Foumtizia zhelezkoi, Malyshkina, 2006
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publication ID |
https://doi.org/ 10.5281/zenodo.13651136 |
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persistent identifier |
https://treatment.plazi.org/id/444087E3-B95D-FF8C-9E7E-0EF07D3FF990 |
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treatment provided by |
Felipe |
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scientific name |
Foumtizia zhelezkoi |
| status |
sp. nov. |
Foumtizia zhelezkoi sp. nov.
Figs. 4 View Fig , 5 View Fig .
Derivation of the name: In honor of Doctor Victor I. Zhelezko, Russian geologist and palaeontologist, who advanced fossil shark research.
Type locality: Kurgan. The clay quarry of the Kurgan brick factory in the northern part of Kurgan city, South Trans−Urals , Russia .
Type horizon: Upper part of the gray−green clays of the Tavda Formation.
Age: Priabonian. Charlesdowinea clathrata angulosa Dinoflagellate Zone.
Holotype: PIN 5088 View Materials /03, lateral tooth ( Fig. 4A View Fig ).
Paratype: PIN 5088 View Materials /04, lateral tooth ( Fig. 4B View Fig ) .
Material. — Kurgan: 11 teeth, Derney: 2 teeth.
Specific diagnosis.—The teeth are stocky. The central cusp is conical and rounded in cross−section. There are two pairs of lateral cusplets with small shoulders distally to them. The labial face of the crown is bulging and slightly overhangs the root. The enameloid of the cusp forms long, well−differentiated folds with two longitudinal edges, extending on the 3/4 of the height of the lingual and labial surfaces. The lateral cusplets are low. The enameloid of the main cusp and cusplets from the base upwards is covered by clear long vertical folds. The folds on the lingual face usually less marked than the labial ones, as they are on the lateral teeth. The folds on the labial face of the main cusp are strong, straight or slightly flexuous, and occupy 2/3 or more of the crown. Each fold has two longitudinal distinct edges, so that it is trapezoid−formed in cross−section. The folds on the lingual face are less pronounced, the longitudinal edges fairly prominent; the folds are flexuous, extend from the base to top or intermittent, or arise in the middle part of the cusp. They may bifurcate. The enameloid folds of the lateral cusplets are like to those on the main cusp. The cutting edge is complete on the lateral teeth or may absents on some lateral teeth. The root has a well−developed central protuberance and a flat base. Both are divided by a deep and wide nutritive groove which is continuous onto the upper side of the root. The central foramen is large and doubled for the most part of teeth. The root is lingually displaced, most markedly when seen in occlusal view. The lingual face of the root has some deep oval margino−lingual foramina. There are some margino−labial foramina.
Description
Holotype ( Fig. 4A View Fig ).—PIN 5088/03, lateral tooth. The tooth is slightly asymmetrical in labial view; the main cusp is slightly bent distally, as well as inclined lingually. The crown has a main cusp and two pairs of the cusplets. The main cusp is massive, bulging in the lower half ( Fig. 4A View Fig 2 View Fig , A 5 View Fig ). The cusplets are small and sharp, triangular in shape, with a broad base and rounded tip. Their axes are slightly divergent from the main cusp. The enameloid below the cusp and cusplets junction is high. The crown overhangs the root labially. The enameloid of almost all crown face excluding the cusp tip is covered by folds. The folds on the labial face of the main cusp are strong, straight or slightly flexuous, reaching up to 2/3 up the crown, trapezoidal in cross−section, due to two longitudinal sharp edges. The folds on the lingual surface are less pronounced, particularly in the medial part, and the longitudinal edges are prominent on part of them. The folds are flexuous and extend from the base to top or intermittent, or rise in a middle part of the cusp; they may dichotomize. The enameloid folds of the lateral cusplets are like to those on the labial surface. The cutting edge is well−developed and entire. The root is low, strongly prominent lingually in occlusal view. The nutritive groove is wide and deep. There is a double central foramen in a deep rounded slightly lingually displaced pit. The lingual face of the root has some deep oval margino−lingual foramina. There are some margino−labial foramina.
Paratype ( Fig. 4B View Fig ).— PIN 5088 View Materials /04, anterior tooth. The main cusp is vertical, massive, more evenly widened from the top to the base than the holotype. The cusplets are reduced almost to shoulders on the both sides of the cusp. The enameloid of the lower half of the cusp and all of the shoulders are covered by the vertical folds. The folds of the labial side are strong, wide, straight or slightly flexuous. The folds of the lingual side are less strong, more flexuous, covering the shoulders and lateral parts of the crown in lower half. The crown overhangs of the root labially. The lingual part of the root is eroded, the remaining part shows a wide and deep nutritive groove with a doubled central foramen. There are some margino−lingual and margino−lateral foramina on the root, and a fairly prominent central protuberance .
Lateral tooth ( Fig. 5 View Fig ).—IGG 8SP/D−03/01, shows the massive cusp, bulging in its lower part. There are two pairs of cusplets flanked by the distal shoulders. The enameloid on the labial and lingual sides is covered by the folds. The folds on the labial face are prominent, some of them are bifurcated, and persistent almost from the upper part of the cusp, excluding the tip, to the base. The folds on the lingual one are undulating and form the wave face. The cutting edges are low developed, they are represented by the outermost labial enameloid folds proceeding to the cusplets. The folds on the cusplets are similar to those on the cusp. The crown overhangs of the root labially forming the riffling border. The root is low, strongly prominent lingually in occlusal view, shows a wide and deep nutritive groove with a doubled central foramen. There are two large foramina in the groove (one lingually to another), one large margino−lingual foramen flanked by some smaller ones on the each side of the root lingual face, and some margino−lateral foramina.
Comparisons.—The teeth of new species Foumtizia zhelezkoi sp. nov. fit exactly the genus description, except the folds characters. The main difference between F. zhelezkoi sp. nov. and other members of the genus are that the new genus is represented by more stocky teeth with prominent folds covering most of both the labial and lingual faces of the enameloid. Another diagnostic character of the genus Foumtizia not always present in F. zhelezkoi sp. nov. is the whole cutting edge on all teeth. F. zhelezkoi sp. nov. has not the whole cutting edge on some lateral teeth, e.g., IGG 8SP/D−03/01 ( Fig. 5 View Fig ).
In comparison with F. pattersoni ( Cappetta, 1976) , F. zhelezkoi sp. nov. has a thicker and more inflated cusp, more rectilinear line of the crown base on the labial side of the anterior teeth, much more striated enameloid on the main part of the crown, and a characteristic fold shape.
From F. abdouni Noubhani and Cappetta, 1997 , F. zhelezkoi sp. nov. differs by having labio−lingually thicker crown and stronger main cusp on the anterior−lateral and lateral teeth, violently folded enameloid, less developed cutting edges, particularly on the lateral teeth, and smaller cusplets on the lateral teeth.
The same differences are more evident in comparison with F. gadaensis Noubhani and Cappetta, 1997 and F. arba Noubhani and Cappetta, 1997 . Moreover, teeth of F. gadaensis have more bulging border at the base of enameloid on their labial side and mesio−distally longer lateral teeth with more cusplets. The teeth of F. arba have root branches more extended labially.
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