TheMonk'sBulldog.pdf (application/pdf Object) When Triceratops Was a Giant Bison | Dinosaur Tracking. The Myth of the Eight-Spiked Stegosaurus | Dinosaur Tracking. O.C. Marsh's conception of an eight-spiked Stegosaurus. Image from Wikipedia. Everybody knows that Stegosaurus had four tail spikes. The formidable weapons this odd dinosaur sported were some of its most prominent features. Yet, when Stegosaurus was new to science, it seemed as if this dinosaur bristled with even more spikes. In 1891, the first full skeletal drawing of Stegosaurus ungulatus was created under the direction of Yale paleontologist Othniel Charles Marsh. Paleontologists Kenneth Carpenter and Peter Galton traced Marsh’s scientific steps in a paper included in The Armored Dinosaurs. Still, the eight-spiked form was a closer approximation of the animal than some of the naturalist’s earlier interpretations. Not long after he proposed the wrist spike hypothesis, Marsh received a quarry sketch from one of his collectors, William Reed, that showed spikes in close association with the tip of the tail.
Ancient Tracks Question Ideas About Tetrapod Origins – Laelaps. Tiktaalik is practically a household name. Since its description in 2006 the flat-headed “fishapod” has appeared in books, on t-shirts, and has even starred in its own music video. Hailed as a “missing link“, Tiktaalik has become a poster child fossil for evolution, but it is hardly the first such creature to be given this honor. Way back in the 1840′s, well over a decade before Charles Darwin’s On the Origin of Species was published, the Victorian anatomist Richard Owen was mulling over the concept of transitional forms. He was not so much thinking about actual fossils as the way anatomical frameworks could be modified by natural laws, but even so the anatomy of several creatures Owen had examined appeared to throw credence to the idea that one form could be derived from another. The lungfish Lepidosiren and Protopterus, for example, were fish that had lungs and wispy fins supported by stacks of bone.
By 1990, though, our picture of tetrapod origins seemed a little more complete.