During the Triassic period, many of the major animal groups we know today were just beginning to evolve. The world was full of unusual creatures experimenting with body shapes and lifestyles that often resembled modern animals or later dinosaurs. A newly identified species, Labrujasuchus expectatusThere is a vivid example.
described in Vertebrate Paleontology Journal, Labrujasuchus Its appearance seemed more domestic among dinosaurs such as ostriches than among crocodile relatives. He walked on two legs, his front legs were small and had no teeth. Instead, its mouth ended in a beak.
What makes it particularly surprising is its place on the evolutionary tree. Labrujasuchus Archosaurs belonged to the lineage that eventually gave rise to crocodiles, animals known today for their four-legged bodies and jaws full of teeth. In contrast, this newly described species looked completely different from its modern relatives.
As researchers note, the Triassic was an era full of evolutionary surprises.
A strange world of Triassic reptiles
The Triassic landscape was home to a remarkable variety of reptiles with unusual adaptations.
Among them were the lagerpetids, small bipedal relatives of dinosaurs whose descendants eventually evolved into pterosaurs. there was also drepanosaurusA tree-dwelling reptile equipped with a large claw similar to that of a tree sloth, as well as a small claw on its prehensile tail. another example was vancliviaAn armored aquatic reptile is often compared to a miniature tank.
Stepped into this already strange ecosystem Labrujasuchus expectatusThe newest known member of Shuvosauridae. This small group of ancient crocodile relatives developed body plans that closely resembled bipedal theropod dinosaurs, despite belonging to a very different branch of the reptile family tree.
“We see that a lot of successful strategies for modern animals and non-avian dinosaurs first emerged in the Triassic, and shuvosaurs are a great example of that convergent evolution,” says Dr. Alan Turner, lead author of the paper. “Bipedalism is certainly a unique path for crocodile relatives, but it is a path well adopted by dinosaurs and later birds. It clearly worked for these animals.”
filling an evolutionary gap
Only five shuvosaur species have been identified so far, making the new discovery particularly significant.
Researchers had previously found shuvosaur fossils from older and younger rock layers in the region, suggesting that additional species existed in between. Labrujasuchus expectatus fills that predicted gap, providing an evolutionary link that paleontologists had long hoped to uncover.
species name, HopeReflects that idea. Scientists speculated that an intermediate form would eventually be found, making this discovery both expected and unexpected at the same time.
The genus name also has local significance. Labrujasuchus Adds reference to an old Spanish name for Ghost Ranch, “Ranchos de los Brujos”, meaning Witches’ Ranch, along with the Greek word Σοῦχος (suchos), meaning “crocodile.”
“Legend has it that local rancheros named this site ‘Ranchos de los Brujos’ to keep people away from the Archuleta brothers’ cattle smuggling,” says Dr. Nate Smith, co-author and Gretchen Augustin, director and curator of the NHMLAC Dinosaur Institute. “We wanted to give a nod to that colorful history, and honor the incredible role that Ghost Ranch has played in expanding our view of the Triassic. We also wanted to highlight how the fossil record works – finding a shuvosaur from earlier in the Triassic and a shuvosaur later meant that we paleontologists knew there were probably a lot more in between that had yet to be discovered and described.”
Ghost Ranch and the Search for Triassic Life
The Triassic can sometimes seem almost alien compared to the modern world. Yet many of the body plans seen in those ancient animals foreshadow features that later appeared in dinosaurs, birds, and other groups. Studying these early evolutionary experiments helps scientists better understand how life evolved and adapted over time.
Ghost Ranch in New Mexico is one of the most important windows into this distant past. The site contains numerous fossil mines that have been excavated over decades and yield exceptionally preserved specimens from the Late Triassic.
“This summer marks the 20th anniversary of Nate and his colleagues excavating at Ghost Ranch, and we are proud to have played a central role in making that incredible research possible,” says Joanne LeFrak, director of experiences and social impact at the Ghost Ranch Education and Retreat Center. “Whether visitors are seeking its iconic landscapes and spiritual healing or digging into ancient history, Ghost Ranch is a place like no other on the planet. We look forward to collaborating with Dr. Turner, Dr. Smith, and all of their colleagues to continue sharing this extraordinary place for years to come.”
Ghost Ranch, known around the world through Georgia O’Keeffe’s dramatic paintings, is also home to an ongoing multi-year excavation effort. Co-led by Dr. Smith at the NHMLAC Dinosaur Institute, this project focuses on uncovering Late Triassic animals from the Hayden Mine and continuing to reveal new pieces of one of Earth’s most unusual prehistoric ecosystems.