Sphyrna robustum
Cicimurri, Ebersole, Stringer, Starnes & Phillips, 2025
Classification: Elasmobranchii Carcharhiniformes Sphyrnidae
Reference of the original description
Late Oligocene fishes (Chondrichthyes and Osteichthyes) from the Catahoula Formation in Wayne County, Mississippi, USA. European Journal of Taxonomy, 984(1), 1–131
Late Oligocene fishes (Chondrichthyes and Osteichthyes) from the Catahoula Formation in Wayne County, Mississippi, USA. European Journal of Taxonomy, 984(1), 1–131
Description:
Citation: Sphyrna robustum Cicimurri, Ebersole, Stringer, Starnes & Phillips, 2025: In: Database of fossil elasmobranch teeth www.shark-references.com, World Wide Web electronic publication, Version 09/2025
Please send your images of "Sphyrna robustum" to info@shark-references.com
Sphyrna robustum Cicimurri, Ebersole, Stringer, Starnes & Phillips, 2025; “Sphyrna” robustum sp. nov., teeth. A–B. SC2013.28.166, upper right anterior tooth. A. Labial view. B. Lingual view. C–E. SC2013.28.167 (paratype), lower right lateral tooth. C. Labial view. D. Lingual view. E. Mesial view. F–G. SC2013.28.170, lower right anterior tooth. F. Labial view. G. Lingual view. H–I. SC2013.28.181, upper right lateral tooth. H. Labial view. I. Lingual view. J–L. SC2013.28.169, lower right antero-lateral tooth (paratype). J. Labial view. K. Lingual view. L. Mesial view. M–N. SC2013.28.172, upper left lateral tooth. M. Labial view. N. Lingual view. O–P. SC2013.28.180, upper left postero-lateral tooth. O. Labial view. P. Lingual view. Q–S. SC2013.28.171 (holotype), upper right lateral tooth. Q. Labial view. R. Lingual view. S. Mesial view. T–U. SC2013.28.182, lower left lateral tooth. T. Labial view. U. Lingual view. V–W. SC2013.28.915, lower right lateral tooth. V. Labial view. W. Lingual view. X–Y. SC2013.28.916, upper left lateral tooth. X. Labial view. Y. Lingual view. Z–AA. SC2013.28.917, lower right posterolateral tooth. Z. Labial view. AA. Lingual view. Scale bars = 3 mm.
Sphyrna robustum Cicimurri, Ebersole, Stringer, Starnes & Phillips, 2025; “Sphyrna” robustum sp. nov., teeth. A–B. SC2013.28.166, upper right anterior tooth. A. Labial view. B. Lingual view. C–E. SC2013.28.167 (paratype), lower right lateral tooth. C. Labial view. D. Lingual view. E. Mesial view. F–G. SC2013.28.170, lower right anterior tooth. F. Labial view. G. Lingual view. H–I. SC2013.28.181, upper right lateral tooth. H. Labial view. I. Lingual view. J–L. SC2013.28.169, lower right antero-lateral tooth (paratype). J. Labial view. K. Lingual view. L. Mesial view. M–N. SC2013.28.172, upper left lateral tooth. M. Labial view. N. Lingual view. O–P. SC2013.28.180, upper left postero-lateral tooth. O. Labial view. P. Lingual view. Q–S. SC2013.28.171 (holotype), upper right lateral tooth. Q. Labial view. R. Lingual view. S. Mesial view. T–U. SC2013.28.182, lower left lateral tooth. T. Labial view. U. Lingual view. V–W. SC2013.28.915, lower right lateral tooth. V. Labial view. W. Lingual view. X–Y. SC2013.28.916, upper left lateral tooth. X. Labial view. Y. Lingual view. Z–AA. SC2013.28.917, lower right posterolateral tooth. Z. Labial view. AA. Lingual view. Scale bars = 3 mm.
Description
Original diagnosis after Cicimurri, Ebersole, Stringer, Starnes & Phillips (2025) p. 41-42 [34348]: “Sphyrna” robustum sp. nov. teeth differ from those of coeval “Sphyrna” gracile sp. nov. (see above) by their greater stoutness, larger overall size, lower cusp height with respect to tooth size, and differing shapes of the mesial cutting edge. These features also serve to distinguish “S.” robustum from the extinct S. integra and S. arambourgi (see Cappetta 1970; Reinecke et al. 2011). Although morphologically similar to “S.” robustum, fossil S. laevissima teeth have a more biconvex cusp and the mesial cutting edge is conspicuously sinuous (Purdy et al. 2001: fig. 60). Of presumed extant descendant species, the teeth of S. mokarran and S. zygaena are comparable to those of “S.” robustum. However, the mesial cutting edges of the new Oligocene species are less convex and lack serrations.
Original diagnosis after Cicimurri, Ebersole, Stringer, Starnes & Phillips (2025) p. 41-42 [34348]: “Sphyrna” robustum sp. nov. teeth differ from those of coeval “Sphyrna” gracile sp. nov. (see above) by their greater stoutness, larger overall size, lower cusp height with respect to tooth size, and differing shapes of the mesial cutting edge. These features also serve to distinguish “S.” robustum from the extinct S. integra and S. arambourgi (see Cappetta 1970; Reinecke et al. 2011). Although morphologically similar to “S.” robustum, fossil S. laevissima teeth have a more biconvex cusp and the mesial cutting edge is conspicuously sinuous (Purdy et al. 2001: fig. 60). Of presumed extant descendant species, the teeth of S. mokarran and S. zygaena are comparable to those of “S.” robustum. However, the mesial cutting edges of the new Oligocene species are less convex and lack serrations.
Remarks
shark-references Species-ID=17564
shark-references Species-ID=17564
References
Late Oligocene fishes (Chondrichthyes and Osteichthyes) from the Catahoula Formation in Wayne County, Mississippi, USA. European Journal of Taxonomy, 984(1), 1–131
DOI: 10.5852/ejt.2025.984.2851
Late Oligocene fishes (Chondrichthyes and Osteichthyes) from the Catahoula Formation in Wayne County, Mississippi, USA. European Journal of Taxonomy, 984(1), 1–131
DOI: 10.5852/ejt.2025.984.2851
