The Mammals Of Paracou, French Guiana: A Neotropical Lowland Rainforest Fauna Part 2. Nonvolant Species Author VOSS, ROBERT S. Author LUNDE, DARRIN P. Author SIMMONS, NANCY B. text Bulletin of the American Museum of Natural History 2001 2001-06-18 2001 263 1 236 http://www.bioone.org/doi/abs/10.1206/0003-0090%282001%29263%3C0003%3ATMOPFG%3E2.0.CO%3B2 journal article 10.1206/0003-0090(2001)263<0003:TMOPFG>2.0.CO;2 0003-0090 5378847 Metachirus nudicaudatus (E. Geoffroy) VOUCHER MATERIAL: AMNH 266435, 266439, 266440, 266449, 266450, 266452, 266453, 266455, 267009, 267010, 267362, 267365; MNHN 1995.905–1995.910. Total = 18 (not including suckling young). IDENTIFICATION: Our voucher material is al­ Fig. 26. Details of palatal and upper canine morphology of Marmosops parvidens ( A, AMNH 267359) and M. juninensis ( B, AMNH 230016). Among other differences between these distinctive species (see text), the posterior palate is more extensively fenestrated in M. juninensis than in M. parvidens , and M. juninensis lacks the distinct accessory cusps that are always present on the unworn upper canines of M. parvidens . most topotypical of this species, which was originally described from a specimen collected at Cayenne (Julien­Laferrière, 1994). The Paracou series agrees closely in qualitative external characters with the description given by Husson (1978), and most craniodental measurements of the type fall within the range of metric variation in our voucher collection (table 11). Although Metachirus has long been thought to contain but a single valid species (Tate, 1939; Cabrera, 1958; Gardner, 1993), this historical consensus is challenged by recently analyzed mtDNA sequences that suggest deep evolutionary divergence among samples from different Amazonian subregions (Patton et al., 2000). In the absence of any revisionary analysis of morphological specimens, however, it is unclear how mitochondrial haplotypes might correspond with named taxa. Inevitably, nominotypical material from French Guiana will play a pivotal role in any future attempt to resolve this unsatisfactory state of affairs. REMARKS: We agree with Julien­Laferrière (1994) that the name Didelphis nudicaudata is available from Geoffroy’s (1803) catalog for the reasons explained by Hershkovitz (1955) and Holthuis (1963). OTHER SPECIMENS EXAMINED: French Guiana —Cayenne (MNHN 1990.420 [ holotype ]). FIELD OBSERVATIONS: We recorded 22 observations of Metachirus nudicaudatus at Paracou, of which 18 are based on collected specimens and 4 are unvouchered sightings. Eighteen records (82%) are of animals shot or sighted on the ground, but one specimen (4%) was trapped on the ground in a Tomahawk live trap, and three specimens (14%, all juveniles) were taken in Victor snap­traps tied to lianas 0.5–1.3 m above the ground. All of our records are from animals shot, sighted, or trapped at night. Fourteen indi­ viduals (64%) were shot, sighted, or trapped in well­drained primary forest, but one (4%) was encountered in swampy primary forest, four (18%) in primary forest of unspecified character, and three (14%) in secondary vegetation. With the exception of females with nursing young, all shot, sighted, or trapped animals were solitary. Fig. 27. Known collection localities for Marmosops parvidens and M. pinheiroi based on specimens examined. 1, BRAZIL, Amapa´, Serra do Navio; 2, BRAZIL, Amazonas, Boca Rio Piratucu; 3, BRAZIL, Amazonas, 80 km N Manaus; 4, BRAZIL, Para´, Belém and Utinga; 5, BRAZIL, Para´, Ilha do Taiuna; 6, FRENCH GUIANA, Arataye; 7, FRENCH GUIANA, Paracou; 8, GUYANA, Demerara ­Mahaica, Hyde Park; 9, GUYANA, Potaro ­Siparuni, Iwokrama Reserve; 10, Upper Takutu ­Upper Essequibo, Karanambo; 11, VENEZUELA, Bolívar, Auyan­tepui; 12, VENEZUELA, Bolívar, Churi­tepui; 13, VENEZUELA, Bolívar, 85 km SE El Dorado. One collection locality for Marmosops pinheiroi (Belém/ Utinga, in the Brazilian state of Para´) lies just outside the right margin of this map. One female shot on 7 July 1991 had seven nursing young measuring 19 mm crownrump, and another shot on 17 August 1991 had eight nursing young measuring 29 mm crown­rump.