Tethylamna twiggsensis
(Case, 1981)
Classification: Elasmobranchii Lamniformes Odontaspididae
Reference of the original description
Late Eocene selachians from South-central Georgia. Palaeontographica, Abt. A, 176(1–3), 52–79
Late Eocene selachians from South-central Georgia. Palaeontographica, Abt. A, 176(1–3), 52–79
Types
Tethylamna twiggsensis
Holotype: UNSM: 23506; Paratype: UNSM: 23507; UNSM: 23508; UNSM: 23509; UNSM: 23510;
Tethylamna twiggsensis
Holotype: UNSM: 23506; Paratype: UNSM: 23507; UNSM: 23508; UNSM: 23509; UNSM: 23510;
Description:
Citation: Tethylamna twiggsensis (Case, 1981): In: Database of fossil elasmobranch teeth www.shark-references.com, World Wide Web electronic publication, Version 12/2024
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Distribution Geographic
Priabonian of Georgia, USA, Priabonian of Egypt, western Sahara, Morocco, of Pakistan and of Peru [24889]
Priabonian of Georgia, USA, Priabonian of Egypt, western Sahara, Morocco, of Pakistan and of Peru [24889]
Distribution Strategraphy
Eocene
Eocene
Description
Diagnosis after Case 1981 [391]: Teeth ranging in size from 1.5 to 3 cms, and averaging 2.5 cms, a vestigial median furrow (groove) on the root area, teeth with from 1 to 2 lateral cusps on either side. Description: Lower jaw teeth erect. Anterior teeth with slender cuspidate lateral cusps. Lateral teeth wider, with from 1 to 2 lateral cusps, triangular in shape, and the larger of the cusps — flaring out in opposite directions from the tooth blade. No medial furrow (groove), but an imperfectly developed "furrow" on some specimens, with a definitive apical foramen positioned on the lingual boss of the tooth's root.
Diagnosis after Case 1981 [391]: Teeth ranging in size from 1.5 to 3 cms, and averaging 2.5 cms, a vestigial median furrow (groove) on the root area, teeth with from 1 to 2 lateral cusps on either side. Description: Lower jaw teeth erect. Anterior teeth with slender cuspidate lateral cusps. Lateral teeth wider, with from 1 to 2 lateral cusps, triangular in shape, and the larger of the cusps — flaring out in opposite directions from the tooth blade. No medial furrow (groove), but an imperfectly developed "furrow" on some specimens, with a definitive apical foramen positioned on the lingual boss of the tooth's root.
Remarks
shark-references Species-ID=15047;
valid after Cappetta & Case (2016) p. 51 [24889];
synonym of Brachycarcharias twiggsensisi after Ebersole et al. (2019) p. 43 [27789];
shark-references Species-ID=15047;
valid after Cappetta & Case (2016) p. 51 [24889];
synonym of Brachycarcharias twiggsensisi after Ebersole et al. (2019) p. 43 [27789];
References
Sharks and rays from the Mokattamian Stage (middle and late Eocene) of Egypt, including some species from the middle Eocene Midra Shale of Qatar. Egyptian Journal of Geology, 66(1), 105–153
DOI: 10.21608/EGJG.2022.173845.1028
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
A Selachian Fauna from the Middle Eocene (Lutetian, Lisbon Formation) of Andalusia, Covington County, Alabama, USA. Palaeontographica, Abt. A, 307(1–6), 43–103
Sharks and rays from the Mokattamian Stage (middle and late Eocene) of Egypt, including some species from the middle Eocene Midra Shale of Qatar. Egyptian Journal of Geology, 66(1), 105–153
DOI: 10.21608/EGJG.2022.173845.1028
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
A Selachian Fauna from the Middle Eocene (Lutetian, Lisbon Formation) of Andalusia, Covington County, Alabama, USA. Palaeontographica, Abt. A, 307(1–6), 43–103
