Ozarkodina, Männik & Miller & Hairapetian, 2015

Männik, Peep, Miller, C. Giles & Hairapetian, Vachik, 2015, A new early Silurian prioniodontid conodont with three P elements from Iran and associated species, Acta Palaeontologica Polonica 60 (3), pp. 733-746 : 741-743

Ozarkodina sp. nov. (aff. Ozarkodina sp. A Mabillard and Aldridge, 1983)

Fig. 5J, L.

2013 Ozarkodina sp. nov. (aff. Ozarkodina sp. A Mabillard and Aldridge, 1983); Männik et al. 2013: 10, fig. 4h, P

1

element.

Material.— P 1 element, 2 specimens from a section located about 65 km north-west of Tabas, on the eastern side of the Dahaneh-e-Kolut Gorge in the Derenjal Mountains , East Central Iran; Hill B, uppermost Unit 11 (sample S19). Pterospathodus amorphognathoides lennarti Conodont Zone, Telychian, Llandovery, Silurian .

Description.— P 1 element (Fig. 5J, L): Carminate, straight, laterally compressed with a straight to slightly arched lower edge in lateral view. Anterior blade short and high, bears 6–7 fused and compressed denticles which are inclined to posterior proximally and more erect distally. Second denticle from anterior margin about twice as wide as all other denticles on blade. Cusp indistinct as all adjacent denticles are similar in size. From immediately above basal cavity, height of denticle row decreases rapidly towards posterior margin, although this margin is not preserved on specimens available. Preserved part of posterior process bears 5 low, posteriorly inclined denticles of irregular height and width. Both processes slightly thickened mid-blade, parallel to basal margin. Basal cavity shallow, strongly flared beneath cusp with prominent asymmetrical lobes, probably extending as shallow groove beneath entire blade as well preserved basal body present below entire element.

Remarks.—P 1 elements of Ozarkodina sp. nov. (aff. Ozarkodina sp. A Mabillard and Aldridge, 1983) resemble Ozarkodina sp. A of Mabillard and Aldridge (1983: pl. 3: 7, 8) in general configuration only. Both taxa have short P 1 elements with a high anterior blade and denticles on the posterior blade that rapidly decrease in height from the cusp. Morphological differences are evident between these two taxa. According to Mabillard and Aldridge (1983), the Pa (= P 1) element of Ozarkodina sp. A has 3–4 short, erect, broad denticles of subequal size on its anterior blade whereas our specimens have relatively small denticles with one considerably larger denticle in the anteriormost part of the blade. The cusp of Ozarkodina sp. A is broad and distinct whereas our specimens have cusps that do not differ in size from the other denticles. The P 1 element basal cavity of Ozarkodina sp. nov. (aff. Ozarkodina sp. A Mabillard and Aldridge, 1983) is shorter but more strongly flared than in Ozarkodina sp. A .