Acheloma (also known as Trematops milleri) is an extinct genus of temnospondyl that lived during the Early Permian. The type species is A. cumminsi. Trematops milleri has been synonymized with Acheloma. Like other trematopids, Acheloma was a large terrestrial carnivore, as shown both by its morphology and bone microanatomy. One species, A. dunni, may have been the top predator of the diverse Richards Spur assemblage in Oklahoma. The following cladogram shows the phylogenetic position of Acheloma, from Polley & Reisz, 2011.
^Polley, B.P.; and Reisz, R.R. (2011). "A new Lower Permian trematopid (Temnospondyli: Dissorophoidea) from Richards Spur, Oklahoma". Zoological Journal of the Linnean Society. 161 (4): 789–815. doi:10.1111/j.1096-3642.2010.00668.x.