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.
New fossil finds from the Jebel Irhoud archaeological site in Morocco do more than push back the origins of our species by 100,000 years. They also reveal what was on the menu for our oldest-known Homo sapiens ancestors 300,000 years ago
The similar pathways to enormous size among whales and sea cows provide new insights into the history of the ocean’s food supply, according to paleontologists Nick Pyenson, curator of Fossil Mammals at the Smithsonian National Museum of Natural History, and Geerat Vermeij, distinguished professor of paleontology at the University of California, Davis.