A newly identified prehistoric crocodile relative, Eosphorosuchus lacrimosa, was discovered alongside another croc species in New Mexico fossils dating back 210 million years.
Around 210 million years ago, two crocodile relatives about the size of modern jackals stood together along a humid riverbank in what is now northern New Mexico.
One of them, Hesperosuchus agilis, had a long snout, powerful hind legs, and smaller forelimbs. It lived on land, moved quickly, and hunted near rivers and streams.
The second crocodile relative was similar in size but built differently. It had a shorter snout, a sturdier skull, and larger jaw muscles suited for biting larger prey. Despite those advantages, both animals met the same fate.
The pair appears to have died at the same moment, likely during a sudden natural disaster such as a mudslide or flash flood. Their bodies remained buried together, and unique geochemical conditions preserved their bones through the Age of Reptiles, the later rise of mammals, and eventually their excavation from massive rock blocks now housed at Yale’s Peabody Museum of Natural History.
New Species Reveals Early Crocodile Diversification
That discovery led Yale paleontologists to identify the short-snouted animal as a previously unknown species called Eosphorosuchus lacrimosa, described in a new study.
“This speaks to the diversification of proto-crocs toward the beginning of the ‘Age of Reptiles,’” said Bhart-Anjan Bhullar, associate professor of Earth and planetary sciences in Yale’s Faculty of Arts 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 journal Proceedings of the Royal Society B.
“During this period, the late Triassic, there were two reptile dynasties vying for dominance: the line that would produce crocodiles and alligators on one side, and that which would produce birds, which of course are dinosaurs, on the other,” Bhullar added. “The dinosaurs at this time were slim, delicate animals that walked on two slender legs almost like herons, and the crocodiles were fast-running, four-legged predators, low-slung and more heavily built—analogous to a jackal, a big fox, or a dog.”
Ghost Ranch Fossils Offer Rare Snapshot of Triassic Life
Bhullar explained that reconstructing ancient ecosystems is often difficult because fossils are usually incomplete, and scientists cannot always confirm whether remains found together actually came from the same time and place. Occasionally, however, researchers uncover exceptionally well-preserved fossil sites.
One such site is Ghost Ranch in New Mexico, where scientists have spent decades studying fossils of crocodile relatives, lizard relatives, fish, and dinosaurs, including the carnivorous Coelophysis bauri. Two large sections from the “Ghost Ranch Bone Bed”, together roughly the size of a car, are preserved at the Yale Peabody Museum.
The fossil was excavated in 1948 and had remained scientifically known for about 75 years without being fully studied or identified. “I had been staring at this fossil for a while,” Bhullar said. “For years, both Ghost Ranch crocs were thought to be examples of Hesperosuchus, but it looked like the Yale animal had a different facial structure.”
For the new study, Miranda Margulis-Ohnuma, a Ph.D. student in Earth and planetary sciences at Yale’s Graduate School of Arts and Sciences (GSAS), analyzed a computed tomography (CT) scan of the fossil. The scan was conducted at the Yale Chemical and Biophysical Imaging Center by former Peabody Museum senior preparator Marilyn Fox.
CT Scans Reveal a Previously Unknown Crocodile Relative
Using the scans, Margulis-Ohnuma digitally separated the fossil bone by bone, uncovering several anatomical differences from known Hesperosuchus specimens.
The newly identified species, Eosphorosuchus, takes its name from the Greek god Eosphorus, meaning “dawn-bringer,” and the Greek word “soukhos,” meaning crocodile.
“Eosphorosuchus is one of only a handful of well-preserved early crocodile relatives, and its coexistence with Hesperosuchus represents the ‘dawn’ of functional diversification in the lineage that would give rise to modern crocodiles,” said Margulis-Ohnuma, who is first author of the new study. “In addition to its unique anatomy and preservational history, the specimen demonstrates the potential of existing museum collections to continue revealing novel insights into the history of life.”
Fossil Discovery Captures a Moment Frozen in Time
Researchers say the discovery offers a rare glimpse into an ancient ecosystem where closely related species occupied different ecological roles by developing specialized feeding adaptations.
“It’s a time-slice of a single moment 210 million years ago,” Bhullar said. “These two individuals had to compete and interact with each other. They were quite possibly looking at each other when they died.”
Reference: “A short-snouted ‘sphenosuchian’ with unusual feeding anatomy demonstrates that ecological specialization occurred early in crocodylomorph evolution” by Miranda Margulis-Ohnuma, Alexander A. Ruebenstahl, Dalton L. Meyer and Bhart-Anjan S. Bhullar, 15 April 2026, Proceedings of the Royal Society B: Biological Sciences.
DOI:10.1098/rspb.2026.0130
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