Hemipristis curvatus Dames, 1883,

Ebersole, Jun A., Cicimurri, David J. & Stringer, Gary 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, inclu, European Journal of Taxonomy 585, pp. 1-274: 66-67

publication ID

https://doi.org/10.5852/ejt.2019.585

publication LSID

lsid:zoobank.org:pub:181B6FBA-ED75-4BB4-84C4-FB512B794749

DOI

http://doi.org/10.5281/zenodo.3664570

persistent identifier

http://treatment.plazi.org/id/18174D41-FFC4-FFED-FD8D-9DFF4C000B9D

treatment provided by

Plazi

scientific name

Hemipristis curvatus Dames, 1883
status

 

Hemipristis curvatus Dames, 1883 

Fig. 24View Fig

Hemipristis curvatus Dames, 1883: 140  , pl. 3, fig. 4a–b.

Hemipristis wyattdurhami White, 1956: 134  , text-pl. figs 40–47, pl. 11, fig. 4.

Hemipristis serra – Woodward 1889: 451  .

Hemipristis wyattdurhami – Thurmond & Jones 1981: 63  , fig. 29.

Material examined

UNITED STATES OF AMERICA – Alabama • 6 isolated teeth; Claiborne Group; ALMNH PV1989.4.189, ALMNH PV1989.4.220, ALMNH PV1989.4.221, MSC 2376.1–2, MSC 2377.

Description

Upper anterior teeth have high, triangular crown. Mesial cutting edge elongate, slightly convex, bearing four large serrae basally but otherwise smooth; basal serrae decrease in size towards crown foot. Upper half of the distal edge smooth, vertical, whereas basal half bears five large serrae decreasing in size towards the crown foot. Mesial edge and upper half of the distal edge form conspicuous cusp that is slightly distally inclined. Root has a large lingual boss bisected by a nutritive groove. Upper lateral teeth have broad-based crown bearing distally curving cusp. Mesial cutting edge very convex, smooth except for one-or-two medially located serrae. Apical one-third of distal edge smooth, forms distally inclined cusp along with mesial edge. Lower two-thirds of distal edge formed into heavily serrated oblique heel; five-to-eight serrae present that decrease in size basally. Root bilobate; very short and highly diverging lobes separated by V-shaped interlobe area; wide, shallow lingual nutritive groove.

Remarks

Woodward (1889: 451) originally reported a tooth collected from Eocene deposits in Clarke County, AL as Hemipristis serra Agassiz, 1843  , noting, however, that the specimen was “doubtfully of this species.” This specimen was later reexamined by White (1956) and referred to a new species, Hemipristis wyattdurhami  , a taxon that Cappetta (1987) later designated as a junior synonym of H. curvatus Dames, 1883  . Teeth of H. serra  attain much larger sizes than those of H. curvatus  , and the mesial cutting edge on the upper teeth and lower lateral teeth of H. serra  bear more denticles than do teeth of H. curvatus  . In contrast, the mesial edge on H. curvatus  teeth in these jaw positions are smooth or with few very weak denticles. H. serra  is also widely regarded as a Neogene taxon (see Cappetta 2012).

Stratigraphic and geographic range in Alabama

The specimens in our sample were collected from the Gosport Sand at site ACh-21. Middle Bartonian, Zone NP17.

ALMNH

Alabama Museum of Natural History

Kingdom

Animalia

Phylum

Chordata

Class

Elasmobranchii

Order

Carcharhiniformes

Family

Hemigaleidae

Genus

Hemipristis

Loc

Hemipristis curvatus Dames, 1883

Ebersole, Jun A., Cicimurri, David J. & Stringer, Gary L. 2019
2019
Loc

Hemipristis curvatus

Dames W. 1883: 140
Loc

Hemipristis wyattdurhami

White E. I. 1956: 134
Loc

Hemipristis serra –

Woodward A. S. 1889: 451
Loc

Hemipristis wyattdurhami – Thurmond & Jones 1981: 63

Thurmond J. T. & Jones D. E. 1981: 63