Warm Blooded Dinos- Ichthyosaurs

When I was looking up reptile facts, I noticed that I kept seeing this statement: most reptiles are warm blooded. I got to thinking, what reptiles don't apply to this statement, if only most reptiles are warm blooded. Turns out, there are no modern day reptiles that are 'warm blooded' per say. However, if you're willing to look back 65 to 250 million years ago. The time is the Mesozoic era. This was a major time in the earths existence due to the major change in vegetation. During the Triassic period (251-199.6 million years ago), the vegetation mainly consists of ferns and very unusual fauna. Moving into the Cretaceous period (145.5-65.5 million years ago), the vegetation had highly diversified. The three reptiles over this time frame that were indeed warm blooded were not land creatures, however. Their names were Ichthyosaurs, Plesiosaurs, and Mosasaurs. This blog focuses on the Ichthyosaurs.

Ichthyosaurs
Though Ichthyosaurs may look like a fish, it is very much a reptile. You may notice a their reptilian features by looking at their jaw and fins. Looking at the skeleton of the creature, you will notice three strange features. The first are skeletons in their fins. They look very similar to a corn cob. This strange fin went through major evolutionary changes over the years. As time progressed, the arm bone as well as 'fingers' became more developed. These fins were mainly used for propulsion. The second thing that is notable is their giant eye socket. They are the largest ever recorded in fact. The Ichthyosaurs had very flat eyes. It is believed that the main purpose of the doughnut shaped bone kept their eyes in shape. It can also be determined that their nocturnal sight ranged from human sight or better. Finally, their vertebrae were very different from most reptiles, not because of the shape, but because of the amount. It is believed that they started out as lizards with the average amount of vertebrae, then evolved into ocean dwelling creatures. During this change, the amount and size of vertebrae also changed. The largest Ichthyosaurs documented reached a length of 15 m. Though, the smallest documented did not reach 17 cm. It is estimated that they weighed about 1230-1200 kg. Through the research of fossils found in the stomach of a Ichthyosaurs, it has been assumed that they thrived off of the ancient kin of squids with occasional other vertebrates. They lived in the area of Canada, China, Japan, Spitsbergen, and Thailand. They are extinct (obviously).

Links: http://www.ucmp.berkeley.edu/mesozoic/mesozoic.php
http://www.ucmp.berkeley.edu/people/motani/ichthyo/forefin.html