About 210 million years ago, two early relatives of modern crocodiles stood huddled in low ferns on a damp riverbank in what is now northern New Mexico. Although each animal was about the same size as a jackal, their bodies suggest that they were adapted for hunting in different ways.
One is Hesperosuchus agilityis a fast land predator with a long snout, powerful hind legs, and small, slender forelimbs. It probably foraged along rivers and streams.
The second animal’s head was noticeably different. The snout was shorter, the skull was stronger, and the enlarged jaw muscles likely helped it capture larger prey.
Neither animal was able to escape the sudden events that followed. Researchers believe both died at the same time, perhaps in a flash flood or landslide. Their bodies were buried together, and favorable chemical conditions preserved their bones until the “age of reptiles,” the subsequent rise of mammals, and finally their excavation as large blocks of rock, now housed at Yale University’s Peabody Museum of Natural History.
New species emerge from old fossils
Paleontologists at Yale University took a closer look at the short-nosed animal and determined it belonged to a previously unknown species. they named it Eosphorosuchus lacrimosa In new research.
“This speaks to the diversification of protocrocodiles toward the beginning of the ‘Age of Reptiles,'” said Bart Anjan Brar, associate professor of Earth and Planetary Sciences in Yale’s School of Humanities and Sciences (FAS), associate curator of vertebrate paleontology and vertebrate zoology at the Peabody Museum, and senior author of the new study published in the same journal. Proceedings of the Royal Society B.
“At this time in the Late Triassic period, two reptilian dynasties were competing for supremacy: one that produced crocodiles and crocodiles, and the other that produced birds (and dinosaurs, of course),” Buhler added. “Dinosaurs at the time were slender, delicate animals that walked on two thin, heron-like legs, while crocodiles were fast-running, four-legged predators that were shorter and more stocky, resembling jackals, giant foxes, and dogs.”
By the Late Triassic, both the crocodile ancestor and the lineage that gave rise to dinosaurs were beginning to play new ecological roles. Unlike today’s primarily aquatic crocodiles, many of the earliest crocodile relatives were agile predators that roamed on land.
A precious window into the Late Triassic
Reconstructing the diversity of life at a particular place and time can be difficult for paleontologists. Fossils are often incomplete, and researchers can’t always tell whether animals found in the same rock layer actually lived together.
Exceptionally preserved fossil sites provide clearer evidence. Ghost Ranch in New Mexico is one such place.
For nearly a century, scientists have studied fossils collected at Ghost Ranch. Fossils include crocodile relatives, lizards, fish, and dinosaurs (most famously the carnivorous Coelophysis bauri). The Peabody Museum at Yale University houses two large sections of the Ghost Ranch Bonebed rock. When you put the blocks together, they are about the same size as a car.
Fossils containing these two crocodile relatives were unearthed in 1948. Although it has been available to scientists for about 75 years, it has never been fully analyzed or formally identified.
“I stared at this fossil for a while,” Buller said. “For years, Ghost Ranch Crocs have both hesperosuchusHowever, the Yale animals appeared to have different facial structures. ”
CT scan reveals hidden anatomical structures
To investigate these differences, Dr. Miranda Margulis Onuma, a student in the Department of Earth and Planetary Sciences at the Yale School of Arts and Sciences (GSAS), studied computed tomography (CT) scans of animals. The scans were performed at the Yale Chemical and Biophysical Imaging Center by former Peabody Museum Senior Preparator Marilyn Fox.
CT imaging allowed Margulis Onuma to examine structures that remain embedded in the rock. She digitally “deconstructed” the fossil one bone at a time, revealing several anatomical features that differed from those known. hesperosuchus Specimen.
These differences supported the following identifications. Eosphorosuchus as a separate genus and species.
The name is a combination of the Greek god Eosphoros, known as the “bringer of dawn,” and the Greek word “sukos,” meaning crocodile.
”Eosphorosuchus It is one of the few well-preserved relatives of early crocodiles. hesperosuchus “This specimen represents the ‘dawn’ of functional diversification of the lineage that gave rise to modern crocodiles. In addition to its unique anatomy and conservation history, this specimen demonstrates the potential of existing museum collections to continue to reveal new insights into the history of life.”
Early crocodile relatives were hunted differently
The discovery is particularly valuable because the two animals likely lived in the same ecosystem at the same time. Their contrasting skulls and jaws suggest that closely related predators were already dividing available food resources by developing different feeding strategies.
hesperosuchus He had a long and narrow nose, Eosphorosuchus It had a shorter, more strengthened skull and stronger jaw muscles. These differences may have allowed the animals to track different types of prey, reducing direct competition.
“This is a momentary time slice from 210 million years ago,” Buller said. “These two people had to compete and interact with each other. They were probably looking at each other when they died.”
Co-authors of the study are Alexander Rubenstahl, a current Yale GSAS student, and Dr. Dalton Meyer, a 25-year graduate of Yale and now an instructor at Roanoke College.
What is Eosphorosuchus lacrimosa?
Eosphorosuchus lacrimosa It was an extinct primitive crocodile identified by researchers at Yale University. About 210 million years ago, it was a fast-running terrestrial predator that lived near rivers and lakes.
why is this so Eosphorosuchus lacrimosa important?
Eosphorosuchus lacrimosa provide evidence that early crocodilian relatives had already developed different feeding adaptations during the Late Triassic period, 252 to 201 million years ago, near the beginning of the “Age of Reptiles.”
That presence next to you hesperosuchus Researchers can gain a rare perspective on two related predators that play different ecological roles within the same ancient environment.
what did you do Eosphorosuchus lacrimosa Looks like?
According to paleontologists at Yale University, Eosphorosuchus lacrimosa It had a short snout, a heavily reinforced skull, and enlarged jaw muscles suitable for closing large prey. It also had large hind legs and small, slender front legs.
