The lifestyle of spinosaurid dinosaurs has been a topic of lively debate ever since the unveiling of important new skeletal parts for Spinosaurus aegyptiacus in 2014 and 2020. Disparate lifestyles for this species have been proposed in the literature; some have argued that it was semiaquatic to varying degrees, hunting fish from the margins of water bodies, or perhaps while wading or swimming on the surface; others suggest that it was a fully aquatic underwater pursuit predator.
Paleontologists generally agree that Spinosaurus aegyptiacus was a fish-eater, but exactly how these dinosaurs caught their prey is the subject of lively debate, with some researchers suggesting that they hunted on the shore, some that they waded or swam in the shallows, and others that they were aquatic pursuit predators.
One recent study provided support for the latter hypothesis using a fairly new statistical method called phylogenetic flexible discriminant analysis (pFDA) to analyze density and proportions of Spinosaurus bones.
In a new study, University of Chicago’s Professor Paul Sereno and his colleagues critically assess the methods of that prior research and identify significant flaws.
“Spinosaurus, and its close relatives, are fascinating because of their unusual anatomical features, the scarcity of specimens, and the fact that scientists had not found bones from parts of its body until very recently,” they said.
“Unlike other meat eating dinosaurs, there are strong clues that it lived near water and ate fish or other aquatic fare.”
“This has fueled a lot of controversy about how Spinosaurus lived — was it a fast swimming predator that chased fish like a sea lion? Or was it an ambush predator at the water’s edge, grasping with its clawed hands like a giant version of a brown bear chasing salmon, or plunging its head into water like a 7-ton heron from hell?”
The authors began by asking new questions about bone density, such as how to digitize thin sections,…
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