Protanancus, Arambourg, 1945

Markov, Georgi N. & Vergiev, Stoyan, 2010, First report of cf. Protanancus (Mammalia, Proboscidea, Amebelodontidae) from Europe, Geodiversitas 32 (3), pp. 493-500 : 494-496

cf. Protanancus sp.

DESCRIPTION

All three molars were found together and apparently belong to the same individual.

VRMH 158, the left M2 ( Fig. 2 ), is preserved together with a portion of the maxilla. The crown is intact, and roots are preserved on the buccal side (the anterior only partially), lingually, the roots are damaged near the cervical line. The tooth is trilophodont, with a small posterior talon comprising four cusps. The crown is curved, with a concave lingual and a convex buccal side. Dentine is exposed on all three lophs. Anterior pretrite conules are strongly developed on the second and third lophs, pretrite mesoconelets are separated from the anterior conules. Posterior pretrite conules are reduced (on the second loph, the posterior pretrite conule is clearly separated from the mesoconelet). On the posttrite side, the posterior conule is well pronounced on the first loph, and weak but visible on the second. An anterior posttrite conule is present on the third loph. Both interlophs are very narrow,with cement.Clear pseudo-anancoid contacts are observable, involving the anterior pretrite and posterior posttrite conules (contact in the second interloph involving the posterior pretrite conule of the second loph as well). The enamel is slightly folded. L: 110; W: 68/68/66.5; ET: 5.5.

VRMH 159, the left M3 ( Fig. 3 ), has four lophs and a small posterior talon built of four cusps. The fourth loph is weakly developed. The molar is at an early stage of wear, with traces of occlusion only on the anterior cingulum and the first loph, with no dentine exposed.The interlophs are very narrow, filled with cement. Alternation of the semilophs is weak but visible on the third and fourth lophs.The pretrite trefoil is well developed on the second loph, with the mesoconelet clearly separated from the main cone, and doubled anterior and posterior pretrite conules. Doubled anterior pretrite conule of the second loph is much stronger than the posterior one and contacts the small posterior posttrite conule of the first. Anterior and posterior pretrite conules are weak on the first pretrite semiloph, smaller than the clearly separated mesoconelet. On the third pretrite semiloph, there is a single cusp positioned mesio-adaxially to the main cone, contacting the posterior pretrite conule of the second loph. The fourth pretrite is built of three cusps aligned in a mesio-adaxial direction and contacts the third posttrite semiloph. There are weak posterior posttrite conules on the first and second lophs, and additional cusps in the first and second interlophs, on the posttrite side. Posttrite mesoconelets are doubled. The fourth posttrite is low, of nearly the same height as the posterior talon but is clearly separated from it. L: 143; W: 79/77.5/72.5/51; H: 58.

VRMH 160, the right M3 ( Fig. 4 ), has four lophs and a posterior talon which is slightly larger than in the left M3 and is built of two cusps. As in VRMH 159, the fourth loph is weak but clearly separated from the third by an ento- and ectoflexus. The anterior talon is high and massive. Alternation of the semilophs is visible on second to fourth lophs and is more pronounced in comparison with the left M3, as are the pseudo-anancoid contacts. A full pretrite trefoil pattern is observable on the second loph, with a reduced but present posterior conule and a strong anterior one, contacting the posterior posttrite conule of the first loph. Posterior posttrite conules of the first and second lophs are somewhat better developed in comparison with the left M3, as are the additional cusps in the second interloph, on the posttrite side. L: 147; W: 77.5/77/74/52.

Figures

FIG. 2. — Cf. Protanancus sp. maxillary fragment with left M2, Vetren, Bulgaria (VRMH 158): A, occlusal view; B, lingual view; C, buccal view. Scale bars: 10 cm.

FIG. 3.— Cf.Protanancus sp.,left M3,Vetren,Bulgaria (VRMH 159), occlusal view. Scale bar: 10 cm.

FIG. 4. — Cf. Protanancus sp., right M3, Vetren, Bulgaria (VRMH 160), occlusal view. Scale bar: 10 cm.