Kalmar "Gopherus agassizii" tana nufin wani nau'in kunkuru na Arewacin Amurka wanda aka fi sani da kunkuru na hamada. Sunan nau'in suna bayan masanin dabbobi dan kasar Switzerland-Amurka, Jean Louis Rodolphe Agassiz. Kunkuru na hamada ya fito ne daga kudu maso yammacin Amurka da arewacin Mexico, kuma an san shi da tsawon rayuwarsa, jinkirin motsi, da kuma iya rayuwa a cikin matsanancin yanayin hamada. Ana kuma la'akari da nau'in nau'in nau'in dutse mai mahimmanci a cikin yanayin hamada, saboda yana taka muhimmiyar rawa wajen tarwatsa iri da hawan keke na gina jiki.