Caluromys J.A. Allen, 1900

Voss, RS & Jansa, SA, 2009, Phylogenetic Relationships And Classification Of Didelphid Marsupials, An Extant Radiation Of New World Metatherian Mammals, Bulletin of the American Museum of Natural History 2009 (322), pp. 1-177 : 92-94

Caluromys J.A. Allen, 1900 Figure 38

CONTENTS: derbianus Waterhouse, 1841 (including antioquiae Matschie, 1917; aztecus Thomas, 1913; canus Matschie, 1917; centralis Hollister, 1914; fervidus Thomas, 1913; guayanus Thomas, 1899; nauticus Thomas, 1913; pallidus Thomas, 1899; pictus Thomas, 1913; pulcher Matschie, 1917; pyrrhus Thomas, 1901; and senex Thomas, 1913); lanatus Olfers, 1818 (including bartletti Matschie, 1917; cahyensis Matschie, 1917; cicur Bangs, 1898; hemiurus Miranda-Ribeiro, 1936; jivaro Thomas, 1913; juninensis Matschie, 1917 ; lanigera Desmarest, 1820; meridensis Matschie, 1917; modesta Miranda-Ribeiro, 1936; nattereri Matschie, 1917; ochropus Wagner, 1842; ornatus Tschudi, 1845; and vitalinus Miranda- Ribeiro, 1936); and philander Linnaeus, 1758 (including affinis Wagner, 1842; cajopolin Müller, 1776; cayopollin Schreber, 1777; cayopollin Kerr, 1792; dichurus Wagner, 1842; flavescens Brongniart, 1792; leucurus Thomas, 1904; trinitatis Thomas, 1894; and venezuelae Thomas, 1903).

These taxa are currently allocated to two subgenera, Caluromys J.A. Allen, 1900 (containing only C. philander ), and Mallodelphys Thomas, 1920 (containing C. derbianus and C. lanatus ), that can be distinguished unambiguously by the traits noted below.

MORPHOLOGICAL DESCRIPTION: Combined length of adult head and body ca. 210– 300 mm; adult weight ca. 190–500 g. Rhinarium with two ventrolateral grooves on each side of median sulcus; dark circumocular mask present; pale supraocular spot absent; dark midrostral stripe present; throat gland absent. Dorsal pelage unpatterned, grayish or reddish brown, or indistinctly mottled with same colors; dorsal underfur grayish; dorsal guard hairs short and inconspicuous; ventral fur gray based or self-colored. Manual digit IV longer than other manual digits; manual claws longer than fleshy apical pads of digits; dermatoglyph-bearing manual plantar pads present; central palmar epithelium smooth or sparsely tuberculate; carpal tubercles absent. Pedal digits unwebbed; pedal digit IV longer than other pedal digits; plantar surface of heel naked. Pouch present, consisting of separate lateral skin folds opening medially (subgenus Caluromys ) or a deep pocket opening anteriorly (subgenus Mallodelphys ); known mammary formulae apparently 2–0–2 5 4 (in C. lanatus ) and 3–1–3 5 7 (in C. philander ); cloaca present. Tail much longer than combined length of head and body, slender and muscular (not incrassate); body fur extends onto tail base to the same extent dorsally as ventrally (subgenus Caluromys ) or much further dorsally than ventrally (subgenus Mallodelphys ); naked caudal integument dark (grayish or brownish) basally and whitish distally with mottled transition; caudal scales in spiral series, each scale with three subequal bristlelike hairs emerging from distal margin (the central hair of each caudal-scale triplet longer than the lateral hairs but not grossly swollen or petiolate); naked ventral caudal surface modified for prehension, with raised tubercles near base ( Mallodelphys only) and apical pad bearing dermatoglyphs.

Premaxillary rostral process present. Nasals long, extending anteriorly above I1 (concealing nasal orifice from dorsal view), and conspicuously widened posteriorly near maxillary-frontal suture. Maxillary turbinals elaborately branched. Lacrimal foramina exposed to lateral view at or near anterior orbital margin, usually two on each side. Large, flattened, triangular postorbital processes of frontals present. Left and right frontals and parietals separated by persistent median sutures. Parietal and alisphenoid in contact on lateral braincase (no frontalsquamosal contact). Sagittal crest weakly developed on interparietal and/or along midparietal suture (not extending anteriorly to frontals) in some large adult specimens. Petrosal not laterally exposed through fenestra in parietal-squamosal suture (fenestra absent). Parietal-mastoid contact present (interparietal does not contact squamosal).

Maxillopalatine fenestrae usually absent (small fenestrae, never extending anteriorly beyond M1 or posteriorly beyond M2, are uni- or bilaterally present in occasional specimens); palatine and maxillary fenestrae absent; posterolateral palatal foramina small, not extending anteriorly between M4 protocones; posterior palate gently sloping ventrally, usually with arched caudal margin and without prominent posterolateral corners (the choanae unconstricted behind). Maxillary and alisphenoid not in contact on floor of orbit (separated by palatine). Transverse canal foramen absent. Alisphenoid tympanic process more or less conical (acutely pointed ventrally), usually without posteromedial lamina enclosing extracranial course of mandibular nerve (secondary foramen ovale absent),24 and contacting or closely approximating rostral tympanic process of petrosal. Anterior limb of ectotympanic indirectly suspended from basicranium (by malleus). Stapes triangular with large obturator foramen (in subgenus Caluromys ) or subtriangular with small but patent foramen (in subgenus Mallodelphys ). Fenestra cochleae concealed in sinus formed by rostral and caudal tympanic processes of petrosal. Paroccipital process small, rounded and subtriangular, adnate to petrosal. Dorsal margin of foramen magnum bordered by supraoccipital and exoccipitals, incisura occipitalis present.

Two mental foramina usually present on lateral surface of each hemimandible; angular process blunt and weakly inflected.

Unworn crowns of I2–I5 asymmetrical (‘‘incisiform’’), with much longer anterior than posterior cutting edges. Upper canine (C1) alveolus contained entirely in maxillary bone; C1 simple, without accessory cusps. First upper premolar (P1) minute, vestigial, and lacking any consistent occlusal features; second upper premolar (P2) much taller than P3; P3 with both anterior and posterior cutting edges; upper milk premolar (dP3) large and molariform. Molars not carnassialized (postprotocristae and postmetacristae are subequal in subgenus Mallodelphys ) or weakly carnassialized (postmetacristae are

24 We examined one old adult male (MVZ 190249) with a secondary foramen ovale formed by a posteromedial lamina.

slightly longer than postprotocristae in subgenus Caluromys ); relative widths usually M1, M2. M3. M4 (subgenus Mallodelphys ) or M1, M2, M3. M4 (subgenus Caluromys ); centrocrista weakly inflected labially on M1–M3; ectoflexus consistently absent on all upper molars; anterolabial cingulum continuous with preprotocrista (complete anterior cingulum present) on M3; postprotocrista without carnassial notch. Last upper tooth to erupt is P3.

Lower incisors (i1–i4) with distinct lingual cusps. Lower canine (c1) erect, acutely pointed, and simple (without a posterior accessory cusp). Second upper premolar (p2) much taller than p3; lower milk premolar (dp3) trigonid with or without paraconid (when present, the paraconid is small and often indistinct). Hypoconid labially salient on m3; hypoconulid twinned with entoconid on m1–m3; entoconid much taller than hypoconulid on m1–m3.

DISTRIBUTION: Caluromys occurs from the Mexican state of Veracruz southward throughout most of the forested regions of Central and South America (including Trinidad) to eastern Bolivia, eastern Paraguay, and northeastern Argentina ( Hall, 1981; Gardner, 2008). Most specimens of C. lanatus and C. philander (e.g., those reported by Handley, 1976; Anderson, 1997) are from lowland or lower montane rainforest; however, C. philander has also been observed in dry forest ( Emmons, 1998), and C. derbianus ranges from sea level to over 2000 m and occurs in both rainforest and dry forest ( Handley, 1966; Bucher and Hoffmann, 1980; Sánchez et al., 2004).

REMARKS: Generic monophyly (vis-à-vis Caluromysiops ) is supported by IRBP sequence data (fig. 28), by the presence of a distinct midrostral stripe, and by the presence of a small but distinct rostral process of the premaxillae (the latter two traits optimize as unambiguous generic synapomorphies; appendix 5).

The genus Caluromys has never been revised, and there is substantial divergence in morphology and/or cytochrome b sequences among some allegedly conspecific populations ( Voss et al., 2001; Patton and Costa, 2003). Indeed, no revisionary study has documented the conspecific status of the many subjective synonyms listed above for either C. philander or C. lanatus . It is an open question as to whether the subgenera Caluromys and Mallodelphys will prove to be reciprocally monophyletic or not in future phylogenetic analyses based on denser taxon sampling.