Chacoan Pygmy Opossum 1690415 224151166 2008-07-07T15:32:54Z Ptcamn 308717 cat {{Taxobox | name = Chacoan Pygmy Opossum | status = NE | status_system = iucn2.3 | regnum = [[Animal]]ia | phylum = [[Chordate|Chordata]] | classis = [[Mammal]]ia | ordo = [[Didelphimorphia]] | familia = [[Didelphidae]] | subfamilia = [[Didelphinae]] | genus = '''''Chacodelphys''''' | genus_authority = [[Voss]] et al., 2004 | species = '''''C. formosa''''' | binomial = ''Chacodelphys formosa'' | binomial_authority = ([[Shamel]], 1930) }} The '''Chacoan Pygmy Opossum''' (''Chacodelphys formosa'') is a recently described genus and species of [[didelphimorph]] [[marsupial]]. The only species in '''''Chacodelphys''''', ''C. formosa'', is known from only one specimen collected in 1920 in the [[Chaco]] of [[Formosa Province]], [[Argentina]]. ==Description== The Chacoan Pygmy Opossum is the smallest known species of [[Didelphidae|didelphid]]. It has a head-body length of 68 mm, a tail of 55 mm and a hind foot of 11. It differs from the other "[[Marmosa|marmosine]]" genera (''[[Marmosa]]'', ''[[Micoureus]]'', ''[[Monodelphis]]'', ''[[Thylamys]]'', ''[[Tlacuatzin]]'', ''[[Gracilinanus]]'', ''[[Marmosops]]'', ''[[Lestodelphys]]'') in having a long third manual digit, no distinctly tricolored [[pelage]], a long fourth pedal digit, and a tail shorter than head-body. No other marmosine genera has this combination of characters. ==Taxonomic history== ''C. formosa'' was originally described as ''Marmosa muscula'' Shamel (1930a); however, this name is preoccupied, so Shamel (1930b) renamed it ''M. formosa''. Afterwards, [[George Henry Hamilton Tate|George Tate]] (1933) considered it a valid member of his "''Elegans'' group" (=''Thylamys'') of ''Marmosa'', whereafter it has been variously synonymized or treated as a distinct species of ''Marmosa'' or ''Thylamys'' until 1989, when Gardner & Creighton (1989) listed it as a synonym of ''Gracilinanus agilis'', and then later separated from this species as ''G. formosus''. Finally, Voss et al. (2004) erected the new genus ''Chacodelphys'' for the species. ==References== *Gardner, A.L. & Creighton, G.K. 1989. A new generic name for Tate's microtarsus group of South American mouse opossums (Marsupialia: Didelphidae). Proceedings of the Biological Society of Washington 102:3–7. *Shamel, H.H. 1930a. A new murine opossum from Argentina. Journal of the Washington Academy of Sciences 20:83-84. *Shamel, H.H. 1930b. A new name for Marmosa muscula Shamel. Journal of Mammalogy 11:311. *Tate, G.H.H. 1933. A systematic revision of the marsupial genus Marmosa with a discussion of the adaptive radiation of the murine opossums (Marmosa). Bulletin of the American Museum of Natural History 66:1–250. * {{MSW3 Gardner|pages 7}} *Voss, R.S., Gardner, A.L. & Jansa, S.A. 2004. On the relationships of "Marmosa" formosa Shamel 1930 (Marsupialia, Didelphidae), a phylogenetic puzzle from the chaco of northern Argentina. American Museum Novitates 3442:1-18, 2 June 2004. {{Didelphimorphia|D.}} [[Category:Opossums]] [[Category:Mammals of Argentina]] [[Category:Animals described in 1930]] [[de:Chaco-Beutelratte]] [[es:Chacodelphys]] [[nl:Chacodelphys]]