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 closely resembled modern animals and later dinosaurs. One of the newly identified species, Rubble Jascus Expetatusis a notable example.
is listed in Journal of Vertebrate Paleontology, Rubble Jascus Ostrich-like dinosaurs had a more friendly appearance than their crocodile relatives. It walked on two legs and had small front legs and no teeth. Instead, its mouth ended in a beak.
What makes this particularly surprising is its place in the evolutionary tree. Rubble Jascus It belongs to the archosaur lineage and eventually gave rise to crocodiles. Crocodiles are the animals best known today for their four-legged bodies and jaws filled with teeth. In contrast, this newly described species bore little resemblance to its modern relatives.
As researchers point out, the Triassic was a period full of evolutionary surprises.
The strange world of Triassic reptiles
The Triassic landscape was home to an amazing variety of reptiles with unusual adaptations.
These included lagerpetids, relatives of small bipedal dinosaurs whose descendants eventually evolved into pterosaurs. There was also drepanosaurusThey are tree-dwelling reptiles with large sloth-like claws and smaller claws on their prehensile tails. Another example is buncley beararmored aquatic reptiles are often compared to small aquariums.
Stepping into this already strange ecosystem Rubble Jascus Expetatusthe newest known member of the Shubosauridae. This small group of ancient crocodile relatives evolved a body design that closely resembled bipedal theropod dinosaurs, despite belonging to a completely different lineage of the reptilian family tree.
“Many successful strategies for modern animals and non-avian dinosaurs first emerged in the Triassic, and Shubosaurs are a great example of convergent evolution,” said lead author Dr Alan Turner. “Bipedalism is certainly a unique path for members of the crocodile family, but it’s also a path well trodden by dinosaurs and later birds. It clearly worked well for these animals.”
bridging the evolutionary gap
This new discovery is particularly important, as only five species of Shubosaurs have been identified to date.
Researchers had previously discovered Shubosaurus fossils in older and younger rock layers in the area, suggesting additional species were likely present in between. Rubble Jascus Expetatus fills that predicted gap and provides an evolutionary link that paleontologists have long hoped to uncover.
The species name is expectedreflects that idea. Scientists expected they would eventually find an intermediate, and the discovery was both expected and unexpected.
The genus name also has regional meaning. Rubble Jascus It is a reference to the old Spanish name for ghost ranches, Ranchos de los Brujos, meaning witch’s ranch, combined with the Greek word Σοῦχος (sucus), meaning crocodile.
“Legend has it that local ranchers named the site ‘Ranchos de los Brujos’ to keep people away from the Archuleta brothers’ cattle raiding operations,” says co-author Dr. Nate Smith, director and curator of the NHMLAC Dinosaur Institute and Dr. Gretchen Augustine. “We wanted to pay homage to its colorful history and pay homage to the great role Ghost Ranch played in broadening our view of the Triassic. We also wanted to focus on how the fossil record works. Early Triassic Shubosaurus and later Shubosaurus The finding of each head means that we paleontologists knew that there was probably an intermediate Shubosaurid waiting to be discovered and described.”
Exploring Ghost Ranch and Triassic Life
The Triassic period can seem almost alien when compared to the modern world. But many of the body plans seen in these ancient animals foreshadow traits that would later appear in dinosaurs, birds, and other groups. Studying these early evolutionary experiments helps scientists better understand how life developed and adapted over time.
Ghost Ranch in New Mexico remains one of the most important windows into this distant past. The site is home to multiple fossil quarries that have been excavated over the decades and continue to yield exceptionally well-preserved specimens from the Late Triassic.
“This summer marks the 20th anniversary of Nate and his colleagues excavating at Ghost Ranch, and we are so proud to play a central role in making that incredible research possible,” said Joanne Lefrak, director of experiential and social impact at the Ghost Ranch Education and Retreat Center, which hosts teams of paleontologists and volunteers each summer. “Whether visitors seek its iconic landscapes, spiritual healing, or delve into ancient history, Ghost Ranch is a place like nowhere else on Earth. We look forward to working with Dr. Turner, Dr. Smith, and all of their colleagues to continue sharing this incredible place for many years to come.”
Known worldwide for Georgia O’Keeffe’s dramatic paintings, Ghost Ranch is also the site of a multi-year excavation. The project, co-led by Dr. Smith from the NHMLAC Dinosaur Institute, focuses on excavating Late Triassic animals from the Hayden Quarry and continues to uncover new parts of one of the most unusual prehistoric ecosystems on Earth.
