I wonder what Nick thinks of Dr. Ji's newest Discovery

A couple years ago, I can across Nick Longrich hiding in the labyrinthine fossil collections of the American Museum of Natural History. He had before him a colossal amount of bone scrap and miscellaneous fossils from the Hell Creek Formation. Inquisitively I asked him what he was looking. He was looking for caudal (tail) vertebrae of a Mesozoic mammal, which he believed showed adaptations for swimming. I thought the idea was interesting, but a bit conjectural. I helped him out by finding more cartons of bone scrap to examine. Nick later when on to present his findings at the Society of Vertebrate Paleontology meetings in 2004.




The cover of last week's Science magazine features a reconstruction of a Mesozoic mammal Castorocauda from the middle Jurassic of China. It is specialized aquatic swimmer with a scaly tail similar to river otter's tail. Castorocauda is a docodont, a group of mammals that specialized in an omnivorous diet with complex molar anatomy. The skeleton also preserves the oldest record of mammal fur, and indicates that Mesozoic mammals were much more diverse then previously believed.


Longrich, N. 2004. Aquatic specialization in mammals from the Late Cretaceous of North America. Journal of Vertebrate Paleontology, vol.24, no.3, Suppl., pp.84-85.


Ji, Q., Luo, Z-X, Yuan, C-X, Tabrum, A. 2006. A Swimming Mammaliaform from the
Middle Jurassic and Ecomorphological Diversification of Early Mammals. Science, vol. 311 p. 1123-1127.