Trichiurus oshosunensis White, 1926,

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: 172-173

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.3664334

persistent identifier

http://treatment.plazi.org/id/18174D41-FF2E-FF03-FDFE-9D904CC80D5F

treatment provided by

Plazi

scientific name

Trichiurus oshosunensis White, 1926
status

 

Trichiurus oshosunensis White, 1926 

Fig. 63View Fig J–R

Trichiurus oshosunensis White, 1926: 65–66  , pl. 16, figs 14–20.

Sphyraena  sp. – Maisch et al. 2016: 8, fig. 2, 19–22.

Trichiurides oshoshunensis – Arambourg 1952: 264  , pl. 35, figs 47–52.

Trichiurides  sp. – Thurmond & Jones 1981: 106, fig. 50.

Material examined

UNITED STATES OF AMERICA – Alabama • 33 isolated teeth; Claiborne Group ; ALMNH PV1985.87.2, ALMNH PV1985.87.3, MSC 37146View Materials, MSC 37173.1 2, MSC 37308.1 7, MSC 37657View Materials, MSC 37666.1 2, MSC 38437, MSC 38438, MSC 38489.1 7, NJSM 24042View Materials, NJSM 24319View Materials, SC 2012.47.97, SC 2012.47.98 (5 specimens), WSU CC 548View Materials  .

Description

Teeth measuring over 1.0 cm in height. In profile, basal one-third of tooth vertical, but then sharply curved posteriorly; apical portion anteriorly directed. Anterior margin formed into sharp carina, whereas posterior margin uniformly convex. Enameloid generally not preserved, but small apical posterior barb sometimes present. Tooth base with teardrop-shaped outline, shallow pulp cavity may be present.

Remarks

The teeth described above appear to be conspecific with White’s (1926) Trichiurus oshosunensis  from the early-to-middle Eocene of Nigeria. Although similar to the Sphyraena  laniary teeth we examined, they can be distinguished by being much more sinuous in profile. In contrast, laniary teeth of Sphyraena  have an oblique, slightly sinuous anterior margin but nearly vertical posterior margin. Arambourg (1952: pl. 35, figs 43–45, 53–56) figured several teeth he assigned to T. oshosunensis  that better fit our definition of Sphyraena  sp. in that they have anterior and posterior carinae and are lanceolate in form. Unfortunately, White (1926) only illustrated laniary teeth, and the morphology of other T. oshosunensis  teeth is uncertain. Until more complete specimens are known, we restrict the usage of T. oshosunensis  to teeth that match White’s (1926) type description.

Trichiurus oshosunensis  differs from Eutrichiurides plicidens  comb. nov. in having a single anterior carina and by lacking posterior crown ornament. It differs from Trichiurides sagittidens  in being laterally compressed along the entire crown height (not just apically), by having a smaller posterior barb (if present), and by having a teardrop-shaped basal outline (not circular). A laniary tooth identified as Sphyraena  sp. by Maisch et al. (2016) is herein considered to be T. oshosunensis  . Also, our examination of a specimen that Thurmond & Jones (1981: fig. 50) referred to Trichiurides  sp. (specimen ALMNH PV2005.6.432) is also referred to T. oshosunensis  .

Several of the teeth in our sample lack a posterior barb, a feature that Gago (1997) noted as being absent on juveniles of extant Trichiurus  and could reflect ontogeny as opposed to jaw heterodonty.

Stratigraphic and geographic range in Alabama

The specimens in our sample were collected from the contact of the Tallahatta and Lisbon formations at sites ACh-14 and ACov-11, and the basal Lisbon Formation at site ACov-11. Lower Lutetian, zones NP14 and NP15.

ALMNH

Alabama Museum of Natural History

WSU

Weber State University, Bird and Mammal Collection

Kingdom

Animalia

Phylum

Chordata

Class

Actinopterygii

Order

Perciformes

Family

Trichiuridae

Genus

Trichiurus

Loc

Trichiurus oshosunensis White, 1926

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

Sphyraena

Maisch H. M. & Becker M. A. & Raines B. W. & Chamberlain J. A. 2016: 8
Loc

Trichiurides oshoshunensis – Arambourg 1952: 264

Arambourg C. 1952: 264
Loc

Trichiurides

Thurmond J. T. & Jones D. E. 1981: 106