Genus Castoroides is a group of extinct giant beavers that lived during the Pleistocene epoch. These animals were some of the largest rodents that ever lived, with their body length reaching up to 2.5 meters. In scientific literature, the genus Castoroides is commonly referred to as giant beavers. However, there are several other synonyms used to describe this group, including Castoroides ohioensis, North American giant beaver, and Pleistocene beaver. The synonym Castoroides ohioensis specifically refers to the species of giant beaver that inhabited the Ohio River Valley and adjoining regions. The use of these synonyms helps to facilitate communication and understanding among scientists studying the biology and ecology of these fascinating animals.