Labrujasuchus expectatus is the most recent recognized member of Shuvosauridae, a group of ancient crocodile family members with body strategies looking like bipedal, small-armed theropod dinosaurs.

“Shuvosauridae is an uncommon clade of Triassic poposauroid pseudosuchians from western North America and Argentina,” stated Dr. Alan Turner of Stony Brook University and coworkers.

“Gracile, bipedal, and edentulous, these pseudosuchian archosaurs appear usually convergent with ornithomimid theropod dinosaurs from the Cretaceous duration.”

“There are presently 3 acknowledged shuvosaurid types: Shuvosaurus inexpectatus from the Cooper Canyon Formation of Texas, Effigia okeeffeae from the Coelophysis Quarry of the uppermost Chinle Formation of northern New Mexico; and Sillosuchus longicervix from the lower Ischigualasto Formation of San Juan province, western Argentina.”

Labrujasuchus expectatus fills a space in the fossil timeline in between Shuvosaurus inexpectatus and Effigia okeeffeae

Approximated to be approximately 212 million years of ages, the fossil was discovered in the Hayden Quarry of northern New Mexico, the United States, situated within the Petrified Forest Member of the Chinle Formation.

The product consisted of an associated partial skeleton and other fossilized remains.

According to the paleontologists, Labrujasuchus expectatus varied just discreetly from its family members, enhancing a pattern of exceptional skeletal conservatism within the group.

“The very little physiological distinctions in between the diagnostic skeletons of these types suggests that this morphological resemblance was preserved within Shuvosauridae for a minimum of 10 million years in western North America,” they stated.

Labrujasuchus expectatus fits conformably with the hypothesis of morphological conservatism and within the presently understood stratigraphic period of North American shuvosaurids.”

The discovery likewise enhances the concept that shuvosaurids were mainly endemic to western North America, a pattern that sets them apart from numerous other uncommon Triassic reptile groups.

“In our phylogenetic analysis, it falls in a clade with the other 2 North American shuvosaurids, supporting an endemic clade of little, bipedal, toothless kinds in the American Southwest,” the scientists concluded.

The group’s paper was released May 26 in the Journal of Vertebrate Paleontology

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Alan H. Turner et alA brand-new shuvosaurid (Archosauria, Poposauroidea) from the Late Triassic (Norian) Hayden Quarry of New Mexico, U.S.A. Journal of Vertebrate Paleontology, released online May 26, 2026; doi: 10.1080/ 02724634.2026.2618182