Ctenacanthiformes Glikman, 1964

Ginter, Michał & Złotnik, Michał, 2019, Mississippian chondrichthyan fishes from the area of Krzeszowice, southern Poland, Acta Palaeontologica Polonica 64 (3), pp. 549-564 : 555-556

Order Ctenacanthiformes Glikman, 1964 Family Ctenacanthidae Dean, 1909 Ctenacanthidae indet.

Fig. 5C .

Material.— One tooth (ZPAL P. IV/307) from the upper Viséan, Czerna, sample Cz-1.

Description.— The tooth is relatively small compared to most of the known ctenacanthiform species (about 0.5 mm mesio-distally). Its crown is cladodont, tricuspid, with a prominent median cusp (unfortunately the upper part is broken) and the lateral cusps considerably diverging laterally. The cusps are compressed labio-lingually, with a carina connecting their bases, and covered with strong cristae on both sides. The base bears an orolingual button and a basolabial prominence narrower than the median cusp.

Remarks.— The tooth from Czerna resembles to some extent those of Ctenacanthus terrelli ( Newberry, 1889) from upper Famennian Cleveland Shale of Ohio ( USA), and particularly the small specimen illustrated by Ginter (2010: fig. 3E, F), with its conspicuous cristation.

Figures

Fig. 5. Chondrichthyan fish teeth from the upper Viséan of Czerna, Poland. A, B. Cladodontomorphi indet. 1. A. ZPAL P. IV/255 in labial (A1) and basal (A2) views. B. ZPAL P. IV/306, small specimen with a broken piece lying nearby in lingual (B1) and oral (B2) views. C. Ctenacanthidae indet., ZPAL P. IV/307 in oral (C1) and labial (C2) views. D. Cladodontomorphi indet. 2, ZPAL P. IV/308 in labial (D1), lingual (D2), and oral (D3) views. E. Cassisodus sp., ZPAL P. IV/309 in oral (D1) and lingual (D2) views. F. Cassisodus sp., ZPAL P. IV/232 in lingual (E1) and oral (E2) views.