Study finds Spinosaurus likely spent most of its life submerged
Yale researchers used machine-learning on thousands of fossil measurements to show that Spinosaurus was predominantly aquatic, while some early marine reptiles were still amphibious.
A Yale University team examined over 11,000 measurements, photographs and CT scans from the Peabody Museum and other collections, applying machine-learning techniques that incorporate evolutionary relationships. The models, adapted from a World War II statistical method, linked skeletal proportions to aquatic habits and inferred the presence of flippers in extinct amniotes. Results suggest Spinosaurus, which lived 113-94 million years ago in present-day northern Africa, was highly aquatic, likely hunting beneath the water surface.
Conversely, mesosaurs and all examined early marine reptiles showed limb ratios consistent with regular terrestrial movement, resembling modern alligators or platypuses. The approach achieved more than 90 % accuracy in predicting soft-tissue adaptations, offering a new, less subjective way to reconstruct the lifestyles of long-extinct vertebrates.
Why it matters
The findings refine our understanding of how major vertebrate groups repeatedly returned to water, informing evolutionary theory and fossil interpretation.
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