like (hint: they’re not pretty people).
On top of that, they’re specialised aquatic herbivores living on inland waterways on cold climates. Surprised, huh?
How the “ugly” duck[ling]s ascended
Swans are almost consistently classified as within Anserinae, the clade that also includes most anatids called geese. I’ve seen arguments that anserines are polyphyletic and thus not a true clade, but for the most part they still tend to be classified as a single clade. True swans almost certainly diverged from other geese early on, during the early/middle Miocene; the modern south american Coscoroba Swan (Coscoroba coscoroba) is sometimes considered the closest living relative of Cygnus, thus rendering it a “true swan”, while some studies place it at the base of Anserinae while Cygnus diverged from the main lineage imediately after. Regardless, Coscoroba is perhaps a living image of what the swan ancestor probably looked like: a red billed, medium sized bird not too different from more “generic” dabbling ducks. Unlike other anserines, which are specialised terrestrial grazers, swans are specialised aquatic herbivores, feeding on vegetation growing on water, both at the surface and on the bottom, so their ancestor was certainly a rather generalistic anatid. Unlike other duck lineages, this lifestyle appearently did not warrant specialisations to diving, just the much cheaper development of a long, sauropod like neck in order to reach the bottom; indeed, given that swans are huge birds that take part in long migrations, becoming specialised divers would perhaps be a handicap.
Swans are thought to have evolved in western Eurasia, more or less in the area that today is eastern Europe; at the time these birds evolved, the Paratethys Sea still covered large extensions of Europe and western Asia. Fossil sites from this epoch in eastern Europe unveil rich wetland and coastoal fauna; crocodyllians, choristoderes, sirenians, several dolphin-like basal odontocetes (some possibly related to the modern Ganges/Indus river dolphins), pseudodontorns and giant salamanders are among the many species present in those estuarine ecosystems that are obviously absent from modern Europe. The early swans were the product of these ancient subtropical coastoal wetland ecosystems, and might have even fed on seagrasses alongside the now gone european manatees and dugongs.
Subsequently, Cygnus became widespread across the northern hemisphere, but their diversity center seems to have remained in Europe, even after the Paratethys and it’s coastoal wetlands began to dry out; only by the Pliocene did the european species began to decline in number, presumably as the climate became colder on the onset of the ice ages. Currently, the only species occuring naturally in Europe are the sometimes sedentary, sometimes migratory Mute Swan (Cygnus olor), the very migratory Whooper Swan (Cygnus cygnus) and some wintering populations of Bewick’s Swan (Cygnus [columbianus?] bewickii), but the ancient european swan diversity blessed the continent with yet another species in the Pleistocene:
Cygnus falconeri was bigger than the modern largest swans (a tough competion between the mute and trumpeter species) by one third, the largest individuals being as tall as 2,10, being slightly smaller than an ostrich and certainly capable of attacking the scalp of most people. This bird was likely the largest animal in it’s insular ecosystem of Pleistocene Malta; the native dwarf elephants were considerablyheavier, but dwarfed (eh) by it’s enormous frame, likely augmented by it’s enormous wingspan. Given it’s size (modern swans already have efford taking off) and it’s insular habitat, it was most likely flightless, but it retained it’s adaptations for flight, namely the enormous wings (it is possible that, much like the Nene-nui, Cygnus falconeri was “semi-flightless”, with some individuals capable of flight, others theoretically capable of flight but not displaying the behaviour, and others completly flightless; interbreeding with mute swans could have muddied things further, just like the hybridisation between the Nene and the Nene-nui).
Unlike modern swans, Cygnus falconeri probably foraged more on land, something encouraged by the dry mediterranean climate and by the absence of competitors and predators (Gypsmelitensis was appearently the largest maltese predator through most of the Pleistocene). In particular, it’s long neck could had allowed the exploitation of browsing niches, much like an avian giraffe (or, if you preffer, an anatid moa/vorompatra), although given the prefference of modern anserines for grazing, I suppose that it was probably a closer equivalent to the long gone diplodocid sauropods, which were long necked grazers as well. This bird governed Malta through most of the Pleistocene, but became extinct before human beings arrived to Malta. The general consensus seems to be that it disappeared due to the temporary landbridge that formed between Malta and Italy, allowing predatory mammals like wolves, hyenas and bears to feast on the native fauna, which evolved with vultures as their only predators; however, I’ve seen discussions that declare a much latter date for the extinction of Cygnus falconeri.
Meanwhile, North America and Australia appearently became the centers of swan diversity, with several species known from fossil sites in both landmasses; most of these species became extinct when humans arrived, just like the contemporary giant mammals that co-existed with these birds. Swans never really became established in Africa, and so far only one species is known from South America.
Swan phylogeny has often been the subject of debate, but there seems to be a consensus that two groups are formed: one consisting of the Black-necked Swan (Cygnus melancoryphus) and the Black Swan (Cygnus atratus), the two southern hemisphere species, and another group composed of the Arctic species, the Whooper Swan, the Tundra Swan (Cygnus columbianus), the Trumpeter Swan (Cygnus buccinator) and the Bewick’s Swan. The first appear to be clearly left-overs of an older lineage common in the northern hemisphere, reduced to southern hemisphere relics (the extinct australian forms, as well as a few of the extinct north american ones, were almost certainly part of this lineage as well), while the latter evolved much more recently, from a single population that was fragmented by the expansion of the glaciers, and indeed nearly all Arctic swans look the same (the trumpeter probably diverged first, followed by the whooper).
Things are more problematic, however, when it comes to the placement of the Mute Swan. Different studies have either placed this species as part of the southern hemisphere swan clade, sometimes as even the sister taxa to the Black Swan, or as having diverged after them and thus being more closely related to the Arctic swans. In terms of behaviour, mute swans more closely resemble their southern relatives, being mostly sedentary and only occasionally migratory or nomadic, although the migratory behaviour of the Arctic swans is most certainly a more recent adaptation, having evolved in order to cope with the ice ages. In terms of colouration, both the mute swan and the southern hemisphere species have bright red/orange beaks, while the Arctic swans either have completly black or black and yellow beaks, although again it is possible that the Arctic species evolved from species with red beaks that lost that colour in order to cope with the harsher climates. Curiously, both southern hemisphere species are dark in colour while their northern cousins are pure white; this in part supports the idea that they are closely related and that may indicate that the ancestral swans were dark coloured, but if the Mute Swan is part of this clade, then it lost the dark feathers for some undiscernible reason.
Swans are Crane mimics
Swans, as previously discussed, are specialised herbivores, feeding almost exclusively on aquatic vegetation, and on submerged vegetation in particular. For this end, they became long necked birds, well adapted to probe deep waters, and they thrive on cold freshwater ecosystems such as the lakes that dot the tundra. They’re also white birds that migrate for miles each year, and are monogamous even though their closest relatives are infamous for their deviant sexual habits. Their trachea’s form loops on their sternum, even diving on it’s inside, an adaptation with the means of aiding with their voacalisations; due to this loop, and their long neck, a vast section of “dead air” means that swans rely a lot on anaerobic muscle power.
If this sounds familiar, it’s because you’re at least somewhat aware of the existence of Gruidae, a lineage of stork-like specialised Gruiformes known vernacularly as “cranes”. And within this clade, it’s the genus Grus in particular that I am talking about; the other cranes spend most of their time foraging on land like anorectic bustards, but Grus cranes specialised in feeding in wetlands like their rail relatives, using their long beaks and necks to gain access to submerged aquatic vegetation to feed on. Unlike swans, they aren’t very competent swimmers, but when you have long legs to wade around, swimming becomes irrelevant. Specially since most wetlands are not even very deep anyway.
Indeed, both swans and most Grus cranes function similarly in their freshwater ecosystems; both birds are almost exclusively vegetarian, feeding on the same plant species, both are primarily Arctic migrators with a few species living permanently on warmer climates (Australia in particular was until very recently a hotspot of both crane and swan diversity), both nest on the ground/shallow waters and both are vicious enough that the only predators that consistently pose a threat are eagles. Even the native mythologies about cranes and swans tend to offer similar connatations to both birds.
Indeed, I dare say that competition between both clades seems to have shape the evolution of both Cygnus and Grus; in North America, the native cranes tend to be more carnivorous, while the european and australian species are generally more terrestrial, all coinciding with the existence of hotspots of swan diversity; there’s also no cranes in South America, and the presence of a single swan species suggests that the latter won the evolutionary battle for the continent’s appearently few resources that matter to these birds. Likewise, swans as a whole are less common on the hotspot of crane diversity, eastern Asia, and their wintering spots tend also to be different, as an efford to avoid competition.
East of the Sun and West of the Moon, mating with both in exchange for eggs
As to be expected, swans were always seen as icons of angelic grace. Their white feathers were honoured in India as the symbol of ascension, representing enlightment as they were always on water but never wet, as saints were always on this world but never attached. The Celts honoured the swan as the herald of Lugh, god of the Sun, love and arts, while the Greeks likewise connected the swan to their own god of light and rationality, Apollo[n]; saint/goddess/whatever Brigid was also associated with swans, as was Artemis and Selene, the latter sometimes depicted with swan wings. Swans feature in norse mythology as drinking from the Well of Urd, painting their feathers white and obtain countless wisdom; the greeks called the black swan “avis rara”, mocking the notion of dark coloured swans as impossible (the swans, of course, got the last laugh), while all over Europe and North America the swans were seen as holy harbingers of Spring, their white wings signalling the rise of the glorious Spring Sun while the ice melted.
However, somestimes swan symbolism gets plain weird. Zeus is iconic for turning into a swan to rape Leda, a legend thought to have been brought upon by the nasty raping habits that Anatidae as a whole praises (amusingly enough, swans don’t seem to engage in rape behaviour, but contrary to popular perceptions of monogamy, they are rather promiscuous, cheating on each other all the time; monogamy is just social among birds, rarely extending to perfect fidelity). In Australia, swans often represent ancient tribes that became prideful or evil in some way, being turned into swans in order to warn future generations. In Finnish Mythology, a swan lives in Tuonela, the world of the dead, swimming in it’s river in solemn creepiness.
Even the seemingly obvious connatations with Apollo seem rather non-inoccent upon further inspection. Apollo, like his sacred birds, is a god of light and sometimes of the Sun (when mixed with Helios) or the Moon (in his aspect as a silver plaguedealer), and his association with arts has been linked with the mute swan’s own lack of vocalisations, in the famous Swan Song that heraldic swans sing as they’re about to die. Apollo is also a god associated with homosexuality (or, more accurately, bisexuality, but I digress); his most iconic lovers were Hyacinth, Cyparissus, Hymenaios and Branchus (the latter also being his son).
In reality, swans are among the animals with the most cases of documented homosexual behaviour. Over one quarter of all black swan pairings are thought to be between males of the same sex, and the same is thought to be the case of other swan species. This is notable because most homosexual pairings among birds are thought to be lesbian in nature, with seabirds in particular often having entire colonies of female/female pairings. Swans, penguins and flamingos, on the other hand, seem to exhibit primarily male/male couples; this dichotomy between male homosexuality and female homosexuality among birds is not well understood, but it is thought to be derived from their breeding strategies.
Contrary to what homophobes think, being gay =/= impairs reproductive advantage. In many birds colonies where homosexuality is prevalent, the opposite sex still functions as donors. Male seagulls provide sperm, female swans provide eggs. As often noted, this is not indicative of bisexuality, as the birds in same sex pairings may only mate once or twice in their entire lifetime with a bird of the opposite sex, thus indicating that it’s only opportunism brought about by parental instincts. In most birds, said donors tend to be the males, because they are sadly the most expendable gender when it comes to reproduction, but in swans the male is stronger than the female as usually amidst anatids, so females in areas where homosexual behaviour is predominant are set free from their reproductive duties, left to enjoy an hedonistic lifestyle while the males receive fertilized eggs.
Both males in the couple then incubate the eggs and raise the chicks, much like hetero pairs. Studies show that, because males are stronger than females, chicks raised this way have higher chances of survival in harsher conditions, with predators consistently kept at bay. However, this strategy seems to work less efficiently when conditions are less harsh, presumably due to some advantage straight parents have in normal conditions. This doesn’t seem to be the case with lesbian couples amidst other bird species, whose efficiency doesn’t faulter when conditions are harsh or not.
Directing swan homosexuality with deities associated with homosexuality seems at large fitting, even if in retrospect. The concept of the Swan Song is nearly always accompanied with the concept that the Mute Swan lives in agony, tormented by existence and crying a final hymn when life reaches it’s finale, dying in joy to ascend to the Sun (in Pythagorean Theology, Helios acts as a psychopomp, because in reality there are five suns; the physical Sun we see, Helios, and the Suns in higher realities, the next one in the line being Apollo, which receives the ones who found enlightment).
A life tormented, to find joy in death, is easily the most chilling connatation the swan has received, not only as a metaphor for repressed homosexuality or people with suicidal wishes in general, but because swans are white, and white, not black, has always been the colour of death in nearly all cultures, with black only representing death in modern christian thought. To see the swan as harbinger of death is not delusional (swans can still break your arm, after all), but rather an expression of purity gone wrong, of a life so pure that it doesn’t belong to this reality, that belongs decaying in a swamp or ascending to the Sun like a phoenix. Both Greek and Finnish mythology intersect in this aspect, given the previous mention of the swan in Tuonela.
In life or death, the swan is something that should not be, an angel from a reptile, a crane in a goose, a soul in constant agony in the most cheery of all bodies.
Historically, and unfortunately still today on most popular culture inaccurate crap, pterosaurs were viewed as exclusively soaring abominations poorly adapted to flapping flight and incapable of taking off from the ground. Add in a rhamphorhynchid fetish and the image of the pterodactyl became that of toothed, long tailed wyverns, often swooping down from the Heavens to carry prey like eagles.
However, in modern times pterosaurs are understood to have been extremely efficient flyers, perhaps the tetrapods most adapted to aerial locomotion that have ever lived, with very complex wings, high metabolisms, catapult style launching. While long tails are turning out to be common among pterodactyloid taxa, their rostrums, toothed or not, are though to have been their weapons, and their feet were plain like those of bears and other plantigrade mammals, playing no role in grasping prey.
However, the traits once associated with pterosaurs have turned out to be common in non-ornithothorace flying dinosaurs:
– Like the classical pterodactyls, these animals were mostly gliders. While I think it’s obvious microraptorines and the like were capable of powered flight, it is very clear that the fact they couldn’t raise their arms much above the back got in the way, forcing these animals to rely mostly on gliding with occasional shallow strokes to stay airborne for longer. Indeed, microraptorines show extensive adaptations to dedicated gliding flight, and Rahonavis, with abnormally long arms, was likely a specialised soarer. By contrast, while pterosaurs were far more efficient at gliding, we’ve now realised that they show a much wider range of flight styles, and were clearly nearly always well adapted to powered flight, just like modern birds.
– The fact that non-ornithothorace maniraptors could not raise their arms much above the back also prevented ground based take-off, meaning that trees and cliffs were necessary as take-off spots. Since always that we’ve known that pterosaurs could raise their arms above the back, but the fact that they could take off quadrupedally like bats further shows that they were capable of ground based take-off, allowing them to colonise terrestrial niches without sacrificing flight.
– Deinonychosaurs had long tails and teeth, just like cartoon and toy pterodactyls. Seeveral species appearently also had crests, although ones made of feathers. True pterosaurs obviously also had teeth, long tails and crest, and in fact some ornithocheiroids and wukongopterids combined the three, so this trait is not unjustified in modern pterosaur iconography.
– The idea that pterosaurs could kill and carry prey eagle style was never taken seriously to begin with, as their feet are plain and barely able to grasp anything, just like those of plantigrade mammals. However, while carrying prey was also impossible for deinonychosaurs as their hallux was vestigial as in most theropods, their iconic killing claws certanly had a role in killing prey (although that exact role has been debated endlessly).
My latest dive into speculation has not been very successful. However, regardless of whereas Samrukia was an azhdarchid, a thalassodromedid, a bird or something else entirely, I’ve adquired an unhealthy obsession with Thalassodromidae after that post. Mark Witton fancies them a lot as well appearently, so at least I can confort myself in it being a normal obsession.
Composed of two genera (Thalassodromeus almost certainly with a single species, while the number of Tupuxuara may vary between one or three species depending on who you ask; there’s also the possibility that all these pterosaurs might be within the same genus, although most likely not the same species), Thalassodromidae is an unique product of the azhdarchoid radiation in the early Cretaceous, having been part of the pterosaur golden age. For the moment, they appear to have been exclusively south american; possible remains have occured in Texas, Morocco and Europe, but they might be assigned to other azhdarchoids. Alongside Pteranodontia, this would make thalassodromids the only other pterodactyloid clade with significant geographical restriction (in contrast with the usually cosmopolitian distribution of most pterodactyloid clades), which could had played a role in their demise, although in both cases there are probably simply taxa that lived elsewhere and weren’t preserved.
Thalassodromids have been in the center of an intense debate in regards to azhdarchoid phylogeny, focusing on whereas these animals were closer to tapejarids or to neoazhdarchs (azhdarchids and chaoyangopterids). Things got even more complicated as one study (Felipe Pinheiro, 2011) dragged chaoyangopterids into “Tapejaridae” as well, rendering Neoazhdarchia nonexistent. However, to my knowledge Neoazhdarchia has been recovered yet again, and frankly I’m leaning more to the Neoazhdarchia interpretation. Thalassodromids have only been included in “Tapejaridae” due to the shape of the crest base, which is frankly not very impressive. By contrast, they share with azhdarchids and chaoyangopterids large nasoanteorbital frenestrae that go significantly above their eyesockets (something unique among pterosaurs), straight jaws with shallow mandibles, long rostrums in front of the nasoanteorbital frenestrae, straight or conclave margins dorsally on the rostrum and a well developed notarium. Thalassodromids also appear to have their shoulders in the same position as in neoazhdarchs, unlike the “plane position” as in tapejarids, futher rendering them more likely to be neoazhdarchs.
What interests me most, however, is the palaeobiology of these pterosaurs. Originally thought to be skimmers, this notion is now considered pathetically inaccurate at best, given that these animals not only were too large, but lacked every single adaptation required for skimming. Other than that, however, not much has been done to examine what exactly they did. Being azhdarchoids, and neoazhdarchs at that, it is almost certain that they fed on the ground, hunting small animals on the foot like modern seriemas and secretary birds, and indeed their relatively short wings and well developed hindlimbs seem to suggest this. Notably, their necks are shorter and more flexible than those of chaoyangopterids and azhdarchids, and they are better flyers than tapejarids (whereas they shared their adaptations for climbing I don’t know), and so it has been suggested that they were rather generalistic predators/omnivores, feeding on whatever small animal or carcasse they found. This seems particularly true for Tupuxuara, but Thalassodromeus seems more specialised. It’s jaws are noted as being superficially scizzor like, not very efficient for grabbing prey, but perfect for slicing flesh. Combined with the short neck. this means that Thalassodromeus could had efficiently attacked large prey. While it’s too early to properly crown it as the “pterosaurian eagle”, I do think modern Haliaeetus offers a decent analogue, since they too are opportunistic predators/scavengers with a slight tendency for larger prey than the larid Charadriiformes they co-exist with.
An equally interesting part of thalassodromid palaeobiology is their growth. Studies regarding Tupuxuara show that the animal grew their crest along the upper jaw, and that only full grown animals had the iconic giant, flamboyant crest, proving that indeed pterosaur crests were just display devices, having no aerodynamic use. Appearently the fossils turned out to belong to Thalassodromeus rather than Tupuxuara if Mark Witton is to be believed, but the basic point remains. While not something that I believe had been explored in detail, it appears azhdarchoids had a slower growth rate than ornithocheiroids, or pteranodontians at least; while Pteranodon is notorious for the neornithe like growth rate, reaching adult size within an year, thalassodromids appear to have taken several years, much like in modern megapodes, thus following the iconic pterodactyloid model of occupying several ecological niches as they grew (hence why the previously mentioned idea that these animals might represent different growth stages of a single species – predictably, this works better with the three Tupuxuara species, with Thalassodromeus truly representing a different species). Unlike non-pterodactyloid pterosaurs and most sauropsids, which grow until they die, pterodactyloids had a clear finite growth, with the animal growing for many years but eventually ceasing to. Studies on Pterodaustro show that pterodactyloids reached sexual maturity before reaching their maximum size, much like in modern slow growing mammals. Yeah, much like us, pterodactyloids had puberty in their teenager years. Although at least they laid eggs.
Thalassodromids had a very short temporal existence. Unless the moroccan, texan and european fossils attributed to them aren’t something else, these animals are known only from the Santana Formation in Brazil, dating to the Cenomanian. With the presence of much earlier chaoyangopterids and azhdarchids, it is almost certain that the temporal range of these animals extends further back in time, and given how they are considered to be outside the Chaoyangopteridae+Azhdarchidae clade, they were probably a quite long lived ghost lineage, possibly dating back to the Jurassic/Cretaceous border. Living as recently as 92 million years ago, they are among the most recent known non-azhdarchid azhdarchoids, but they too appear to be absent in the post-Turonian Cretaceous (keep reading though), much like a good chunk of the known pterosaur taxa. The exact reasons for their disappearence are not well established; as I previouslyindicated, pterosaurs being replaced by birds is unlikely, and in fact not taken seriously anymore among pterosaur specialist circles. In the case of thalassodromids, though, I’m more willing to accept possible replacement by birds than in other pterosaurs because of their generalistic lifestyle, which would perhaps not been very different from that of countless enantiornithe and ornithurine taxa.
However, a more likely reason for their disappearence is probably competition with their relatives, the azhdarchids. A number of post-Turonian azhdarchids have rostrums remarkably similar to those of thalassodromids, Bakonydraco and TMM 42489-2 in particular having been historically mistaken for thalassodromids. Either these azhdarchids replaced thalassodromids directly, or merely filled vacant niches left from earlier extinctions.
Still, it is possible that thalassodromids did survive after the Turonian, although so far remains possibly identified as thalassodromids might represent more azhdarchids that converged upon them. I’m waiting for Mark Witton’s book for clarification.
Previously I’ve brought up the idea that Samrukia might be a thalassodromid, because it was the only pterosaur clade that I think that have similar enough jaws. Darren Naish told me such wasn’t the case. Atypically of him, he did not provide further explanations as to why it isn’t the case, and I am genuinely curious. I don’t submit myself to authorithy without evidence, as even widely respected biologists need to justify their stances, but for the moment I won’t force my ideas about Samrukia‘s identity, because I’m sincerily confused about the specimen. While the thalassodromid identity is attractive, it is just that, an idea, and there might be countless other options, including more basal azhdarchoids, merely a juvenile Aralazhdarcho or even something else altogether. Hell, I even think my previous statements about it not being a chaoyangopterid are bogus now.
Still, I’m not the only one attracted to the Samrukia mystery. David Peters, infamous for his lizard pterosaur fetish, has given a shot at trying to pin point what exactly Samrukia is, and his answer is basically this:
And before you question my sanity, you should question David Peters’, for he was the one who suggested this. Not that anyone is questioning his sanity after 2006 though; I believe it has become really obvious.
His basic idea is that Samrukia‘s ramus are closest in shape to those of Criorhynchus, an ornithocheirid pterosaur, possibly synonimous with Ornithocheirus itself (ornithocheirid nomenclature and phylogeny are essencially just one big bitch fight, which will never have any consensus). One would be questioning how much sense that would make considering that Samrukia‘s ramus are considered to be incomplete, rendering his comparasion flawed as the similarity in shape is accidental (to be fair, the rami of Criorhynchus are probably incomplete as well though). One would also question the fact that ornithocheiroids like Criorhynchus have an extension of the jaw where the teeth are located, while Samrukia‘s jaw doesn’t appear to have this extension and other than the ramus the jaw is noted to be complete, meaning that in life the animal had a toothless, wide lower jaw. But like we all know by now, David Peters is like The Crazy Nastyass Honey Badger when it comes to fossils.
Never the less, a Crazy Nastyass Samrukia/Criorhynchus/Ornithocheirus/whatever is very appealing, so for the moment I too won’t care or give a shit and just classify Samrukia as an ornithocheiroid until Darren posts about it.
Before I end the post, I would like to remind you that I did talk about DP’s questionable sanity earlier. While I offered a stream of insults for polluting Google, I don’t think that he is necessarily stupid, just that he is insane. According to anecdotal evidence, he appears to be quite intelligent, and I currently believe that he is, in fact, the most successful troll in paleontological circles.
Found in the Bostobynskaya Formation in Kazakhastan in 2011, Samrukia is a puzzling creature. It was first described as a bird, possibly within Carinatae, an example of the existence of large terrestrial birds in the late Cretaceous. While some people have suggested it to be a large volant bird, I’ve never been very concerned about it, because it would most likely turn out to be a giant flightless bird. Flightless birds are already known from the Cretaceous, such as Patagopteryx and Gargantuavis, all of them not remote island dwellers, but having evolved in territories filled with non-avian dinosaurs, proving that flight is sufficiently expendable to be lost even in the presence of predators (see my previous post on elephant birds).
Most surprisingly, however, is that, it turns out, that Samrukia might not had been a bird, but a pterosaur instead. So far, only Eric Buffetaut’s analysis (already published in November) seems to claim his, but then again there are few published papers on Samrukia. So far, on the DinosaurMailingList, the main issue seems to be the usage of the name*, so maybe it is safe to say that the “phoenix” is in fact a dragon, so to speak.
* Samrukia is not an official genus name, because so far none of the papers about it classify under ICZN’s snobbish standards. For the moment, I’ll use the name, and I honestly hope that Samrukia is chosen as the official genus name, because having a bird or pterosaur named after a phoenix is nice.
If Samrukia is a pterosaur, then a whole new can of worms is opened. As a bird, it was unique for being big; as a pterosaur, it’s estimated 30 centimeter skull (the mandibula we have is 27.5 cm long; the rami are incomplete, and the skull is not just jaw alone anyway) is remarkably small for a pterosaur. Pterodactyloids, the dominant pterosaurs through all of the Cretaceous period, are iconic for their ridiculously gigantic heads, and in azhdarchids (the most common pterosaurs in the post-Turonian Cretaceous), the jaws are so big that the torso actually fits in the nasoanteorbital frenestra. To see a pterodactyloid (and it has to be a pterodactyloid; the only other option are anurognathids, whose presence in the late Cretaceous is ambiguous, and they have much shorter and wider jaws, which are also toothed, unlike Samrukia‘s) with such small jaws is jarring to say the least. Most likely, Samrukia represents a juvenile, but it probably might be a small pterosaur overall. Notably, Gwawinapterus appears to have had similar sized jaws.
What kind of pterosaur Samrukia is?
Samrukia lived during the Santonian/Campanian boundary, it’s temporal range probably larger forwards or backwards in time. In this time period, the dominant pterosaurs were azhdarchids and pteranodontians, with isitodactylids almost certainly present given the presence of Gwawinapterus in the late Campanian/Maastrichtian. Other pterosaurs probably were present, but only undescribed ornithocheiroids are known for sure. So, where did Samrukia fit in the pterosaur tree of life?
I can right away tell that it sure wasn’t a pteranodontian; not only defenite pteranodontians are only known from the Western Interior Seaway (although nyctosaurids might had occured elsewhere), but their long, stork like jaws don’t resemble the shorter, wider mandibula of Samrukia. For this reason, I will also provide the controversial statement that Samrukia was most likely not an azhdarchid either, as even forms with atypical mandibulae like Bakonydraco still had less wide jaws. The azhdarchid Aralazhdarcho co-existed with Samrukia; the two pterosaurs certainly had an unique niche partitioning, avoiding direct competition with each other.
So, if not a pteranodontian or an azhdarchid, what kind of pterosaur Samrukia was?
A non-azhdarchid azhdarchoid?
While azhdarchids already existed in the lower Cretaceous, they only became promenient after the Turonian. This is because a large variety of other azhdarchoid pterosaurs dominated terrestrial ecosystems, and only after they became extinct did azhdarchids expand. However, I would not be surprised if these animals did in fact survive longer, specially because their ecological niches as generalistic carnivores and omnivores would allow them to survive well through events like the Turonian extinctions.
However, I think thalassodromedids are a decent possibility. These pterosaurs have mandibulae that are fairly close in shape to that of Samrukia, and given their relative rarity in non-lagerstätten fossil sites I think they’d easily could had survived without being preserved. Thought to have been generalists, they could easily co-exist with azhdarchids, perhaps opting for wetter terrains while their more common cousins took drier habitats. Samrukia would likely have represented a stem-thalassodromedid, that survived well after it’s well known and larger South American relatives became extinct. Amusingly, Darren Naish did consider that thalassodromedids did survive into the Maastrichtian, but appearently Mark Witton talked him out of that. I’m waiting for the latter’s book; maybe he changed his mind.
If Samrukia is indeed a thalassodromedid, it, alongside Gwawinapterus, further indicates that late Cretaceous pterosaur diversity was higher than previously thought. The greatest irony is that the phoenix of Bostobynskaya, once a proof of a higher avifauna diversity in the latest Mesozoic, now indicates that pterosaurs kept the tight leash on large volant animal niches.
Elephant birds, or, as they are known in Malagasy, Vorompatra (“marsh bird”) are iconic giant ratites from the island subcontinent of Madagascar. While they are very commonly present in prehistory books, very little is actually presented of these birds; their eggs, the largest among birds and in fact the largest dinosaur eggs ever found until the discovery of even larger eggs in China, attributed to sauropods and oviraptorids, are usually the focus when they are mentioned, and if you’re lucky they might also reference how they were heavier than their taller New Zealand relatives, the moas.
In truth, while admittedly hardly charismatic even to some ornithologists, are rather interesting because they heavily hint at how Madagascar’s fauna evolved during the Cenozoic, and further illustrate the way palaeognath diversity was established.
All aepyornithids are known from the Pleistocene/Holocene, a given due to the nigh-absence of earlier Cenozoic Malagasy fossils (the exception being a few sea cow fossils from the Eocene, Miocene and Pliocene). They are represented by two genera: the famous Aepyornis and the extremely obscure Mullerornis. The number of species is not certain; four species of Aepyornis and three of Mullerornis are recognized, but it has been suggested that many so called “species” might represent animals at different growth stages. For the sake of convenience, I will focus more on the genera as a whole and not on the supposed individual species.
As to be expected from flightless birds, aepyornithids suffered several anatomical modifications. The notarium was lost, as was most of the forelimbs with the exception of the minuscule humerus, which was probably located internally, rendering the bird completely wingless. As to be expected from a ratite, the sternum was small and flat, no longer exhibiting a recognizable keel. The skeleton in general is very robust; although many bones remained pneumatic as means to control body temperature as in other dinosaurs, being free from the pressures of powered flight meant that marrow production could become more extensive, and as such the hind limbs and pelvis were nothing short of massive. In life, the largest Aepyornis weighted over 400 kg, and were considered the biggest Neornithes of all time (the largest moas and terror birds were taller, but much less heavy), until later research gave that title to australian dromornithids, which managed to be both heavier and taller.
The skulls of Aepyornis were unusually large for ratite standards; while not proportionally the largest skulls among birds, in sheer size they were among the biggest, apparently only surpassed by the terror bird Kelenken. Palaeognaths, due to their lack of an ossified palate, are generally noted for having small skulls in comparison to other birds; even long billed forms like kiwis have very shallow beaks. This seems to be refuted by the very deep rostrums of aepyornithids, which superficially vaguely resembled those of azhdarchoid pterosaurs, particularly chaoyangopterids. The size of the skull was presumably an adaptation for the hot climate of Madagascar; the nares, anteorbital frenestrae and the eye sockets were fused into one large cavity, allowing the passage of air in other to keep the head cool.
Despite the large beaks, the animals probably had a weak bite force, due to the lack of a bony palate, although, given the strong gastric acids of most birds, this probably did not impair the animal much. Aepyornithids are thought to have been high browsers, occupying on Madagascar the same ecological niche that giraffids occupy on mainland Africa. Many Malagasy rainforest tree species have fruits with thick, highly sculptured endocarps, often dark blue or purple in color, much like those consumed by modern cassowaries, so aepyornithids might have played important roles as frugivores, dispersing the seeds of the species they fed on. In the presence of the also browsing giant lemurs, aepyornithids might have had a more flexible diet, feeding on small animals in addition to leaves like modern cassowaries and rheas, but this is not certain. While they were almost certainly present in rainforests, most aepyornithid remains were found in Madagascar’s wetlands; it’s not certain if this was a preferred environment or if was just where the fossils were best preserved.
Not much is known about aepyornithid social behavior; probably it was fairly loose, likely tending towards being solitary but without the aggressive territory creation that cassowaries and kiwis engage on. The male was almost certainly the one responsible for incubating the eggs and raising the young like in most modern ratites; it’s not clear if they formed harems like most modern ratites or if they only raised one or two eggs laid by a single female. The chicks were certainly precocial; the presence of more predators perhaps indicates that were guarded by their parents like in most modern ratites, unlike modern kiwis and maybe the extinct moas, which are essentially superprecocial. Regardless, the period of parental protection was likely short, as aepyornithid growth rates are slow like those of moas and kiwis, with the birds reaching sexual maturity after several years.
Gradma, what big eggs and bones you have!
Aepyornithids are generally dismissed as the product of an environment without macropredators, much like practically every flightless bird in existence.
However, this view is erroneous; while many birds lost flight in the absence of predators, we now know that flight is more expendable than that, and in fact many flightless avifaunas evolved in environments ruled by many predators, such as the Cretaceous hesperornithes and patagopterygids. Even ostriches and rheas likely evolved in the company of predators; while their ancestry goes back to a time where predatory mammals were rare, sebecian and pristichampsid crocodillians ruled the ancient forests of the Eocene and were soon joined by avian bathornithids and mammalian “creodonts”, and forms like Palaeotis and Diogenornis were already cursorial.
Did aepyornithids evolve in a world without predators? A look at Malagasy Holocene fauna indicates the presence of three macropredators; the giant osteolamine crocodile Voay robustus and the giant fossa Cryptoprocta spelea likely posed a threat to the juveniles, probably even the adults of Mullerornis in Voay‘s case. However, all aepyornithids probably feared the remaining Malagasy macropredator, Stephanoaetus mahery, the Malagasy Crowned Eagle, also known as Mahery. The similar Harpagornis moorei from New Zealand was a moa specialist, capable of dealing with even the larger species, so it is likely that the Mahery, with the ability to fly and thus strike at the vulnerable neck and head, was a threat to even the largest Aepyornis.
For obvious reasons, its not clear if aepyornithids have been under the influence of similar predators across the Cenozoic, and if they evolved flightlessness in a time when Madagascar had no predators. However, it seems clear that modern aepyornithids do have some adaptations that can be interpreted as defenses against the contemporary predators; the sheer robust built of these birds in comparison to other ratites, specially to the also insular moas, seems to suggest that these creatures became so massive in order to defend themselves. The only other birds that are equally as robust are gastornithids and dromornithids, which also evolved in environments with terrestrial predators. In fact, these three groups evolved in the company of large crocodillians, with pristichampsids co-existing with gastornithids, mekosuchines with dromornithids and Voay with the aepyornithids, so this might suggest that the robust built of these birds might be related to fending off crocodillians specialized in killing terrestrial prey.
Similarly, the eggs of aepyornithids are unusually large. While ratites in general lay very large eggs, the only ones with such proportionally large eggs are kiwis, which are superprecocial. It is possible that aepyornithid eggs became that large in other to decrease predation on the young; no known malagasy carnivore can break the shell, and the young would have been born big enough to be only threatened by the larger carnivores. This too seems indicative that aepyornithids evolved to cope with the native predators.
Like moas, aepyornithids are clearly not specialised runners. However, the metatarsals (like in all neornithes, they are fused) appear to be proportionally slightly longer than in moas, and the hallux is absent. This seems to suggest that aepyornithids were more efficient runners than moas, presumably relying on speed to escape, although fully grown Aepyornis probably didn’t not had to run.
The origins of the Vorompatra
Historically, the closest relatives of the elephant birds have been considered to be the ostriches, a rather logical conclusion given that ostriches live in Africa and aepyornithids live in Madagascar; since both landmasses were part of the supercontinent Gondwanna, both bird clades would had evolved from an ancestor that became isolated in Africa and Madagascar.
In reality, things are not as simple. Ratite diversity took place in the Cenozoic or late Cretaceous, long after Gondwanna was largely split apart; Africa was already an island continent in the early Cretaceous, long before neornithes evolved. Indeed, no african paleognaths have been recognised so far with the possible exception of Eremopezus, and ostriches evolved in Asia, not in Africa. It is possibe that ostriches and aepyornithids evolved from a common ancestor when India and Madagascar were a single landmass, with both groups evolving independently once India broke apart and moved northwards towards Asia.
However, genetic studies revealed that aepyornithids were not a sister clade with ostriches, but were surprisingly more closely related to emus, cassowaries and kiwis, the ratites of Oceania. More impressively, their closest ancestors are none other than kiwis, endemic to New Zealand.
Thus, as fitting our understanding of early palaeognaths like lithornithids, the ancestors of elephant birds and kiwis were widely widespread and competent flyers, to the point that some members of this clade remained volant well into the Miocene, after the palaeognath heyday was over (i.e. kiwis; the Saint Bathans proto-kiwi Proapteryx retains features associated with flying birds, meaning it was either volant or recently flightless).
The the prevalence of the closely related Casuariiformes in Australia and the fact that moas reached New Zealand through a trans-Antarctic route, we have two scenarios:
– The aepyornithid + kiwi last common ancestor lived in Australasia, with the ancestors of elephant birds being blown into Madagascar. There is a lot of precedent: many bird species in Madagascar and the Mascarenes evolved from asian or australian ancestors, most notably the dodos and solitaires, which evolved from Papuan pigeons.
– The aepyornithid + kiwi last common ancestor lived in Antarctica and simply migrated northwards. Antarctica was in fact a ratite hotspot in the early Cenozoic, with the tinamou + moa clade being yet another example that flying palaeognaths occurred here and migrated either way.
In either case, the process of becoming flightless took widely different turns. Elephant birds must have lost their ability to fly by the Eocene, being massive, specialized herbivores by the Holocene with almost no wings, while kiwis clearly remained volant until the Miocene and indeed are currently smaller and have somewhat more developed wings. The proportionally massive eggs are unique among ratites, and could suggest that they either evolved in the last common ancestor between elephant birds and kiwis, or that they evolved independently in response to a need for superprecociality.
Eggs attributed to aepyornithids are known from the Canary Islands, precisely on the opposite side of Africa, as well as mainland African and Indian sites from the Eocene to Pliocene. Needless to say, in the absence of known aepyornithid fossils from mainland Africa and Asia, they are thought to belong to other birds instead, such as the albatross-like pelagornithids or even ostriches and less well known ratites.
Aepyornithids, like the rest of the Holocene megafauna, were brought to extinction due to anthropogenic influence. The humans that colonized Madagascar likely hunted aepyornithids, but apparently not to the extent that they hunted moas; for some reason, vorompatras were apparently considered sacred, and accordingly there’s relatively few specimens that indicate death by humans; notably, nearly all of these specimens belonged to Mullerornis, and not to the larger Aepyornis. The eggs, however, were not regarded to the same standard, and they are much more common in archeological sites.
Other possible causes of extinction were the introduction of diseases transmitted by chickens brought by the human colonizers. Being of Indonesian ancestry, the early colonizers of Madagascar brought with them junglefowl, that likely carried pathogens that affected the native birds of Madagascar. For obvious reasons, this hypothesis has not been tested yet.
In spite of these factors (in part thanks to their sacred status), aepyornithids might have outlived the other members of the Malagasy megafauna by several hundreds of years. Mullerornis is known to have lived until at least the end of the first millenium, and Aepyornis might have lived to see Europeans arrive to the island. Indeed, the Androy region of Madagascar might have been one of the last places where these birds still dealt; Étienne de Flacourt described the giant birds of the Ampatres. The name “elephant bird” was attributed due to the legend of the Roc, a bird of arabian lore capable of carrying elephants, and due to the neotenous appearance of ratites, it would had been easy to see the vorompatras as chicks of a gigantic bird. It is possible that folk memories of the Mahery helped as well.
As familiar as they are alien, vorompatras are one of those seriously underestimated prehistoric animals that nonetheless make it into the broader conscious, as vaguely as that happens. They do remind me of giraffes, in a way: always there, in the scenery, rarely in the foreground.
Hopefully, I’ve inspired to take a closer look at Madagascar’s avian giants.
Mitchell, Kieren J.; et al. 2014. “Ancient DNA reveals elephant birds and kiwi are sister taxa and clarifies ratite bird evolution”. Science, vol. 344, no. 6186, pp. 898-900; doi: 10.1126/science.1251981
Buffetaut, E.; Angst, D. (November 2014). “Stratigraphic distribution of large flightless birds in the Palaeogene of Europe and its palaeobiological and palaeogeographical implications”. Earth-Science Reviews. 138: 394–408. doi:10.1016/j.earscirev.2014.07.001.
Cheke, Anthony S.; Hume, Julian Pender (2008). Lost Land of the Dodo: an Ecological History of Mauritius, Réunion & Rodrigues. New Haven and London: T. & A. D. Poyser. ISBN978-0-7136-6544-4.
Yonezawa, T.; Segawa, T.; Mori, H.; Campos, P. F.; Hongoh, Y.; Endo, H.; Akiyoshi, A.; Kohno, N.; Nishida, S.; Wu, J.; Jin, H.; Adachi, J.; Kishino, H.; Kurokawa, K.; Nogi, Y.; Tanabe, H.; Mukoyama, H.; Yoshida, K.; Rasoamiaramanana, A.; Yamagishi, S.; Hayashi, Y.; Yoshida, A.; Koike, H.; Akishinonomiya, F.; Willerslev, E.; Hasegawa, M. (2016-12-15). “Phylogenomics and Morphology of Extinct Paleognaths Reveal the Origin and Evolution of the Ratites”. Current Biology. 27 (1): 68–77. PMID27989673. doi:10.1016/j.cub.2016.10.029.
Following is a text written by a person I’m following on dA. You can see it here.
Another Hidden Victim: Gay Teens at risk of sexual exploitation
In August, the media created a buzz in Atlanta’s LGBT community when it covered the arrest of popular drag queen personality Pasha Nicole (Christopher Lynch) and dancer Stephen Lang (Steven Lemery). The two were arrested and later collectively charged with human trafficking of a minor for sexual servitude, two counts of sexual exploitation of a child, and pandering by compulsion. Four male teens had been enticed by Lemery from several states surrounding Georgia and later pimped out of Lemery and Lynch’s apartment, where they’d been imprisoned. The story shatters a significant stereotype regarding sex trafficking: it isn’t only heterosexual men and underage girls that are involved in commercial sexual exploitation.
Traffickers are notorious for seeking out the most vulnerable members of society: those who are financially destitute, socially alienated, abused by family, or in need of food and shelter. Runaway teens make the perfect target – but this “target” is not just the young girls we expect. The targets come from different ethnicities, social backgrounds, economic circumstances, even gender and sexual orientation. Current estimates are that 90% of teens who runaway from home are approached by traffickers for the purpose of exploitation. And an overhwhelming amount of runaway teens identify as gay or lesbian – this makes them a wide target for pimps.
An estimated 325,000 minors are sexually exploited in the U.S each year. Of this number, 121,911 are runaway cases and 51,602 are “throwaway” cases (told to leave by a parent or guardian). According to the National Runaway switchboard, nearly half of these teens are runaways because of conflict with their sexual orientation. Tana Hall, licensed counselor at YouthPride, describes the sad reality that gay teens face when they’re not accepted at home: “The number one thing we get on our help line is ‘I’ve been kicked out and I don’t know what to do and I don’t know where to go’.”
Once on the street, both straight and gay runaways face enormous risk of being picked up by a trafficker. The National Runaway switchboard estimates that “…many [gay identifying homeless teens] get involved with prostitution and other abusive behaviors as a way of surviving”. Just like young girls who are exploited by pimps and traffickers, gay youth face the paradoxical classification of “teen prostitutes” despite often being under the legal age of consent. Unfortunately, the mentality that they choose to be prostitutes is even more prevalent with gay youth because some groups view their orientation as taboo or perverse.
Sex trafficking is difficult to talk about- and not just for emotional reasons. There are simply too few resources to help clear up the nature of the crime. Just how many people are being exploited- and who they are, exactly- is not readily understood. Even less is known about male victims of sex trafficking than is known about females, and there are no rehabilitative systems of care designed for gay youth who are victims or potential victims of sex trafficking.
In a press release, Deb Price claims that the Federal Runaway and Homeless Youth Act is in need of attention and renewal: “So much hostility and violence are directed at gay teens in foster care, homeless shelters or correctional facilities that many conclude they’re safer living on a sidewalk,” Price writes. “Our nation is failing these kids.”
After being driven from both home and homeless shelters, gay teens with nowhere else to go present particularly high-risk cases for commercial exploitation.
So how can we help gay youth who are being exploited or at risk of being exploited?
First: it starts with acceptance in the family. Home must be a safe place.
P-FLAG offers a hotline for parents who are struggling to cope with their child’s sexual orientation at 866-627-9749.
Secondly, shelters must be a safe place.
In the past, some Georgia shelters have refused to accept gay or lesbian homeless/runaway teens. Others have only accepted them if they were willing to undergo behavior modification programs. Still others are unable to protect young gay men and women from violence and harassment inside the shelter. Homeless youth already have limited ‘safe places’ – but for gay runaways, shelter is even scarcer. If you are or know someone who is a gay or lesbian runaway teen in need of shelter or resources, contact:
The National Runaway Switchboard at 1-800-RUNAWAY (1-800-786-2929)
Chris Kids (Rainbow Project) at 404.486.9034
Lastly: awareness works. Recognizing that gay teens are victims of sex trafficking in Atlanta is one of the key steps we must take in rescuing them.
Human trafficking, in all of its forms, is a blemish on the nation’s status as democratic city on a hill. We’re a country that is rich with rhetoric about freedom. But we’re also a country that contains roughly a third of the world’s slaves. The faces of these slaves are diverse: and each one deserves and requires recognition, review, and restoration.