Tethylamna dunni

Cappetta & Case, 2016


Classification: Elasmobranchii Lamniformes Odontaspididae

Reference of the original description
Cappetta, H. & Case, G.R. (2016)
A Selachian Fauna from the Middle Eocene (Lutetian, Lisbon Formation) of Andalusia, Covington County, Alabama, USA. Palaeontographica, Abt. A, 307(1–6), 43–103

Types
Tethylamna dunni
Holotype: USTL: UM-PAD 59; Paratype: USTL: UM-PAD 53; USTL: UM-PAD 54; USTL: UM-PAD 58; USTL: UM-PAD 63;


Description:


Citation: Tethylamna dunni Cappetta & Case, 2016: In: Database of fossil elasmobranch teeth www.shark-references.com, World Wide Web electronic publication, Version 02/2024

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Description
Original diagnose after Cappetta & Case (2016) p. 52 [24889]: Compared with Tethylamna twiggsensis, T. dunni possesses teeth of smaller size (34.46mmtotal height for the largest anterior tooth). Anterior teeth are also more slender, and mainly more labio-lingually lattened. he lateral cusplets are usually more slender, sharper, and more hook-shaped. In lateral teeth, the cusp of T. dunni is less wide, with an apical part more bent distally. he main diferences can be noted for the marginal cusplets. In T. dunni they are not very large, rather erect, with a triangular outline and almost of the same size for each pair. In T. twiggsensis the lateral cusplets are larger with clearly asymmetrical pairs. he mesial pair shows a main cusplet triangular, erect and slightly diverging. he main cusplet of the distal pair is larger, asymmetrical, and strongly bent distally, with a covering of its basal mesial part by the cutting edge of the cusp in labial view.

Remarks
shark-references Species-ID=14824;
type species of Tethylamna Cappetta & Case, 2016 p. 50 [24889] by original designation (Art. 68.2 ICZN);

valid after Cappetta & Case (2016) p. 51 [24889]; Ebersole et al. (2019) p. 53 [27789];


References
Ebersole, J.A. & Cicimurri, D.J. & Stringer, G.L. (2019)
Taxonomy and biostratigraphy of the elasmobranchs and bony fishes (Chondrichthyes and Osteichthyes) of the lower-to-middle Eocene (Ypresian to Bartonian) Claiborne Group in Alabama, USA, including an analysis of otoliths. European Journal of Taxonomy, 585, 1–274
DOI: 10.5852/ejt.2019.585
Condamine, F.L. & Romieu, J. & Guinot, G. (2019)
Climate cooling and clade competition likely drove the decline of lamniform sharks. Proceedings of the National Academy of Sciences of the United States of America, 116(41), 20584–20590
DOI: 10.1073/pnas.1902693116
Cappetta, H. & Case, G.R. (2016)
A Selachian Fauna from the Middle Eocene (Lutetian, Lisbon Formation) of Andalusia, Covington County, Alabama, USA. Palaeontographica, Abt. A, 307(1–6), 43–103