Labrujasuchus expectatus – A newly identified shuvosaurid from about 212 million years ago—found in a New Mexico quarry—adds another piece to the evolutionary story that runs from distant reptile relatives to today’s crocodiles.
More than 200 million years ago, a bizarre reptile with a beak-like face and tiny forearms stomped across what is now New Mexico. It walked on its hind legs and, despite crocodile-like connections, had no teeth at all.
The fossil remains were first uncovered in 2006 in a New Mexico quarry known among paleontologists for a rich haul of Triassic-era fossils. In the lab. the bones looked close to those of the two recognized North American species in the Shuvosauridae family—an ancient group of bipedal reptiles that lived through the Late Triassic.
But the new specimen didn’t match perfectly. Alan Turner. a professor of anatomical sciences at Stony Brook University and leader of the team that discovered the remains. said the differences are “subtle. ” starting with timing and continuing into anatomy. The bones were dated to around 212 million years ago—more recent than one of the North American shuvosaurid species and later than other known members. Turner and his colleagues also pointed to fine physiological differences. including the humerus. in a study published in the Journal of Vertebrate Paleontology.
“We look at those fine details, because those are the things that the evolutionary processes are shaping, and that lets us get at their family tree that way,” Turner said.
The species was named Labrujasuchus expectatus. It belongs to a lineage that today includes crocodiles, though Turner stressed that the relationship is not close. L. expectatus is “definitely not direct ancestors to modern alligators and crocodiles.” Turner compared it to a “very. very distant cousin. ” explaining that the split happened “hundreds of millions of years ago from the group that eventually leads us to alligators and crocodiles. ” making it a “side branch.”.
That matters because the reptile’s overall look would have invited confusion. Like modern crocodiles, the animal sits in a broader family that includes creatures with a fearsome reputation. But the new discovery is a reminder that evolution doesn’t build copies—it builds outcomes. Modern crocodiles are known for rows of razor-sharp teeth. L. expectatus didn’t have any. Even without teeth, Turner said it’s difficult to pin down diet. A beak-and-no-teeth setup exists in birds, he noted, and it doesn’t stop predators like eagles from hunting.
What about food in L. expectatus’s world? Turner said that because the reptile lived so far back in time, fruit “didn’t really exist.” While he can’t say definitively what the animal ate, Turner believes it was a meat eater and possibly a scavenger.
The find also lands in the boundary between familiar and false labels. L. expectatus was technically not a dinosaur, even though it likely moved and behaved in ways that can resemble dinosaur life. Turner said learning more about the reptile helps scientists understand convergent evolution—when lineages arrive at similar solutions through different evolutionary paths.
“That’s the thing I think I find the most interesting about an animal like L. expectatus,” Turner added. “It’s one more data point that we have in furthering these models about that important evolutionary process.”
Labrujasuchus expectatus Shuvosauridae crocodile relatives Triassic fossils New Mexico quarry convergent evolution Journal of Vertebrate Paleontology Alan Turner bipedal reptile