Ohio used to be home to amazing prehistoric creatures including the Giant Beaver and the Dunkleosteus! Mary shares the history of the animals that used to roam our state.
Class Discussion Questions:
1) Create a Venn diagram comparing modern beavers to the castoroides (giant beaver).
2) What adaptations do mastodons have that would help them in today's world?
3) What can Ohio's oldest fossils teach us about ancient Ohio?
Read the Script:
[Mary] I don't know about you, but I've got some pretty fierce predators in my neighborhood. Like once I saw a squirrel, that was like this big, terrifying. Oh, and there was a spider in my basement that was huge, like sort of hairy. And don't get me started about this ferocious beast I found in my living room. I mean, I really have to watch myself around here.
But, okay, I will admit that the animals that live among us today are probably not as big or bad as the creatures that roamed Ohio in prehistoric times. Take, for instance, the Castoroides, also know as the giant beaver. It looked a lot like today's cute little beaver that we all know and love but, as the name suggests, the giant beaver was much, much larger. In fact, it could grow as large as 7 feet tall and weigh up to 276 pounds, about the size of a black bear, making it the largest rodent in North America during the Ice Age.
We know about this animal because its fossils were first discovered in a swamp about 50 miles west of Columbus. By looking closely at the fossils, scientists have figured out that these beavers had much larger teeth. And, since they're shaped differently, some scientists say, they may not have built dams like today's beavers.
Another thing scientists discovered, giant beavers did not have giant brains. Their brains were proportionately smaller than modern beavers, so giant beavers were not only big they were big and kind of dumb. These big dumb beavers shared Ohio with some hairy elephants You've likely heard of wooly mammoths, and we've found a few mammoth fossils. But even more common in Ohio is a very close relative, the mastodon.
Mastodons called Ohio home 20,000 years ago. And they're known for their shaggy haircuts and long tusks that could extend to over 16 feet long. They were also on the menu of Ohio's first Native tribes. And one of these guys could feed a lot of people. Mastodon bones have been found all over the state including a number of complete skeletons like the Conway Mastodon found in 1887 and the Johnston Mastodon found in 1926 and displayed at the Cleveland Museum of Natural History.
But these are far from the oldest fossils that have been found in Ohio. In fact, we've uncovered animal fossils that are hundreds of millions of years old. And there's something interesting about these old fossils, they are all of aquatic animals. That's because Ohio Was once covered in a shallow sea. Some of the oldest are these guys, trilobites. They lived at the bottom of Ohio's sea, and had segmented bodies and exoskeletons, like crabs and lobsters. We found so many trilobites here that it's Ohio's official state fossil.
But many animals that shared Ohio's sea were not nearly as friendly. I'm thinking about the Dunkleosteus. Doesn't exactly what warm and cuddly, does he? Well, he wasn't, you're looking at likely the meanest, scariest predator to ever swim in the ocean. Their heads were covered in thick bony armor, which extended into sharpened fangs in the front of the mouth, these fangs, combined with an amazingly powerful jaw, made them the most feared predator in the ancient ocean capable of chomping nearly every other species in their habitat. If you're getting freaked out, let me remind you the Dunkleosteus has been gone a long time.
They went extinct about 360 million years ago and left no true descendants, so let's all go ahead and breathe a sigh of relief.
Instructional Links
Website Article & Timeline: Ohio History Central, Ohio's Prehistoric Timeline
Website Article: ThoughtCo, The Dinosaurs and Prehistoric Animals of Ohio
PDF: Ohio Department of Natural Resources. Division Of Wildlife, Ohio’s Listed Species | Includes Endangered, Threatened, Species Of Concern, Or Extinct
Magazine Article: EBSCOhost, Popular Science, June 1, 2015, HOW to Clone a Mammoth: The Science of De-Extinction | May need password.