Velociraptor mongoliensis

[I made a soundtrack for this painting, which can be heard here: ]

Mongolia, late afternoon in the Campanian Age of the Late Cretaceous:

Hunger pangs and hot winds, bleached bones of a half-remembered feast and the faint scent of fresh prey. The swift thief wakes and begins his crepuscular patrol, wary of rivals, nimble and silent between the whispering dunes.

Perhaps down to the arroyo again, where that lizard had lingered too long on the sunny rock near the bank and was pierced by the hunter’s claws, swallowed whole; or towards the oasis where that old, fuzzy mammal had been too slow in returning to its burrow. Or maybe to the Protoceratops nesting grounds – a tasty hatchling would fill his belly nicely – but the place triggers unpleasant memories now: his mate grappling with an aggressive bull 'ceratops, her feathered forelimb caught in its beak, and her talons lashing into its underside before the dune collapsed and entombed them both, sand too deep to dig through…

Instincts war within, briefly, the urge for nutrients winning out over the incessant drive towards genetic legacy, and the swift thief prowls into Djadochta dusk, moments lost in deep time.

[Please don’t use or reproduce without permission, and thanks for viewing, reading and listening!]

Alright listen up noobs, Velociraptor mongoliensis was less than a metre tall and, like most (if not all) dromaeosaurids was covered in feathers. Welcome to the real game (yeah I just drew this).

This is the famous Velociraptor mongoliensis in its native late Cretaceous Gobi Desert. Velociraptor was a small dromaeosaur, or raptor dinosaur, and contrary to its most famous depictions was almost certainly feathered from head to tail. This is no longer based merely on phylogenic evidence, either - as of 2007, reanalysis of the fossil has shown that its posterior forearm contains quite obvious quill knobs.

Velociraptor surely went after larger prey like Protoceratops at least occasionally, as we have fossil evidence that it certainly did so. However, like many modern mid-sized carnivores, its diet probably consisted of a large proportion of much smaller animals, which it may have ambushed or sniffed out of crevices. I imagine such a predation event would have been rather felid in nature, wherein the animal displayed a curious mixture of predatory grace and pure silly ridiculousness as it bounced and flailed after a frantic prey animal. In this case the prey in question is Zalambdalestes, a small shrewlike eutherian from the Djadochta Formation of Inner Mongolia.


Andrewsarchus mongoliensis (“Andrew’s Ruler”)

….One of my favorite prehistoric mammals for semi-obvious reasons, Andrewsarchus was a species of mammal that lived during the Eocene epoch. Although Andrewsarchus looks similar to a creodont or carnivoran it is actually more closely related to Artiodactyls.

A.mongoliensis is known only from a single meter long skull found in Mongolia and as such much of its paleobiology is up for debate. Some sources claim it could of been a predator and others claim it was a scavenger. Newer theories claim that it could of been an omnivore due to its ‘blunt’ teeth. However, Andrewsarchus did posses a very strong set of jaws, one of the strongest of all land mammals, and could bite straight through bones. Judging from the coastal location of its fossil Andrewsarchus probably frequented beaches and likely fed beached whales, turtles, shellfish and large land mammals (such as brontotheres)



Images: DiBgd and Ryan Somma



NamePsittacosaurus, assigned species: P. mongoliensis, P. sinensis, P. xinjiangensis, P. meileyingensis, P. sattayaraki, P. neimongoliensis, P. ordosensis, P. mazongshanensis, P. sibricus, P. lujiatunensis, P. gobiensis 

Name Meaning: Parrot Lizard

First Described: 1923

Described By: Osborn

ClassificationDinosauria, Ornithischia, Genasauria, Neornithischia, Cerapoda, Marginocephalia, Ceratopsia, Psittacosauridae 

Requested By klipty!

Psittacosaurus is one of the best known non avian dinosaurs. It was a small little herbivore, about 2 meters long, and its been found in China, Mongolia, Russia, and also potentially Thailand. It lived for a long time, from the Barremian to the Albain ages of the Early Cretaceous, about 123.2 to 100 million years ago. It is the most species rich non avian dinosaur genus, with nine to eleven species being recognized to date. All of the species in this genus were about the size of gazelles, were bipedal, and had a very powerful beak on the upper jaw. One species, P. mongoliensis, has also been found with long quills on its tail and lower back, and it’s reasonable to suppose that the other species did as well (re: Kulindadromeus). Psittacosaurs represent a stepping stone on the long line of evolution to neoceratopsians, sharing many similar traits to Triceratops and Protoceratops. Over 400 fossils have been found for this genus, with many different age classes allowing for a very detailed picture of its life history to be known. 


Psittacosaurus was well adapted for eating plants, with teeth that could easily slice through them and they were self-sharpening. They couldn’t grind (chew) food, though, so they potentially swallowed gastroliths to grind up food in the stomach; indeed, some Psittacosaurus specimens have been found with rounded stones in their stomachs. Its lower jaw was good at sliding, allowing for shearing tough plants. It probably was a selective browser, having a specific preference for certain plant parts but not necessarily being limited to just eating them. They also probably ate a lot of seeds. Their upper and lower jaws behaved as a single unit, and they could only slide their jaws forward and backward for a shearing action. 

Specimen with Integuments on the Tail. Source:

The animal has been shown through its scleral rings to have been cathemeral, or active throughout the day and night at short intervals. It is known from a wide variety of aged specimens, with a hatchling skull that is only 4.6 centimeters long. These animals grew rapidly compared to reptiles and marsupial mammals, but slower than modern birds and placental mammals, indicating that they had a mesothermic metabolism (or somewhere between cold and warm blooded, closer to warm, but not quite as fast as that of birds and placentals.) It lived between 10 and 11 years. These were extremely social animals, with many sites having lots of specimens found and nests, with juveniles and adults living together. Young psittacosaurs could chew their own food, meaning the shearing action of adults was developed later. They also have been shown to care for their young, with older individuals caring for the hatchlings. 

P. sibiricus 


It has been proposed that Psittacosaurus was semi aquatic, using its tail like that of a crocodile’s to propel through the water. They also have been found in association with lake deposits, have eyes and nostrils positioned for semi aquatic life, tails that could easily propel through the water, and gastroliths could be used as a ballast. More evidence will, of course, need to be found. It was a prey animal for the region and juvenile specimens have been found in association with predatory mammals, one of the rare examples of mammals eating on dinosaurs. It probably was subject to R-selection, or where many offspring are produced to counteract loss to predation. It was so common it was probably a staple animal in Asia at the time, sort of like a Cretaceous sheep. It probably was also fed on by dromaeosaurids and crocodiles. 


The species are distinct from one another mainly due to head shape, given that many specimens of Psittacosaurus are only known from the skull. P. mongoliensis is the type species, and it lived alongisde Protoceratops, Oviraptor, and Velociraptor. It had a flat skull, and a flange on the lower jaw, which is not particularly prominent. Protiguanodon mongoliense, Psittacosaurus protiguanodensis, P. osborni, P. tingi, and P. guyangensis are all junior synonyms of this species. 

P. mongoliensis 


P. sinensis is also from Asia, specifically China (as opposed to Mongolia.) It has fewer teeth than other species and a smaller skull, with horns flaring out from the jugals (cheeks) that are wider than any other Psittacosaurus species except for P. sibiricus and P. lujiatunensis. The skull is thus wider than it is long and it also had smaller horns above the eye, and a slight underbite. P. youngi is a junior synonym of this species. 

P. sinensis Source:

P. xinjiangensis was found in Xinjiang China, and it also had a prominent jugal horn that is flattened out on the front end. It also had very long pelvic bones and femurs compared to other species. P. meileyingensis is also from China, in Liaoning, and had the shortest snout and neck frill of all the species. Thus it had a nearly circular skull. It had a triangular eye socket and prominent flanges. P. sattayaraki was found in Thailand in the Khot Kruat Formation, and its validity has been question, however it had flanges similar to P. mongoliensis, but less pronounced. It would be the southernmost species of the genus if the material is considered to be valid. 

P. neimongoliensis 


P. neimongoliensis is from Mongolia, and it had a distinctly narrow frontal bone with a narrower skull over all. It was probably smaller than P. mongoliensis, with a longer skull and tail proportionally. 

P. ordosensis 


P. ordosensis was also found in Mongolia, from a nearly complete skeleton and three other specimens. It, like P. neimongoliensis, was found in the Eijnhoro Formation. It had ver prominent jugal horns and was the smallest known species, and is potentially a nomen dubium. P. mazongshanensis was found in Gansu Province, a location near the border with Inner Mongolia. Its skull was damaged in transit, making it hard to characterize. It had a long snout compared to other species, and a prominent bony protuberance on the upper jaw. 

P. sibiricus, shown above (fourth picture), was found in Kemerovo in Siberia, making it one of the most northern species of the genus. It is the largest known species of the genus, which may be due to its northward location, the large size giving it more body heat in colder temperatures. It had quite a few horns around its eyes, with three on each postorbital and one in front of each eye, as well as prominent horns on the jugal bone, and a flange on the lower jaw. 

P. lujiatunensis 


P. lujiatunensis was found in China, in the Yixian Formation in Liaoning. It was contemporaneous with another psittacosaurid, Hongshanosaurus, which was found in the same beds. It had fossa in front of th eeye like in P. mongoliensis and jugal bones that flared outwards widely, like in P. sinensis. It had quite a few primitive characteristics compared to other species of the genus, and was potentially the most basal species. P. major and P. houi are considered junior synonyms of the species. 

And finally, P. gobiensis was found in Inner Mongolia, and was very small bodied, and it had many minor differences from the other species. It had a pyramidal horn on the postorbital, a depression in the postorbital-jugal contact, and thicker enamel. It also lived alongisde P. mongoliensis

There are many other Psittacosaurus specimens not assigned to a genus, making this animal extremely numerous and fascinatingly diverse. There is a lot more to learn about this animal, and I encourage you all to read up on your own!


Shout out goes to klipty!


Velociraptor Mongoliensis”

This is my interpretation of the little raptor. After studying corvid/raptor feet as well as bird of prey markings and feathers and combining it’s environment and fossils of it’s ancestors; This is what I came up with. I used a little bit of RoadRunner for the face marking.

I also added an egg tooth to the tip of the nose along with shortening the mouth like birds, instead of the split face look you get with lizards and other reptiles.

I also made the boot(the part the raptor sits on when sitting down), vent exposed.

It’s a shot in the dark, but it was fun to do in the end.

Done on 9x12’ sketchbook paper, india inks, watercolor, and colored pencils

The Andrews’ ruler, Andrewsarchus (1924)

Phylum : Chordata
Class : Mammalia
Order : Artiodactyla
Suborder : Cetruminantia
Genus : Andrewsarchus
Species : A. mongoliensis

  • Middle Eocene (46,5 - 41,1 Ma)
  • 4 m long and 800 kg (size)
  • Gobi desert, Mongolia (map)

Considering that all we know about Andrewsarchus is based on a single, incomplete skull discovered in the Gobi Desert almost 100 years ago, on an expedition led by the famous paleontologist Roy Chapman Andrews, this prehistoric mammal has made quite a reputation for itself. Based on well-informed reconstructions—guided by similarities with its close relative, the North American Mesonyx—Andrewsarchus may have been the largest carnivorous land mammal that ever lived, its 13-foot length and 1,000 to 2,000-pound weight putting it in a different class entirely than modern polar or grizzly bears. (Still, Andrewsarchus would have been a mere snack for the truly gigantic carnivorous dinosaurs, like the seven-ton Tyrannosaurus, that preceded it by 25 million years.)

As little was we know about what Andrewsarchus looked like, we know even less about how this late Eocene predator behaved. Andrewsarchus may or may not have hunted in packs, and it may or may not have supplemented its diet of fresh-killed meat by scavenging already-dead carcasses. So huge and powerful were its jaws that, conceivably, Andrewsarchus might have been able to bite through shelled mollusks or turtles, and it may even have supplemented its carnivorous diet with the occasional plant. One likely scenario is that Andrewsarchus fed on the enormous, herbivorous brontotheres (genus: Brontotherium) that shared its Eurasian habitat.