16.

Rigid-spined Atlantic Spiny-rat

Trinomys paratus

French: Rat-épineux hérissé / German: Lanzen-Atlantikstachelratte / Spanish: Rata espinosa de espinas duras

Other common names: Spiked Atlantic Spiny-rat

Taxonomy. Proechimys (Trinomys) iheringi paratus Moojen, 1948,

“Floresta da Capela de Sao Braz, Santa Teresa, Espirito Santo, Brasil; altitude 630 meters.”

Trinomys paratus was originally described as a subspecies of “ Proechimys ” iheringi and placed in the subgenus 7 Trinomys. Later Trinomys was elevated to generic status by M. C. Lara and J. L. Patton in 2000 and paratus was treated as a full species in the 2015 review of this genus by L. M. Pessoa and colleagues. Monotypic.

Distribution. SE Brazil, known only from a few localities in the S one-half of Espirito Santo and EC Minas Gerais states.

Descriptive notes. Head-body 187-246 mm, tail 171-235 mm; weight 195-350 g. Dorsum of the Rigid-spined Atlantic Spiny-rat varies from cinnamon to blackish brown, becoming paler on sides, but sharply contrasting white venter. Tail length is about the same as head-body length; it is markedly bicolored dark above and white below and terminates in conspicuous pencil of hairs at its tip. Aristiform hairs are most rigid and large among congeners, very long and wide over mid-dorsum, averaging 24-2 mm in length and 1-6 mm in width, and are whitish or pale buff basally, gradually becoming sepia along shaft and terminating with black tips. Mid-dorsal setiform hairs are white or pale buff basally, merging into sepia toward tips but are interrupted by light brownish olive intermediate zone. Setiforms over rump display same general color pattern but are overall paler. Skull is large, elongated, and stout, with well-marked ridges;it averages 52-4 mm. Incisive foramina are fusiform to oval and medium in size, occupying ¢.40% of diastema; septum is complete and columnar,its long premaxillary part constituting ¢.75% of foraminal opening length; maxillary part is small but wide; and vomeris notvisible in ventral view. Post-orbital processes of zygoma are well developed and often slightly pointed,typically composed ofjugal and squamosal. Auditory bullae are large, smooth, and slightly inflated. Upper cheekteeth have one major fold and two counterfolds. Baculum is geographically variable but generally elongated and moderate to thin (average length 9-8 mm), with slight dorso-ventral curvature and without distal expansions or apical wings; proximal end is only slightly broader than shaft and somewhat rectangular; distal end is concave. Karyotype is unknown.

Habitat. Atlantic Forest at elevations below 400 m. Type series was collected in submontane region of undisturbed, moist, and dense forest, but the Rigid-spined Atlantic Spiny-rat also inhabits lowland moist forests, coastal sand vegetation (restingas) close to the littoral zone, and inland semideciduous forest.

Food and Feeding. There is no specific information available for this species, but the Rigid-spined Atlantic Spiny-rat probably feeds on various plant materials, including fruit and seeds, and insects.

Breeding. There is no information available for this species.

Activity patterns. There is no specific information available for this species, but the Rigid-spined Atlantic Spiny-rat is probably primarily nocturnal.

Movements, Home range and Social organization. There is no information available for this species.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. There is an absence of recent information on extent of occurrence, threats, local population status, and ecological requirements of the Rigid-spined Atlantic Spiny-rat. Much ofits original distribution has been heavily converted to agriculture and pasture.

Bibliography. Lara & Patton (2000), Moojen (1948), Pessoa, Tavares, de Oliveira & Patton (2015).