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, including an analysis of otoliths
Author
Ebersole, Jun A.
Author
Cicimurri, David J.
Author
Stringer, Gary L.
text
European Journal of Taxonomy
2019
2019-12-06
585
1
274
journal article
24105
10.5852/ejt.2019.585
dca608e8-fccf-4c1c-b8df-ef0c28e1d518
3660259
181B6FBA-ED75-4BB4-84C4-FB512B794749
Pseudabdounia recticona
(Winkler, 1874)
gen. et comb. nov.
Fig. 32
S–JJ
Galeocerdo recticonus
Winkler, 1874a: 26
.
Galeus recticonus
–
Leriche 1905: 135
, pl. 8, figs 44–53.
Eugaleus recticonus
–
Casier 1950: 18
, pl. 2, fig. 9.
Galeorhinus recticonus
–
Von der Hocht 1979: 40
.
Abdounia recticonus
–
Cappetta 1980a: 37
.
Abdounia recticona
–
Ward & Wiest 1990: 84
.
Material examined
UNITED STATES OF AMERICA
–
Alabama
• 168 isolated teeth;
Claiborne Group
;
ANSP
23414
, GSA-V694, GSA-V703,
MMNS
VP-8213 (
2 specimens
),
MSC
34405.4
,
MSC
35767.1
–
5
,
MSC
37115.1
–
3
,
MSC
37138,
MSC
37155,
MSC
37160,
MSC
37167.1
–
4
,
MSC
37193,
MSC
37318.1
,
MSC
37318.3
,
MSC
37629.1
–
5
,
MSC
37634.1
–
22
,
MSC
37635.1
,
MSC
37647,
MSC
37665.1
–
3
,
MSC
37679.1
–
2
,
MSC
37680.1
–
3
,
MSC
38286,
MSC
38287.1
–
2
,
MSC
38831,
MSC
38970,
NJSM
24025
(
3 specimens
),
SC
2012.47.164 (
28 specimens
),
SC
2012.47.178,
SC
2012.47.46,
SC
2012.47.47,
SC
2012.47.48 (
27 specimens
),
WSU
5016
,
WSU
5018
,
WSU
5042
(
30 specimens
),
WSU
CC 506
(
3 specimens
),
WSU
CC 507
(
2 specimens
),
WSU
CC 508
,
WSU
CC 509.1
,
WSU
CC 509.2
,
WSU
CC 832.2
.
Description
Anterior teeth somewhat taller than wide; lateral teeth mesiodistally wider than tall. Teeth with broadly triangular crown; large, triangular main cusp. Main cusp on anterior teeth erect, flanked by two pairs of cusplets. Main cusp distally inclined on lateral teeth, flanked by three-to-four cusplets; distal side often with one more cusplet than mesial side. Cusplets large compared to overall size of main cusp; triangular, divergent, decreasing in size towards the crown foot; terminal cusplet can be difficult to distinguish from preceding cusplet. Cutting edges on main cusp nearly straight on anterior teeth, more convex on lateral teeth; all cutting edges smooth and continuous. Labial crown face flat; lingual face concave; crown enameloid is smooth. Root bilobate with short, pointed to rounded, diverging lobes. Lingual attachment surface flat, bisected by deep nutritive groove.
Remarks
The teeth of
Pseudabdounia recticona
gen. et comb. nov.
have two-to-four pairs of lateral cusplets, distinguishing them from those of
Abdounia enniskilleni
and
Abdounia minutissima
, which have only a single pair. Teeth of
Pseudabdounia claibornensis
gen. et comb. nov.
have four-to-eight pairs of cusplets. Although the anterior teeth of
A. beaugei
only have a single pair of lateral cusplets, the lateral teeth have two pairs. These lateral teeth differ from those of
P. recticona
gen. et comb. nov.
by having lateral cusplets that are more separated from the main cusp. In contrast, the cusplets on the lateral teeth of
P. recticona
gen. et comb. nov.
are joined to the main cusp and the teeth are more broadly triangular in outline.
Stratigraphic and geographic range in
Alabama
The specimens in our sample were collected from the lower Tallahatta Formation at site ADl-1, the Tallahatta Formation at site AMo-8, the contact of the Tallahatta and
Lisbon
formations at sites ACh- 14, ACov-11, and ACon-6, the basal
Lisbon
Formation at site ACov-11, and the contact of the
Lisbon
Formation and Gosport Sand at site AMo-4. Upper Ypresian to middle Bartonian, zones NP14 to NP17.