Megalolamna paradoxodon
Shimada, Chandler, Lam, Tanaka & Ward, 2017
Classification: Elasmobranchii Lamniformes Otodontidae
Reference of the original description
A new elusive otodontid shark (Lamniformes: Otodontidae) from the lower Miocene, and comments on the taxonomy of otodontid genera, including the ‘megatoothed’ clade. Historical Biology, 29(5), 704–714
A new elusive otodontid shark (Lamniformes: Otodontidae) from the lower Miocene, and comments on the taxonomy of otodontid genera, including the ‘megatoothed’ clade. Historical Biology, 29(5), 704–714
Synonyms / new combinations and misspellings
Cretalamna bassanii
Cretalamna bassanii
Description:
Citation: Megalolamna paradoxodon Shimada, Chandler, Lam, Tanaka & Ward, 2017: In: Database of fossil elasmobranch teeth www.shark-references.com, World Wide Web electronic publication, Version 10/2024
Please send your images of "Megalolamna paradoxodon" to info@shark-references.com
Megalolamna paradoxodon Shimada, Chandler, Lam, Tanaka & Ward, 2017 collection and © Jean-Marie Canevet
Megalolamna paradoxodon Shimada, Chandler, Lam, Tanaka & Ward, 2017 collection and © Jean-Marie Canevet
Description
Original diagnose after Shimada et al. (2017) p. 706 [24480]: Lamniform differing from all known species of otodontids (sensu this paper; see Discussion) by the following combination of characters: tooth consisting of a sharply-pointed, relatively tall, triangular main cusp, one prominent pair of triangular lateral cusplets, and strongly bilobed root; main cusp erect, slightly inclined distally, or gently curved distally; lingual crown face very convex without ornamentation; labial crown face flat or subtly convex except center of base with weak depression; height and width of each lateral cusplet nearly equal with tendency to point outward; both mesial and distal cutting edges of main cusp and lateral cusplets smooth and razor-like, and continuous from apex to base; main cusp and lateral cusplets nearly erect to gently curved lingually; concave crown base and distinct tooth neck on lingual face; prominent tooth neck also on labial face in tall teeth, forming rounded ledge with thin enameloid layer that grades into enameloid of main cusp and lateral cusplets; bilobed root with rounded basal tips and moderately tight basal concavity in between; root overall robust but particularly at lingual protuberance that generally exhibits one or two prominent and a few smaller nutritive foramina; root width slightly wider than total crown width; osteodentine tooth histology.
Original diagnose after Shimada et al. (2017) p. 706 [24480]: Lamniform differing from all known species of otodontids (sensu this paper; see Discussion) by the following combination of characters: tooth consisting of a sharply-pointed, relatively tall, triangular main cusp, one prominent pair of triangular lateral cusplets, and strongly bilobed root; main cusp erect, slightly inclined distally, or gently curved distally; lingual crown face very convex without ornamentation; labial crown face flat or subtly convex except center of base with weak depression; height and width of each lateral cusplet nearly equal with tendency to point outward; both mesial and distal cutting edges of main cusp and lateral cusplets smooth and razor-like, and continuous from apex to base; main cusp and lateral cusplets nearly erect to gently curved lingually; concave crown base and distinct tooth neck on lingual face; prominent tooth neck also on labial face in tall teeth, forming rounded ledge with thin enameloid layer that grades into enameloid of main cusp and lateral cusplets; bilobed root with rounded basal tips and moderately tight basal concavity in between; root overall robust but particularly at lingual protuberance that generally exhibits one or two prominent and a few smaller nutritive foramina; root width slightly wider than total crown width; osteodentine tooth histology.
Remarks
shark-references Species-ID=14704;
type species of Megalolamna Shimada et al., 2016 p. 706 [24480] by original designation (Art. 68.2 ICZN);
valid after Shimada et al. (2017) p. 706 [24480];
shark-references Species-ID=14704;
type species of Megalolamna Shimada et al., 2016 p. 706 [24480] by original designation (Art. 68.2 ICZN);
valid after Shimada et al. (2017) p. 706 [24480];
References
New geographic and stratigraphic occurrences of the enigmatic extinct lamniform shark, Megalolamna (Lamniformes: Otodontidae), from the eastern USA. Historical Biology, in press
DOI: 10.1080/08912963.2023.2282664
The first recognition of the enigmatic fossil shark genus Megalolamna (Lamniformes, Otodontidae) from the lower Miocene of Europe and M. serotinus (Probst, 1879) as the newly designated type species for the genus. Zitteliana, 95, 1–XX
A Review of the Paleobiology of Some Neogene Sharks and the Fossil Records of Extant Shark Species. Diversity, 16(3), Article 147
DOI: 10.3390/d16030147
Trophic relationships in the Early Miocene Upper Marine Molasse of Baden-Württemberg, Southwest Germany, with special emphasis on the elasmobranch fauna. Palaeontologia Electronica, 26(3), Article a46
DOI: 10.26879/1233
Feeding ecology has shaped the evolution of modern sharks. Current Biology, 31(23), 5138–5148
DOI: 10.1016/j.cub.2021.09.028
Diversity and paleoenvironmental implications of an elasmobranch assemblage from the Oligocene–Miocene boundary of Ecuador. PeerJ, 8, Article e9051
DOI: 10.7717/peerj.9051
The early Miocene elasmobranch assemblage from Zamaca (Chilcatay Formation, Peru). Journal of South American Earth Sciences, 91, 352–371
DOI: 10.1016/j.jsames.2018.08.004
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 new elusive otodontid shark (Lamniformes: Otodontidae) from the lower Miocene, and comments on the taxonomy of otodontid genera, including the ‘megatoothed’ clade. Historical Biology, 29(5), 704–714
DOI: 10.1080/08912963.2016.1236795
New geographic and stratigraphic occurrences of the enigmatic extinct lamniform shark, Megalolamna (Lamniformes: Otodontidae), from the eastern USA. Historical Biology, in press
DOI: 10.1080/08912963.2023.2282664
The first recognition of the enigmatic fossil shark genus Megalolamna (Lamniformes, Otodontidae) from the lower Miocene of Europe and M. serotinus (Probst, 1879) as the newly designated type species for the genus. Zitteliana, 95, 1–XX
A Review of the Paleobiology of Some Neogene Sharks and the Fossil Records of Extant Shark Species. Diversity, 16(3), Article 147
DOI: 10.3390/d16030147
Trophic relationships in the Early Miocene Upper Marine Molasse of Baden-Württemberg, Southwest Germany, with special emphasis on the elasmobranch fauna. Palaeontologia Electronica, 26(3), Article a46
DOI: 10.26879/1233
Feeding ecology has shaped the evolution of modern sharks. Current Biology, 31(23), 5138–5148
DOI: 10.1016/j.cub.2021.09.028
Diversity and paleoenvironmental implications of an elasmobranch assemblage from the Oligocene–Miocene boundary of Ecuador. PeerJ, 8, Article e9051
DOI: 10.7717/peerj.9051
The early Miocene elasmobranch assemblage from Zamaca (Chilcatay Formation, Peru). Journal of South American Earth Sciences, 91, 352–371
DOI: 10.1016/j.jsames.2018.08.004
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 new elusive otodontid shark (Lamniformes: Otodontidae) from the lower Miocene, and comments on the taxonomy of otodontid genera, including the ‘megatoothed’ clade. Historical Biology, 29(5), 704–714
DOI: 10.1080/08912963.2016.1236795