The species of spiny rats in the genus Trinomys are apparently all Brazilian.[3] In particular many of them are endemic to the Atlantic Forest of southeastern Brazil. Not much is known for certain about their ranges however, which still are being investigated, with frequent extensions to the recorded distributions of several species in various ecological classes of forest and dry land. They do not however appear to occur at high altitudes, and several of their ranges appear to be parapatric.[4] Most species of Trinomys are terrestrial and ambulatory, though Trinomys yonenagae is unusual that it is semi-fossorial, living in colonial burrows, and exhibits incipient specializations for saltatorial locomotion.[5]
Phylogeny
Genus level
Trinomys is the sister genus to the fossorial genera Clyomys and Euryzygomatomys.
In turn, these three genera — forming the clade of Euryzygomatomyinae — share phylogenetic affinities with a clade containing Carterodon and members of the family Capromyidae.
Cladogram of the Euryzygomatomyinae with their relationship to Carterodon and Capromyidae.
^Rocha, P.L.B.; Renous, S.; Abourachid, A.; Höfling, E. (June 2007). "Evolution toward asymmetrical gaits in Neotropical spiny rats (Rodentia: Echimyidae): evidences favoring adaptation". Canadian Journal of Zoology. 85 (6): 709–717. Bibcode:2007CaJZ...85..709R. doi:10.1139/Z07-049.
^Galewski, Thomas; Mauffrey, Jean-François; Leite, Yuri L. R.; Patton, James L.; Douzery, Emmanuel J. P. (2005). "Ecomorphological diversification among South American spiny rats (Rodentia; Echimyidae): a phylogenetic and chronological approach". Molecular Phylogenetics and Evolution. 34 (3): 601–615. Bibcode:2005MolPE..34..601G. doi:10.1016/j.ympev.2004.11.015. PMID15683932.
^Upham, Nathan S.; Patterson, Bruce D. (2012). "Diversification and biogeography of the Neotropical caviomorph lineage Octodontoidea (Rodentia: Hystricognathi)". Molecular Phylogenetics and Evolution. 63 (2): 417–429. Bibcode:2012MolPE..63..417U. doi:10.1016/j.ympev.2012.01.020. PMID22327013.
^Fabre, Pierre-Henri; Galewski, Thomas; Tilak, Marie-ka; Douzery, Emmanuel J. P. (2013-03-01). "Diversification of South American spiny rats (Echimyidae): a multigene phylogenetic approach". Zoologica Scripta. 42 (2): 117–134. doi:10.1111/j.1463-6409.2012.00572.x. S2CID83639441.
^Upham, Nathan S.; Patterson, Bruce D. (2015). "Evolution of Caviomorph rodents: a complete phylogeny and timetree for living genera". In Vassallo, Aldo Ivan; Antenucci, Daniel (eds.). Biology of caviomorph rodents: diversity and evolution. Buenos Aires: SAREM Series A, Mammalogical Research — Sociedad Argentina para el Estudio de los Mamíferos. pp. 63–120.