Anchisaurus lived from the Mid-Triassic Period (250 to 200 million years
ago) to the Early Jurassic Period (199 to 175 million years ago). Anchisaurus
fossils have been found in what is now North America, Africa and Asia, and it
may have lived all over the world during the period of its existence.
At full maturity, Anchisaurus was approximately 6.5 to 8 feet long and 3 to
4 feet tall. It was a quadruped, meaning that it walked on four legs, but
paleontologists believe that it could also stand on its two back legs. It had
serrated, triangular teeth, a small head, five “fingers” on its hands, five
“toes” on its feet (including one reduced toe), a long neck and a long tail.
Although most scholarship identifies Anchisaurus as an herbivore
(plant-eating) there is some research indicating that Anchisaurus may have
been an omnivore, meaning that it ate both meat and plants. Paleontologists
have pointed to its diamond-shaped teeth as evidence that the dinosaur probably
ate meat as well as foliage. Herbivorous dinosaurs typically had flatter teeth,
sometimes shaped like a spoon, which allowed the dinosaurs to strip leaves off
of trees and plants. In contrast, carnivorous dinosaurs typically had pointed,
serrated and sharp teeth that could be used to stab and puncture their prey,
and to tear meat apart so that it could be eaten.
Anchisaurus is classified as a prosauropod dinosaur. The word “prosauropod”
means “before the sauropods.” Sauropods were a group of large plant-eating
dinosaurs that walked on four legs. Sauropods thrived during the Jurassic
period, and are believed to have died out by the Cretaceous period (65 million
years ago). Paleontologists believe that prosauropods such as Anchisaurus were
either ancestors to the Sauropods, or shared a common ancestor with them. The
name “anchisaurus” means “near lizard.” Anchisaurus was given its name because
of its closeness to the sauropods in the dinosaur family tree.
Anchisaurus remains were first discovered in Connecticut in 1818 by Nathan
Smith and Solomon Ellsworth, Jr. At the time of the discovery, very little
was known about dinosaurs; it was only sixteen years earlier in 1802, that the
evidence of North American dinosaurs had been discovered, when Pliny Moody
unearthed a slab of sandstone bearing unidentifiable tracks, in South Handley,
Massachusetts. When Smith and Ellsworth discovered the Anchisaurus fossils,
they believed
them to be human remains.
Anchisaurus remains were discovered again in Wolcott’s Quarry in Manchester,
Connecticut, in the 1880s. The Quarry (which has since been filled in) yielded
three partial skeletons. This time, the task of naming and describing
them fell to Yale University paleontologist O.C. Marsh.
Marsh examined the fossils, and determined that each fragmentary skeleton
belonged to a separate species, which he called Anchisaurus major, Anchisaurus
colurus and Anchisaurus solus. Marsh later changed the name of
Anchisaurus major to Ammosaurus, and the name of Anchisaurus colurus was
changed to Yaleosaurus (in honor of Yale University’s Peabody
Museum) by Frederich von Huene. This
history is recounted by Paleontologist Adam Yates, who took on the
question of identifying the correct name for these dinosaurs.
A complete Anchisaurus skeleton can be seen at
Yale’s Peabody Museum, and the dinosaur continues to fascinate both
scholars and the public alike.
