Marmosops parvidens ( Tate, 1931 )

Díaz-Nieto, Juan F. & Voss, Robert S., 2016, A Revision Of The Didelphid Marsupial Genus Marmosops, Part 1. Species Of The Subgenus Sciophanes, Bulletin of the American Museum of Natural History 2016 (402), pp. 1-72: 21-25

publication ID

http://doi.org/ 10.1206/0003-0090-402.1.1

DOI

http://doi.org/10.5281/zenodo.4630816

persistent identifier

http://treatment.plazi.org/id/03A68972-9803-FFCA-0562-756ED619F96E

treatment provided by

Felipe

scientific name

Marmosops parvidens ( Tate, 1931 )
status

 

Marmosops parvidens ( Tate, 1931)  

Figures 2 View FIG , 5A View FIG , 7A View FIG , 11–13 View FIG View FIG View FIG , 14A View FIG

Marmosa parvidens Tate, 1931: 13   (original description).

Marmosa parvidens parvidens: Pine, 1981: 60   (name combination).

Marmosops parvidens: Gardner and Creighton, 1989: 4   (name combination).

TYPE MATERIAL: The holotype (by original designation) consists of the skin and skull of an adult female ( FMNH 18545 View Materials ; original number 8) collected by S.B. Warren on 8 September 1906 at Hyde Park (fig. 10: locality 50), a locality near sea level on the Demerara River in East Demerara– West Coast Berbice about 35 km south of Georgetown. No other specimens were mentioned in the original description of this species   .

DISTRIBUTION, HABITATS, AND SYMPATRY: Examined specimens suggest that Marmosops parvidens   occurs throughout most of the Guiana Region (north of the Amazon and east of the Rio Negro), but the species appears to be unknown from Venezuela ( García et al., 2014), and we have not examined any material from northern Pará. Although we have not personally examined material from Amapá, M. parvidens   has recently been reported to occur there ( Silva et al., 2013). A single specimen is also known from SE Amazonia (on the lower Rio Tocantins, fig. 10: locality 13). All specimens associated with definite elevational data were collected between sea level and about 500 m. The predominant vegetation throughout the range of this species, which broadly overlaps that of M. pinheiroi   , is lowland rain forest (e.g., in French Guiana, where both species occur sympatrically; Voss et al., 2001; Catzeflis et al., 2014).

DESCRIPTION: Body pelage dusty reddish brown (near Bister or Snuff Brown) middorsally, but indistinctly paler laterally, and about 6–8 mm long at midback; ventral pelage extensively self-white from chin to anus (including the inner surfaces of the fore- and hind limbs), usually with only narrow lateral-abdominal borders of gray-based fur. Manus covered dorsally with uniformly pale hairs (the metacarpals not contrasting sharply in color with the digits); lateral carpal tubercles spoon shaped in all examined adult males. Mammae 3–1–3 = 7 or 4–1–4 = 9. Tail much longer than combined length of head and body (mean LT/HBL × 100 = 150%); dorsal caudal surface uniformly dark from base to tip, but ventral surface indistinctly paler (especially near the base of the tail).

Nasal bones long (extending well behind the lacrimals) and much wider posteriorly than anteriorly (laterally expanded at the maxillary-frontal suture). Lacrimal foramina usually concealed from lateral view inside anterior orbital margin; zygomatic process of squamosal broadly overlapped dorsally by the jugal. Palatine fenestrae absent. Dorsolateral margin of ethmoid foramen usually formed by the orbitosphenoid.

Upper canine (C1) short, with anterior and posterior accessory cusps in both sexes. Upper third molar (M3) anterolabial cingulum narrowly continuous with preprotocrista (anterior cingulum complete). Lower canine (c1) premolariform (procumbent, with posterior accessory cusp) and small, subequal in height to p1; c1 anterolingual accessory cusp absent. Entoconid of m1 subequal in height to adjacent m2 paraconid; unworn m4 talonid with three distinct cusps.

COMPARISONS: Marmosops parvidens   is approximately the same size as M. pinheiroi   (tables 2, 3) in external dimensions, and differences in dorsal pelage coloration (usually some shade of dusty reddish brown in M. parvidens   versus dull brownish gray in M. pinheiroi   ) are sometimes less than obvious. By contrast, ventral pelage coloration provides a consistently useful external criterion for separating these broadly sympatric species: whereas M. parvidens   has a broad, continuous band of self-whitish fur that extends from chin to groin and along the inner surfaces of the fore- and hind limbs, M. pinheiroi   has a much narrower, discontinuous midventral streak of self-white hairs that apparently never extends onto the throat nor along the inner surfaces of the fore- and hind limbs. Marmosops parvidens   averages smaller than pinheiroi   in most craniodental dimensions (WM 3 in males is the unique exception; tables 2, 3), but all measurements show overlapping variation between the two species, so none is diagnostic (despite unambiguous multivariate separation; Voss et al., 2001: fig. 24). Instead, qualitative aspects of craniodental morphology provide better characters for species identification: (1) whereas M. parvidens   has lacrimal foramina that are usually concealed within the orbit (fig. 14A), the lacrimal foramina of M. pinheiroi   are more prominently exposed laterally (fig. 14B); (2) the dorsolateral margin of the ethmoid foramen is usually formed by the orbitosphenoid in M. parvidens   , whereas the corresponding bony margin in M. pinheiroi   is often formed by the frontal; (3) the unworn M3 of M. parvidens   has a narrowly complete anterior cingulum, whereas the anterolabial cingulum and preprotocrista of this tooth are discontinuous in M. pinheiroi   ; (4) the talonid of m4 is consistently tricuspid in M. parvidens   but often appears to be bicuspid in M. pinheiroi   .

Comparisons between Marmosops parvidens   and M. pakaraimae   are provided in the account of the latter species (above).

REMARKS: The binomina “ Marmosa parvidens   ” and “ Marmosops parvidens   ” were previously applied to specimens of several distinct species, including M. bishopi   , M. juninensis   , M. ojastii   , M. pakaraimae   , and others (e.g., by Handley, 1976; Pine, 1981; Linares, 1998; Patton et al., 2000). The restricted sense in which this species is now understood was first defined by Voss et al. (2001). Current phylogeographic sampling of M. parvidens   consists of 10 cytochrome- b sequences from six localities in French Guiana, Guyana, and Surinam; these differ from one another by an average uncorrected distance of just 1.6%, well below the threshold value for species recognition in coalescent analyses performed by Díaz-Nieto et al. (2016a). Additionally, we have not observed any geographic variation in morphology that corresponds to geographic variation in cytochrome- b sequence data from this species.

We carefully reexamined AMNH 97333, which remains the only specimen of Marmosops parvidens   collected south of the Amazon. Although this specimen differs from material collected north of the Amazon in having the dorsolateral margin of the ethmoid foramen bordered by the frontal, and by lacking a continuous anterior cingulum on M3, it closely resembles typical M. parvidens   in other respects, notably in its extensively self-white ventral pelage. Although molecular confirmation that M. parvidens   occurs south of the Amazon would be welcome, we feel reasonably confident in the current identification of this unique specimen.

SPECIMENS EXAMINED (N = 42): Brazil — Amazonas, Boca Rio Paratucu ( AMNH 93970 View Materials ), 80 km N Manaus ( INPA 1758 View Materials , 1762–1769 View Materials , 1772–1779 View Materials ; USNM 579985–579989 View Materials )   ; Pará, Ilha do Taiuna ( AMNH 97333 View Materials ). French Guiana — Les Nouragues ( ISEM V-1633), Paracou ( AMNH 267344 View Materials , 267347 View Materials , 267348 View Materials , 267353 View Materials , 267359 View Materials , 267361 View Materials ; MNHN 1995-929 View Materials , 1995-933 View Materials , 1995-939 View Materials ), River Arataye ( USNM 548439 View Materials ). Guyana — Demerara-Mahaica, Hyde Park ( FMNH 18545 View Materials ), Upper Takutu–Upper Essequibo, Karanambo ( ROM 97938 View Materials ). Surinam — Brokopondo, Brownsberg Nature Park ( ROM 113997 View Materials , 114009 View Materials , 114144 View Materials )   ; Nickerie, Kayser Gebergte Airstrip ( FMNH 93169 View Materials )   ; Sipaliwini, Bakhuis Transect 13 ( ROM 117348 View Materials )   .

ROM

Royal Ontario Museum

Kingdom

Animalia

Phylum

Chordata

Class

Mammalia

Order

Didelphimorphia

Family

Didelphidae

Genus

Marmosops

Loc

Marmosops parvidens ( Tate, 1931 )

Díaz-Nieto, Juan F. & Voss, Robert S. 2016
2016
Loc

Marmosops parvidens: Gardner and Creighton, 1989: 4

Gardner, A. L. & G. K. Creighton 1989: 4
1989
Loc

Marmosa parvidens parvidens:

Pine, R. H. 1981: 60
1981
Loc

Marmosa parvidens

Tate, G. H. H. 1931: 13
1931