Prolistriodon smyrnensis, Pickford & Kaya & Tarhan & Erylmaz & Mayda, 2020
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publication ID |
https://doi.org/ 10.37520/fi.2020.026 |
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persistent identifier |
https://treatment.plazi.org/id/03E7A555-A702-B26D-FEF2-4478FA13FBF6 |
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treatment provided by |
Felipe |
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scientific name |
Prolistriodon smyrnensis |
| status |
sp. nov. |
Prolistriodon smyrnensis sp. nov.
Text-figs 3–6 View Text-fig View Text-fig View Text-fig View Text-fig
H o l o t y p e. EUNHM PV 3300.a, right I1/.
D e r i v a t i o n o m i n i s. The species name is for Smyrna, the ancient name for Izmir, with the suffix “ ensis ” with the sense of “from”.
Ty p e l o c a l i t y a n d a g e. Sabuncubeli, Turkey, early Miocene, MN 3 basal part.
D i a g n o s i s. As for the genus (length m/1–m/3 ca.
53.5 mm).
O t h e r m a t e r i a l f r o m S a b u n c u b e l i. EUNHM PV 3300.b – 3300.w, diverse isolated upper and lower teeth ( Tab. 2).
D e s c r i p t i o n. The upper central incisors from Sabuncubeli are slightly spatulate with a concave lingual surface interrupted by a low central ridge, bordered cervically by a well-developed, lightly beaded cingulum. The labial surface is convex, and there is a slight distal extension of the crown, but no development of a separate cusp (metacone in the terminology of Van der Made 1996). The root is twice as tall as the crown, is compressed conical and tapers apically to a point. In the lightly worn holotype specimen ( PV3300 .a; Text-fig. 3b View Text-fig ) the apical margin shows slight indentations, one to the mesial side of the lingual ridge, the others along the distal margin of the crown .
In labial and lingual views, the upper third incisors from Sabuncubeli have low, triangular crowns. There is a strong lingual cingulum, a well-developed lingual ridge on a generally concave lingual surface, and a slightly convex labial surface ( Text-fig. 3d View Text-fig ).
The upper female canine is two-rooted, with the roots fused together almost to their apices ( Text-fig. 3e View Text-fig ). The crown is labio-lingually compressed and in labial view is triangular, with a short anterior crista and an elongated posterior crista with a distal heel.
In occlusal view, a P2/ from Sabuncubeli (PV 3300.q) is almost quadrangular with rounded corners, being slightly narrower mesially than distally ( Text-fig. 4a View Text-fig ). The main cusp is almost centrally positioned with an oblique precrista terminating in the mesio-lingual corner of the crown, and a postcrista leading distally to the bucco-distal corner of the tooth. There is a moderately-sized lingual concavity bordered by a lingual cingulum.
The D4/ (PV 3300.h) has a trapezoidal occlusal outline, the buccal border being significantly longer than the lingual one ( Text-fig. 4b View Text-fig ). It has thinner enamel than the permanent molars. There are four main cusps with relatively shallow Furchen (sensu Hünermann 1968) and small anterior, median and posterior accessory cusplets. Mesial and distal cingula are present and the buccal cingulum is narrow and discontinuous. The hypocone has a prominent precrista leading towards the lingual end of the median transverse valley but not blocking it.
The upper molars from Sabuncubeli are typical of bundont suids, with four main cusps (protocone, paracone, hypocone, metacone) arranged in two lophs, and three accessory cusplets (anterior, median, posterior) disposed along the midline of the crown ( Text-fig. 4c–e View Text-fig ). The Furchen are shallow. The hypocone has a well-developed lingual precrista that leads towards the lingual end of the median transverse valley. There are strong mesial, buccal and distal cingula. The median transverse valley is partly blocked by the median accessory cusplet but this cusplet is mostly positioned between the mesial aspects of the metacone and hypocone.
The lower second incisors from Sabuncubeli have quite tall crowns, with a slightly scoop-shaped depression on the distal side of the central lingual ridge ( Text-fig. 5b, c View Text-fig ). There are clear mesial and distal ridges bordering the lingual side of the crown.
The third lower incisor, in contrast to the i/2, is a lowcrowned tooth, significantly lower than the i/2 ( Text-fig. 5a View Text-fig ). It has a lingual cingulum and a lingual ridge that runs towards the distal corner of the crown, thereby separating the lingual surface of the tooth into two concave parts. On the lingual side there are low mesial and distal crests.
The lower female canine is a single-rooted tooth with a strongly labio-lingually compressed crown ( Text-fig. 5d View Text-fig ). The precristid is short and steep, the postcristid long and more gently sloping distally, ending in a low heel-like cusplet.
The p/2 of the Sabuncubeli suid is two-rooted, with a bucco-lingually compressed crown ( Text-fig. 6a View Text-fig ). The protoconid is tall and centrally positioned with steep pre- and postcristids, the latter one separating buccal and lingual concavities in the crown profile. It descends towards the disto-buccal corner of the crown where it joins a disto- lingual swelling in the crown. There are weak anterior and posterior cingulids.
The p/3 is larger than the p/2, and has a distinct swelling in the posterior part of the postcristid which almost forms a separate cusplet in the mid-line of the tooth ( Text-fig. 6b View Text-fig ). The mesial and distal cingulids are well developed and the disto-lingual part of the crown extends distally further than the disto-buccal part.
Only the third lophid of the d/4 is preserved in the Sabuncubeli sample ( Text-fig. 6c View Text-fig ). The main cuspids are scored by shallow Furchen and the median and posterior accessory cusplets are positioned in the centre-line of the tooth.
The first and second lower molars from Sabuncubeli are tetracuspidate with anterior, median and posterior accessory cusplets ( Text-fig. 6d–f View Text-fig ). The Furchen are shallow. The precristids of the protoconid and metaconid extend towards the anterior accessory cusplet. The distal surfaces of the protoconid and metaconid have two cristids descending from their apices, the outer ones descending almost vertically, the inner ones approaching each other in the mid-line of the crown, the ensemble forming an ‘m’-shaped structure somewhat resembling the ‘M’-structure in tragulid teeth. The hypoconid has two cristids, one joining the median accessory cusplet, the other reaching steeply towards the posterior accessory cusplet. The entoconid is conical with four cristids, the outer ones stronger than the inner ones. The mesial and distal cingulids are weak and there is a cingular structure traversing the buccal end of the median transverse valley.
The m/3 is like the m/2 but has a third lophid behind the posterior accessory cusplet ( Text-fig. 6g View Text-fig ). This talonid (hypoconulid) is comprised of two parts, a large distal cusplet with a strong mesially directed, beaded cristid on the lingual side, and a slightly smaller buccal cuspid which touches the posterior accessory cusplet. The mesial cingulum is quite strong, and there are cingular remnants in the buccal and lingual ends of the median and posterior transversevalleys.
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