Taxonomic review of the slender mouse opossums of the “ Parvidens ” group from Brazil (Didelphimorphia: Didelphidae: Marmosops), with description of a new species Author Ferreira, Claudilívia Laboratório de Mastozoologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Av. Fernando Corrêa da Costa, 2367, Cuiabá, Mato Grosso 78060 - 900, Brazil & claudiliviafs @ gmail. com; https: // orcid. org / 0000 - 0003 - 3306 - 023 X & Programa de Pós-Graduação em Zoologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso, Brazil Author Oliveira, Ana Cristina Mendes De Laboratório de Ecologia e Zoologia de Vertebrados - Mastozoologia, ICB, Universidade Federal do Pará, Belém, Pará, Brazil cris. mastozoologia @ gmail. com; https: // orcid. org / 0000 - 0002 - 7863 - 9678 Author Lima-Silva, Luan Gabriel Laboratório de Mastozoologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Av. Fernando Corrêa da Costa, 2367, Cuiabá, Mato Grosso 78060 - 900, Brazil & lglsilva 16 @ gmail. com; https: // orcid. org / 0000 - 0002 - 3771 - 3560 Author Rossi, Rogério Vieira Laboratório de Mastozoologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Av. Fernando Corrêa da Costa, 2367, Cuiabá, Mato Grosso 78060 - 900, Brazil & rogerrossi @ gmail. com; https: // orcid. org / 0000 - 0003 - 2353 - 5000 text Zootaxa 2020 2020-12-02 4890 2 201 233 journal article 9380 10.11646/zootaxa.4890.2.3 dafd0c73-e9bf-43f0-9e11-95a6e69e32d2 1175-5326 4301829 54F20D85-7110-465D-914C-26FA34847A02 Marmosops ( Sciophanes ) woodalli ( Pine, 1981 ) Marmosa parvidens woodalli Pine, 1981: 62 . Marmosops pinheiroi : Voss et al . 2001: 49 (part); name combination. Holotype . USNM 393532 consists of skin and skull of an adult female collected on 14 June 1968 , Ronald H. Pine field no. 5054. Type locality. Nova Área Experimental, Utinga ( 1º27’S , 48º29W ; the wooded area surrounding the Belém waterworks), Pará, Brazil . Geographic distribution . It occurs on the right bank of the Xingu River , including the Marajó Island in the state of Pará, extending east to the state of Maranhão and south to the state of Tocantins , Brazil ( Figure 5 ) . Amended diagnosis. Dorsal coloration usually dark brown; tail length (LT: 92–158 mm ) relatively longer in relation to head and body length ( HBL : 70–120 mm ); ventral coloration white, with narrow lateral bands of graybased and white-tipped hairs arranged irregularly, which may or may not join on the throat and/or mid-chest and usually do not extend to the inner surface of the hind limbs; supraoccipital rounded in dorsal view (due to its con-vex shape); M3 with posterior portion of the stylar shelf more labially designed than the anterior portion (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 undeveloped; and talonid of the m4 usually tricuspid. Morphological description. Marmosops woodalli has head body size ranging from 70 to 120 mm and a longer tail (LT: 92–158 mm ; Tables 4 and 5 ); dorsal hairs 6–9 mm long; dorsal fur smooth, usually dark brown, being slightly lighter laterally; rostrum lighter than the top of the head, presenting grayish brown coloration, with some gray hairs; mask around the eyes blackish, with conspicuous posterior portion (except in UFMT 3975; UFPA-M 371, 384; MPEG 40177, 40178, 40181); cheeks with both white hairs and gray-based and white-tipped hairs; hands covered dorsally with whitish hairs; tail bicolor, brown dark (54%, n=79) or grayish-brown (46%, n=79); tail scales arranged in a spiral, each with three hairs inserted in the posterior margin; the central hair of the triplet clearly thick-er and more pigmented than the lateral ones; white venter, with narrow lateral bands of gray-based and white-tipped hairs arranged irregularly, which may or may not join on the throat and/or mid-chest and usually do not extend to the inner surface of the hind limbs (83.3%, n=88); hands with lateral spoon shaped carpal tubercle in adult males. Craniodentally, M. woodalli exhibits zygomatic process of the squamosal widely overlapped dorsally by the jugal; lacrimal foramina may be exposed or not exposed in lateral view (less common); supraorbital margin slightly rounded with non-prominent crest; long nasal bones (extending slightly behind the lacrimal) and generally wider posteriorly than anteriorly (71.4%, n=49); supraoccipital with rounded shape in dorsal view, due to its markedly convex shape; paraoccipital process long and narrow; tympanic process of the alisphenoid with ventral surface oval or globose; cochlear fenestrae exposed in ventral view (except in UFMT 1251, 1258; MZUSP : AS 30; MPEG 40183, MPEG : SBER 02, 11, 15); palatine fenestrae absent, but diminutive perforations are present in the palatine and/or maxillary bones in 45% of the specimens (n=70); C1 with anterior and posterior accessory cusps in males and females; M3 with posterior portion of the stylar shelf more labially projected than the anterior portion (in oc-clusal view); upper molars with preprotocrista and anterolabial cingulum separated, not forming a continuous shelf along the anterior margin of the tooth crown (except in UFPA-M 376; MPEG 40167, 40296, MPEG : CAX 098, 293, MAR 428); metaconule of upper molars slightly developed; lower canine (c1) premolariform, (with posterior accessory cusps) subequal in height with first lower premolar (p1) (except in UFMT 3719, 3718, 3966; MZUSP : AS 30; MPEG : MAR 222, 428, 485, 1294; in which c1 is slightly higher than p1); m2 paraconid usually higher than the entoconid of m1 (70%, n=70); and talonid of the m4 usually tricuspid (83%, n=70; except in UFPA-M 382, 429; MNRJ 75117, 75121, 75122, 75139; UFMT 765; MPEG 40378, 40380; MPEG : CAX 293, MAR 589, PEB 12). Geographic variation . Specimens of M . woodalli from the Cerrado biome (states of Maranhão and Tocantins ) exhibit lighter dorsal fur (reddish brown) than specimens from forested areas (dark brown). In addition, specimens from the right margin of the Tocantins River have larger body size ( HBL = 110.1 ±17.8 mm) than those from the left bank ( HBL = 102.8±17.6 mm), and Student´s t tests showed that females from the right margin exhibit larger CBL , PL , MTR , UMS , WM4, BRC , BRJ , LMS , Lm4, and smaller TBO , while males exhibit larger PL , MTR , UMS , PPB , WET , POC , LMS , and Lm4 ( Table S5 ). Comparisons with M . parvidens and other species of the “Parvidens” group ( Table 6 ). Comparisons between M. woodalli , M. marina and M. pinheiroi ( s.s. ) are provided above. Marmosops woodalli can be discriminated from M . parvidens by exhibiting dark brown dorsal coloration (versus slightly reddish brown); white (versus cream) ventral fur; lateral bands of gray-based hairs on the venter narrow and irregularly arranged, joining or not on the throat and/or mid-chest (versus usually absent, never joining together; Figure 4A and D ); rounded supraoc-cipital ( Figure 9A ), due to its markedly convex shape in dorsal view (versus slightly convex); tympanic process of the alisphenoid with ventral surface oval or globose (versus usually globose); posterior portion of the stylar shelf of the M3 more labially projected than the anterior portion (versus anterior and posterior portions equally projected labially); preprotocrista and anterolabial cingulum separated, not forming a continuous shelf on the anterior margin of crown of the upper molars (versus united, forming a continuous shelf on the anterior margin of crown the upper molars; Figures 7 B-C); and small accessory cusp between the metaconid and the entoconid of lower molars absent ( Figure 8 A-B). Habitats and sympatry. Marmosops woodalli is geographically distributed in the Babaçu Forests of Maranhão , Xingu/Tocantins-Araguaia Humid Forests, Tocantins-Araguaia/ Maranhão Humid Forests, Marajó Várzea Forests, and Tropical Dry Forests ecoregions ( sensu Olson et al. 2001 ). One specimen collected in Itapecuru Mirim, state of Maranhão , Brazil ( MPEG 45528), was associated to disturbed forest (secondary vegetation) according to its tag information. There is no record of sympatry between M. woodalli and other Marmosops species. Natural history data . Mammary formula 4–1–4 = 9. Pregnant females were recorded in October, in Primavera, state of Pará, Brazil . In this locality, M. Aragona captured four specimens in live-traps (Sherman), three of which set on the ground (three individuals – UFMT 3975, 3978, and UFMT : TC 189) and one in the understory ( UFMT 3966); two other individuals were captured in pitfall-traps. Specimens examined (n=165). BRAZIL - Maranhão : Bacabeira , 3°0’S , 44°19’W , 1 F, 1 M ( UFPA-M 966 , 980 ) ; Ferrovia Norte Sul , 5°35’S , 47°26’W , 1 M ( MZUSP : AS 30 ) ; Itapecuru Mirim , 3°24’S , 44°21’W , 1 M ( MPEG 45528 ) ; Miranda do Norte , 3°31’38”S , 44°30’46”W , 1 M ( UFPA : EFC 08-03 ) . Pará : Barcarena , 1°30’S , 48°37’W , 12 M, 2 F ( UFPA-M 345 , 368 , 369 , 371-374 , 376 , 377 , 379 , 380 , 381 , 382 , 384 ) ; Belém , Agropalma , 1°19’S , 48°28’W , 4 F, 2 M ( MPEG : AGPM 06 , 11 , 33 , 38 , 109 , 152 ) ; Canaã dos Carajás , 6°32’S , 49°51’W , 1 M ( MZUSP : CA 20 ) ; Caxiuanã , 1°55’S , 51°22’W , 9 M, 3 F, 4? ( MPEG 40167 , 40169 , 40171 , 40172 , 40298 ; MPEG : MAR 222 , 428 , 589 , 683 , 1294 ; CAX 098, 186, 209, 293, 360, 407) ; Estrada de Ferro Carajás , 6°16’S , 50°34’W , 7 M (UFPA-M 423, 426, 429, 458, 459, 487, 521) ; Chaves , Fazenda Tauari , Ilha de Marajó , 0°39’S , 50°11’W , 5 M, 2 F ( MPEG 40388 , 40389 , 40390 ou 40392 (double), 40391, 40393, 40394, 40395) ; Linha de Transmissão do Tucurui-Xingu (Jurupari), 3°42’0”S , 49°41’59”W , 2 M, 1 F ( MZUSP : LTBM 02 , 09 ; LTC 24 ) ; Marabá , 5 M, 3 F ( UFPA-M 257 , 347 , 355 , 356 , 358 , 382 , 1824 , 1907 ) ; Marabá , Flona Tapirapé , 5°49’0”S , 50°30’60”W , 3 F, 7 M, 7? ( MPEG 40174- 40179 , 40181 , 40183 ; MPEG : PSA 065 , 087 , 154 ; UFMT 1241, 1245, 1247, 1251, 1252, 1258) ; Melgaço , Estação Científica Ferreira Penna , 1°41’33”S , 50°28’43”W , 5 M, 4 F, 4? ( MPEG 40375-40378 , 40380 , 40381-40384 , 40385- 40387 ; MPEG : EPM 095 ) ; Parauapebas , 6°4’S , 49°54’W , 1 M ( MPEG 38941 ) ; Peixe-boi , 01º05’53”S 47º19’54”W , 2 F, 1 M ( MPEG : PEB 06 , 12 , 25 ) ; Primavera , 0°57’S , 47°6’W , 7 M, 6 F, 2? ( UFMT 765 , 3703 , 3704 , 3716 , 3718 , 3719 , 3964 , 3966 , 3975 , 3977-3979 , 3981 ; UFMT: TC 178 , 189 ) ; São Felix do Xingu , 7°1’S , 52°21’W , 5 M, 3 F ( MPEG 42460 , 42721 , 42723 , 42725 , 42726 , 42728 , 42730 , 42793 ) ; Santa Barbara , 1°12’26”S , 48°16’14”W , 6 M, 1 F ( MPEG : SBER 01 , 02 , 07 , 11 , 15 , 17 , 32 ) ; São Geraldo do Araguaia 6°23’S , 48°33’W , 2 M ( MNRJ 75242 , 75244 ) ; Senador José Porfírio , 3°51’S , 51°51’W , 6 M ( MPEG 41851 , 41862 , 42447 , 42458 , 42459 , 42460 ) ; Tucu-ruí, 3°42’S , 49°42’W , 1 F, 1 M ( MPEG 12296 , 12297 ) ; Nova Área Experimental, Utinga, Belém , 1º27’S , 48º29’W , 1 F ( USNM 393532 , photograph of the holotype ) ; Utinga , Parque Ambiental de Belém , 1°25’33”S , 48°26’39”W , 6 M, 9 F, 1? ( MPEG 8787 , 12701 , 12960 , 15257 , 38654 , 38657 , 38658 , 38666 , 38667 , 38669 , 38671 , 39695 , 39697 , 39698 , 39706 ; MPEG : PAB 017 ) ; Viseu , 1°10’58”S , 46°17’32”W , 1 M ( MPEG : VIS 45 ) . Tocantins : Goiatins , 7°47’53”S , 47°16’40”W , 2 M, 1 F ( MNRJ 75121 , 75122 , 75136 ) ; Ribeiro Gonçalves , 7°47’48”S , 47°16’47”W , 1 M, 2 F ( MNRJ 75117 , 75139 , 75140 ) . Others specimens examined: Marmosops parvidens ( n=34 ). BRASIL - Amazonas : Balbina , 1º53’S 59º28’W , 2 F ( MZUSP 22940 ; MPEG 22141 ) ; Urucará , 2º23’S , 57º38’W , 2 M ( MPEG 40065 , 40068 ) . Pará : Floresta Estadual Faro ( Flota Faro ), left bank of Rio Nhamundá , 1°16’44”S , 58°2’24”W , 2 F, 4 M, 1? ( MPEG 39959 , 39963 , 30075 , 39976 , 39982 , 39984 ; MPEG : CN 080 ) ; Óbidos , Flota Trombetas , 0°58’S , 55°31’W , 3 M, 4? ( MPEG 40401 , 40403 , 40404 ; MPEG : CN 182 , 186 , 207 , 210 ) ; Oriximiná , Porto Trombetas , 1º49’S 56º30’W , 6 M, 6 F ( MPEG 39802 , 39807 , 40070 , 40074 , 42404 , 42422 , 42364 , 42372 , 42405 , 42424 , 42437 , 42441 ) ; Terra Santa , 2°6’S , 56°29’W , 2 M, 1 F ( MPEG 40081-40083 ) . GUYNA : “Hyde Park, 30 miles up the Demarara River,” Demerara-Mahaica ( FMNH 18545 , photograph of the holotype ) .