#phytosaurs

Phytosaur Smilosuchus gregorii, of Late Triassic, USA!

While the pseudosuchians were still figuring things out in the Triassic, trying out diverse body types, the entirely unrelated phytosaurs had already perfected the semi-aquatic reptilian predator bodyplan. Phytosaurs are known from many different morphologies, specifically with vastly different skull forms, though they can be told apart from pseudosuchians by the position of their nostrils close to their eyes on their snout. One of the largest phytosaurs was the North American Smilosuchus. There are three known species of Smilosuchus, each with different skull morphologies. Smilosuchus gregorii, seen here, had a robust skull, less long and slender than its relatives. Like other phytosaurs, it had heterodont teeth; with large tusks at the front of its mouth for impaling prey, and smaller, blade-like teeth near the back for slicing flesh. It had powerful jaw muscles, and was likely able to hunt large prey, perhaps ambushing the giant dicynodonts and even aetosaurs of the time.

Smilosuchus gregorii was found in the Late Triassic Chinle Formation of Arizona, USA. It would have lived alongside its Smilosuchus relatives, S. adamanensis and S. lithodendrorum, and other phytosaurs like Leptosuchus, Machaeroprosopus, Pravusuchus, and Protome. Pseudosuchians lived here too, though they had the land colonized while the phytosaurs dominated the waters. These included the aetosauriformes Acaenasuchus and Revueltosaurus, the true aetosaurs Adamanasuchus, Calyptosuchus, Desmatosuchus, Kryphioparma, Paratypothorax, Rioarribasuchus, Scutarx, Typothorax, and Tecovasuchus, the small, cat-like Hesperosuchus and Parrishia, the bipedal, theropod-like predator Poposaurus, and the giant land predator Postosuchus. Other archosaurimorphs Smilosuchus would have come across would have been the tanystropheid Akidostropheus, doswelliids like Doswellia and Vancleavea, allokotosaurs like Puercosuchus and Trilophosaurus, and others like Syntomiprosopus. Other animals that lived here (and could have been preyed on by Smilosuchus) included the enigmatic Acallosuchus, drepanosaurs like Ancistronychus, Fabanychus, and Skybalonyx, cynodonts like Kataigidodon, the dicynodont Placerias (thought to be Smilosuchus’ preferred prey), and temnospondyl amphibians like Anaschisma.

and its not by ibrahim OR sereno!!!! another player has thrown their hat into the ring!

as some of you know, i work for the st. george dinosaur discovery site museum. the museum is really struggling with finances after a slow summer, so we're hosting a fundraiser in the form of an art contest to help raise money.

the subject of the contest is phytosaurs, since we finally just received our phytosaur skull replica. the entry fee is $2 per entry, via a donation to the museum (linked on the form). the three winners will be printed and displayed within the museum!!

Phytosaurus and Protosuchus. Animal Ghosts. Edited by Claudia Clow. Illustrated by Walt Disney Productions. 1971.

#Archovember Day 17 - Paleorhinus bransoni

While pseudosuchians were trying all sorts of things in the Late Triassic, the unrelated phytosaurs had already nearly perfected the crocodile body plan. These “crocs before crocs were crocs” were short legged and long-jawed, carnivorous, semi-aquatic, and even covered in bony scutes like the later crocodilians would be. Visually, the biggest difference was the placement of their nostrils. Yet, while pseudosuchians continued on to eventually arrive at this body plan independently, phytosaurs did not survive the Triassic-Jurassic extinction event.

The phytosaur Paleorhinus bransoni would have been found in lakes and rivers across the Late Triassic American Southwest. It had two nostrils that jutted up from the middle of its skull and acted almost like a snorkel. Paleorhinus would have lived alongside temnospondyl amphibians likes Anaschisma and Apachesaurus, rhyncosaurs like Beesiiwo, the dicynodont Eubrachiosaurus, and large pseudosuchian predators like Heptasuchus and Poposaurus, which could have even preyed on basking Paleorhinus if they caught them out of the water. Most of Paleorhinus’s hunting would have been done in the water, though, and it seemed well equipped for catching fish and amphibians with its long jaws and sharp teeth.

A sketch from 2020 showing the phytosaur Mystriosuchus steinbergeri, named the year prior from remains found in the Dead Mountains of Salzburg. Phytosaurs like this one almost look like modern crocodiles with the exception of the fact that the nostrils were located just before the eyes, oftentimes raised even higher than the eyes. Back in the Triassic these guys lived in the shallow sea that covered much of Austria. I later got the chance to see fossils of Mystriosuchus steinbergeri at the Natural History Museum in Vienna.