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
Fisherichthys
aff.
F. folmeri
Weems, 1999
Fig. 66
A–L
Fisherichthys folmeri
Weems, 1999: 63
, pls 4.7d, 4.8a–b.
Albula eppsi
–
Case 1994b: 142
, pl. 1, figs 372–375.
cf.
Fisherichthys
sp. –
Clayton
et al.
2013
: fig. 6k–l.
Material examined
UNITED STATES OF AMERICA
–
Alabama
• 6 isolated teeth;
Claiborne Group
;
MSC
38501,
SC
2012.47.125 (
2 specimens
),
SC
2012.47.237,
SC
2012.47.238,
SC
2012.47.239
.
Description
Small teeth measuring up to
1.5 mm
diameter, 1.0 mm crown height. Tooth crown conical in profile, with flat apex. Crown covered by smooth enameloid; apical surface with shallow depression surrounded by small tubercles. Occlusal surface of worn teeth composed of dentine, with a thin outer enameloid layer. Crown base thick, with basal cingulum. Circular basal pulp cavity centrally located.
Remarks
Six specimens in our sample are tentatively assigned to
Fisherichthys folmeri
because they exhibit the features of the
type
and only known species. The conical profile, apical tubercles, and basal cingulum serve to distinguish teeth of
Fisherichthys
in our sample from the somewhat similar teeth of
Albula
,
Paralbula
,
Pycnodus
, and
Egertonia
.
The occurrence of
Fisherichthys
in Claiborne
Group strata, particularly in the Gosport Sand, represents the stratigraphically youngest records for the genus, which was previously not known to occur beyond Zone NP11 of the Ypresian Stage (
Case 1994b
;
Weems 1999
;
Cicimurri & Knight 2009
). Our tentative species identification is due to our small sample size and much younger stratigraphic occurrence.
Fig. 66.
Fisherichthys
aff.
F. folmeri
Weems, 1999
and
Ostraciidae Rafinesque, 1810
, elements.
A–L
.
Fisherichthys
aff.
F. folmeri
.
A–C
. Tooth,
SC
2012.43.125.1, basal Lisbon Formation.
A
. Profile view.
B
. Oral view.
C
. Aboral view.
D–F
. Tooth,
SC
2012.43.125.2, basal Lisbon Formation.
D
. Profile view.
E
. Oral view.
F
. Aboral view.
G–I
. Tooth,
SC
2012.43.125.3, basal Lisbon Formation.
G
. Profile view.
H
. Oral view.
I
. Aboral view.
J–L
. Tooth,
MSC
38501, Gosport Sand.
J
. Profile view.
K
. Oral view.
L
. Aboral view. —
M–U
.
Ostraciidae
.
M–O
. Dermal plate,
MSC
35771.1, lower Tallahatta Formation.
M
. External view.
N
. Internal view.
O
. Profile view.
P–R
. Dermal plate,
MSC
37121, Tallahatta/Lisbon formation contact zone, courtesy of Bruce Relihan.
P
. External view.
Q
. Internal view.
R
. Profile view.
S–U
. Dermal plate,
MSC
37418, basal Gosport Sand.
S
. External view.
T
. Internal view.
U
. Profile view. Scale bars: A–L=1 mm; M–R =5 mm; S–U= 2 mm.
Stratigraphic and geographic range in
Alabama
The specimens in our sample were collected from the basal
Lisbon
Formation at site ACov-11 and the basal Gosport Sand at site ACl-4. Lower Lutetian to middle Bartonian, zones NP15 to NP17.