Anewly described reptile from New Mexico is giving scientists a fresh look at the evolutionary experiments that unfolded before dinosaurs came to dominate Earth. Named Labrujasuchus expectatus, the species lived around 212 million years ago during the Late Triassic.
Described in the Journal of Vertebrate Paleontology, the fossil belongs to a rare group known as shuvosaurids. Researchers say the find helps fill an important gap in the fossil record and sheds light on a poorly understood branch of reptile evolution.
More than 200 million years ago, the Triassic was a period of rapid diversification. Dinosaurs were only beginning to emerge, while numerous reptile groups were adapting to different ecological niches and developing a remarkable variety of forms.
Among them were the shuvosaurids, members of the crocodile lineage that evolved an unusual body plan. With their long hind limbs, lightweight build and toothless beaks, they closely resembled small theropod dinosaurs despite belonging to a completely different branch of the reptile family tree.
A Crocodile Relative Looked Like a Dinosaur
As reported in the study published in the Journal of Vertebrate Paleontology, Labrujasuchus was a member of Shuvosauridae, an extinct group known for its unusual anatomy. At first glance, the animal would not have looked much like a crocodile. It moved on two legs, carried small forelimbs, and had a beak instead of teeth. Its body plan closely resembled that of ornithomimosaurs, the fast-running, ostrich-like dinosaurs that appeared much later during the Cretaceous.
That similarity evolved independently. Scientists describe the phenomenon as convergent evolution, when unrelated groups develop comparable traits because they adapt to similar lifestyles.
“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,” said lead author Dr. Alan Turner.
He noted that while bipedalism may seem unusual for a crocodile relative, it proved to be an effective strategy for several groups of animals over time.
A Fossil Scientists Were Expecting To Find
Onlyfive shuvosaur species have been identified so far, making every new discovery important for understanding the group’s history. What makes Labrujasuchus expectatus particularly interesting is where it fits in the fossil record.
Researchers had already found one shuvosaur species from an earlier period and another from a later one in the same region. That left a gap that suggested an intermediate species was likely waiting to be discovered.
The research team said that expectation inspired the species name expectatus. The fossil turned out to be exactly the kind of missing link scientists had been searching for.
The genus name also has local roots. Labrujasuchus combines “Ranchos de los Brujos,” an old Spanish name for the Ghost Ranch area that translates roughly as “Ranch of the Witches,” with the Greek word suchus, meaning crocodile.
“We wanted to give a nod to that colorful history,” said co-authorDr. Nate Smith, adding that: “We also wanted to highlight how the fossil record works—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.”
Another Extraordinary Find From Ghost Ranch
The fossil was uncovered at Hayden Quarry in Ghost Ranch, New Mexico, one of the most important Triassic fossil sites in North America. According to information released alongside the study, paleontologists have been working in the area’s quarries for decades, recovering exceptionally preserved fossils from a time when reptiles were experimenting with an extraordinary range of body plans.
The discovery arrives as researchers mark 20 years of collaborative excavations at Ghost Ranch. Teams from the Natural History Museums of Los Angeles County and other institutions continue to investigate the site, which has become a key window into life during the Late Triassic.
“Whether visitors are seeking its iconic landscape and spiritual healing or digging into ancient history, Ghost Ranch is a place like nowhere else on the planet. We’re looking forward to collaborating with Dr. Turner, Dr. Smith, and all their colleagues to continue sharing this extraordinary place for years to come,” Joanne Lefrak, Director of Experience and Social Impact at the Ghost Ranch Education and Retreat Center, noted.
