Archelon Exhibit
The largest sea turtle that ever roamed our earth is now commonly referred to as Archelon. In 1895 Archelon was discovered in South Dakota by Othniel Charles Marsh, who went on to hypothesize that this magnificent specimen was in fact from the Cretaceous period, dating back 70 million years ago.
Origin & History
Archelon inhabited the Western Interior Seaway (also sometimes referred to as the Cretaceous Seaway), which was an inland, shallow sea that covered a great portion of what is now known as North America, during the Late Cretaceous period. The majority of Archelon fossils have been found in the Pierre Shale geological formation which ranges from South Dakota to North Dakota.
This seaway was a large inland sea that split the continent into two landmasses known as Laramidia and Appalachia, for 34 million years.
Archelon ischyros
Archelon is extinct, estimated to have been from the late Cretaceous period between 65-70 million years ago, and is the largest known sea turtle ever documented. The biggest specimen was measured at 15ft from head to tail, 13ft from flipper to flipper, and was approximated to weigh 4,900lbs. Archelon has been named part of the Protostegidae family, despite ongoing debate among researchers that suggests it should be classified in its own family, Archelonidae. A common early theory was that the Leatherback Sea Turtle was Archelon’s closest living relative, but now it is believed that Protostegidae is a separate lineage altogether from any living sea turtle species.
Archelon had a leathery carapace with small ridges, each peaking at around 1-2 inches in height. It had an exceptionally hooked beak, and its jaws were adept at crushing making it perfectly adapted to predating fish, jellyfish, and cephalopods, making it an obligate carnivore.
