At Ghost Ranch in New Mexico, paleontologists have unearthed a creature that defies everything we think we know about crocodiles: a two-legged animal with tiny arms, no teeth, and a beak. Meet Labrujasuchus expectatus, a newly described member of Shuvosauridae—a group of ancient crocodile relatives that chose an evolutionary path so radically different from their four-legged, sharp-toothed descendants that you'd hardly recognize the family resemblance.
The discovery, described in the Journal of Vertebrate Paleontology and led by Dr. Alan Turner of Stony Brook University, reveals just how experimental evolution was in the Triassic period, before dinosaurs took over the world. While modern crocodilians are the picture of predatory efficiency—built low to the ground with powerful jaws—Labrujasuchus moved through its ancient landscape on two legs with a lightweight frame, much like the ostrich-like dinosaurs called ornithomimosaurs that would emerge much later. But here's the twist: Labrujasuchus came from the crocodile branch of the family tree, not the dinosaur branch, making it a remarkable example of convergent evolution—when distantly related animals independently evolve similar body plans to solve the same survival problems.
The Triassic was a time of evolutionary experimentation. Alongside Labrujasuchus roamed lagerpetids, two-legged dinosaur cousins whose descendants would eventually take to the skies as pterosaurs; the bizarre tree-dwelling Drepanosaurus with its single sloth-like claw; and Vancleavea, an armored aquatic reptile unlike anything alive today. In this menagerie of oddities, a bipedal crocodile relative was just one more unexpected player in an alien world.
What makes Labrujasuchus especially significant is that it's only the fifth identified species of Shuvosauridae, and it fills a crucial gap in the fossil record. Paleontologists had found shuvosaurs from earlier in the Triassic and others from later periods, but nothing in between—until now. "We see a lot of the successful strategies for modern animals and non-avian dinosaurs first arise in the Triassic, and shuvosaurs are a great example of that convergent evolution," Dr. Turner explains. "Bipedalism is certainly a unique path for crocodile relatives to take, but it's a path well-trod by dinosaurs and later birds. It obviously worked for these animals."
The discovery itself is wrapped in local history. The name Labrujasuchus references "Ranchos de los Brujos"—the Ranch of the Witches—an old Spanish name for Ghost Ranch supposedly given by local ranchers to deter cattle rustlers. The species name, expectatus, captures the delicious irony that paleontologists had been expecting this fossil to exist in the fossil record, and there it was. Dr. Nate Smith, co-author and Director of the Dinosaur Institute, emphasized how the discovery honors Ghost Ranch's role in expanding our understanding of the Triassic era. "Finding one shuvosaur from earlier in the Triassic and one from later meant that we paleontologists knew there were probably more from in-between waiting to be discovered and described," he notes.
These Triassic weirdos matter more than just as curiosities. The body plans that emerged during this bizarre experimental period echo through time, mirroring the diversity we see in modern animals. Understanding this ancient past helps us appreciate the evolutionary possibilities still open to life today—and, just as importantly, the urgency of protecting the species still walking the Earth.