Monodelphis touan

Pavan, Silvia Eliza, Rossi, Rogerio Vieira & Schneider, Horacio, 2012, Species diversity in the Monodelphis brevicaudata complex (Didelphimorphia: Didelphidae) inferred from molecular and morphological data, with the description of a new species, Zoological Journal of the Linnean Society 165 (1), pp. 190-223: 201-202

publication ID

http://doi.org/ 10.1111/j.1096-3642.2011.00791.x

DOI

http://doi.org/10.5281/zenodo.5479830

persistent identifier

http://treatment.plazi.org/id/3C758792-FFE0-FFAE-DC8A-EE67986AFC3A

treatment provided by

Marcus

scientific name

Monodelphis touan
status

 

MONODELPHIS TOUAN   ( SHAW, 1800)

Type information: Holotype lost, from ‘Cayenne’, French Guiana. Neotype FMNH 21720, designated by Voss et al. (2001), an adult male from Cayenne, 04 ° 56′N, 52 ° 20′W ( Gardner, 2008) preserved as skin and skull. Collected by S. Klages on 26.ii.1917.

Synonyms: Viverra Touan Shaw, 1800   ; Mustela touan Bechstein, 1800   ; Mustela touan Daudin   in Lacépède, 1802; Didelphis tricolor Geoffroy, 1803   .

Morphological diagnosis: Same as for the M. brevicaudata   complex with the following additions: HBL averages 137 mm in adult females and 159 mm in adult males (Supporting Information Table S2). Dorsal pelage with grizzled, grey coloured stripe at mid-dorsum, contrasting with reddish sides ( Fig. 4 View Figure 4 ); head pelage reddish laterally, with mid-dorsal stripe narrow, sometimes ill-defined, confined by a band of red hairs above each eye; underparts greyish cream, sharply differentiated from the reddish sides ( Fig. 4 View Figure 4 ); throat and chin distinctly reddish; tail dorsally covered with body fur to about one third of the caudal length; ventrally, body fur coverage is limited to the tail’s connection with the body. CBL averages 35.5 mm in adult females and 39.8 mm in adult males; interorbital region relatively narrow ( Fig. 5 View Figure 5 ); zygomatic arches slightly convergent anteriorly; maxillopalatine foramina relatively short ( Fig. 5 View Figure 5 ); UMS averages 7.8 mm in adult females and 8.0 mm in adult males (Supporting Information Table S2).

Geographical distribution: North-eastern South America, from French Guiana and the Brazilian state of Amapá southward to the Brazilian state of Pará south of the Amazon river and east of the Xingu river, including Marajó Island ( Fig. 6 View Figure 6 ). Specimens of M. touan   from south of the Amazon river were found in sympatry with specimens of M. glirina   in the municipality of Marabá, in south-eastern Pará. Both species were caught in the same line of pitfall traps at Serra dos Carajás (A. C. M. Oliveira, UFPA – Universidade Federal do Pará, Belém, Brazil, pers. comm.), indicating syntopy for them.

Geographical variation: Specimens from localities south of the Amazon river are effectively distinguished from specimens from north of the Amazon river by exhibiting broader mid-dorsal stripe on head, coverage of the tail by body fur extending only about one fifth (in contrast to one third or one half) of caudal length, darker colour of tail (the portion not covered by body pelage), ears, and feet. Cranially, when comparing individuals from the same sex and age class, specimens from south exhibit larger molars, larger bulla, and slightly broader braincase and nasals.

Amongst specimens from the north of the Amazon river, the extension of body fur on the dorsal surface of the tail corresponds to about one third of caudal length in specimens from Amapá, and to about one half of caudal length in specimens from French Guiana. Specimens from Amapá also have skulls slightly longer when compared to French Guianan specimens, which show proportionally broader skulls.

Remarks: Based on Buffon’s (1789) description of Le Touan, with type locality in Cayenne, French Guiana, Shaw (1800) described Viverra touan   . Shaw noted a blackish dorsal fur, ferrugineous sides and white lower parts, being the first reference to a tricoloured specimen of the M. brevicaudata   group. Mustela touan Bechstein, 1800   and Mustela touan Daudin   in Lacépède, 1802 were also based on Buffon’s specimen, and are objective synonymies of Viverra touan   . Geoffroy (1803) described Didelphis tricolor   based also on a tricoloured specimen from Cayenne ( MNHN 1990.421). Until now, D. tricolor   has been regarded as a synonym of M. brevicaudata   (e.g. Thomas, 1888; Cabrera, 1919; Gardner, 2005; Pine & Handley, 2008). Our new taxonomic arrangement, however, implies that D. tricolor   should be considered as a synonym of M. touan   .

The association of the name M. touan   to the specimens from the eastern clade of our molecular analyses is explained by the morphological similarity of the neotype of V. touan Shaw, 1800   ( FMNH 21720) with those specimens. Our genetic samples of this clade include specimens from Cayenne, the type locality of the nominal taxa. The resurrection of M. touan   to include the eastern clade is supported by the monophyly and genetic distinctiveness of this group, allied to a morphological differentiation from the species M. brevicaudata   (sensu stricto).

Amongst the haplotypes of the eastern clade, the ones from the Brazilian state of Pará (localities south of the Amazon river) were regarded as Monodelphis species   ‘D’ by Pine & Handley (2008). These specimens are morphologically distinct from specimens from the north of the Amazon river (see the Geographical variation section above), and form a strongly supported, truly monophyletic lineage that is embedded amongst haplotypes from French Guiana and the state of Amapá, Brazil (north of the Amazon river) in most analyses, rendering a paraphyletic group of northern specimens in most analyses ( Fig. 2 View Figure 2 ). However, the monophyly of the northern specimens was also recovered in some analyses. Faced with the absence of resolution in our molecular analyses, we took a conservative decision, considering M. species ‘D’ under M. touan   as a geographical variant of the latter, instead of describing it as a new species.

FMNH

Field Museum of Natural History

MNHN

Museum National d'Histoire Naturelle