Did Plesiosaurs Swim like Penguins or Sea Lions?

[Indy 4]

Another interesting debate in paleontology, is plesiosaur swimming motion. Plesiosaurs are those long-necked, four-flippered marine reptiles that resemble the legendary Loch Ness Monster. There was also a group of short necked plesiosaurs with large crocodile-like heads,called pliosaurs.
Paleontologists have long debated how these ancient marine reptiles swam. Some say since there flipper shape is like that of a penguin wing, most feel that they flew through the ancient seas like modern penguins do. Others feel that had a flipper motion more like of a sea-lion, due to their body shape, which they feel wold make it harder for the animal to swim like a penguin.
I for one favor the sea lion motion, because since they are such large animals a penguin style of swimming would cause a great loss of energy. Plus there body shapes are more like that of a seal or sea-lion than a penguin's body shape. The plesiosaurs with the long-necks would also have better propulsion and steering thru the water column if they swam sea-lion style. Their long necks could also manuver them better if they swam this way. Which way do you think these ancient marine reptiles swam? I look foward to reading your comments.

[swords]

What you said, sea lion style! however, since it is shaped like a penguin wing, maybe I will support that claim. Because, though some would think they would be too slow, or it wouldn't be able to maneuver around, I think that maybe we got to think proportionally. It slims like a penguin, but to it's own body mass, do you get me?

Ya, the penguin one sounds great....

[Indy 4]

Originally posted by swords
What you said, sea lion style! however, since it is shaped like a penguin wing, maybe I will support that claim. Because, though some would think they would be too slow, or it wouldn't be able to maneuver around, I think that maybe we got to think proportionally. It slims like a penguin, but to it's own body mass, do you get me?

Ya, the penguin one sounds great....

Your probabley right Swords. Ever since you posted this, I have been looking over plesiosaur flipper bones and shape again. You are indeed correct in stating they are shaped like penguin wings. So maybe, they did manuever thru the Mesozoic seas like gigantic reptilian penguins to catch their prey. The question raised now is, did long and short necked plesiosaurs hunt in two different ways. Was one an ambush predator? Or did they both rapidly pursue prey like many marine mammals do today?

[Patrick]

Haha This seemed like a funny post at first... This is paleontology. But whatever, I don't care...hmmm probably sea lion.