Fossil Friday: Dinnebitodon

Species: Dinnebitodon amarali (Dee-neh-beet-oh-don a-mah-rah-lee)

What it means: Dinnebito Wash tooth

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: Seeds, nuts, roots…I’m an herbivore!

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’m surrounded by meat-eating dinosaurs like Dilophosaurus, Kayentavenator, and Coelophysis, and plant-eating dinosaurs like Sarahsaurus (an early sauropod) and Scutellosaurus (armored dinosaur). I have to be careful not to get stepped on, or end up as lunch for crocodile cousins the prowl the rivers and the dry land. In the sky, flying pterosaurs with long tails keep an eye out for insects like beetles, dragonflies, an ancient cousin of the moth, and something called a snakefly. While frogs and turtles swim with the fish in the river.

Fun Facts:

  • I may look a bit like a weird beaver or rat, but I’m not a mammal at all! I’m from a group of animals called cynodonts, and I’m a close relative of Kayentatherium, one of the other mammal-ish critters here at the Kayenta Formation.
  • It’s pretty common to name creatures after the place they were found. My bones were found in a place called Dinnebito Wash, so my genus name is Dinnebito + don (from the Greek word for tooth, odous). The species name honors William W. Amaral of Harvard University, who helped greatly in collecting and preparing many of the fossils from the Kayenta Formation.
  • Dinnebito Wash gets its name from the Navajo language. Diné (the people) + bitoo (speaking of the juice of something, or water within something. “tó” translates to water). 😀 You can learn all sorts of languages by doing a little extra digging on the names of prehistoric animals!

Fossil Finds: Partial remains from about 10 animals, mostly fragmentary, and a few only of teeth. One or two are moderately well preserved, but incomplete. A few fragments from other parts of the skeleton, but not enough to determine size or distinguish species. The teeth are the only way to identify it as a separate genus to Kayentatherium.


Sues, Hans-Dieter. 1986. Dinnebitodon amarali, a new Tritylodontid (Synapsida) from the lower Jurassic of western North America. Journal of Paleontology v. 60 no. 3. pp. 758-762

6 thoughts on “Fossil Friday: Dinnebitodon

  1. I was first introduced to this cynodont in a book and I like how you gave it some attention. What do you think of it?


    1. I find it interesting! It’s pretty cool to think that cynodonts were diverse enough to specialize in different niches. To the point that we have two close relatives that diverged into different species. Even if the only we have that marks them as two different species is teeth, their teeth are very different from each other and suggest quite a bit of specialization. Also that Kayentatherium is usually found in different areas than Dinnebitodon. Perhaps one preferred a more watery or swampy environment, and the other liked drier burrows?


  2. Thank-you for posting another mammal-like critter. The information on the plants and seasonal changes in the floodplains was interesting. Including information about the name was a nice detail.


    1. Thank you, I’m glad you like it! It was neat to find out more about the environment, even if it’s more of a best-guess than anything else. We can really only make an educated guess of weather and the details of an environment based onthe type of rock and few plant fossils that are known. The sheer number of turtles and freshwater mollusk fossils says a bit about the environment too. 🙂


  3. Thank you for posting this. I really appreciate the emphasis that you are giving on prehistoric mammals and mammal-like reptiles. They don’t get enough attention as they should.


    1. Thank you Jason, I’m glad you like it! I’m really enjoying going through the formation and discovering animals I otherwise would never have known about. There is so much diversity of life, and when I’ve spent my whole life believing the tiny, mouse-like mammal under the feet of dinosaurs trope, it’s pretty exciting to see how unique these creatures really are. 🙂

      Liked by 1 person

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