![]() These were the plesiosaurs as I first encountered them in my childhood, but paleontologists have known for quite some time that these marine reptiles were not actually capable of such poses.Ĭontrary to popular images of the marine reptiles, the necks of Plesiosaurus and its kin were not as flexible as cooked spaghetti noodles. In his painting of Cretaceous marine reptiles created in the mid-1950’s, for example, the artist Rudolph Zallinger presented long-necked plesiosaurs in both modes, and in his 1981 book The Dinosaurs William Stout painted a gallery of snake-necked plesiosaurs raising their necks out of the sea to snap at a heard of passing sauropod dinosaurs. While the animal’s body shape suggested that it swam like a shell-less turtle, Conybeare proposed, might the long neck of Plesiosaurus have obligated the animal to swim at the surface, “arching its long neck like the swan, and occasionally darting it down at the fish which happened to float within its reach?” Alternatively, Conybeare imagined that Plesiosaurus was the underwater equivalent of a snake in the grass, relying on “the suddenness and agility of the attack which enabled it to make on every animal fitted for its prey, which came within its extensive sweep.”Ĭonybeare’s twin visions of Plesiosaurus sculling the Mesozoic seas with their heads held high and ambushing unwary fish just beneath the waves remained the canonical visions of these creatures for over a century and a half. Clearly the creature carried such a bizarre form to fill some essential role in the economy of nature, but there was no modern analog to draw clues from. Just what Plesiosaurus was doing with such a long neck was a mystery. No other animal had a neck quite like it. The better specimen had a small, short skull at the end of a ridiculously long neck consisting of thirty five vertebrae. Three years later, though, Conybeare reported on “an almost perfect skeleton of the Plesiosaurus” which has been discovered by paleontologist and highly-skilled fossil hunter Mary Anning, and he gave the marine reptile a makeover. ![]() There was no reason to think that the neck was very much longer, and the skulls of ichthyosaurs and crocodiles hinted that Plesiosaurus, too, would have had an elongated noggin. The specimen De la Beche and Conybeare initially studied was missing the skull and had only twelve neck vertebrae. Missing bones were what caused them to miscast their mosnter. What the naturalists did not realize was that Plesiosaurus was not an intermediate form between crocodiles and ichthyosaurs, after all, but a unique and starkly different sort of marine reptile. Instead, the Plesiosaurus testified to a natural plan in which “every place capable of supporting animal life should be so filled, and that every possible mode of sustenance should be taken advantage of.” The stout-bodied and paddle-limbed monster was part of the static balance of nature, and the thought that such links indicated true transformation of one being into another was “most ridiculous.” Plesiosaurus simply took up an intermediate place between semi-aquatic crocodiles and the fish-like ichthyosaurs so that there would be no gap in the natural order. Speculation about the transmutation of species was “absurd and extravagant,” the naturalists said. De la Beche and Conybeare were not advocating an evolutionary view. ![]() A paddle-legged marine reptile akin to the recently-discovered, shark-shaped animals known as ichthyosaurs, the new animal was cast as “a link between the Ichthyosaurus and Crocodile” in the “connected chain of organized beings.”ĭon’t let the language lead you on. In 1821, British geologists Henry De la Beche and William Conybeare presented a bizarre, previously-unknown fossil creature to their colleagues in the Geological Society of London.
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