Palaeocybium proosti ( Storms, 1897 ),

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: 173-175

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.3664314

persistent identifier

http://treatment.plazi.org/id/18174D41-FF29-FF01-FDFD-9B314E570D9B

treatment provided by

Plazi

scientific name

Palaeocybium proosti ( Storms, 1897 )
status

 

Palaeocybium proosti ( Storms, 1897) 

Fig. 64View Fig A–I

Cybium proosti Storms, 1897: 242  , figs 1–2.

Cybium proosti – Leriche 1905: 79  , 150, 192, pl. 10, fig. 2.

Cybium  sp. – Case 1981: 2, fig. 17.

Cybium proosti – Case 1986: 6  , figs 10–11.

Acanthocybium proosti – Weems 1999: 66  , pl. 4.6, fig. g.

Palaeocybium proosti – Monsch 2005: 460  .

Material examined

UNITED STATES OF AMERICA – Alabama • 6 isolated teeth; Claiborne Group; ALMNH PV1989.4.130, MSC 37423View Materials, MSC 38433View Materials, MSC 38500.1–2, MSC 37194.4.

Description

Teeth lanceolate, measuring up to 6.15 mm in height. Anterior and posterior carinae sharp, smooth, convex; carinae extend to tooth base, form rounded apex. Labial and lingual faces bi-convex, of equal dimension, smooth. Tooth base slightly thickened, with deep pulp cavity.

Remarks

The specimens in our sample compare well to Palaeocybium proosti ( Storms, 1897)  teeth reported from Europe and North America (see Casier 1946; Kemp et al. 1990; Weems 1999). Palaeocybium proosti  was originally placed within Cybium  , a genus that is now regarded as a junior synonym of Scomberomorus Lacépède, 1802  (see Bannikov 1982; Collette 2003). Weems (1999) placed this morphology within Acanthocybium Gill, 1862  based on two partial dentaries from the Nanjemoy Formation in Virginia, suggesting it was a primitive species within the genus. Monsch (2005) later noted that Storms’ (1897) type specimen has two rows of teeth on the dentary, an inner and outer, which is a characteristic that distinguishes the proosti  morphology from the dentitions of Acanthocybium  and Scomberomorus  . As a result, Monsch (2005) placed the proosti  species within a new genus, Palaeocybium  .

Teeth of Palaeocybium  are conspicuously thicker than morphologically similar teeth of Sphyraena  (see above), and they have a larger and deeper pulp cavity. The Palaeocybium  teeth in our sample were differentiated from those of Scomberomorus  (see below) by having carinae that extend to the base of the teeth, they have a symmetrical basal outline (with carinae visible) and are not basally constricted.

Stratigraphic and geographic range in Alabama

The specimens in our sample were collected from the contact of the Tallahatta and Lisbon formations at site ACov-11, the basal Gosport Sand at site ACl-4, and the Gosport Sand at site ACh-21. Lower Lutetian to middle Bartonian, zones NP14 to NP17.

ALMNH

Alabama Museum of Natural History

Kingdom

Animalia

Phylum

Chordata

Class

Actinopterygii

Order

Perciformes

Family

Scombridae

Genus

Palaeocybium

Loc

Palaeocybium proosti ( Storms, 1897 )

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

Cybium proosti

Storms R. 1897: 242
Loc

Cybium proosti –

Leriche M. 1905: 79
Loc

Cybium

Case G. R. 1981: 2
Loc

Cybium proosti –

Case G. R. 1986: 6
Loc

Acanthocybium proosti –

Weems R. 1999: 66
Loc

Palaeocybium proosti –

Monsch K. A. 2005: 460