Thomasomys rhoadsi Stone, 1914

VOSS, ROBERT S., 2003, A New Species of Thomasomys (Rodentia: Muridae) from Eastern Ecuador, with Remarks on Mammalian Diversity and Biogeography in the Cordillera Oriental, American Museum Novitates 3421, pp. 1-48 : 33

Thomasomys rhoadsi Stone

Figures 11–13

SPECIMENS COLLECTED: None.

OTHER MATERIAL: Five specimens ( FMNH 43246–43250 ) collected by R. Olalla in 1934 are labeled ‘‘ Cerro Antisana, Andes Orientales’ ’, and two others ( BMNH 54.553, 55.554) collected by C.S. Webb in 1937 are labeled ‘‘ Mt. Antisana , E. Andes 12,500 – 13,000 ft’ ’.

TAXONOMY: Thomasomys rhoadsi was originally described from material collected in 1911 by S.N. Rhoads on Volcán (‘‘Mt.’’) Pichincha in the western Andes above Quito ( Stone, 1914: 12). The Antisana specimens listed above were compared with a series of topotypes, which they resemble qualitatively despite averaging slightly larger in several external and craniodental dimensions (table 8). In the absence of other character differences between these samples, I assume that they represent the same taxon. An apparently related form originally described as T. rhoadsi fumeus is substantially smaller than typical rhoadsi and also differs from it in qualitative external and cranial characters as remarked by Anthony (1924b).

REMARKS: Although Olalla’s and Webb’s labels do not state whether their specimens were collected on the eastern or western slopes of Antisana, it seems probable they were collected near Hacienda Antisana on the western side, the only inhabited site described in published accounts of visitors to this famous mountain (e.g., Orton, 1870; Whymper, 1892; Emerson and Johnson, 1960).

Figures

Fig. 11. Dorsal cranial views of eight Thomasomys species that occur in the Cordillera Oriental of northern Ecuador. Top row (left to right): T. aureus (UMMZ 127114), T. baeops (UMMZ 155708), T. cinnameus (UMMZ 155671), T. erro (UMMZ 155713). Bottom row (left to right): T. paramorum (UMMZ 155737), T. rhoadsi (AMNH 66256), T. silvestris (USNM 513592), T. ucucha (UMMZ 155644).

Fig. 12. Ventral cranial views of eight Thomasomys species from the Cordillera Oriental of northern Ecuador. Top row (left to right): T. aureus (UMMZ 127114), T. baeops (UMMZ 155708), T. cinnameus (UMMZ 155671), T. erro (UMMZ 155713). Bottom row (left to right): T. paramorum (UMMZ 155737), T. rhoadsi (AMNH 66256), T. silvestris (USNM 513592), T. ucucha (UMMZ 155644).

Fig. 13. Lateral cranial and mandibular views of eight Thomasomys species from the Cordillera Oriental of northern Ecuador. Left side (top to bottom): T. aureus (UMMZ 127114), T. baeops (UMMZ 155708), T. cinnameus (UMMZ 155671), T. erro (UMMZ 155713). Right column (top to bottom): T. paramorum (UMMZ 155737), T. rhoadsi (AMNH 66256), T. silvestris (USNM 513592), T. ucucha (UMMZ 155644).