Results from the Flocking #paleostream!

🧵 A herd of Silesaurus opolensis, a medium-sized basal ornithischian, alongside the crocodile relative Stagonolepis olenkae, and the giant amphibian Cyclotosaurus intermedius, all found at the Late Triassic Krasiejów locality in Poland.

Silesaurus opolensis, a basal ornithischian dinosaur once thought to be almost-a-dinosaur, a dinosauriform. This slender, beaked quadruped from Silesia in southern Poland probably fed on plants and insects, as shown by its teeth and beetle remains in fossilised feces.

Stagonolepis olenkae, a relatively small aetosaur, distant relative of modern crocodiles. This armored herbivore from southern Poland was a low browser, with forelimbs adapted for scratch-digging and a shovel-like snout tip, likely used to unearth roots and vegetation.

here's today's #Paleostream flocking sketches!!!

today we sketched Himalayasaurus, Typothorax, Lunataspis (i drew L. aurora), and Kunpengopterus (drinking the nectar from a Weltrichia)

Pseudosuchian Typothorax coccinarum, of Late Triassic, North America!

Our next archosaur, and our first pseudosuchian of this Archovember is Typothorax coccinarum! Pseudosuchians, the lineage that would eventually lead to crocodilians, dominated the Triassic, and did many of the things first that dinosaurs would do later on. Typothorax was an aetosaur, a unique group of pseudosuchians that evolved body armor similar to ankylosaurs. Typothorax was herbivorous, possessing small, leaf-shaped teeth, and had an upturned, shovel-like snout. Their forelimbs also seemed to be uniquely adapted to digging, suggesting they may have found food by rooting around in the soil for roots and tubers.

Typothorax coccinarum is known from the Late Triassic Chinle Formation of Arizona, as well as the Bull Canyon Formation of New Mexico and Texas. In the Chinle Formation, Typothorax would have lived alongside other aetosaurs like Rioarribasuchus and Scutarx, along with smaller pseudosuchians like Hesperosuchus and Revueltosaurus. It would have been preyed on by large rauisuchids like Postosuchus and Vivaron. Other archosaurs Typothorax could have seen in the Chinle Formation would have included lagerpetids like Dromomeron, allokotosaurs like Trilophosaurus, and dosweliids like Vancleavea. Dinosaurs were only just getting a foothold in the Late Triassic, and Typothorax could have come across early saurischians like Chindesaurus and Coelophysis. In the Bull Canyon Formation, the environment was similar, with the addition of the giant, beaked poposauroid Shuvosaurus, as well as the aetosaur Paratypothorax and the phytosaur Machaeroprosopus.

"Placerias Problem" Placerias/Desmatosuchus Triassic, 220 million years ago, Chinle Formation During the Triassic, the continents were all one - this was, of course, the landmass Pangea. The presence of such a massive supercontinent produced an extreme weather effect known as the Pangean megamonsoon - a seasonal wind reversal taking the coasts from arid and dry to incredibly rainy. This is also the cause of the stampede we see here. Placerias was one of the latest-surviving dicynodonts. Having made it straight through the Great Dying, they'd experience a rediversification during the Triassic before dying out by the Jurassic's beginning. Not only did it have actual tusks on the inside of its mouth - it also had two "false" tusks on its beak - known as maxillary caniniforms! These were sexually dimorphic - longer in males and shorter in females.

-ANGUIRUS-