How massive long-necked dinosaurs rose to rule the Jurassic herbivores

Carolyn Gramling | Science News
Wednesday, November 18, 2020

A new study from the MIT EAPS Isotope Lab and others "pins in time the rise of large herbivore dinosaurs at the expense of their evolutionary precursors in the Early Jurassic, which coincided with a major change in ancient plant communities," says MIT co-author and research scientist Jahan Ramezani. Carolyn Gramling writes for Science News: "The find comes from the discovery of a new fossil of one of the earliest “true” sauropods in Argentinian Patagonia. Sediments bearing the newly described dinosaur, dubbed Bagualia alba, are precisely dated to 179 million years ago, paleontologist Diego Pol of the Paleontological Museum Egidio Feruglio in Trelew, Argentina, and colleagues report November 18 in Proceedings of the Royal Society B." The MIT EAPS Isotope Lab used high-precision U-Pb geochronology of ash beds to provide age determinations. They found that "the close proximity in space and time to a prominent volcanic province in the southern hemisphere points out to volcanism-induced climate change as a driver of ecologic change and dinosaur evolution."

Read coverage of the paper at Science News and Phys.org

Story Image: The tooth of Bagualia alba, discovered in Argentinian Patagonia, bears the typical thick enamel and spoon shape of sauropods. These features helped the creatures munch on the tough leaves of conifers, which flourished after about 180 million years ago. New research suggests this ability may have enabled sauropods to become dominant in the Jurassic Period. (Credit: Santiago Reuil)