The Coastal Paleontologist has a very interesting piece on early seal evolution. It can be found at the following location: Pinniped ancestry: the “Oligocene Seal” from South Carolina.
Following is the first paragraph from the blog, just as a teaser:
One of the most fascinating aspects of the study of marine mammals are the origins of the land to sea transition in various groups. Often marine mammals are so adapted for marine existence, that it is difficult to identify what group (fossil or modern) they descended from. Such has been the case with the origin of whales, for example. While I’m certainly interested in cetaceans, there has been a ton written about them, and I’m currently more intrigued by pinnipeds.