Trinomys eliasi
Creators: name: Don E. Wilson
name: Thomas E. Lacher, Jr
name: Russell A. Mittermeier
Publisher: name: Lynx Edicions
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Echimyidae
Trinomys
Trinomys eliasi

description: 15.
Elias’s Spiny-rat
Trinomys eliasi
French: Rat-épineux d'Elias / German: Elias-Atlantikstachelratte / Spanish: Rata espinosa de Elias
Other common names: Elias’s Atlantic Spiny-rat
Taxonomy. Proechimys eliasi Pessoa & dos Reis, 1993,
“Restinga da Barra de Marica (22°31’S, 47°17°'W), Municipio de Marica, Rio de Janeiro, Brazil.”
Trinomys eliasi was originally placed in Proechimys and subsequently listed as a species in the subgenus Trinomys; first use of current name combination was by M. C. Lara and colleagues in 1996. Three reciprocally monophyletic mtDNA clades have been identified, with estimated temporal splits in the early Pleistocene (c.2-1 million years ago) and late Pleistocene (c.0-6 million years ago), suggesting that recognition of additional taxa may be warranted. Monotypic.
Distribution. SE Brazil, E & NE Rio de Janeiro State.
Descriptive notes. Head-body 170- 244 mm, tail 150-220 mm; weight 100- 290 g. Dorsum of Elias’s Spiny-rat is ocherous buff, finely lined with blackish brown; it gradually becomes paler on sides and contrasts sharply with white venter. Tail is bicolored, brownish above and white below, averaging 90% of head-body length; it lacks conspicuous pencil of elongated hairs at its tip. Dorsal aristiform hairs are narrow and soft, imparting soft rather than spiny appearance to fur. Setiform hairs on mid-dorsum are whitish basally, gradually blackening toward tips but interrupted by ocherous-full sub-distal zone; those on outer thighs are whitish on basal one-half and become gradually grayish in middle and light ocherous buff along distal one-third, often with blackish tips. Skull is elongated and slender, without conspicuous ridges, and averages 51-7 mm. Auditory bullae are small, smooth, elongated, and not inflated. Elias’s Spiny-rat is uniquely distinguished from conspecifics by combination of lack of differentiated light-colored pelage on outer thighs, posteriorly wide incisive foramina with complete and columnar septum that is especially thick and wide across maxillary part, primarily squamosal contribution to post-orbital processes of zygoma, and karyotype with 2n = 60, FN = 116 and without dot-like supernumerary elements.
Habitat. Prefers semideciduous and evergreen moist forests in the Atlantic Forest, most commonly on forest floor in dense, vine undergrowth and in and around fallen trees and complex tree roots. Elias’s Spiny-rat also occurs exclusively in forest patches within coastal sandy lowlands at sea level, otherwise characterized by open vegetation dominated by species of Myrtaceae, Erythoxilaceae, Bromeliaceae, Cactaceae, and Mimosaceae.
Food and Feeding. There is no specific information available for this species, but Elias’s Spiny-rat probably feeds on various plant materials, including fruit and seeds, and insects.
Breeding. Elias’s Spiny-rats reproduce throughout the year, except in April, with the largest proportion of sexually active individuals in January.
Activity patterns. Elias’s Spiny-rat is reported to be crepuscular but probably is also nocturnal.
Movements, Home range and Social organization. Few data are available for Elias’s Spiny-rat, but females and juveniles are occasionally captured in the same trap, suggesting that young may follow their mothers during foraging bouts.
Status and Conservation. Classified as Endangered on The IUCN Red List. Elias’s Spinyrat has a small and highly fragmented distribution, in which extent and quality of habitat continues to decline. It occurs at only three known localities, and only one apparently affords sufficient protection. Continued habitat destruction is the major conservation threat to Elias’s Spiny-rat.
Bibliography. Allen (1899a), Brito & Figueiredo (2003), Davis (1945a, 1945b, 1947), Glnther (1877a), Lara et al. (1996), Moojen (1948), Pessba & dos Reis (1993), Pessba, Tavares, de Oliveira & Patton (2015), Tavares et al. (2015).
description: Published as part of Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Echimyidae, pp. 552-604 in Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona :Lynx Edicions on page 561, DOI: 10.5281/zenodo.6623649