Scoliodon conecuhensis Cappetta & Case, 2016,

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: 80-82

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.3664593

persistent identifier

http://treatment.plazi.org/id/18174D41-FFCA-FFFE-FE3B-99844CF1094D

treatment provided by

Plazi

scientific name

Scoliodon conecuhensis Cappetta & Case, 2016
status

 

Scoliodon conecuhensis Cappetta & Case, 2016 

Fig. 29View Fig

Scoliodon conecuhensis Cappetta & Case, 2016: 59  , pl. 9, figs 1–6.

Material examined

UNITED STATES OF AMERICA – Alabama • 130 isolated teeth; Claiborne Group ; ALMNH PV1993.2.440b (2 specimens), ALMNH PV1993.3.408 (2 specimens), GSA-V702, MSC 188.130, MSC 188.268, MSC 188.323, MSC 2175.17, MSC 2175.38, MSC 2394.2 5, MSC 34405.14, MSC 34405.2, MSC 37133View Materials, MSC 37316.1 4, MSC 37326.1 3, MSC 37627, MSC 37672, MSC 37678.1 7, MSC 37753.1 8, MSC 37754, MSC 37755, MSC 37756.1 19, MSC 37757.1 2, MSC 37758.1 2, MSC 37759.1 2, MSC 37760View Materials, MSC 37761.1 5, MSC 37762View Materials, MSC 38490.1 5, MSC 38498.1 3, MSC 38523.1 2, MSC 38553.1 4, NJSM 24028View Materials, SC 2012.47.170 (4 specimens), SC 2012.47.247 (2 specimens), SC 2012.47.249 (4 specimens), SC 2012.47.69 (4 specimens), WSU 5028View Materials (4 specimens), WSU 5038View Materials (10 specimens), WSU 5045View Materials (9 specimens), WSU CC 530.2View Materials (2 specimens), WSU CC 553View Materials  .

Description

Anterior teeth taller than wide, lateral teeth wider than tall. Teeth with narrow, elongate, triangular, sharply distally inclined crown. Lingual crown face strongly convex; labial face weakly convex; enameloid smooth. Cusp apex with slight lingual flexure; apex extends nearly to, or slightly beyond, distal edge of crown. Mesial cutting edge elongate, smooth, straight, sinuous or convex; straighter on lower teeth. Distal cutting edge short, smooth, oblique. Short, smooth distal heel on all lateral teeth; heel lacking on some anterior teeth. Root very low, bilobate, with highly diverging lobes. Interlobe area lacking to weakly U-shaped. Conspicuous lingual root boss bears narrow, deep nutritive groove.

Remarks

Scoliodon conecuhensis  was named by Cappetta & Case (2016) for a series of teeth collected from site ACov- 11 in Covington County, AL. The teeth of S. conecuhensis  are morphologically similar to those of Physogaleus  and Rhizoprionodon  . However, Scoliodon  teeth are easily distinguished from Physogaleus  by their lack of denticulations on the mesial cutting edge and distal heel. They were separated from Rhizoprionodon  by having a narrower and more elongated cusp that extends to, or beyond, the distal edge of the crown.

The extant Scoliodon laticaudus Müller & Henle, 1838  , and some species of Rhizoprionodon  , exhibit gynandric heterodonty. The extinct species S. conecuhensis  also appears to have displayed a strong degree of gynandric heterodonty. Male teeth have a cusp that is mesiodistally thinner than those on female teeth, and male upper teeth have a more sinuous crown than do female teeth. In addition, male lower lateral teeth have a shorter, upturned cusp. Also, male lower lateral teeth have an elongated mesial heel, but the heel is very short or absent altogether on anterior teeth. The cusp on S. conecuhensis  anterior teeth have a lingually twisted apex, which is lacking on equivalent teeth of Rhizoprionodon ganntourensis  .

Stratigraphic and geographic range in Alabama

The specimens in our sample were collected from the lower Tallahatta Formation at site ADl-1, the contact of the Tallahatta and Lisbon formations at site ACh-14 and ACov-11, the basal Lisbon Formation at site ACov-11, the contact of the Lisbon Formation and Gosport Sand at site AMo-4, the basal Gosport Sand at site ACl-4, and the Gosport Sand at sites ACh-21 and ACl-15. Upper Ypresian to middle Bartonian, zones NP14 to NP17.

ALMNH

Alabama Museum of Natural History

Kingdom

Animalia

Phylum

Chordata

Class

Elasmobranchii

Order

Carcharhiniformes

Family

Carcharhinidae

Genus

Scoliodon

Loc

Scoliodon conecuhensis Cappetta & Case, 2016

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

Scoliodon conecuhensis

Cappetta H. & Case G. R. 2016: 59