Yes, you read it correct because the giant beavers truly existed.
With the scale indicating 100 kilograms, the super-sized version of the modern beaver as it appears to be, the giant beavers, being the size of black bears, lived by the lakes and wetlands of North America. Researchers say that the mega-rodents died out at the end of the last ice age.
The fossil remains of the giant beavers, once a very successful species, were discovered at some sites from Florida to Alaska and the Yukon.
Being almost six times taller than the modern beaver, the giant beaver had two crucial differences.
It is known for a fact that the iconic paddle-shaped tail that we can see today on the modern beavers was missing at the extinct ones, having, instead it, a long skinny tail muskrat likely.
The second big difference is that the teeth looked different from the modern beaver which has the front teeth (the incisors) sharp and chisel-like. The incisors of the ice aged beaver were bulkier and curved and not sharpen.
As many other large-bodied ice age animals, the giant beaver became suddenly extinct 10,000 years ago.
Scientists found out recently why the giant rodent had died out and, in order to explain why it did so, we’ll have to understand how the giant beaver lived.
Was there plenty of food in its environment? Did the climate change and contributed to its extinction?
The conclusions of some studies were that the giant beaver flourished in the areas with a warmer and wetter climate. In those studies, the researchers found the fossils being most commonly found in the ancient’s wetlands sediments. But how much of its behavior was similar to the modern beaver that cuts down trees? Was the food the same with our present small fellow?
Food is important for everyone, even for the beavers! The chemical signature, as known as stable isotopes, contained by the food an animal eats, are embodied into body tissues like bones and are being static for very long periods of time, like tens of thousands of years, and offers the researchers a great opportunity to study the past. These stable isotopes were used only in this study to find out what a giant beaver served for his meals.
By analyzing the stable isotope signatures of the ancient bone tissues, the fossils of the giant beavers from the areas of the Yukon and Ohio who lived between 50,000 and 10,000 years ago were studied. Having as a fact that the isotopic signatures linked to woody plants differ from those linked to aquatic plants, it was discovered that the giant beaver didn’t cut down trees and ate it, but it ate aquatic plants. While the modern beaver is an “ecosystem engineer”, the giant beaver was not cutting down big trees for food, nor building anything across the ice aged landscape.
The wetland habit was perfect for them in order to eat aquatic plants to survive and being sheltered from the ice age predators. But this environment made it vulnerable to climate change.
The Ice Age climate changes
The wetland habitats of the last ice age, 10,000 years ago, began to dry up as the climate became increasingly warm and dry and, even though the modern beavers and the giant beavers co-existed in the same landscape for tens of thousands of years, only the first one survived the climate changes.
Having the sharp teeth, the modern beaver can alter the landscape to create a wet habitat for it to stay alive and this ability may have been a truly life or death advantage in front of the giant beaver.
All of these studies contribute in solving a bigger puzzle: knowing the global megafauna extinction event which took place at the end of the last ice age and finding an explanation on why many species of large-embodied animals, like mastodons and giant ground sloths, disappeared at the same time.
All the gathered evidence shows us that the climate change and the human impact were the cause of these extinctions.
Even though is very challenging to study the ecological vulnerabilities of long-extinct animals, it is very important to us to find out and understand the impact of climate change on all terrestrial species.