Analysis of computed tomography scans applied to a specimen dating back several decades, housed at the Yale Peabody Museum of Natural History, has unveiled a novel species of short-snouted crocodylomorph. This ancient creature exhibited exceptionally robust jaw musculature, offering a singular glimpse into the ecological adaptations present during the Late Triassic period.
Eosphorosuchus lacrimosa (on the left) is shown being disturbed by Hesperosuchus agilis (on the right) in proximity to a Coelophysis carcass within the geographical confines of what is now known as Ghost Ranch, New Mexico, USA. The artwork is credited to Julio Lacerda.
Eosphorosuchus lacrimosa inhabited riparian and lacustrine environments approximately 210 million years ago in the region now recognized as New Mexico, United States.
This particular reptilian entity was characterized by its swift terrestrial locomotion, possessing pronounced hind limbs and comparatively diminutive, slender forelimbs.
Furthermore, it featured a truncated facial structure, a cranium exhibiting significant reinforcement, and well-developed masticatory musculature, ideally suited for the forceful occlusion necessary to capture and subdue large prey items.
“This finding underscores the evolutionary diversification of ancestral crocodilians at the inception of the Age of Reptiles,” commented Dr. Bhart-Anjan Bhullar, a distinguished paleontologist affiliated with Yale University and the Yale Peabody Museum of Natural History.
“During this specific geological era, the Late Triassic, two dominant reptilian lineages were engaged in a struggle for supremacy: one lineage ultimately gave rise to the crocodiles and alligators, while the other evolved into the lineage that produced avian species, which are, of course, dinosaurs.”
“The dinosaurs of this epoch were comparatively gracile, delicate organisms that ambulated on two slender legs, exhibiting a gait reminiscent of herons. In contrast, the proto-crocodilians were agile, quadrupedal predators, characterized by a low-slung body plan and a more robust build – analogous in ecological role and physical form to extant animals like jackals, large foxes, or dogs.”
The designated holotype specimen of Eosphorosuchus lacrimosa encompasses cranial fragments, a mandible, vertebral elements, appendicular bones, and ossified dermal armor.
This fossil, unearthed in 1948 at Ghost Ranch, New Mexico, has been available to the scientific community for seventy-five years but had not undergone thorough investigation or definitive identification until this recent study.
The phylogenetic assessment conducted by the research consortium positions Eosphorosuchus lacrimosa at an early juncture within the evolutionary tree of Crocodylomorpha, external to a distinct taxonomic grouping that includes another small crocodylomorph known as Hesperosuchus agilis.
This taxonomic placement suggests that its unique morphological characteristics emerged early in the evolutionary trajectory of crocodylomorphs.
Significantly, the fossilized remains of Eosphorosuchus lacrimosa were discovered within the same fossil assemblage as Hesperosuchus agilis.
The concurrent existence of these two distinct forms implies that early crocodylomorphs were already engaging in the partitioning of ecological niches, even among terrestrial predators of comparable size.
“Eosphorosuchus lacrimosa represents one of a limited number of well-preserved early relatives of crocodiles, and its co-occurrence with Hesperosuchus agilis signifies the initial stages of functional divergence within the lineage that eventually led to modern crocodiles,” stated Miranda Margulis-Ohnuma, a doctoral candidate at Yale University.
“Beyond its distinctive anatomy and remarkable preservation status, this specimen highlights the latent potential residing within current museum collections to continue yielding novel insights into the chronicle of life on Earth.”
“What renders this discovery particularly noteworthy, according to the researchers, is its capacity to provide a snapshot of an ancient ecosystem characterized by a biodiversity so substantial that closely related species delineated their ecological roles through specialized feeding adaptations.”
The scientific publication detailing these findings was issued this month in the journal Proceedings of the Royal Society B.
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Miranda Margulis-Ohnuma et al. 2026. A short-snouted ‘sphenosuchian’ with unusual feeding anatomy demonstrates that ecological specialization occurred early in crocodylomorph evolution. Proc Biol Sci 293 (2069): 20260130; doi: 10.1098/rspb.2026.0130
