Do a Google Image search for the word “Triassic” and you’re going to see variations of the same scene over and over again. Svelte little dinosaurs snap and squawk around an ancient lake or river, with the also-rans of their era – such as the armored aetosaurs and superficially-crocodile-like phytosaurs – shuffling through the undergrowth and basking at the water’s edge. Such vignettes are classic Triassic imagery, and yet they’re only a narrow view of one part of the opening chapter in the Age of Reptiles triology. There’s far more to the Triassic story than Coelophysis and its neighbors, with the latest wrinkle to the tale arriving in the form of a beautiful skull found in Brazil.
The fossil, described by paleontologist Felipe Pinheiro and colleagues, was that of an archosauromorph. This was a line of reptiles that first evolved back in the Permian, when the protomammals held sway, and underwent explosive diversification during the Triassic, eventually sprouting branches that would include dinosaurs, pterosaurs, and crocodiles.
Named Teyujagua paradoxa by the researchers, the 251 million year old animal lived just before the great reptilian radiation really took off. So while not necessarily the ancestor of the various lineages that would come later, Pinheiro and coauthors point out that the skull of Teyujagua is a significant part of the story given that it exhibits some characteristics of older forms of reptiles as well as novelties that would come to mark the “ruling reptiles” such as serrated teeth and an opening in the sidewall of the lower jaw. When you look at the skull of Teyujagua, you’re looking at a face that helped set evolutionary trends from the dawn of the Triassic until today.
Meaning: The genus was named after Teyú Yaguá, a dog-headed lizard in Guarani mythology, while paradoxa underscored the “unusual” combination of characteristics.
Age: Around 251 million years ago.
Where in the world?: Southern Brazil.
What sort of critter?: An archosauromorph, or an ancient member of the lineage that includes dinosaurs, pterosaurs, crocodiles, and their relatives.
Size: The skull is about four and a half inches long.
How much of the creature’s body is known?: A nearly-complete skull and several neck vertebrae.
Pinheiro, F., França, M., Lacerda, M., Butler, R., Schultz, C. 2016. An exceptional fossil skull from South America and the origins of the archosauriform radiation. Scientific Reports. doi: 10.1038/srep22817
Previous Paleo Profiles:
The Unfortunate Dragon
The Cross Lizard
The South China Lizard
Zhenyuan Sun’s dragon
The Fascinating Scrap
The Sloth Claw
The Hefty Kangaroo
The Rain-Maker Lizard
The Ancient Agama
The Cutting Shears of Kimbeto Wash
The False Moose
“Miss Piggy” the Prehistoric Turtle
Mexico’s “Bird Mimic”
The Greatest Auk
Catalonia’s Little Ape
Pakistan’s Butterfly-Faced Beast
The Head of the Devil
Spain’s Megatoothed Croc
The Smoke Hill Bird
The Vereda Hilarco Beast
The North’s Sailback
Amidala’s Strange Horn
The Northern Mantis Shrimp
Spain’s High-Spined Herbviore
Wucaiwan’s Ornamented Horned Face
Alcide d’Orbigny’s Dawn Beast
The Shield Fortress
The Dragon Thief
The Purgatoire River’s Whale Fish
Russia’s Curved Blade
The Dawn Mole
The Oldest Chameleon
The Wandering Spirit