11. Cope Reconstructs Laelaps, 1869


The Hayden surveys of 1855 had turned up a tooth of what appeared to be a carnivorous dinosaur, and Leidy had assigned it the name of Aublysodon, but it wasn't until 1866 that more substantial evidence was discovered of carnivorous dinosaurs in the United States. In that year there was discovered in Barnesboro, New Jersey, the fossil remains of a new dinosaur. The fossils consisted of a jaw fragment, several limb bones, and some phalanges, or claws, and it was evident to Edward Cope of Philadelphia that this was a predator much like Megalosaurus. He named it Laelaps aquilunguis, and he was pleased at finding a carnivorous counterpart to the herbaceous hadrosaur of Leidy. As Cope later put it: "The discovery of this animal filled a hiatus in the Cretaceous Fauna, revealing the carnivorous enemy of the great Herbivorous Hadrosaurus, as the Aublysodon was related to the Trachodon of the Nebraska beds, and the Megalosaurus to the Iguanodon of the European Wealden and Oolite. In size this creature equalled the Megalosaurus bucklandii, and with it and Aublysodon, constituted the most formidable type of rapacious terrestrial vertebrata of which we have any knowledge."

Cope described his find in a number of scientific journals, but he chose a popular journal for a pictorial reconstruction of the dinosaurs of New Jersey. Laelaps is the foreground dinosaur standing on a rock, confronting a marine Elasmosaurus, while Hadrosaurus feeds from a tree in the background.

Although the Elasmosaurus, not being a dinosaur, is outside the scope of this book, we cannot resist pointing out something about Cope's restoration. It is well known in the history of paleontology that Cope initially reconstructed the skeleton with the head on the wrong end, that is, on the end of the tail. His error was pointed out by Othniel C. Marsh, thus precipitating a life-long feud, and a mortified Cope attempted to buy up the plates with the erroneous reconstruction and replace them with correct versions. The skeletal restorations, in both versions, have often been reproduced, but it has not been generally noticed that in this restoration, Elasmosaurus has its head on the short end, which is unfortunately the wrong end. Cope was unable to correct this one.


Cope, Edward Drinker. "The fossil reptiles of New Jersey," in: American Naturalist, vol. 3 (1869), pp. 84-91. This work was on display in the original exhibition as item 11.

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