Several recently extinct North American forms were larger: the capybara Neochoerus pinckneyi (another neotropic migrant) was about 40% heavier; the giant beaver (Castoroides ohioensis) was similar.
Neke sjeverne nedavno izumrle forme su bile veće: Neochoerus pinckneyi je bila oko 40% teža; Castoroides ohioensis je bio sličan.