Trogontherium was originally described in 1809 from a skull given to Gotthelf Fischer von Waldheim from the collection of Russian aristocrat Alexander Sergeyevich Stroganov found near Taganrog on the coast of the Sea of Azov in southern Russia, suggested to be Early Pleistocene in age.

[1] A distinctly smaller species, T. minus, named by Edwin Tulley Newton in 1890, is known from the Late Pliocene-earliest Pleistocene of Europe, where it co-existed with T. cuvieri.

[2] Trogontherium has been placed as part of the subfamily Castoroidinae, which notably also includes North American giant beavers (Castoroides),[2] though the large body size seems to have developed independently in both lineages.

[1] Dental microwear analysis of teeth of T. cuvieri from China, spanning the Pleistocene, suggest that it was ecologically plastic, and able to adapt its diet to local conditions.

[5] Trogontherium first appeared in Europe during the Pliocene, with the species T. cuvieri dispersing over to East Asia and Siberia at the Pliocene-Pleistocene boundary, around 2.6 million years ago.