phylogenetic relationships and classification of didelphid marsupials ...

2009 VOSS AND JANSA: DIDELPHID MARSUPIALS 169
Taxon 2n a
karyotype, whereas the smaller metacentric can be
homologized with acr6 + acr9 of the 2n 5 22
karyotype and with met4 of the 2n 5 14 karyotype
(op. cit.). As explained by Voss and Jansa (2003:
42–44; see also Dobigny et al., 2004), these
transformational homologies are appropriately
coded as separate characters, one for each set of
Robertsonian equivalents—for example, {acr2 +
TABLE 18
Exemplar Didelphid Karyotypes
References
Caluromys lanatus 14 Reig et al. (1977), Palma and Yates (1996), Patton et al. (2000)
Caluromys philander 14 Reig et al. (1977)
Chironectes minimus 22 Reig et al. (1977), Palma and Yates (1996)
Cryptonanus chacoensis b
14 Wainberg et al. (1979)
Didelphis albiventris 22 Reig et al. (1977), Palma and Yates (1996)
Didelphis marsupialis 22 Gardner (1973), Reig et al. (1977), Palma and Yates (1996), Patton et al. (2000)
Didelphis virginiana 22 Gardner (1973), Reig et al. (1977)
Glironia venusta 18 Fantin and da Silva (in press)
Gracilinanus agilis 14 Carvalho et al. (2002)
Gracilinanus microtarsus 14 Wainberg et al. (1979), Carvalho et al. (2002)
Lestodelphys halli 14 Birney et al. (1996)
Lutreolina crassicaudata 22 Reig et al. (1977), Palma and Yates (1996)
Marmosa (Micoureus) demerarae c
14 Reig et al. (1977), Palma and Yates (1996), Patton et al (2000)
Marmosa (Marmosa) mexicana 14 Biggers et al. (1965)
Marmosa (Marmosa) murina 14 Reig et al. (1977)
Marmosa (Micoureus) paraguayana d 14 Carvalho et al. (2002)
Marmosa (Micoureus) regina 14 Patton et al. (2000)
Marmosa (Marmosa) robinsoni 14 Reig et al. (1977)
Marmosops impavidus 14 Patton et al. (2000)
Marmosops incanus 14 Carvalho et al. (2002)
Marmosops noctivagus 14 Palma and Yates (1996), Patton et al. (2000)
Metachirus nudicaudatus 14 Reig et al. (1977), Palma and Yates (1996), Patton et al. (2000)
Monodelphis brevicaudata e
18 Carvalho et al. (2002)
Monodelphis emiliae 18 Patton et al. (2000)
Philander frenatus 22 Carvalho et al. (2002)
Philander mcilhennyi 22 Reig et al. (1977), Patton et al. (2000)
Philander opossum 22 Reig et al. (1977)
Thylamys macrurus 14 Palma (1995)
Thylamys pallidior 14 Palma and Yates (1996)
Thylamys pusillus 14 Palma and Yates (1998)
Thylamys venustus f
14 Palma and Yates (1996)
Tlacuatzin canescens 22 Engstrom and Gardner (1988)
a
Diploid number.
b
Identified as ‘‘Marmosa agilis chacoensis’’ by Wainberg et al. (1979).
c
Identified as ‘‘Marmosa cinerea’’ by Reig et al. (1977), and as ‘‘Micoureus cinereus’’ by Palma and Yates (1996).
d
The specimens of ‘‘Micoureus demerarae’’ that Carvalho et al. (2002) karyotyped from Rio Grande do Sul are
referable to this taxon.
e
Some karyotyped specimens previously identified in the literature as Monodelphis brevicaudata (sensu lato) may
represent other species. Based on known geographic ranges (Voss et al., 2001), the Venezuelan karyotypes described by
Reig et al. (1977) were probably obtained from M. palliolata, whereas the Bolivian karyotypes described by Palma and
Yates (1996) were probably obtained from M. glirina.
f
Karyotyped Bolivian material identified as Thylamys elegans by Palma and Yates (1996) was reidentified as T.
venustus by Palma and Yates (1998).
acr8, met2}—which can exist in two states: fused
(metacentric) or fissioned (acrocentric).
Character 127: Robertsonian equivalents {acr2 + acr8,
met2} present as a single metacentric chromosome
(0); or as two acrocentric chromosomes (1).
Character 128: Robertsonian equivalents {acr3 + acr10,
met3} present as a single metacentric chromosome
(0); or as two acrocentric chromosomes (1).