Photo of the Day #127: Thalassomedon haningtoni

Before I knew very much at all about ancient marine reptiles, I had only encountered two names for the long-necked plesiosaurs (Plesiosaurus & Elasmosaurus) and had assumed that the incredibly long skeleton hanging from the 4th floor ceiling of the AMNH was a representative of the latter. I wasn't right, but I wasn't far off; it was a skeleton of Thalassomedon haningtoni, and elasmosaurid and close relative of Elasmosaurus.

While not scientifically accurate, today's photo reminded me of Will Cuppy's sketch of "The Plesiosaur" collected in How to Become Extinct (just remember that this is meant to be a humorous essay and not scientifically accurate);

There were no real Sea Serpents in the Mesozoic Era, but the Plesiosaurs were the next thing to it. The Plesiosaurs were reptiles who had gone back to the water because it seemed like a good idea at the time. As they knew little or nothing about swimming, they rowed themselves around in the water with their four paddles, instead of using their tails for propulsion like the brighter marine animals (1). This made them too slow to catch fish, so they kept adding vertebrae to their necks until their necks were longer than all the rest of their body. Then they would dart their heads at the fish from a distance of twenty-five or thirty feet (2). Thus the Plesiosaurs resembled the modern Sea Serpent above the water-line, though they were almost a total loss farther down. They might have had a useful career as Sea Serpents, but they were before their time. There was nobody to scare except fish, and that was hardly worth while. Their heart was not in the work. As they were made so poorly, Plesiosaurs had very little fun. They had to go ashore to lay their eggs and that sort of thing (3). They also tried to get along with gizzards instead of stomachs, swallowing pebbles after each meal to grind their food. At least, pebbles have been found near fossil Plesiosaurs, and to a scientist that means the Plesiosaur had a gizzard (4). During the Cretaceous Period many of the inland seas dried up, leaving Plesiosaurs stranded without any fish (5). Just about that time Mother Nature scrapped the whole Age of Reptiles and call for a new deal. And you see what she got.

(1) Such as the Ichthyosaurs, who used their paddles for balancing and steering. The Plesiosaurs did everything wrong.

(2) They got the fish, but it would have been much simpler to learn the Australian crawl.

(3) The Ichthyosaurs stayed right in the water and gave birth to living young. It can be done if you know how.

(4) This is Gimmick's Law.

(5) Here we see the working of another Law of Nature: No water, no fish.