Pattonomys flavidus ( Hollister, 1914 )

Emmons, Louise H. & Fabre, Pierre-henri, 2018, A Review of the Pattonomys / Toromys Clade (Rodentia: Echimyidae), with Descriptions of a New Toromys Species and a New Genus, American Museum Novitates 2018 (3894), pp. 1-52 : 32-33

Pattonomys flavidus ( Hollister, 1914)

Loncheres flavidus Hollister 1914: 143 (original description).

TYPE SPECIMEN AND TYPE LOCALITY: The holotype (by original designation, USNM 63218 ) consists of the skin and skull of an adult male with shot damage to the head, collected by W. Robinson on 9 July 1895 at “ El Valle , Margarita Island,” Nueva Esparta, Venezuela .

DIAGNOSIS: Perhaps as large as Pattonomys punctatus , cranium intermediate in size between P. punctatus and P. carrikeri (based on one individual, tables 5, 6). Dorsal pelage grizzled ochraceous yellowish lined with black, slightly browner over the rump. White-tipped spines robust and confined to the rump. Underhairs ochraceous yellow. Head and neck grayish; underparts yellow-buff. The postauricular patches seem gray-white, but head skin badly damaged. Feet gray above. Cranium with zygomatic arches tapering anteriorly, not bowed outward; masticatory and buccinator foramina separate. Palatal notch V-shaped, with straight borders; bullae not inflated (9F, 10F). Mandible robust and deep below the toothrow ( fig. 7F : arrow).

REMARKS: Based on the holotype, Pattonomys flavidus is not more clearly aligned in morphology with any one of the other three species. We failed to obtain good mitochondrial sequences for P. flavidus , however, some 100 bp Illumina reads indicate a close relationship to its geographical neighbor P. carrikeri (sequences identical), but with insufficient data to place it definitively, so we provisionally maintain it as an independent lineage. This island endemic is apparently represented in collections only by the 1895 type specimen. Three recent specimens were karyotyped, but not preserved ( Aguilera et al., 1998). Nonetheless, they prove that the species was extant in the mid-1990s.

GEOGRAPHIC RANGE AND HABITAT: The type locality is El Valle, on the eastern end of Margarita Island, Venezuela, but recent specimens were from the Macanao Peninsula at the western end of that island ( Aguilera et al., 1998). The lowlands of the island are largely deforested, but there is a forested protected area on the western side, where the recent specimens were captured, and the highlands of the eastern side, the provenance of the holotype, remain patchily forested (Google Earth, 2017). This continental-shelf island is separated from the mainland by two shallow (<10 m deep), open-water channels (9 km, 10 km) and it would have been connected to the mainland during glacial periods as recent as 8000 y.b.p. ( Guilderson et al., 2000). Two specimens were captured by hand from tree holes ( Aguilera et al., 1998).

SPECIMENS EXAMINED: VENEZUELA: Nueva Esparta, Margarita Island , El Valle ( USNM 63218 * [holotype]) .

Figures

FIG. 7. Crania and mandibles, lateral view. A, Toromys grandis AMNH 93601; B, T. rhipidurus BMNH 28.7.21.89 (holotype); C, T. sp. nov., FMNH 55483 (holotype), D, Leiuromys occasius. AMNH 71897; E, Pattonomys punctatus BMNH 98.12.1.18 (holotype); F, P. flavidus USNM 63218 (holotype); G, P. carrikeri AMNH 130790; H, P. semivillosus USNM 280205. Black arrow in F indicates the deep mandible of P. flavidus relative to its congeners.