A zoologist believes birds didn’t evolve from dinosaurs but rather both had a shared ancestor:
Almost 20 years of research at OSU on the morphology of birds and dinosaurs, along with other studies and the newest PNAS research, Ruben said, are actually much more consistent with a different premise – that birds may have had an ancient common ancestor with dinosaurs, but they evolved separately on their own path, and after millions of years of separate evolution birds also gave rise to the raptors. Small animals such as velociraptor that have generally been thought to be dinosaurs are more likely flightless birds, he said.
Benton, who directs the Palaeobiology and Biodiversity Research Group at the University of Bristol, and his colleagues conducted one of the most extensive studies yet on the Hateg Island dinosaur remains. They analyzed the dinosaurs’ limb proportions and bone growth patterns, comparing them with those of mainland dinos.
The analysis determined that at least four of the Hateg dinosaurs were dwarves.
The diminutive dinosaurs included the titanosaurian sauropod Magyarosaurus, which had a body length of about 16 to 19 feet. That’s impressive by human standards, but is miniature compared to a sauropod such as Argentinosaurus, which grew to be at least 82 feet long.
Finally, isotopic analysis suggests spinosaurus and its kin spent much of its time lurking and hunting in shallow water just like modern alligators and crocodiles. This allowed them to exist alongside other large Cretaceous theropods since spinosaurids weren’t in competition with terrestrial meat-eaters.
Photo of T-rex taken at the AMNH.