Late Miocene large mammals from Ivand (Northwestern Iran)
Author
Ataabadi, Majid Mirzaie
Author
Mohammadalizadeh, Jafar
Author
Zhang, Zhaoqun
Author
Watabe, Mahito
Author
Kaakinen, Anu
Author
Fortelius, Mikael
text
Geodiversitas
2011
2011-12-31
33
4
709
728
http://dx.doi.org/10.5252/g2011n4a7
journal article
7713
10.5252/g2011n4a7
03becb1a-f3c9-410a-997c-37416648bc7d
1638-9395
4597129
Bovidae
indet.
LOCALITY. — Quarry 1, Ivand district, northwest of Tabriz,
Iran
.
MATERIAL EXAMINED. — Fragmentary right mandible with m2-m3 (
HMNH-IV
59;
Table 3
), right m1 (
HM-
TABLE 3. — Measurements (in mm) of the length and width (L/W) of the Bovid teeth from the Ivand locality (NW Iran). Question mark (
?
) indicates unavailable measurements.
Specimen
|
DP3
|
DP4
|
P4
|
M1
|
M2
|
p4
|
m1
|
m2
|
m3
|
HMNH-IV57 |
27.5/? |
HMNH-IV58 |
14/16 |
HMNH-IV59 |
23/14.5 |
30/14.6 |
HMNH-IV64 |
23.5/? |
23.7/? |
HMNH-IV65 |
20.7/12.2 |
HMNH-IV67 |
8.4/4.7 |
9.7/6.1 |
10.8/6.4 |
16.3/6.1 |
HMNH-IV69 |
10.8/? |
14.5/5.8 |
HMNH-IV70 |
18/11.7 |
20/19.5 |
25/? |
NH-IV
65;
Table 3
), broken right m2 (
HMNH-IV
68;
Table 3
), left maxilla with DP2-M1 (
HMNH-IV
70;
Table 3
), fragmentary right maxilla with M1-M2 (HMNH-
IV
64;
Table 3
), fragmentary right maxilla with P4-M1 (
HMNH-IV
58;
Table 3
), fragmentary left maxilla with M1-M2 (
HMNH-IV
57;
Table 3
).
DESCRIPTION
The mandibles and maxillae are too fragmentary to provide any detailed character. DP2 is heavily worn and is long and narrow. The parastyle is prominent but low. There is no mesostyle, and the metastyle is weak. The paracone is the highest cusp, and the metacone is slightly lower. The protocone is large and located anteriorly to the paracone. The hypocone is larger than the protocone. There is no central fossette visible on the occlusal surface. DP3 is longer than DP2 and is submolarized. The parastyle is strong and well separated from the paracone by a wide groove. The mesostyle, however, is less developed, and the metastyle is the least developed. The anterior rib is very strong, and the posterior rib is weak. The central cavities bear a simple enamel outline. DP4 is highly molarized and, except for its smaller size, closely resembles molars. The central fossettes are open in the medium wear.
P4 is subtriangular. The hypocone is relatively well developed, though smaller than protocone, thus rendering the inner wall a less angled shape. The parastyle and metastyle are well developed, while the mesostyle is weak.
On M1, the parastyle is robust, the mesostyle is well developed as a vertical ridge, and the metastyle projects much less. The anterior rib is large, and the posterior rib is weak. There is no basal pillar. M2 closely resembles M
1 in
tooth morphology. The hypocone triangle is relatively short and is rounder than the protocone triangle. The metastyle is slightly more developed.
m1 shows a rectangular occlusal outline. The parastylid, metastylid, and the entostylid are much reduced. The lingual wall is flat with slightly convex metaconid and entoconid. The protoconid and hypoconid on m2 are triangle shaped. The parastylid is slightly more developed than the metastylid and entostylid. There is no goat fold but there is a low basal pillar. m3 resembles m2, except for its strongly labially offset hypoconulid with a central cavity.
COMPARISON
With no cranial or horn-cores found, discussing the systematic position of these isolated fragmentary materials in detail is difficult. Based on size and morphology, these teeth are tentatively assigned to one form herein, pending the discovery of better specimens.
This form, like
Urmiatherium polaki
Rodler, 1889
, features a developed parastyle, very strong mesostyles, a prominent anterior rib, and a concave labial metacone wall on the upper molars. It differs by having a lower tooth crown, no additional cavities near the central lingual edge of the occlusal surface on the upper molars, a convex shape of the lingual wall, and the well developed basal pillars on the lower molars.
De Mecquenem (1924
,
1925
) reported some material of
Palaeoryx pallasi
(Wagner, 1857)
from Maragheh. The size of the present form from Ivand locality is comparable to this Maragheh
A
550
500
450
400
350
FIG. 6. —
A
, distal width (
DW
) plotted against maximum length (
ML
) of femur in
Rhinocerotinae
indet. from the Ivand locality and some other
Rhinocerotidae Owen, 1845
from Eurasia (Akkaşdaşi data from
Antoine & Saraç [2005]
; Linxia data from
Deng [2002]
);
B
, ulna proximal width (
PW
) plotted against its width at process olecrani (
POW
) in
Deinotherium giganteum
Kaup, 1829
from Ivand locality and several other specimens from Europe (Unterzolling data from
Huttunen & Göhlich 2002
).
taxon. They share similar tooth morphology, such as strong parastyles and mesostyles, weak metastyles, developed anterior ribs, no basal pillars on the upper molars, a slightly convex lingual wall of the lower molars, low but distinct basal pillars, triangular labial lobes on the lower molars, and strongly labially offset hypoconulids on m3. The skull figured by
de Mecquenem (1924
,
1925
: pl. 4, fig. 1), however, was believed to be that of a
Miotragocerus
Stromer, 1928
(=
Tragoportax
Pilgrim, 1937
) by
Bohlin (1936)
and
Gentry (1971
,
2000
).
Gentry (1971)
further stated that there was no other convincing evidence of
Palaeoryx pallasi
from Maragheh. Given these poor materials and pending the discovery of more complete fossils, we avoid naming them.