Bulaklestes kezbe Nessov, 1985

Archibald, J. David & Averianov, Alexander O., 2006, Late Cretaceous asioryctitherian eutherian mammals from Uzbekistan and phylogenetic analysis of Asioryctitheria, Acta Palaeontologica Polonica 51 (2), pp. 351-376 : 364-368

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).

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 ).

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 .

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 ).

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.

Figures

Fig. 8. Stereopairs of Bulaklestes kezbe Nessov, 1985; Dzharakuduk, Uzbekistan, Late Cretaceous (Turonian). A. 1985. CCMGE 19/12176, right P4; in labial (A1) and occlusal (A2) views. B. ZIN 82591, left M1 lacking paracone; in occlusal (B1), labial (B2), and anterior (B3) views. C. CCMGE 12/12176, type, right M3; in occlusal (C1), labial (C2), and anterior (C3) views.

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 (A1), labial (A2), and lingual (A3) views. B. URBAC 00−61, left dentary with i3?–4?, c, p1–2, 4, in occlusal (B1), labial (B2), and lingual (B3) views.

Fig. 10. Stereopairs of Bulaklestes kezbe Nessov, 1985; Dzharakuduk, Uzbekistan, Late Cretaceous (Turonian). A. URBAC 98−141, left m1, in lingual (A1) and occlusal (A2) views. B. URBAC 03−94, m2 from left dentary with m2 and alveoli for p5, m1, and m3, in lingual (B1) and occlusal (B2) 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 (D1) and occlusal (D2) views.

Fig. 3. Stereopairs of Daulestes inobservabilis (Nessov, 1982); Dzharakuduk, Uzbekistan, Late Cretaceous (Turonian). A. URBAC 98−146, right P4 missing small part of anterior margin, in labial (A1) and occlusal (A2) views. B. URBAC 02−91, P5 and M1 from right maxilla with P5, M1, and alveoli for P4 and M2–3, in labial (B1), occlusal (B2), and lingual (B3) views. C. URBAC 98−140, left M2, in occlusal (C1), labial (C2), and anterior (C3) views.

Fig. 1. Stereopairs of Daulestes kulbeckensis Trofimov and Nessov, 1979; Dzharakuduk, Uzbekistan, Late Cretaceous (Turonian). A. URBAC 98−126, probably associated lingual and labial parts of a left M1 in, occlusal (A1), labial (A2), and anterior (A3) views. B. URBAC 98−127, a right M2 lacking the metacone, in occlusal (B1), labial (B2), and anterior (B3) views.