PZ Myers. 2004 Jun 21. Thalassocnus. <http://pharyngula.org/index/weblog/thalassocnus/>. Accessed 2008 Dec 04.

Posted on M00o93H7pQ09L8X1t49cHY01Z5j4TT91fGfr on Monday, June 21, 2004

Thalassocnus

An aquatic sloth?

Skull of Thalassocnus yaucensis, sp. nov., holotype, MUSM 37 in lateral (A), ventral (B), dorsal (C), views; mandible in lateral left (D) and dorsal (E) views.

Carl Zimmer has the details. This is very cool—yet another series of transitional fossils, showing a set of Peruvian sloths, of all things, that adapted to an aquatic lifestyle over the course of several million years.

1. Nice scans--thanks!
   #: Posted by Carl Zimmer  on  06/21  at  05:19 PM
2. Read Carl's article everyone...not "an" aquatic sloth, but at least 5 species with gradually evolving adaptations spanning from 8 to 1.5 million years ago. Talk about your least likely divers...a truly unintelligent design brought about by biological necessity.
   #: Posted by  on  06/21  at  05:45 PM
3. Aquatic sloth... Reminds me of my last vacation at the beach.
   #: Posted by  on  06/21  at  06:05 PM
4. Poppycock. We all know there are no transitional fossils.
   
   Could someone more in the know comment on the theory that polar bears are a species in transition toward an aquatic lifestyle? Or at least (to avoid the suggestion that evolution is somehow directional) that the changes polar bears have undergone are similar to those that might happen to a species moving into an aquatic lifestyle? It's something I heard tossed off on PBS; I'm curious whether there's anything to it.
   
   Of course they'll likely all be dead in 100 years.
   #: Posted by  on  06/21  at  06:30 PM
5. "But it's still a sloth...."
   #: Posted by  on  06/21  at  06:38 PM
6. I note that Carl is in the fine tradition of creatively spelling your name. A man after my own typing abilities...
   
   I also note that modern sloths can swim just fine, using a kind of dogpaddle. They are almost comical to wacth.
   #: Posted by  on  06/21  at  09:55 PM