Late Cretaceous asioryctitherian eutherian mammals from Uzbekistan and phylogenetic analysis of Asioryctitheria
Author
Archibald, J. David
Author
Averianov, Alexander O.
text
Acta Palaeontologica Polonica
2006
51
2
351
376
journal article
10.5281/zenodo.13644131
1732-2421
13644131
Bulaklestes kezbe
Nessov, 1985
Figs. 8–10
,
Tables 1
,
2
.
1985
Bulaklestes kezbe
sp. nov.
;
Nessov 1985: 16
, pl. 3: 6. 1985 Theria [indet.];
Nessov 1985
: pl. 3: 2. 1993
Bulaklestes kezbe
;
Nessov 1993
: pl. 4: 10. 1994
Bulaklestes kezbe
;
Nessov et al. 1994: 64
, pl. 4: 2. 1997
Bulaklestes kezbe
;
Nessov 1997
: pl. 48: 2. 1997 Theria [indet.];
Nessov 1997
: pl. 48: 4.
Holotype
:
CCMGE 12
/12176, right M3.
Type locality and horizon
: CBI−4b, Dzharakuduk, Kyzylkum Desert,
Uzbekistan
. Bissekty Formation, Upper Cretaceous (Turonian). Found in 1980.
Referred specimens
.—
CCMGE
19/12176, right P4 (CBI−4v);
URBAC
99−104, right P4 (CBI−14);
ZIN
82591, left M1 lacking paracone (CBI−14, 1998);
URBAC
00−61, left dentary with i3?–4?, c, p1–2, 4 (CBI−14);
URBAC
03−142, right dentary with p4 missing most of the crown, p5, m1, and alveoli for two−rooted c and p1–2 (CBI−14);
URBAC
98−132, left m1 (CBI−14);
URBAC
98−141, left m1 (CBI−14);
URBAC
99−101, left m1 lacking paraconid, metaconid and hypoconulid (CBI−14);
URBAC
98−128, right m1 lacking metaconid and hypoconulid (CBI−14);
URBAC
98−129, left m1 trigonid (CBI−14);
URBAC
98−131, right m1 trigonid (CBI−14);
URBAC
98−143, left m1 trigonid lacking protoconid (CBI−14);
URBAC
04−163, left dentary with m2–3, m1 lacking most of the crown, and alveoli for p5 (CBI−14);
ZIN
84971, right dentary with m2–3 talonids, m1 roots, and alveoli for c, p1–2, 4–5 (CBI−14, 1985);
URBAC
03−94, left dentary with m2 and alveoli for p5, m1, and m3 (CBI−14);
URBAC
04−170, right dentary with erupting m3 and posterior alveolus for m2 (CBI−14);
URBAC
02−22, left dentary with m
3 in
crypt and alveoli for m1–2 (CBI−4e);
URBAC
03−22, left dentary with m
3 in
crypt and alveoli for m2 (CBI−14);
ZIN
84970, left dentary with m3 talonid and posterior alveolus for c, double−rooted alveoli for p1–2, 3–4, m1–2, and anterior alveolus for m3 (CBI−14, 1980);
URBAC
04−51, right dentary with m3 lacking trigonid and part of the coronoid process (CBI−14);
URBAC
02−37, left dentary with m3 lacking most of the trigonid and alveoli for m1–2 (CBI−4e);
URBAC
04−21, left dentary with m3 lacking metaconid and alveoli for m2 (CBI−14);
URBAC
98−133, left m3 (CBI−14);
ZIN
88440, right dentary with alveoli for p1–2, 4 (CBI−4a, 1989);
URBAC
03−140, right dentary with alveoli for p2, 4–5 and posterior alveolus for p1 (CBI−14);
URBAC
02−39, left dentary with fragments of p4–5 and alveoli for m1–2 (CBI−4e);
URBAC
04−83, right dentary with alveoli for p4–5, m1–3 (CBI−14);
URBAC
03−201, right dentary with alveoli for p4–5, m1–2 (CBI−14);
URBAC
04−210, left dentary with alveoli for p4–5, m1–2 (CBI−14);
ZIN
88439, left dentary with posterior alveolus for p5, alveoli for m1–3 and part of angular process (CBI−14, 1989);
URBAC
02−11, left dentary with alveoli for p5, m1–3 (CBI−4e);
URBAC
03−82, left dentary with alveoli for p5, m1–3 (CBI−14);
URBAC
97−12, left dentary with alveoli for m1–3 and parts of coronoid and angular processes (CBI−14);
ZIN
88927, left dentary with alveoli for m1–3 and parts of coronoid and angular processes (CBI− uncertain locality);
URBAC
03−149, left dentary with alveoli for m1–3 and part of angular process (CBI−14);
ZIN
88960, left dentary with roots of m1–3 (CBI−14, 1987);
URBAC
00−58, left dentary with alveoli for m1–3 (CBI−14);
ZIN
88442, left dentary with alveoli for m1–3 (CBI−14, 1989);
ZIN
88487, right dentary with alveoli for m1–3 (CBI−4a, 1989);
URBAC
02−31, left dentary with posterior alveolus for m1 and alveoli for m2–3 (CBI−4e);
URBAC
00−38, right dentary with alveoli for m2 and erupting m3 (CBI−4e);
ZIN
88492, left dentary with alveoli for m2–3 (CBI−14, 1987);
ZIN
88496, left dentary with alveoli for m2–3 (CBI−14, 1980);
URBAC
04−78, left dentary with alveoli for m2–3 (CBI−14);
URBAC
04−167, left dentary with alveoli for m2–3 (CBI−14);
URBAC
04−216, left dentary with alveoli for m2–3 (CBI−14);
URBAC
04−222, left dentary with alveoli for m2–3 (CBI−14);
URBAC
03−1999, right dentary with alveoli for m2–3 (CBI−14);
ZIN
88956, right dentary with alveoli for m1–3 (CBI−15, 1985);
URBAC
98−144, left dentary with alveoli for m3 (CBI−14);
URBAC
02−42, left dentary with alveoli for m3 (CBI−4e);
URBAC
04−142, left dentary with alveoli for m3 (CBI−14).
Fig. 8. Stereopairs of
Bulaklestes kezbe
Nessov, 1985
; Dzharakuduk, Uzbekistan, Late Cretaceous (Turonian).
A
. 1985. CCMGE 19/12176, right P4; in labial (A
1
) and occlusal (A
2
) views.
B
. ZIN 82591, left M1 lacking paracone; in occlusal (B
1
), labial (B
2
), and anterior (B
3
) views.
C
. CCMGE 12/12176, type, right M3; in occlusal (C
1
), labial (C
2
), and anterior (C
3
) views.
Diagnosis
.—As for the genus.
Description
.—There are two P4s referred to this species. They differ slightly in size, but are similar in morphology. The crown is very high, with the apex canted slightly posteriorly (
Fig. 8A
). The faint anterior and posterior crests extend from the apex toward the anterior and posterior basal cusps respectively. The posterior crest possesses a distinct swelling. The labial side of the single, large cusp is gently concave. On the lingual side there is a swelling in the middle of the crown, which is not complete on either specimen. This swelling possibly was supported by a small separate (third) root, but this is not certain. There is a faint posterolingual cingulum.
Except in size, M1 differs from M1s in
D. inobservabilis
in having a relatively larger parastyle (also pronounced in M3) and a thickened, cusp−like crest between the stylocone and parastyle. There are no pre− or postcingula (
Fig. 8B
).
For a description of M3 see the description of
CCMGE
12/
12176 in
Nessov et al. (1994: 64–65)
, here shown in
Fig. 8C
. This tooth has some very faint swellings in the postcingular region.
The dentary symphysis terminates below p1 or p2 (
URBAC
00−61,
URBAC
03−142,
ZIN
84971) (
Fig. 9B
3
). There are two anterior mental foramina. The first is below i4? (
URBAC
00−61), while the second is below the anterior root of p1 (
ZIN
84970, 84971), the posterior root of p1 (
URBAC
00−61), or between c and p1 (
URBAC
03−142) (
Fig. 9B
2
). The posterior mental foramen is below the anterior root of p5 (
ZIN
84970, 84971,
URBAC
02−11, 02−39, 03−94, 03−142, 04−210), or the middle of this tooth (
URBAC
03−82,
URBAC
03−142) (
Fig. 9A
2
). In
ZIN
84971 there is a smaller, second posterior mental foramen below the posterior root of p5. The depth of the dentary increases markedly with age (deepest in
URBAC
04−163 at
2.7 mm
,
Fig. 10D
1
).
Fig. 9. Stereopairs of
Bulaklestes kezbe
Nessov, 1985
; Dzharakuduk, Uzbekistan, Late Cretaceous (Turonian).
A
. URBAC 03−142, right dentary with p4 missing most of the crown, p5, m1, and alveoli for two−rooted c and p1–2 (p4–5, m1 shown), in occlusal (A
1
), labial (A
2
), and lingual (A
3
) views.
B
. URBAC 00−61, left dentary with i3?–4?, c, p1–2, 4, in occlusal (B
1
), labial (B
2
), and lingual (B
3
) views.
A single larger mandibular foramen or several smaller masseteric foramina are present. In
ZIN 88439
,
URBAC 97−12
, and 03−149 the base of the mandibular angle and the mandibular foramen are preserved, which are similar to those in
Uchkudukodon nessovi
. The angle is somewhat inflected medially. On the medial side of the coronoid process on
ZIN 88439
and
URBAC 04−83
, there is a subhorizontal line delimiting the ventral border for the temporalis muscle. Only three of
32 specimens
that preserve the posterior portion of the dentary come from individuals with m
3 in
some stage of eruption
.
Fig. 10. Stereopairs of
Bulaklestes kezbe
Nessov, 1985
; Dzharakuduk, Uzbekistan, Late Cretaceous (Turonian).
A
. URBAC 98−141, left m1, in lingual (A
1
) and occlusal (A
2
) views.
B
. URBAC 03−94, m2 from left dentary with m2 and alveoli for p5, m1, and m3, in lingual (B
1
) and occlusal (B
2
) views.
C
. URBAC 04−170, erupting m3 from right dentary with erupting m3 and posterior alveolus for m2; occlusal.
D
. URBAC 04−163, left dentary with m2–3, m1 lacking most of the crown, and alveoli for p5, in lingual (D
1
) and occlusal (D
2
) views.
What we here identify as i3 and i4 (known only in
URBAC
00−61) are slightly procumbent (
Fig. 9B
). The presumed i4 is less than half the size of the presumed i3, but both have similar crown construction. The crown is anteroposteriorly expanded, with a single cusp and short anterior and longer keels, and a lingual cingulid, which is more pronounced on the presumed i3. In
URBAC
00−61, the presumed i4 is displaced labially compared to the presumed i3.
The lower canine is double−rooted and higher than the presumed i3. There is a very faint posterior cusp (
Fig. 9B
).
The p1–2 and 4 are double−rooted and similar in structure, gradually increasing in size posteriorly (
URBAC
00−61) (
Fig. 9B
). The same is characteristic for other specimens. There is no paraconid and the talonid cusp is small on p1–2 and 4 of
URBAC
00−61, while p
4 in
URBAC
03−142 has a small paraconid (
Fig. 9A
1
). The p4 is similar in height to the lower canine. In p5 the paraconid is much larger and there is a distinct anterolingual cingulid (
URBAC
03−142). The talonid cusp is similar to the paraconid in size, but positioned higher on the crown. The very short and narrow talonid occupies only the lingual side of the crown, not extending as far labially as the anterior portion of the crown (
Fig. 9A
).
Fig. 11. Stereopairs of composite occlusal views of M1’s and M2’s. All specimens from Dzharakuduk, Uzbekistan, Late Cretaceous (Turonian).
A
.
Uchkudukodon nessovi
(
McKenna, Kielan−Jaworowska, and Meng, 2000
)
(URBAC 98−124, left M1 reversed and URBAC 03−213, right M2).
B
.
Daulestes kulbeckensis
Trofimov and
Nessov, 1979
(URBAC 98−126, probably associated lingual and labial parts of a left M1, reversed and URBAC 98−127, a right M2 lacking the metacone).
C
.
Daulestes inobservabilis
(
Nessov, 1982
)
(URBAC 02−91, right M1 and URBAC 98−140, left M2, reversed).
D
.
Bulaklestes kezbe
Nessov, 1985
(ZIN 82591, left M1 lacking paracone, reversed).
Lower molars (
Figs. 9
,
10
) are similar to those in
D. inobservabilis
, with a rather oblique protocristid on m1, and the cristid obliqua is lingual to or at the protocristid notch. The m3 hypoconulid is posteriorly procumbent, as in other Dzharakuduk asioryctitheres.
Measurements
.—See
Tables 1
and
2
.