#castoroides

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Trilobite: Phacops rana (D) Problematic Fossil: Parvancorina (Pre Cambrian) Fish: Bothriolepis (D)

Shark: Cladoselache (D) Misc Reptile: Cotylorhynchus (P) Theropod: Nanuqsaurus (K)

Sauropod: Brachytrachelopan (J) Ornithopod: Parasaurolophus (K) Thyreophoran: Stegosaurus (J)

Marginocephalian: Chasmosaurus (K) Crocodylomorph: Sarcosuchus (K) Whale: Basilosaurus (Pg)

Ice Age Critter: Castoroides (Q) Recent Extinction: Great Auk (H) Modern Critter: Horseshoe Crab (H)

Happy Ice Age Week: Castoroides better known as the giant beaver, is an extinct genus of beaver that lived throughout North America during the Pleistocene to early holocene some 2.1 million to 11,000 years ago. The first remains of castoroides known to science were consisting of a skull was unearthed from a peat bog near Nashport Ohio in 1837 during the digging of the Ohio Canal. These remains would be formally described by American geologist John Wells Foster in 1838, who named the animal castoroides meaning “beaver like” in latin. Since then hundreds of castoroides specimens have been found from Alaska and Canada on down to Florida, being especially concentrated around the midwestern United States in states near the Great Lakes, particularly Illinois and Indiana. Today two species are considered valid: C. ohioensis & C. dilophidus. Reaching some 6 to 7.5ft (1.8 to 2.3m) in length and 170 to 275lbs (77 to 125kgs) in weight, Casteroides was the largest known rodent in North America during the Pleistocene and the largest known beaver. The hind feet of the giant beaver were much larger than in modern beavers, while the hind legs were shorter. The tail was longer and may not have been paddle-shaped as in modern beavers. The shape of Castoroides large incisors would have made it much less effective at cutting down trees than living beavers, meaning that they likely didn’t build damns and lodges in the same manner. In life castoroides would have been heavily reliant on lakes and wetlands where it would both avoid predators and feed upon primarily aquatic plants. Remains of the giant beaver, along with human artifacts and the remains of other megafauna from several sites shows that there were some interactions between Paleo-Indians and Casteroides. Many native tribes such as the Innu, Mississaugas, Algonquin, & Anishinaabe all feature giant beavers in their traditional mythology, which many believe is evidence of there ancestors interaction with Castoroides.

Art used can be found at the following links:

Castoroides (Castoroides dilophidus)

(Photo from Canadian Museum of Nature)

Conservation Status- Extinct

Habitat- Southeastern United States

Estimated Size (Weight/Length)- 120 kg; 2 m

Diet- Leaves; Bark

Time Period- Pleistocene

Cool Facts- The Castoroides is the ancestor to beavers that still roam the wilds today. Considered the largest beaver to ever exist, they are thought to have a semi aquatic lifestyle similar to modern beavers, and yet they lacked a paddle-like tail. Their massive 15 cm long teeth would tear through wetland trees and provide defense against megafauna predators. It is unknown whether or not Castoroides built dams based on their living ancestors, however paleontologists believe this may have been the case due to finding a massive, ancient beaver lodge alongside several Castoroides remains in Ohio. The Castoroides went extinct at the beginning of the Holocene, either from climate change or overhunting from migrating humans.

Last week I asked what should be the national fossil of the USA and (to the surprise of absolutely no one) Tyrannosaurus won that title by a mile.

I liked the idea, so I thought I‘d do that again, but this time ask you guys what should be the national fossil for Canada. Honestly, I‘d like to do this for a lot of countries and maybe I can make a map for it in the end or something.

Same as last time: it could be a fossil that is just exceptionally well preserved and beautiful, had a huge impact on paleontology and our knowledge of the past, is very common/representive of the area, is beloved and famous in the public eye, is just a very unique and interesting find, or has any other justification.

Here are my suggestions:

Anomalocaris: Everybody‘s favorite “weird shrimp“, one of the earliest complex life forms and apex predator from the famous Burgess Shale fossil site in British Colombia, one of the best places to find creatures from the Cambrian, more than 500 million years ago.

Tiktaalik: An important step in the transition from fish to land-living tetrapods first found in Nunavut (Art by Zina Deretsky)

Edmontosaurus: A large duck-billed dinosaur with populations raging across large parts of North America and named after the Canadian city Edmonton

Albertosaurus: A large carnivorous dinosaur closely related to Tyrannosaurus and named after the Canadian province Alberta, where it was first found

Borealopelta: Only discovered in 2011, the beautifully preserved ankylosaur included osteoderms (the armor on its body), skin and even stomach contents. It was in such good conditions that even the color could be studied (it was reddish brown)

Castoroides: Since Canada‘s national animal is the beaver and I wanted to give you a mammal option/something more recent, may I present to you Castoroides, the giant beaver. The pleistocene animal was one of the biggest rodents of all time and common across North America