Stenolaemate bryozoans from the Graham Formation, Pennsylvanian (Virgilian) at Lost Creek Lake, Texas, USA
Author
Ernst, Andrej
Author
Claussen, Anna Lene
Author
Seuss, Barbara
Author
Wyse Jackson, Patrick N.
text
Palaeontologia Electronica
2022
a 15
2022-05-31
25
2
1
56
http://dx.doi.org/10.26879/1174
journal article
294467
10.26879/1174
77c06bea-bbd5-46af-8ef1-f434aa25c6a8
1094-8074
11032471
A4A07D50-3DDB-4E45-A255-1ECCF45F147A
Acupipora elliptica
(
Rogers, 1900
)
Figures 14E
,
15
A-D; Appendix
1900
Polypora elliptica
Rogers
, p. 7, pl. 4, fig. 2.
1924
Polypora elliptica
Rogers, 1900
; Morgan, p. 116, pl. 37, fig. 9.
1929
Polypora elliptica
Rogers, 1900
; Moore, p. 23-24, pl. 3, figs. 7, 8, 20.
1930
Polypora elliptica
Rogers, 1900
; Sayre, p. 89-90, pl. 3, figs 2-4.
1930
Polypora elliptica
Rogers, 1900
; Moore, p. 155-156.
1937
Polypora elliptica
Rogers, 1900
; Elias, p. 327-328, fig.
3m
.
1980
Protoretepora elliptica
(
Rogers, 1900
)
; Simonsen and Cuffey, p. 15, figs. 3F, 4F, 6F,
7F.
Material.
SNSB-BSPG 2020 XCI 60, SNSB-BSPG 2020 XCI 64, SNSB-BSPG 2020 XCI 70, SNSB-BSPG 2020 XCI 77, SNSB-BSPG 2020 XCI 113.
Exterior description.
Reticulate colonies composed of moderately wide branches joined by moderately wide dissepiments. Autozooecia arranged in 3–5 alternating rows on branches, 2–3 after bifurcation. Autozooecial apertures rounded to oval, having a prominent rim with spine-like projection toward nearest fenestrule, 3–5 spaced per length of fenestrule. Fenestrules oval to slightly rectangular. Nodes large, elliptical, spaced regularly between autozooecial apertures.
Interior description.
Autozooecial chambers moderately long, rectangular to roughly hexagonal in the shallow tangential section, becoming rhombic in the mid and deep tangential sections. Superior hemisepta blunt, placed at the proximal part of the vestibule. Inferior hemisepta well-developed, situated in the distal third of autozooecial chambers. Interior hyaline skeleton well-developed, wrinkled on the reverse side of the branches. External laminated skeleton well-developed, traversed by abundant small microstylets. Microstylets
0.005
–0.010
mm
in diameter. Apparent reproductive heterozooecia in form of isolated zooecia with enlarged endozonal chambers present. Chambers rounded,
0.15 mm
in diameter. Nanozooecia present.
Remarks.
Acupipora elliptica
(
Rogers, 1900
)
is similar to
A. mexicana
Ernst and
Vachard, 2017
, from the Pennsylvanian (Moscovian-Kasimovian) of
Mexico
but differs from the latter due to the closer spacing of branches (average distance between branch centres
0.88 mm
vs.
1.10 mm
in
A. mexicana
).
Acupipora elliptica
differs from
A. subborealis
(
Schulga-Nesterenko, 1951
)
in having larger fenestrules (fenestrule width
0.27–0.60 mm
vs.
0.30–0.40 mm
in
A. subborealis
; fenestrule length
0.70–0.99 mm
vs.
0.70–0.80 mm
in
A. subborealis
).
Occurrence.
Drum Limestone, Pennsylvanian (Missourian);
Kansas
,
USA
. Deese Group, Boggy Formation, Pennsylvanian (Missourian);
Oklahoma
,
USA
. Topeka Limestone, Pennsylvanian (Virgilian);
Kansas
,
USA
. Upper Graham Formation, Pennsylvanian (Virgilian);
Texas
,
USA
. Graham Formation, Pennsylvanian (Virgilian); TXV-200 (“Spillway section at Lost Creek Lake”),
Texas
,
USA
.