Marmosops (Sciophanes) pinheiroi ( Pine, 1981 )

Ferreira, Claudilívia, Oliveira, Ana Cristina Mendes De, Lima-Silva, Luan Gabriel & Rossi, Rogério Vieira, 2020, Taxonomic review of the slender mouse opossums of the “ Parvidens ” group from Brazil (Didelphimorphia: Didelphidae: Marmosops), with description of a new species, Zootaxa 4890 (2), pp. 201-233 : 222-225

Marmosops (Sciophanes) pinheiroi ( Pine, 1981)

Marmosa parvidens pinheiroi Pine, 1981: 61 .

Marmosops pinheiroi: Voss et al. 2001: 49 (part); name combination.

M [armosops]. pirenhoi Flores, 2004: 133 (part); incorrect spelling of Marmosops pinheiroi ( Pine, 1981) .

[ Marmosops Schiophanes ] pinheiroi: Díaz-Nieto et al. 2016: 928 ; first use of the current name combination.

Holotype. USNM 461459 (original numbers T-391 and L5049) consists of the skin and skull of an adult female collected on 08 May, 1969, by personnel of the Institute Evandro Chagas.

Type locality. Serra do Navio (0º59’N, 52º03’W), left bank of the Rio Amapari, state of Amapá, Brazil .

Geographic distribution. It occurs in the Guiana Shield and east of the Negro River, from southeastern Ven-ezuela to the Amazon River, through Guyana, Suriname, French Guiana and the states of Amapá, Roraima and Pará in Brazil ( Figure 5 ).

Amended diagnosis. Dorsal coloration grayish-brown; tail length (LT: 120–167 mm) much longer than head and body length ( HBL: 75–115 mm); ventral coloration ranging from white to cream, with wide lateral bands of gray-based and white-tipped hairs, which usually join on the throat and do not extend to the inner surface of the hind limbs; lacrimal foramina exposed in lateral view; supraoccipital with slightly convex shape in dorsal view; upper third molar (M3) with anterior and posterior portions of the stylar shelf projected labially in the same proportion (in occlusal view); upper molars with preprotocrista and anterolabial cingulum seperated, not forming a continuous shelf along the anterior margin of the tooth crown; metaconule of the upper molars slightly developed; and talonid of the lower fourth molar (m4) usually bicuspid.

Morphological description. Marmosops pinheiroi (s.s) has a head and body size of 75–115 mm and longer tail (LT: 120–167 mm; Tables 4 and 5 ); dorsal hairs 6–8 mm long; dorsal fur smooth, grayish-brown, being slightly lighter laterally; rostrum lighter than the top of the head, presenting light brown coloration, with some pale red and gray hairs; mask around the eyes blackish, with conspicuous posterior portion; cheeks with a greater amount of white hairs, but gray-based and white-tipped hairs also present; hands covered dorsally by whitish hairs; tail bicolor, generally grayish brown dorsally (73.8%, n=42); tail scales arranged in a spiral, each with three hairs inserted in the posterior margin; the central hair of the triplet clearly thicker and more pigmented than the lateral ones; venter varying from cream to white, with wide lateral bands of gray-based and white-tipped hairs (except in MPEG 40017, 40027, 40406, 40407, which have slightly narrower lateral bands), usually joining on the throat (74%, n=42) and not extending to the inner surface of the hind limbs (64.3%, n=42); hands with lateral spoon shaped carpal tubercle in adult males.

Craniodentally, Marmosops pinheiroi (s.s.) exhibits a zygomatic process of the squamosal widely overlapped dorsally by the jugal; lacrimal foramina exposed in lateral view (except in MPEG 39972 and 40025, in which foramina are not exposed); supraorbital margin slightly rounded with non-prominent crest; long nasal bones (ex-tending slightly behind the lacrimal) and wider posteriorly than anteriorly (except in MPEG 2277; MNRJ 70256, 70359, 70362 70730, 70798, whose nasal bones are similarly wide along all extension); supraoccipital with slightly convex shape in dorsal view; paraoccipital process generally long and narrow (77.7%, n=36); tympanic process of alisphenoid with ventral surface usually oval (75.7% n=37); cochlear fenestrae exposed in ventral view (except in MNRJ 70256, 70730); palatine fenestrae absent, but diminutive perforations in the palatine and/or maxillary bones may be present ( MPEG 40002, 40005, 40013, 40017, 40406; MNRJ 70256); upper canines (C1) with anterior and posterior accessory cusps in males and females; upper third molar (M3) with anterior and posterior portions of the stylar shelf projected labially in the same proportion; upper molars with preprotocrista and anterolabial cingulum separated, not forming a continuous shelf along the anterior margin of the tooth crown; metaconule of the upper molars; Figures 7B and C ) undeveloped; lower canine (c1) premolariform, with posterior accessory cusp, subequal (63%, n=35) or slightly higher (37%, n=35) to the first lower premolar (p1); paraconid of the second lower molar (m2) higher than the entoconid of the lower first molar (m1); and talonid of the lower fourth molar (m4) usually bicuspid (61%, n=38).

Geographic variation. We did not observe any geographic variation among samples of M. pinheiroi examined in this report.

Comparisons with M. parvidens and other species of the “Parvidens” group ( Table 6). Comparisons between M. pinheiroi (s.s.) and M. marina are provided above. Externally, M. pinheiroi (s.s.) is distinguished from M. parvidens and M. woodalli by exhibiting grayish-brown dorsal color ( Figure 4C ), versus slightly reddish brown in M. parvidens ( Figure 4B ) and usually dark brown in M. woodalli ( Figure 4D ); ventral coloration varying from cream to white ( Figure 4C ), versus cream in M. parvidens ( Figure 4B ) and white in M. woodalli ( Figures 4D ); lateral bands of gray-based hairs wide on the venter, usually joining on the throat and not extending to the inner surface of the hind limbs ( Figure 4C ), versus usually absent in M. parvidens , whose venter is covered with a continuous band of cream colored hairs extending along the inner surface of the anterior and posterior limbs ( Figure 4B ), and narrow and irregularly arranged, joining or not on the throat and/or mid-chest in M. woodalli ( Figure 4D ). Is also differs from M. parvidens by exhibiting conspicuous blackish facial mask around the eyes that extends posteriorly (versus usually inconspicuous; Table 6). Finally, M. pinheiroi (s.s) has, on average, longer feet ( Tables 4 and 5 ) and shorter dorsal fur than M. woodalli (6.9 mm in the former versus 7.6 mm in the latter species).

Craniodentally, M. pinheiroi (s.s.) differs from M. parvidens and M. woodalli by exhibiting lacrimal foramina exposed (versus variably exposed) in lateral view; tympanic process of the alisphenoid with ventral surface usually oval, versus usually globose in M. parvidens and variable in M. woodalli ; and talonid of the lower fourth molar (m4) usually bicuspid (versus usually tricuspid). It also differs from M. parvidens by exhibiting preprotocrista and anterolabial cingulum separated, not forming a continuous shelf on the anterior margin of crown of the upper molars (versus attached, forming a continuous shelf on the anterior margin of crown of the upper molars; Figures 7B and C ); and small accessory cusp between the metaconid and the entoconid of lower molars absent ( Figure 8 A-B). Marmosops pinheiroi (s.s.) can also be discriminated from Marmosops woodalli by exhibiting a slightly convex supraoccipital (versus rounded and markedly convex; Figures 9 A-B); anterior and posterior stylar portions of the M3 projected labially in the same proportion (versus posterior portion more projected labially than anterior portion; Figures 6 A-B).

Habitats and sympatry. Marmosops pinheiroi (s.s.) extends along Humid Forests of Uatumã-Trombetas and Savannas of Guiana ecoregions (sensu Olson et al. 2001). The species has been recorded in sympatry with M. parvidens in Floresta Estadual de Faro , on the left bank of the Nhamundá River, state of Pará, Brazil; in Floresta Estadual de Trombetas, Óbidos, Pará, Brazil; in Oriximiná, Pará, Brazil ( Figure 5 ); in Paracou, French Guiana ( Voss et al. 2001; Voss et al. 2013; Díaz-Nieto & Voss 2016); and in Demerara-Mahaica, French Guiana ( Voss et al. 2013; Díaz-Nieto & Voss 2016).

Natural history data. Mammary formula 4–1–4 = 9. Lactating females were recorded in March and April in Parque Nacional Viruá, state of Roraima, Brazil.

Specimens examined (n=69). BRAZIL - Amapá: Macapá, rigth bank of Rio Amapari , 0°2’N, 51°4’W, 1 M ( MPEG 2277 ) ; Serra do Navio, Rio Amapari , 0º54’3”N, 52º0’14”W, 1 M, 1 F ( MPEG 15255 , 15256 ) ; Serra do Navio, Rio Amapari , 0°59’N, 52°03’W, 1 F ( USNM 461459 , photograph of the holotype) . Pará: Floresta Estadual Faro (Flota Faro), left bank of Rio Nhamundá , 1°16’44”S, 58°2’24”W, 1 F ( MPEG 39972 ) ; Parque Estadual de Monte Alegre, Monte Alegre , 2°3’6”S, 54°10’58”W, 1 M ( MPEG 38171 ) ; Óbidos, Flota Trombetas , 0°58’0”S, 55°30’60”W, 19 M, 6 F, 2? ( MPEG 40002 , 40005 , 40012 , 40013 , 40016-40019 , 40023-40027 , 40030 , 40032 , 40033 , 40037 , 40402 , 40405-40409 , 40410-40412 ; MPEG: CN063 ) ; Oriximiná , 1°45’S, 55°51’W, 1 M, 1 F ( MPEG 39805 , 39806 ) . Roraima: Caracaraí, Parque Nacional Viruá , 01º15’N, 61º9’W, 23 M, 10 F, 2? ( MNRJ 70256 , 70359 , 70362 , 70389 , 70396 , 70397 , 70410 , 70412 , 70421 , 70422 , 70487 , 70730 , 70738 , 70745 , 70746 , 70753 , 70754 , 70757 , 70760 , 70762 , 70763 , 70765 , 70772 , 70793-70795 , 70798 , 70802 , 70819 , 70833 , 70856 , 70923 , 70950 , 70953 ) .

Figures

FIGURE 4. Dorsal and ventral pelage of Marmosops species: A, M. marina sp. nov. (UFMT 4078 ♁, Holotype); B, M. parvidens (MPEG 39976 ♁); C, M. pinheiroi (UFPA 40026 ♁); D, M. woodalli (MPEG 40388 ♁). Scale bar 50 mm.

FIGURE 5. Distribution (polygons) and collection localities (symbols) for Marmosops species of the “Parvidens” group in- cluded in this report: M. parvidens (yellow circles); M. pinheiroi (stricto sensu; green circles); M. woodalli (red circles); M. marina sp. nov. (blue circles); sympatry between M. parvidens and M. pinheiroi (s. s.; crosses); type localities (stars). The ranges of M. parvidens and M. pinheiroi were partially based on Voss et al. (2001; 2013) and Díaz-Nieto & Voss (2016). The range of M. woodalli was partially based on Nascimento et al. (2015).

FIGURE 6. Occlusal view of upper molars M2–M4 of Marmosops. A, M. marina sp. nov. (UFMT 4081 ♁ Paratype); B, M. woodalli (MPEG: AGPM 109 ♀). Abbreviations: mecl, metaconule; mec; metacone; pac, paracone; prc, protocone. Note the presence of a metaconule on the M3 in M. marina, and a labial projection of the posterior portion of the stylar shelf in relation to the anterior portion on M3 in M. woodalli. Scale bar 1.6 mm.

FIGURE 7. Occlusal view of upper molars M2–M4 of Marmosops species. A, M. marina sp. nov (UFMT 1427, Paratype ♁); B, M. parvidens (MPEG 40403 ♁); C, M. woodalli (MPEG 38667 ♁). Abbreviations: alci, anterolabial cingulum; prprcr, preprotocrista. Note the presence of a continuous shelf along the anterior margin of crown of the upper molars formed by the preprotocrista and the anterolabial cingulum in both M. marina and M. parvidens, which is narrow in the former (constriction indicated by arrows) and wide in the latter species. This condition is absent in M. woodalli. Scale bar 1.65 mm.

FIGURE 8. Lingual view of left lower molars m1–m3 of Marmosops species. A, M. woodalli (UFMT 3719 ♁); B, M. parvidens (MPEG 40404 ♁). The arrow indicates a small accessory cusp between the metaconid and the entoconid. Abbreviations: mecd, metaconid; encd, entoconid. Scale bar 1 mm.

FIGURE 9. Dorsal view of the braincase of Marmosops species. A, M. woodalli (UFMT 3966 ♁); B, M. pinheiroi (MPEG 40017 ♁). Abbreviations: ip, interparietal; par, parietal; sup, supraoccipital. Note the rounded and markedly convex shape of the supraoccipital in M. woodalli and the slightly convex shape of this bone in M. pinheiroi. Scale bar 5 mm.