A 30 million year-old fossil whale may not be the heaviest animal of all time after all, according to a new analysis by paleontologists at UC Davis and the Smithsonian Institution. The new analysis puts Perucetus colossus back in the same weight range as modern whales and smaller than the largest blue whales ever recorded. The work is published Feb. 29 in PeerJ.
We live in a geometric world. From the rectangular skylines of our cities and the orbiting planets of our solar system to the symmetry of butterfly wings and the spiraling double helix of DNA, every shape has its place.
For as long as he can remember, Ryosuke Motani has been fascinated by shapes. And he’s built an illustrious paleobiology career studying them.
Modern birds and mammals are “warm-blooded” or endothermic, maintaining a constant body temperature and generating heat internally, while reptiles rely on heat from their surroundings. It has been known for some time that at least some dinosaurs, including the direct ancestors of modern birds, were also endotherms.
Working in the lab of Professor of Earth and Planetary Sciences Ryosuke Motani, doctoral candidate Benjamin Faulkner is exploring how plant-eating developed in diapsids, a lineage that includes dinosaurs and modern day lizards, snakes, turtles, birds and crocodilians.
No animal alive today looks quite like a duck-billed platypus, a semi-aquatic, egg-laying mammal hailing from eastern Australia. But about 250 million years ago, something very similar swam the shallow seas in what is now China, finding prey by touch with a cartilaginous bill. The newly discovered marine reptile Eretmorhipis carrolldongi from the lower Triassic period is described in the journal Scientific Reports Jan. 24.
What drives species to move into such a different habitat? Two paleontologists at UC Davis, Geerat Vermeij and Ryosuke Motani, set out to test these ideas by compiling a list of all the groups of mammals, birds, reptiles and amphibians that have re-occupied marine environments and comparing their time of return to the ocean with known mass-extinction events.
