Hemipristis cf. serra Agassiz, 1835
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publication ID |
https://doi.org/ 10.4202/app.00341.2017 |
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persistent identifier |
https://treatment.plazi.org/id/03844047-FF86-FFBC-C76A-F8EDD03BF2FE |
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treatment provided by |
Felipe |
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scientific name |
Hemipristis cf. serra Agassiz, 1835 |
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Hemipristis cf. serra Agassiz, 1835 (1843)
Fig. 12D View Fig .
Material.—Nine teeth (CGM67186: one, CGM67191: one, CGM67195: seven), three badly damaged, from the BOS,
early Oligocene, Minqar Tibaghbagh, Qattara Depression, Egypt. Dimensions: height 9–23 mm, width 5–22 mm.
Description.—Teeth are highly distinctive. The cusp is strongly curved distally, with the tip of the cusp being approximately above the tip of the distal root lobe. The large serrations on the mesial edge of the cusp are only present close to the tip, whilst larger serrations still are present on the distal cusp edge, being largest in the mid, most concave part of the cusp. The root is high and raised in the central part with a robust labial protuberance. Only upper teeth have been collected.
Remarks.—The teeth of Hemipristis cf. serra are larger than those of H. curvatus Dames, 1883 at the middle to late Eocene sites of the Fayum Depression. The length of the H. cf. serra teeth from the BOS at Minqar Tibaghbagh is larger than a figured tooth of H. curvatus (7.1 mm in length) from “site 26” of the Priabonian Birket Qarun Formation, the Fayum Province ( Underwood et al. 2011: fig. 5b). The larger size is suggestive of a younger geological age. Some teeth have the same overall morphology as H. curvatus , with only small serrations at the mesial edge, but one tooth (the largest) has larger serrations at this side. This tooth bears a strong resemblance to H. serra Bourdon 2011 ). An origin from Miocene layers higher in the succession is possible for this unexpectedly large tooth. Similar teeth from the early Oligocene of Balochistan, Pakistan were described as H. cf. serra Agassiz, 1843 by Adnet et al. (2007). Teeth of H. cf. serra can be distinguished from H. curvatus by being larger and by the presence of more than three large serrations on the mesial edge of the upper teeth. The only weak serrations of the mesial edge, slighter than in typical H. serra teeth are suggestive of a transitional form between H. curvatus and H. serra Adnet et al. 2007 ). Whilst this Oligocene species probably represents an unnamed species, naming this is beyond the scope of this study.
Hemipristis cf. serra is known from the Eocene of Saudi Arabia, the Oligocene of Oman and Pakistan in Asia and of South Carolina, North America. The genus Hemipristis is known from the middle and late Eocene of Europe, Africa, North and South America, and Asia to Recent in the Indian Ocean ( Cappetta 2012).
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