Coendou vestitus Thomas

VOSS, ROBERT S. & DA SILVA, MARIA N. F., 2001, Revisionary Notes on Neotropical Porcupines (Rodentia: Erethizontidae). 2. A Review of the Coendou vestitus Group with Descriptions of Two New Species from Amazonia, American Museum Novitates 3351, pp. 1-36 : 6-11

Coendou vestitus Thomas

Figures 3 , 4 , 5A , 6A

Coendou vestitus Thomas, 1899: 284 (original description).

Coendou (Sphiggurus) vestitus: Tate, 1935: 307 (new name combination).

Coendou (Sphiggurus) vestitus vestitus: Cabrera, 1961: 603 (new name combination).

Sphiggurus vestitus: Honacki et al., 1982: 572 (new name combination).

TYPE MATERIAL: The holotype only , BMNH 54.6 .26.1, consisting of the skin, skull, and mandibles of a subadult animal of unknown sex. The skin, much faded with age, is understuffed and lacks the left fore­ foot; the left hindfoot is detached but intact. The skull lacks the occiput, a common consequence of early to mid­19th century specimen preparation methods. The original label gives the place of origin only as ‘‘N[ouvel] le Grenade’ ’ (= Colombia). According to Thomas (1899), the specimen was purchased in 1854 .

GEOGRAPHIC DISTRIBUTION: Coendou vestitus is only known from two definite localities, both of which are in the western foothills of the eastern Andean cordillera of Colombia. The first, where Hermano Nicéforo María collected six specimens from 1923 to 1925, is San Juan de Río Seco , a small village located about 60 km WNW of Bogotá at ca. 1300 m elevation. The second, where the same collector took a single specimen in 1925, is Quipile, a village only about 15 km SSE of San Juan and at approximately the same altitude .

DESCRIPTION: External —The dorsal fur, soft in texture and dull in appearance, is uniformly blackish brown and averages about 50–60 mm middorsally; the fur is shorter and sparser along the flanks, but it is long enough to conceal most of the quills except on the face. The quills (ranging in length from about 25 to 35 mm middorsally) are bicolored, pale yellow or ivory­white basally and dark­brown or blackish distally; usually only the distalmost 1 ⁄  or less of each quill is dark, so the pale quill bases are exposed when the fur is parted or ruffled. None of the quills anywhere on the body is pale­tipped. Scattered abundantly but inconspicuously throughout most of the dorsal pelage are long (to 70–80 mm) polished bristle­quills that emerge from the fur like fine wires; these are yellowish basally, but the emergent tips are dark. No bristle­quills occur over the rump, however, which is clothed only by short, sharp quills and fur. The ventral surface of the body is densely covered with soft and uniformly dark­brown fur from chin to anus. Two classes of hairs can be distinguished in the ventral fur (fine, wavy wool hairs and coarser, straighter guard hairs), but there are no conspicuously thickened spinous hairs grouped in triads or other clusters.

The tail is short, apparently averaging about half the length of the combined head­ and­body (see measurements in table 1). The proximal half of the tail is clothed dorsally with quills and woolly fur like the rump, and the tip has a naked, calloused dorsal prehensile surface, but the rest of the tail is covered above and below with blackish bristles; the bristles under the base of the tail are much stiffer and denser than those on the lateral and dorsal surfaces. The dorsal surface of the hands and feet are densely covered with coarse brownish hairs.

The long mystacial vibrissae are uniformly blackish and extend behind the pinnae when laid back alongside the head. Supraorbital (superciliary), genal, submental, and postcranial vibrissae are also present. The postcranial vibrissae occur on the forelimb between the elbow and wrist, on the hindlimb between the knee and ankle, and along the ventral surface of the body between the forelimb and hindlimb.

Skull —The frontal and nasal sinuses are uninflated, resulting in a flat dorsal profile from the nasal tips to the midparietal region in all the specimens examined. The rostrum is short and tapering in younger animals, but old adults have proportionately longer rostrums with prominent lateral excavations for the origin of the infraorbital muscle. The nasal bones are more­or­less parallel­sided, neither increasing nor decreasing posteriorly in breadth, with rounded posterior margins that extend well behind the premaxillae. Viewed from above, the zygomatic arches converge anteriorly from their widest point at the level of the squamosal roots with only a slight lateral deflection at the level of the orbits. The jugals are slender elements, lacking any conspicuous postorbital expansion. The dorsolateral contours of the braincase are strongly sculpted by the origin of the temporalis muscle, but the left and right temporal scars are widely separated and do not join middorsally to form a sagittal crest.

The small incisive foramina are completely contained in the premaxillae (e.g., BMNH 24.2.21.2) or shallowly contact the maxillae (e.g., AMNH 71359), but do not deeply penetrate between the latter bones; the left and right foramina are incompletely separated and are recessed in a common fossa in some specimens, but in others they are completely separated and are not recessed together. The posterior diastema is marked by shallow and widely separated lateral sulci. In all of the specimens examined, the palatal bridge (between the toothrows) has a well developed central keel and deep lateral gutters (fig. 5A). The mesopterygoid fossa penetrates anteriorly to or between the second molars, and the bony roof of the fossa is perforated by well­formed sphenopalatine vacuities (> 1 mm in diameter) in all of the specimens at hand. The alisphenoid is incompletely ossified, with the result that the sphenopterygoid canal is open laterally and the buccinatormasticatory foramen is confluent with the foramen ovale (fig. 6A). The auditory bullae are small (ca. 14–15 mm) rounded capsules that are well separated from the base of the paroccipital process on each side. The dorsal roof of the external auditory meatus has an indistinct bony ridge that is less well developed than that seen in some congeneric taxa (e.g., Coendou melanurus ; Voss et al., 2001: fig. 70A).

The mandible is distinctive in the absence of a well­defined coronoid process, which is represented only as a rounded convexity at the base of the ascending ramus in all specimens examined.

Dentition —The upper incisors have pale yellow­orange enamel bands and are moderately procumbent. The cheekteeth essentially resemble those of other erethizontids (except Chaetomys ) in occlusal morphology, and the toothrows are subparallel to weakly convergent. The permanent fourth upper premolar is only slightly larger than the first molar in some specimens (e.g., AMNH 70529), but P4 is conspicuously larger than M 1 in others (e.g., USNM 240035).

COMPARISONS: See the accounts for Coen­

TABLE 1 Measurements (mm) of All Known Specimens of Coendou vestitus

de Río Seco ( AMNH 70596 , 71359 ; BMNH 24.2.21.2; MNHN 1929.631 , 1929.632 ; USNM 240035 ); ‘‘Colombia’’ (no other locality data, AMNH 71360 ); ‘‘N[ouvel]le. Grenade’’ ( BMNH 54.6 .26.1 [holotype]) .

Figures

Fig. 3. Dorsal view of the skin of Coendou vestitus (BMNH 24.2.21.2). Approximately ×0.4.

Fig. 4. Dorsal, ventral, and lateral cranial views of Coendou vestitus (MNHN 1929–632). All views approximately ×1.5.

Fig. 5. Ventral cranial views of Coendou vestitus (A, MNHN 1929–632) and C. pruinosus (B, MCZ 18738) showing species differences in palatal morphology. In Coendou vestitus, the bony palate between the toothrows is marked by a high median keel that is flanked by deep lateral grooves or gutters (lg); in addition, the mesopterygoid fossa (mpf) extends anteriorly between the second molars, and the roof of the fossa is perforated by large sphenopalatine vacuities (spv). In C. pruinosus, the palate is sometimes weakly keeled but never has deep lateral gutters; also, the mesopterygoid fossa extends anteriorly only between the third molars, and the roof of the fossa is not perforated by distinct sphenopalatine vacuities.

Fig. 6. Ventrolateral cranial views of Coendou vestitus (A, AMNH 71360) and C. pruinosus (B, MCZ 18738) showing species differences in alisphenoid morphology. In Coendou vestitus, the alisphenoid is incompletely ossified, resulting in an open sphenopterygoid canal and a buccinator­masticatory foramen (bmf) that is confluent with the foramen ovale (fo). By contrast, the alisphenoid is fully ossified in C. pruinosus, whose sphenopterygoid canal (arrow) is laterally enclosed and whose buccinator­masticatory and oval foramina are separate.