New Paleogene Notohippids and Leontiniids (Toxodontia; Notoungulata; Mammalia) from the Early Oligocene Tinguiririca Fauna of the Andean Main Range, Central Chile
Author
Wyss, André R.
Author
Flynn, John J.
Author
Croft, Darin A.
text
American Museum Novitates
2018
2018-06-25
2018
3903
1
44
http://www.bioone.org/doi/10.1206/3903.1
journal article
10.1206/3903.1
0003-0082
10110614
Eomorphippus bondi
,
species novum
Figure 1
HOLOTYPE
:
SGOPV 3046
: partial skull preserving orbital rims, portions of both zygomatic arches, rostrum, and LI1–C, P3–M3; RI1–C, P3, M1–3.
PARATYPE
:
SGOPV 2891
, partial left lower dentition including i1–3 and p2–m3, plus remnants of the right dentition, including i1 and molds and external (labial) slivers of some posterior cheekteeth
.
TENTATIVELY REFERRED SPECIMEN: SGOPV 3085, labiolingually crushed right?p4–m1.
TYPE LOCALITY
:
The
type,
paratype
, and tentatively referred specimen all derive from volcaniclastic sediments currently mapped as belonging to the
Abanico
(= Coya-Machalí)
Formation
in the
Tinguiririca River valley
(~35° S), in the
Andean Main Range
of central
Chile
, some
7 km
west of the international boundary. (Geologic maps dating from before the late 1980s mistakenly identified these deposits as belonging to the Cretaceous Colimapu Formation; Charrier et al., 1996.)
All
specimens described below were recovered from 35°–50° west-dipping strata, north of an unnamed
2738 m
pass (indicated on the topographic sheet; Anonymous, 1985), approximately
3 km
south of the town of
Termas del Flaco
, at what is termed the “main locality” in
Charrier
et al. (1996: fig. 6)
.
AGE: Early Oligocene (to potentially late Eocene), Tinguirirican
SALMA
. The diverse Tinguiririca Fauna recovered from near Termas del Flaco, of which the notohippids are an important constituent, formed the basis for the formalized Tinguirirican
SALMA
(Flynn et al., 2003), which lies temporally between the Mustersan and Deseadan of the classical
SALMA
sequence. An extensive series of isotopic dates (summarized in Flynn et al., 2003) have been generated for strata hosting and underlying the Tinguiririca Fauna, indicating that
E. bondi
and its contemporaries described below are no younger than ~31.5 million years old (early Oligocene) and could be ~1–2 million years older (Bradham et al., 2015).
ETYMOLOGY: In honor of Mariano Bond, for his enormous and influential contributions to the understanding of notoungulate phylogenetics and taxonomy.
DIAGNOSIS:
Eomorphippus bondi
generally resembles
E. obscurus
,
differing from the latter mainly in being roughly 20% larger in most dental dimensions, in having a slightly smaller upper canine, and in having an I3 that is substantially wider than both I1 and I2.