Pattonomys semivillosus

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 : 29-30

Pattonomys semivillosus (I. Geoffroy St.-Hilaire, 1838)

Nelomys semivillosus I. Geoffroy St. -Hilaire 1838: 887 (original description).

TYPE SPECIMEN AND TYPE LOCALITY: Geoffroy St. -Hilaire (1838) examined three specimens sent to de Blainville and Roulin from Cartagena by the French consul, M. Pavageau. One syntype is known (MNHN-ZM-MO-1995-1397, C. Callou, personal commun), an adult skull without mandible and A-7672 written on the cranium, original no. 408b). The original external measurements (body and tail each 195 cm) cannot be associated with the syntype skull; “Carthagène, (Nouvelle-Grenade),” Cartagena, Bolívar, Colombia . 4

DIAGNOSIS AND DESCRIPTION: The smallest ( tables 5, 6) and most heavily spined member of the genus. Upperparts generally gray with middorsum tinged brown; back and sides sprinkled with white-tipped spines posteriorly from neck; rump densely spiny and white speckled ( figs. 4B , 14B ). Head grizzled gray above, heavily lined with black, with prominent white postauricular patches visible above the rims of the ears, and narrow dusky eye rings ( fig. 14B ). Muzzle, cheeks, and throat white or cream. Underparts sharply demarcated white or tinged pinkish buff, colored especially behind the forelegs and in the inguinal region. Dorsal aristiforms wide, strong, and sharp, with blackish subterminal bands and dark or white tips. Dorsal underhairs ochraceous yellow to slightly reddish. Distal tail hairs brown. Hind foot of a dried skin is like those of P. carrikeri ( fig. 6B ), with six wellseparated pads, a supplementary lateral pad, and the space between pads filled with small tubercles. Skull is lightly built for the genus, with supraorbital shelves not greatly expanded or curved upward. Inferior jugal processes slender and delicate. Upper incisors slightly opisthodont ( fig. 7H ). Buccinator and masticatory foramina separate ( fig. 15A ). Palatal notch (mesopterygoid fossa) narrow and straight sided, bordering a narrow opening. Teeth as for genus.

GEOGRAPHIC RANGE AND HABITAT: Known only from northern Colombia (fig. 1), in the basin of the lower Río Magdalena and its tributaries, where it has been collected in forested swampy areas (locally known as ciénagas). In Isla de Salamanca National Park it occurs in mangrove forest ( fig. 14B ).

SPECIMENS EXAMINED: COLOMBIA: Bolívar, Cartagena, (MNHN-ZM-MO-1995-1397 [holotype]); César, Valledupar, Río Guaimaral , ( USNM 280204 *) ; Valledupar, El Orinoco, ( USNM 28205 , 28206 , 38207 , 280208 ) ; Magdalena; Atlántico, lower Río Magdalena, opposite Barranquilla, ( FMNH 69117 , 69118 *) .

Figures

FIG. 4. Pelage of dorsum at rump. A, Leiuromys occasius. FMNH 84529, high density of sharply pointed spines and fine, wavy red underhairs; B, Pattonomys semivillosus USNM 280204, dense, more tapered, white-tipped spines, abundant pale bristles, straight ochraceous underhairs; C, Makalata cf. didelphoides USNM 549593, agouti pelage, sparser narrowly buff-tipped spines, tapered hairlike spine tips; D, Toromys grandis AMNH 94036, thick bristles, no spines; E, T. rhipidurus AMNH 73273, fine-banded agouti bristles; F, T. sp. nov., narrow aristiforms and a few narrow spines with hairlike tips, abundant thin, agouti bristles. The resemblance between Toromys congeners is evident. Spine tips are more sharply tapered in A than in B.

FIG. 14. Living Toromys and Pattonomys. A, Toromys grandis, lower Rio Purus, (fig. 1, locality 31). Note the elongate body, the longer black hair on the proximal tail, and the broad foot with narrow heel. There is a postauricular patch of pale skin. The anterior bright eyeshine spot seems to show an oval, vertical pupil, the other spot is a reflection of the flash (image by Vinicius Carvalho). B, Pattonomys semivillosus in a black mangrove tree (Avicennia germinans) in Parque Nacional Isla de Salamanca, Magdalena, Colombia. The white postauricular tufts above and behind the ear are striking (photograph by Fabrice Schmitt). C, Toromys rhipidurus, captured near Iquitos, Peru. The evident cream-colored postauricular patches are not visible on most museum skins. The camera-flash has accentuated the yellow midbody hues (image by Pamela Sánchez-Vendizú).

FIG. 6. Variation among genera in plantar surfaces of hindfeet, fluid-preserved specimens. A, Toromys rhipidurus AMNH 276710; B, Pattonomys carrikeri USNM 496501; C, Phyllomys pattoni, UFES 121; D, Makalata cf. didelphoides USNM 581981 (Bolivia); E, M. cf. macrura USNM 496480 (Venezuela); F, Echimys chrysurus, USNM 549839 (Rio Xingu). Note small digital pads, especially D3, and collars of small tubercles around pads in (A–C); large digital pads and no collars of tubercles in (D–F); merged D1 and thenar pad in (E–F), leaving three separated digital pads; and differences in digital pad shapes (see text). Abbreviations: D, digital pads; Th, thenar pad; Hy, hypothenar pad. Arrow in A indicates supernumerary separated pad of Pattonomys spp. Figures not to scale. Photo panel C, Yuri Leite.

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.

FIG. 15. Pattonomys basicrania. A, Pattonomys punctatus USNM 374741; B, P. carrikeri USNM 456429. Note separate masticatory and buccinator foramina (arrows), robust extra bony rings below meatus, wide mesopterygoid fossa, and less inflated auditory tympanic bullae in A; joined foramina and more inflated bullae in B.