About 95 million years ago, a little crocodyliform no bigger than a household lizard scurried around what is now southwest Montana.
Nicknamed Elton, this tiny reptile was only about 2 feet long as a juvenile and, even as an adult, would have reached just 3 feet—making it far smaller than most of its crocodile cousins.
Unlike modern crocodiles, which spend much of their lives in the water and have simple, cone-shaped teeth designed for catching prey, Elton lived on land.
Its teeth were unusual—different shapes and specialized in ways that suggest it ate a mixed diet of plants, insects, and maybe small animals.
This distinctive dental pattern revealed that Elton belonged to a previously unknown family of crocodyliforms that lived only in North America during the Cretaceous period.
The story of Elton’s discovery begins in the summer of 2021, when Harrison Allen, then an undergraduate student at Montana State University, spotted something unusual in the Blackleaf Formation near Dillon, Montana.
He noticed a tiny fossil with a “weird texture,” no bigger than the tip of his pinkie finger.
Excited, he showed it to his professor, David Varricchio, who quickly realized it was the beginning of something special—a nearly complete tiny croc skull preserved in extraordinary detail.
This find became the centerpiece of Allen’s undergraduate research and later his doctoral work at Stony Brook University.
Alongside fellow student Dane Johnson, Allen carefully excavated dozens of fragile bone fragments, all small enough to fit in the palm of his hand.
While working in the lab, the students often played music, including Elton John’s hit Crocodile Rock—a fitting soundtrack that inspired the fossil’s nickname long before it received its scientific name, Thikarisuchus xenodentes, which means “strange-sheathed tooth crocodile.”
Because the bones were too delicate to physically reconstruct, Allen turned to technology. Using CT scans, he digitally pieced together Elton’s skeleton, spending more than 100 hours coloring and separating bone from rock in the images.
The result was a detailed digital model that revealed not only the animal’s anatomy but also its lifestyle.
The fossil bones were found in a dense cluster, suggesting Elton’s remains were preserved in a burrow—similar to other fossils found in the region.
The discovery also shed light on crocodyliform evolution. Elton’s newly named family, Wannchampsidae, shows striking similarities to another group, Atopasauridae, found in Eurasia. Though not closely related, both groups evolved small bodies and land-based adaptations, likely due to similar environmental pressures.
This is an example of convergent evolution, where unrelated animals develop similar traits because they face the same challenges in their environments.
For Allen, what began as a lucky find on a summer dig turned into a life-changing project. He is now pursuing a Ph.D. in croc paleontology and has expanded his research to explore the incredible diversity of ancient crocs, which included everything from marine species to shell-crackers to plant eaters.
As Professor Varricchio put it, Elton’s discovery wasn’t just about a fossil—it was about the excitement of science, the joy of discovery, and the bright future of a young paleontologist whose enthusiasm matched his find.
