A GEOLOGY LIBRAR
n.s.
T LDIANA
Geology
NEW SERIES, NO. 49
Large Archaeohyracids (Typotheria,
Notoungulata) from Central…
Information for Contributors to Fieldiana
Fieldiana is a peer-reviewed monographic serics published by the Ficld Museum. The…
FIELDIANA
Geology
NEW SERIES, NO. 49
Large Archaeohyracids (Typotheria,
Notoungulata) from Central Chile and
Patagonia,…
© 2003 Field Museum of Natural History
1SSN 0096-2651
PRINTED IN THE UNITED STATES OF AMERICA
Table of Contents
ABSTRACT
INTRODUCTION ...
Taxonomic Notes
Abbreviations ...
TOOTH WEAR AND DENTAL MEASUREMENTS…
Contributors
Darin A. Croft
Department of Organismal Biology
and Anatomy
The University of Chicago
1027 East 57th Street…
Large Archaeohyracids (Typotheria, Notoungulata)
from Central Chile and Patagonia, Including a
Revision of Archaeotypotherium…
Fe. [
Ameghino, 1897). Scale bar = 1 cm.
ell, et al., 1992; Wyss, Flynn, et al., 1993; Wyss,
Naorell, et al., 1993).…
typotheres) were members of the endemic South
American group Notoungulata. George Guaylord
Simpson’s views on the taxonomic…
6L ST 56 €9 8y Ts LL Ts1 ST ¥ AD
FHETT=%T6 BSTT—%HE] HBOT1-%HI8 %BHIT-%B68 BLHI-%HO6 BEH-%BI6 HEII-B06 HBYTI~%EE BHIOI-%…
Tooth Wear and Dental
Measurements
W
(n = 13)
40*03
7.5
81%-107%
95
3.6-44
The early auainment of hypsodonty (the pres…
isolated), or heavy wear (central fossa absent; fea-
tureless occlusal surface). Although division of
tooth wear into a…
75 50
30 M1 WEAR m1 WEAR
WLt m Litle
7.0 } AN A & Moderats ® @ A Moderate
se &, ® Heavy 551 O @ Heayy |
P…
Chubut
Salla Archaeoliyrax Psendhyrax
MI-3 (n = 11) ml-3 (n = 19) ml-3 (n = 5)
Mean + SD 25013 260 + 1.8 30.8 £ 08
Range…
bar = 1 cm,
much larger size. Differs from Pseudhyrax by
higher-crowned cheek teeth (HI = 1.3-1.6 in
Pseudhyrax), relatively…
FiG. 6. Specimens included in hypodigm of Ar-
chacotypotherium propheticus, A. MACN AS2-630.
right M2 and right m3. B. MACN…
AnzoH #609°C5Y NOVIN
95 Lyl ACRPON L0E9-TEY NOVI
gS 66 2ARIRPOIN 9-STIX€6 ITW
Fo Sl QIBIPOW 150601 NOVIN
[l QBP0 450601…
but]™). MLP 69-111-31-2 comes from “Campo de
Velazquez, Paso de Indios, Chubut.” MLP 89-
X11-29-1 was collected by Santiago…
sential characters of the remaining upper check
teeth have been given in the diagnosis of Ar-
chacotypotherium. Detachment of…
proportionately smaller and more triangular pre-
molars.
ETymoLoGY—1In reference to the Rio Tinguirir-
ica and the…
FiG. 8. Epoxy cast of SGOPV 2851, palate with left [1-3, left and right P2-M3, in o
iltustrates heavily worn upper dental…
caense with left il
bar = 1 cm.
mon Archacohyrax sp. nov. from the younger fau-
na at Saila, Bolivia (Deseadan SALMA} but…
L I
.
.
.
d Fic. 11, Epoxy casts of skull and deciduous dentition of Archaeotypotheriion tinguiriricaense. A. SGOPV 2900…
Upper dentition
Pl ¥2 P3 P4 ML a2 M3
Specimen Wear L W L W L W L W L W L W L W
SGOPV 2823 Light 49 39 75 52 72 60 10D 66 (…
stage, the internal cingulum is slightly below the
occlusal surface of the lingual portion of the
tooth, The presence of a…
structure 10 i3 in other specimens, we favor the
latter alternative. pending additional specimens
that might suggest…
present within the lateral depressions on the sym-
physis, almost dircctly beneath the canine.
The premolars arc all heavily…
is the least worn of the molars, it is likely that
these fossettes (if indeed present in more anterior
molars) disappeared…
in parentheses are estimated.
Upper dentition
P2 P3 P4 Mi M2 M3
Specimen Wear I W L W L W L W L W L W
SGOPY 2918 Moderate…
IncLUDED SPECIES—The type species, Pseudhy-
rax sirangulatus (Ameghino, 1901), and the in-
determinate material described…
archacohyracid lower dentitions, one or both of
the Tinguiririca Favna lower dentition specimens
identified as Pseudhyrax…
featurcless occlusal surfaces, save for an elongate
central fossa oriented anterolabially.
The first two molars alsa display…
Fi. 16, Occlusal views of P. euirachytherides
specimens from the Mustersan of Chubul. Argentina. A.
MLP §1-1V-9-1, slightly…
Identifications of archacoliyracid specimens included in Wyss et al., 1994.
TABLE 7.
CROFT ET AL: LARGE ARCHAEOHYRACIDS FROM…
Fic. 17. SGOPV 2901, Psendiyrax sp. indet., lefc
mandibular fragment with partial m1-m3 in oblique la-
bial view (left) and…
a small fossettid directly posterior to the central
fossa, a condition characteristic of Pseudhyrax; no
other characters of…
Tarts 8. Matrix of characters used in phylogenetic analysis of archaeohyacid relationships.
0060000000 1 1 L 1 L I 11 1202 2…
Oldfieldthomasia
Acropithecus
Eohyrax
Pseudhyrax
Archaeotypotherium
Protarchaeohyrax
Archaeohyrax
Hegetotherium
FiG. I8…
(in the classical sensc of that name) is now shown
lo be paraphyletic.
Trom the perspective of phylogenetic taxonomy
{de…
nation of the members (e.g., Archacohegetotheria,
Hegetoarchaeohyracoidea) could also be used.
Some combination of these…
mostly kaie Oligocene Deseadan SALMA, Filling
a niche that presumably was similar (o that of the
hypsodent archaeohyracids,…
South American Land Mammal Ages: Correlation to
global geachronologies, pp. 317-333. In Berggren, W.
A D. V. Kent, M.-E Aubry…
R & e
VR TS
REcuiko, M. A., D. A. CrorT, . ). FLYNN, AND A. R.
Wyss. (2003). Small archacohyracids (Typotheria,…
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