Dipoides were about two thirds the size of modern Canadian beavers.[ Where modern beavers have square chisel shaped teeth, Dipoides teeth were rounded. However an excavation of a site that was once a marsh, in Ellesmere Island, showed signs that they dined on bark and young trees, like modern beavers. The excavation seemed to show that, like modern beavers, Dipoides dammed streams.[4]]
Natalia Rybczynski, of the Canadian Museum of Nature, analyzed the teeth, and wood chips, of modern beavers, and Dipoides.[ She concluded that they all used just one of their teeth at a time, when cutting down trees. She concluded that modern beavers square teeth required half as many bites as Dipoides less evolved round teeth.]
Rybczynski argues that eating bark and building dams are unlikely to have evolved twice, so modern beavers and Dipoides shared a wood eating common ancestor, 24 million years ago.[[4]]
References
1. ^1 2 {{cite book | url = https://books.google.ca/books?id=k-VfDwAAQBAJ&pg=PA22&dq=%22once+they+were+hats%22+dipoides&hl=en&sa=X&ved=0ahUKEwjdjoTnwIffAhUK0FkKHZUuBmgQ6AEIMjAB#v=onepage&q=%22once%20they%20were%20hats%22%20dipoides&f=false| title = Eager: The Surprising, Secret Life of Beavers and Why They Matter| author = Ben Goldfarb| publisher = Chelsea Green Publishing| year = 2018| isbn = 9781603587402| page = 22| accessdate = 2018-12-04| deadurl = No | quote = }}
2. ^1 {{cite book | url = https://books.google.ca/books?id=zS7FZkzIw-cC&printsec=frontcover&dq=%22Classification+of+Mammals+Above+the+Species+Level%22&hl=en&sa=X&ved=0ahUKEwiw1qqk1YffAhUVsXEKHaDmAkcQ6AEIKjAA#v=onepage&q=%22Classification%20of%20Mammals%20Above%20the%20Species%20Level%22&f=false| title = Classification of Mammals Above the Species Level| publisher = Columbia University Press| author = McKenna, Malcolm C., and Bell, Susan K| date = 1997| page = | isbn = 9780231528535| accessdate = 2018-12-04| deadurl = No | quote = }}