Creighton's Slender Opossum

description

DESCRIPTION: Marmosops creightoni is a medium­sized species (see table 3 for measurements and weights), much larger than members of the M. parvidens group (ca. 20 – 35 g adult weight; Voss et al., 2001: tables 9, 10) but substantially smaller than some lowland forms like M. incanus (adults of which can weigh as much as 120 g; Lorini et al., 1994). The body pelage is almost entirely dark, the colors probably somewhat faded in our fluid­preserved specimens, but still a rich chocolate­brown dorsally on the holotype (collected in 1999) and only a little more bleached on the 24 ­ year­old paratypes. The ventral body coloration is slightly paler brown, but there is no sharp distinction between dorsal and ventral color zones, and all of the thoracic and abdominal fur is graybased. The chin is self­white in all of the material at hand, and white fur extends posteriorly onto the throat of one paratype (UMMZ 155601). The blackish mask that surrounds the eye on each side of the head does not extend anteriorly to include the mystacial pads (which are covered with short brownish fur) or posteriorly to the base of the ears. The mystacial and genal vibrissae are blackish, whereas the submental an

An Introduction to Marmosops (Marsupialia: Didelphidae), with the Description of a New Species from Bolivia and Notes on the Taxonomy and Distribution of Other Bolivian Forms

distribution

DISTRIBUTION: Known only from wet montane forest in the valley of the Río Zongo, Departamento La Paz, Bolivia, between 2000 and 3000 m above sea level (fig. 10).

An Introduction to Marmosops (Marsupialia: Didelphidae), with the Description of a New Species from Bolivia and Notes on the Taxonomy and Distribution of Other Bolivian Forms

etymology

ETYMOLOGY: For G. Ken Creighton, collector of the first known specimens of this species and author of the first modern analysis of didelphid phylogeny based on morphological characters (Creighton, 1984).

An Introduction to Marmosops (Marsupialia: Didelphidae), with the Description of a New Species from Bolivia and Notes on the Taxonomy and Distribution of Other Bolivian Forms

materials_examined

HOLOTYPE: An adult male specimen in the Colección Boliviana de Fauna (CBF 6552) collected by Eric Yensen (original number 1705) on 5 August 1999 near the Saynani hydroelectric generating station (ca. 16 ° 07 ' S, 68 ° 05 ' W; 2500 m above sea level) in the valley of the Río Zongo, Departamento La Paz, Bolivia. The holotype is a whole (unskinned) fluid­preserved specimen with an extracted skull and mandibles. PARATYPES: Five additional specimens (listed as unidentified ‘‘ Marmosa ’’ by Anderson, 1997: 151) were collected by G. K. Creighton in 1979 at two adjacent localities in the valley of the Río Zongo, Departmento La Paz, Bolivia. Two of these (UMMZ 155999, 156000) were taken above the type locality near the Cuticucho hydroelectric generating station (ca. 16 ° 08 ' S, 68 ° 07 ' W) at a recorded elevation of 2967 m, whereas three others (UMMZ 156001 – 156003) were trapped below the type locality at a recorded elevation of 2000 m. All five paratypes are adult animals preserved as whole (unskinned) fluids with extracted skulls and mandibles.

An Introduction to Marmosops (Marsupialia: Didelphidae), with the Description of a New Species from Bolivia and Notes on the Taxonomy and Distribution of Other Bolivian Forms