Tylosaurus pembinensis (Marsh, 1872)
Central / Western United States
Length: 15 m
More than a century after Cope and Marsh first dug up fossils of this giant sea lizard, our view of her has changed drastically. We now know that she swam mostly using an asymmetrical tail fluke, was countershaded, and lacked a dorsal crest.
Sunday, September 13th, 2015