Marmosa simonsi Thomas, 1899

Part, Tate’, The Species In, Mexicana’, And, Closely, Mitis’ Sections And Other & Forms, Related, 2010, A Revision Of The Didelphid Marsupial Genus Marmosa, Bulletin of the American Museum of Natural History 2010 (334), pp. 1-83 : 58-60

Marmosa simonsi Thomas, 1899 Figure 27

? Didelphys murina: Thomas, 1882a: 111 .

Marmosa Simonsi Thomas, 1899: 287 . Type locality ‘‘Puná, Puná Island, and Guayaquil.’’

[ Didelphis (Caluromys) ] simonsi: Matschie, 1916: 269 . Name combination.

[ Marmosa (Marmosa) ] simonsi: Cabrera, 1919: 39 .

Marmosa simonsi: Tate, 1933: 121 .

Marmosa mitis simonsi: Hershkovitz, 1951: 552 . Name combination.

Marmosa [( Marmosa )] robinsoni simonsi: Cabrera, 1958: 25 . Name combination.

Marmosa robinsoni: Honacki et al., 1982: 23 . Part, not Marmosa robinsoni Bangs, 1898 .

Marmosa robinsoni: O’Connell, 1983: 1 . Part, not Marmosa robinsoni Bangs, 1898 .

Marmosa robinsoni: Gardner, 1993: 18 . Part, not Marmosa robinsoni Bangs, 1898 .

Marmosa robinsoni: Emmons, 1997: 26 . Part, not Marmosa robinsoni Bangs, 1898 .

Marmosa robinsoni: Eisenberg and Redford, 1999: 62 . Part, not Marmosa robinsoni Bangs, 1898 .

Marmosa robinsoni: Nowak, 1999: 21 . Part, not Marmosa robinsoni Bangs, 1898 .

Marmosa robinsoni: Brown, 2004: 65 . Part, not Marmosa robinsoni Bangs, 1898 .

[ Marmosa robinsoni ] simonsi: Gardner, 2005: 9 . Part.

M [armosa]. r [obinsoni]. simonsi: Creighton and Gardner, 2008: 50 . Part.

TYPE MATERIAL: The holotype (by original designation, BMNH 99.8.1.20) is a young adult (age class 6) male, preserved as a skin and skull in good condition.

TYPE LOCALITY: The holotype was collected by P.O. Simons on 3 November 1898 at Puná (gazetteer entry 197; appendix), a village on the island of Puná in the Ecuadorean province of Guayas. The island of Puná (855 km 2) is covered with Ecuadorean dry forests and Gulf of Guayaquil / Tumbes mangroves ( Olson et al., 2001) .

MORPHOLOGICAL DIAGNOSIS: Midrostral fur pale, contrasting sharply with darker fur of crown; dark median rostral stripe absent; dark facial mask often extending posteriorly to contact base of ear; dorsal body pelage distinctly grayish; dorsal cover hairs 8–10 mm in length, guard hairs 10–11 mm in length; most of ventral surface (including chest, abdomen, and the inner parts of the fore- and hind limbs) covered by gray-based fur with yellowish hair tips; self-colored ventral pelage (present only on chin or as a narrow median stripe extending from chin to upper chest) yellowish buff. Exposed caudal skin brownish basally but abruptly whitish on distal M to K of tail; caudal scales without any clear pattern of arrangement (both spiral and annular patterns coexisting); about 14 scales/cm on dorsal surface at caudal midlength; caudal-scale hairs usually whitish, detectable without magnification; central hair of each caudal-scale triplet slightly longer than two scales. Gular gland present. Mammary formula unknown. Lateral and medial carpal tubercles present in mature adult males; medial carpal tubercle short and comma-shaped, not reaching base of pollex, and not segmented into distinguishable proximal and distal parts.

Rostral process of premaxillae short, usually a little less than half of I1 height. Orbitosphenoid-alisphenoid suture about twice as long as sphenorbital fissure height in lateral view. Supraorbital ridges moderately to strongly divergent posteriorly, tending to become thick and produced laterally over orbital fossae in adults; postorbital processes consistently present and distinct; temporal ridges weakly developed and moderately to strongly convergent posteriorly. Palatine fenestrae present (usually as a single welldeveloped rounded or irregular hole on each side); posterolateral palatal foramina large, typically about as long or longer than M3 (measured across paracone-metacone). Tympanic wing of alisphenoid globular; medial process of ectotympanic usually well developed. I1 hypsodont; crown of I2 sharply defined in relation to root; C1 without accessory cusps; preparacrista connected to stylar cusp B on M1–M2; stylar cusps D and E usually separated by a distinct notch.

COMPARISONS: Comparisons of Marmosa simonsi with M. mexicana , M. zeledoni , M. isthmica , M. robinsoni , and M. xerophila are provided in the preceding accounts. Marmosa simonsi and M. rubra are compared below.

Marmosa simonsi is smaller than M. rubra in most measured external and craniodental dimensions (tables 4–7), with the notable exception of its relatively and absolutely larger ears, longer upper canines, and larger bullar dimensions. In qualitative external traits, M. simonsi is easily distinguished from M. rubra by its long facial mask (often extending posteriorly to the ear), distinctly grayish dorsal pelage, almost entirely graybased ventral pelage, particolored (whitetipped) tail, annularly and spirally arranged caudal scales, and long caudal-scale hairs. By contrast, M. rubra has a short facial mask, reddish dorsal fur, more extensively selfcolored ventral fur, an all-dark tail, spirally arranged caudal scales, and much shorter caudal-scale hairs. In addition, whereas M. simonsi lacks a dark midrostral stripe and possesses a gular gland, M. rubra possesses a dark midrostral stripe and lacks a gular gland.

In qualitative craniodental traits, these species are most readily distinguished by the rostral process of the premaxillae (shorter in simonsi than in rubra ), postorbital processes (consistently well developed in simonsi , indistinct or absent in rubra ), palatine fenestrae (present in simonsi , absent in rubra ), tympanic wing of the alisphenoid (relatively more inflated and globular in simonsi than in rubra ), medial process of the ectotympanic (better developed in simonsi than in rubra ), and by the attachment of the preparacrista (to stylar cusp B in simonsi , to stylar cusp A in rubra ).

GEOGRAPHIC DISTRIBUTION AND SYM- PATRY: The known distribution of Marmosa simonsi extends along the Pacific littoral zone and adjacent hilly country of western Ecuador (between sea level and 1600 m elevation) from Jama (locality 208; fig. 28) in Manabí province southward to Naranjito (locality 228) in the Peruvian department of Piura. Although a wide range of terrestrial habitats occur in this region (e.g., mangroves, dry forests, lowland moist forests, and montane moist forests), most collection localities appear to be from mangroves or dry (deciduous) forests.

The geographic range of Marmosa simonsi partially overlaps that of M. isthmica . Geographic details about the extent of this overlap and the localities where these species occur sympatrically are described in the preceding account for M. isthmica .

GEOGRAPHIC VARIATION: We did not observe any noteworthy variation among geographic samples of this species.

TAXONOMIC HISTORY: Marmosa simonsi was briefly assigned to the genus Caluromys by Matschie (1916), an obvious mistake that was soon rectified by Cabrera (1919). Tate (1933) recognized simonsi as a valid species that he associated with chapmani and mitis (both treated as synonyms of M. robinsoni in this report) and with ruatanica (5 M. mexicana) in his Mitis Section of Marmosa . Hershkovitz (1951), however, considered simonsi to be a subspecies of mitis , alleging that it grades into the darker mimetra (a taxon that he also regarded as a subspecies of M. mitis ) in northern Ecuador. Hershkovitz’s broad concept of M. mitis (5 M. robinsoni) has been accepted by all subsequent authors (e.g., Cabrera, 1958; Honacki et al., 1982; Gardner, 2005; Creighton and Gardner, 2008).

SPECIMENS EXAMINED (N 5 117): ECUA- DOR— El Oro, Río Puyango (MSB 87083– 87087), Santa Rosa (AMNH 61195; USNM 513423). Guayas, Cerro Bajo Verde (AMNH 63416), Chongoncito (AMNH 63012, 63401– 63414), Guayaquil (BMNH 99.8.1.50– 99.8.1.57, 99.9.9.140; USNM 121155, 121156, 121158), Isla Puná (AMNH 140232, 140233), Puná (BMNH 99.8.1.20 [holotype of Marmosa simonsi Thomas, 1899 ], 99.8.1.21–99.8.1.26), San Ramón (AMNH 66851–66868, 66870– 66881, 66883–66885; 5 Hacienda San Ramon: FMNH 41402–41404). Loja, Hacienda Casanga (5 Casanga: AMNH 47181; 5 Río Casanga: AMNH 93797), Malacatos (FMNH 53356–53366), Zozoranga (USNM 461643). Los Ríos, Vinces (5 Hacienda Pijigual: AMNH 63343–63346, 63350). Manabí, Jama (FMNH 53353), Los Pozos (AMNH 67282, 67283), Río Briceño (AMNH 64525, 64526, 64530–64533, 64536). PERU — Piura, Huásimo (FMNH 81448–81451), Naranjito (USNM 551640). Tumbes, Matapalo (FMNH 81452–81455), Papayal (USNM 302980).