First Potwarmus from the Miocene of Saudi Arabia and the early phylogeny of murines (Rodentia: Muroidea)
Author
Antoñanzas, Raquel López
text
Zoological Journal of the Linnean Society
2009
2009-07-31
156
3
664
679
http://dx.doi.org/10.1111/j.1096-3642.2008.00494.x
journal article
3167
10.1111/j.1096-3642.2008.00494.x
d59ef689-6666-421e-8e46-c3fa65865db4
0024-4082
4687752
PARADAKKAMYS CHINJIENSIS
LINDSAY, 1988
This species was erected by
Lindsay (1988)
on the basis of 23 isolated cheek teeth from the Middle Miocene localities YGSP 76, YGSP 491, YGSP 504, YGSP 634, YGSP 636, and YGSP
726 in
the Chinji Formation, and from the early Late Miocene YGSP 259 locality in the Nagri Formation, Potwar Plateau,
Pakistan
. Additional material has been found in the Nagri Formation at locality Y797 (
Flynn & Morgan, 2005
). The
holotype
(YGSP 24656) of this species is an isolated right M1 from locality YGSP 76 (
Lindsay, 1988
: pl. 8, fig. h).
Wessels (1996)
suggested that this species should be re-allocated to
Myocricetodon
because, in particular, of its resemblance to
Myocricetodon eskihisarensis
. However, the phylogenetic study below corroborates the validity of
Paradakkamys
.
The M1s of
Paradakkamys chinjiensis
have a prominent enterostyle connected to the posterior side of the protocone, a paracone with a small posteriorly directed spur, a long anterior arm of the protocone joined with the anterocone near its midpoint, and a short lingual cingulum. In AJ7 the enterostyle is small and isolated, the spur of the paracone is lacking, the anterior arm of the protocone is only a relict, and the lingual cingulum is long. On the M2 of
P. chinjiensis
the enterostyle is small, but connected to the posterior side of the protocone by a short loph, and the lingual anterior cingulum is normally absent. In AJ11 and AJ12, the enterostyle is isolated and the lingual anterior cingulum is strong. The m1s of
P. chinjiensis
are not reduced anteriorly: they show a well-developed anteroconid, a large ectostylid, short anterior arms of the labial cusps, and a labial cingulum. In contrast, the anteroconid, the anterior arms of the labial cusps, and the labial cingulum are lacking in AJ13, and it has a minute ectostylid.