Species: Kayentachelys aprix (Kah-yen-ta-kel-ees A-pricks)
What it means: Kayenta shell
Other species: none
Where I live: Arizona in the U.S.A.- The Kayenta formation
When to find me: The Early Jurassic period, about 196 million years ago.
My favorite food: Bugs, plants that grow along the riverbank, whatever I can snap at really! I’m an omnivore.
My neighborhood: The Kayenta formation used to be a tropical floodplain, a bit like African savannah today- but no grass or flowers. Ferns cover the open plains, dotted with islands of spiky cycad groves. Rivers crisscross the land with lush tree ferns, ginkgo trees, and conifers. Every year during the wet season the plains turn into a flooded marsh, but the hottest months bring no rain, and the rivers shrink until the plains are almost as dry as the great desert that lies to the north.
A few of my neighbors: I have to watch out for all sorts of predators like Dilophosaurus, Kayentavenator, Coelophysis (meat-eating dinosaurs), and crocodile cousins. More friendly neighbors are Sarahsaurus (an early sauropod), and Scutellosaurus (small armored dinosaur). I like to hang out on the riverbank with the frogs and the flying pterosaurs. There’s always a steady hum of insects like beetles, dragonflies, an ancient cousin of the moth, and something called a snakefly.
- There are two groups of modern turtles. Cryptodira- the group of turtles that can hide their heads inside their shells, and Pleurodira- turtles that tuck their necks sideways so their heads fit under the rim of their shells. Some say I am the oldest known Cryptodire, but others say I am not a direct relative to modern turtles at all! I look a lot like one though!
- Using the place a critter is found in a name is pretty common. Kayenta + chelys (latin for a turtle or tortoise shell) = Turtle from the Kayenta Formation. Aprix is Greek for tight, and describes how all the bones in the base of the skull are fused.
Fossil Finds: Abundant, fragmentary remains of head, shell, and body.
Gaffney, E.S. and Jenkins Jr, F.A. (2010), The cranial morphology of Kayentachelys , an Early Jurassic cryptodire, and the early history of turtles. Acta Zoologica, 91: 335-368. doi:10.1111/j.1463-6395.2009.00439.x
Gaffney ES, Hutchison JH, Jenkins FA Jr, Meeker LJ. Modern turtle origins: the oldest known cryptodire. Science. 1987;237(4812):289‐291. doi:10.1126/science.237.4812.289
Joyce, Walter. (2009). Phylogenetic Relationships of Mesozoic Turtles. Bulletin of the Peabody Museum of Natural History. 48. 3-102. 10.3374/0079-032X(2007)48[3:PROMT]2.0.CO;2.
Cherepanov, Gennady. (2006). Ontogenesis and evolution of horny parts of the turtle shell. Fossil turtle research. Suppl. Russian J. Herpetology. 1. 19-33.