Cepola anderssoni, Schwarzhans & Mors & Engelbrecht & Reguero & Kriwet, 2017

Schwarzhans, Werner, Mors, Thomas, Engelbrecht, Andrea, Reguero, Marcelo & Kriwet, Jurgen, 2017, Before the freeze: otoliths from the Eocene of Seymour Island, Antarctica, reveal dominance of gadiform fishes (Teleostei), Journal of Systematic Palaeontology 15 (2), pp. 147-170 : 160-162

Cepola anderssoni sp. nov.

( Figs 5Q, R , 6R )

Material. Holotype: NRM-PZ P.15996 ( Figs 5Q, R , 6R ) (only specimen, broken into two halves during handling) .

Occurrence. Telm 5 unit; ‘ Natica horizon’, Cucullea I member, La Meseta Formation, late Ypresian, early Eocene. Site IAA 2/95, Seymour Island, Antarctica.

Etymology. Named in honour of Johan Gunnar Andersson, a Swedish pioneer of geological research in Antarctica.

Diagnosis. OL:OH = 1.85. Dorsal rim shallow, with broadly rounded postdorsal angle. Rostrum sharp; posterior tip less sharp. OsL:CaL = 2.1; OCL: CCL = 2.0. Ostial colliculum reduced anteriorly, terminating at considerable distance from anterior rim of otolith. Outer face flat.

Description. Otolith elongate, thin, 4.4 mm long. OH:OT = 3.2. Dorsal rim shallow, gently curving, smooth, with broadly rounded postdorsal angle and highest at postdorsal angle. Ventral shallow, very regularly curving, highest at its middle, smooth. Rostrum long and sharp; dorsal margin of ostial opening regularly ascending without marked excisura or antirostrum. Posterior tip pointed, but considerably less sharply and projecting as rostrum.

Inner face convex with distinctly supramedian positioned narrow sulcus. Sulcus typically S-shaped with cauda being curved upwards from collum prior to terminating with an inferior tip. Ostium twice as long as cauda, slightly wider and narrower. Ostial colliculum not extending to opening of ostium to anterodorsal otolith rim. Collum ascending, wide, with feeble pseudocolliculum. Cauda very short, its small colliculum distinctly deepened. Dorsal depression large, well marked towards sulcus; ventral furrow feeble, running moderately distant from ventral rim of otolith. Outer face flat and smooth.

Remarks. Cepolid otoliths are well known from the Eocene of Europe represented by a number of species (see Nolf 2013). Of those, Cepola excavata (Stinton, 1978) and C. bartonensis Schubert, 1916 resemble the proportions of the otolith ( Nolf 2013; Schwarzhans 2007), while other species are more compressed ( C. densa (Frost, 1934) and C. robusta Nolf, 1988 ). Cepola anderssoni differs from all those species by the anteriorly restricted ostial colliculum and the very small cauda. Cepola yrieuensis Steurbaut, 1984 from the early Oligocene of south-west France is similar in the short cauda, but differs in the distinct postdorsal angle (vs. rounded postdorsal region) and the ostial colliculum reaching to or close to the anterior rim (vs. anteriorly restricted).

Figures

Figure 5. Drawings of Eocene otoliths from Seymour Island. A—C, Hoplobrotula? antipoda sp. nov.; A, B, holotype, NRM-PZ P.15984, mirror imaged; A, inner face; B, ventral view; C, paratype, NRM-PZ P.15985, inner face. D—G, Notoberyx cionei gen. nov., sp. nov.; D—F, holotype, NRM-PZ P.15987; D, anterior view; E, inner face; F, ventral view; G, paratype, NRM-PZ P.15988, inner face. H, Centroberyx sp., NRM-PZ P.15986, mirror imaged, inner face. I, J, Acanthopterygii indet., NRM-PZ P.15990, mirror imaged; I, inner face, J, ventral view. K, L, Percoidei indet., NRM-PZ P.15992, mirror imaged; K, inner face; L, ventral view. M, N, Haemulidae? indet., NRM-PZ P.15993, mirror imaged; M, inner face; N, ventral view. O, P, Sparidae? indet., NRM-PZ P.15994, mirror imaged; O, inner face; P, ventral view. Q, R, Cepola anderssoni sp. nov., holotype, NRM-PZ P.15996, mirror imaged; Q, inner face; R, ventral view.

Figure 6. Eocene otoliths from Seymour Island. A, Argentina antarctica sp. nov., holotype, NRM-PZ P.15964, mirror imaged, inner face. B, C, Diaphus? marambionis sp. nov., holotype, NRM-PZ P.15966; B, inner face; C, ventral view. D—F, Macruronus eastmani sp. nov., holotype, NRM-PZ P.15970, mirror imaged; D, inner face; E, ventral view; F, outer face. G—I, Palimphemus seymourensis sp. nov., holotype, NRM-PZ P.15973, mirror imaged; G, inner face; H, ventral view; I, outer face. J—L, Coelorinchus nordenskjoeldi sp. nov., holotype, NRM-PZ P.15978; J, inner face; K, ventral view; L, outer face. M, N, Coelorinchus balushkini sp. nov., holotype, NRM-PZ P.15976; M, inner face; N, ventral view. O, P, Hoplobrotula? antipoda sp. nov., holotype, NRM-PZ P.15984, mirror imaged; O, inner face; P, ventral view. Q, Notoberyx cionei gen. nov., sp. nov.; holotype, NRM-PZ P.15987, inner face. R, Cepola anderssoni sp. nov., holotype, NRM-PZ P.15996, mirror imaged, inner face.