Toros look like large
rats with soft fur on the body and long
guard hairs on the scaly tail.[3] Head and body is 18-27.5 cm and tail is 17–30 cm.[2] Weight is 320-570 grams.
Natural history
These animals appear to be
arboreal, based on the shape of their hind feet.[2] They are thought to spend the day in holes in the ground near trees.
Systematics
The etymology of the genus name Isothrix corresponds to the two
ancient greek words ἴσος (ísos), meaning "of equal length", and θρίξ, τριχός (thríx, trikhós), meaning "hair".[4][5] The etymology of the genus name
synonymLasiuromys corresponds to the three
ancient greek words λάσιος (lásios), meaning "furry, with tufted hair", οὐρά (ourá), meaning "animal tail", and μῦς (mûs), meaning "mouse, rat".[4][5]
There are currently five
species recognized in the
genusIsothrix:[6]
There does appear to be good support for the
monophyly of three species found in this genus.[3]
Phylogeny
Isothrix is a member of the
Echimyini clade of
arboreal Echimyidae rodents.[8] Although tentatively considered an
echimyine, it has been suggested that Isothrix may not be particularly closely related to other members of its subfamily.[3] This is confirmed by molecular phylogenies in which Isothrix appears as a distant relative of the three clades of
Echimyini: (i) Echimys, Phyllomys, Makalata, Pattonomys, and Toromys ; (ii) the bamboo rats Dactylomys, Olallamys, Kannabateomys together with Diplomys and Santamartamys ; and (iii) the arboreal eumysopines Mesomys and Lonchothrix.[9]
The taxon Callistomys pictus was previously member of the genus Isothrix, but most authors considered it distinct enough to warrant a separate genus.[10] This distinctness has been confirmed by DNA comparative studies in which Callistomys even appears to branch with members of a distinct tribe (i.e.,
Myocastorini) of the subfamily Echimyinae.[11][8][9] The arboreal genera of the subfamily Echimyinae therefore constitute a
polyphyletic assemblage.
^
abcNowak, Ronald M. 1999. Walker's Mammals of the World, 6th edition. Johns Hopkins University Press, 1936 pp.
ISBN0-8018-5789-9
^
abcEmmons, L.H. 2005. A Revision of the Genera of Arboreal Echimyidae (Rodentia: Echimyidae, Echimyinae), With Descriptions of Two New Genera. pp. 247–310 in Lacey, E.A. & Myers, P. 2005. Mammalian Diversification: From Chromosomes to Phylogeography (A Celebration of the Career of James L. Patton). University of California Publications in Zoology.
^Lara, Márcia C.;
Patton, James L.; da Silva, Maria Nazareth F. (1996). "The Simultaneous Diversification of South American Echimyid Rodents (Hystricognathi) Based on Complete Cytochrome b Sequences". Molecular Phylogenetics and Evolution. 5 (2): 403–413.
doi:
10.1006/mpev.1996.0035.
PMID8728398.
^Leite, Yuri L. R.;
Patton, James L. (2002). "Evolution of South American spiny rats (Rodentia, Echimyidae): the star-phylogeny hypothesis revisited". Molecular Phylogenetics and Evolution. 25 (3): 455–464.
doi:
10.1016/s1055-7903(02)00279-8.
^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.
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.
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.
ISSN1463-6409.
^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.