Bull. Tohoku Univ. Museum. No. 21, pp. 1‒19, 2022
© by The Tohoku University Museum

Virgilian (Late Pennsylvanian) coiled nautiloids from theFinis Shale Member of the Graham Formation in Texas,
southern Midcontinent North America
Shuji Niko*, Royal H. Mapes** and Barbara Seuss****Department of Environmental Studies, Faculty of Integrated Arts and Sciences, Hiroshima University, Higashihiroshima
739-8521, Japan, **American Museum of Natural History, Central Part West at 79th Street, New York 10024-5192, U.S.A.,***GeoZentrum Nordbayern-Paläoumwelt, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Loewenichstraße 28,91054 Erlangen, Germany
Abstract: Nine species of Virgilian (Late Pennsylvanian) coiled nautiloids are described from theFinis Shale Member of the Graham Formation in north-central Texas, southern Midcontinent of North
America. They include Tainoceras monilifer Miller, Dunbar and Condra, Metacoceras quadratum sp.
nov., Endolobus sturgeoni sp. nov., Domatoceras tuckeri sp. nov., Titanoceras sp., Solenochilus
jackense sp. nov., Liroceras liratum (Girty), Peripetoceras bridgeportense Tucker and Mapes, andEphippioceras ferratum (Cox). The habitat of the nautiloid assemblage was the low latitudes in the
Marginal Sea of the Panthalassic Ocean. Strong biotic linkage between the Marginal Sea and thesouthern Late Pennsylvanian Midcontinent Sea is confirmed.

Introduction
The Finis Shale Member, introduced by Plummer andMoore (1922), is an early Virgilian (Late Pennsylvanian =latest Carboniferous) unit in the Graham Formation, Cisco
Group. It varies between 15−60 m in thickness and consists
mainly of shale characterized by the abundant presenceof ironstone concretions; it also contains sandstone andlimestone in its basal part (Plummer and Hornberger,
1936). This member outcrops in north-central Texas near
the Oklahoma border and west of Dallas on the southern
Midcontinent of North America (McGowen et al., 1972;
Barnes et al., 1987). A diverse marine fauna, including
foraminifers, sponges, cnidarians and mollusks, is recorded
from the member, and exceptionally well-preserved
cephalopod specimens provide material for taxonomic (Miller
et al., 1933; Plummer and Scott, 1937; Miller and Downs,
1950; Furnish et al., 1962; Hansman, 1965; Mapes, 1979;
McKinzie and McLeod, 2003; Doguzhaeva et al., 1999,
2006; Niko and Mapes, 2010, 2011; Mutvei et al., 2012;
Mutvei and Mapes, 2018), biostratigraphic (Boardman etal., 1994), and bionomic (Mapes, 1987; Mapes et al., 1995;
Mapes and Chaffin, 2003; Wani et al., 2012) studies. Adding
to these, the present paper analyzes coiled nautiloids as thethird fascicle in our recent studies describing non-ammonoid
cephalopods of the member and discusses their faunalsignificance.
Fossil material used in this serial project was recoveredfrom dark gray (to brownish-yellowish in weathered parts)
shales near Jacksboro, north-central Texas at 16 localities.
These comprise exposures (Figure 1) at pond dams (TXV34, 84), on hill sides (TXV-36, 78), at barren glades withgrooves, gullies to ravines (TXV-40, 54, 55, 56, 61, 120),at road sites (TXV-60, 62), on the east slope of Lost Creek(TXV-63), at the Old Lake Jacksboro Dam and spillway(TXV-69), near an abandoned oil well pad excavation(TXV-92), and at the excavation that serves as emergency
spillway for Lost Creek Lake (Lake Jacksboro; TXV-200).
Repository.―The specimens examined in the present
paper are reposited in the paleontological collections of
the American Museum of Natural History in New York City
(prefixed AMNH) and the Tohoku University Museum in
Sendai (prefixed IGPS).
Systematic Paleontology
Subclass Nautiloidea Agassiz, 1847
Order Nautilida Agassiz, 1847
Superfamily Tainoceratoidea Hyatt, 1883
Family Tainoceratidae Hyatt, 1883
Genus Tainoceras Hyatt, 1883
Type species.―Nautilus quadrangulus McChesney, 1859.

2

Shuji Niko, Royal H. Mapes and Barbara Seuss

Figure 1. Map showing the geographic positions of
non-ammonoid cephalopod localities in the Finis Shale
Member near Jacksboro, north-central Texas.
Tainoceras monilifer Miller, Dunbar and Condra, 1933
Figure 2
Tainoceras monilifer Miller, Dunbar and Condra, 1933, p.
148–151, pl. 10, figs. 1–5, text-fig. 23; Unklesbay, 1962, p.
31–33, pl. 2, fig. 10; Tucker, 1976, p. 59, pl. 1, fig. 7, textfigs. 1a, b.
[not] Tainoceras monilifer; Miller and Unklesbay, 1942a,
p. 142, 143, pl. 4, figs. 1–3 [figs. 1, 2 = T. sexlineatum
Tucker, 1976; fig. 3 = T. sp. nov.]; 1947, p. 322, 323.
Tainoceras sp., Mapes and Chaffin, 2003, figs. 4A, 4D, 4F;
McKinzie and McLeod, 2003, p. 88, fig. 4-32 top.
Description.―Conchs moderate in size, having 140
mm in reconstructed diameter, discoidal and evolute with

gradual whorl expansion; umbilicus perforated; except forembryonic to juvenile shell indicating subcircular whorl
sections, more adoral shells have dorsoventrally depressedand subquadrate whorl sections with width/height ratios of
1.3–2.1; profiles of adoral whorls consist of weakly inflated
venter with a median groove, straight flanks, straightumbilical zone obtusely converging to dorsum and shallowly
rounded impressed area; apex corn-shaped. Shell surface
ornamented by oblique lirae in embryonic to juvenile shell,
then these lirae become subdued and nodes are added
on venter and at ventrolateral and umbilical angles; ventral
nodes closely spaced, laterally elongated, forming two rows
due to separation by a median groove; nodes at ventrolateralangles are strongly protruded. Septa shallow forming
sutures with sub-triangular to broadly rounded ventral lobes,
weak ventrolateral saddles, and relatively deep lateral lobes;
siphuncle central to faintly subcentral in position.
Material examined.―AMNH 5998–6014, 6016–6080,
6474–6483.
Occurrence.―The holotype of Tainoceras monilifer wascollected from the Finis Shale Member near Jacksboro,
Texas (Miller et al., 1933). Specimens of this species arealso known from the Upper Pennsylvanian of the Iatan
Limestone in Nebraska (Miller et al., 1933), the Lawrence
Shale, the Kereford and Burlingame Limestones in Kansas,
and the Vamoosa Formation in Oklahoma (Unklesbay,1962).
Localities of each examined specimen in this study are
as follows; TXV-34 (AMNH 5998–6010, 6474–6483), TXV55 (AMNH 6011), TXV-56 (AMNH 6012–6014, 6016–6022),
TXV-120 (AMNH 6023–6025), TXV-200 (AMNH 6026–6080).
Discussion.―Miller and Unklesbay (1942a) assigned
three specimens, Carnegie Museum cat. nos. 149, 10.434,
and 22.299, from the Upper Pennsylvanian Conemaugh
Formation of Pennsylvania to Tainoceras monilifer. Tucker(1976) reexamined them and concluded that 1) the former
one is undoubtedly assignable to T. monilifer and 2) the
latter two need to be separated from the species anddesignated as the types of a new species, T. sexlineatum
Tucker, 1976. Although his second opinion is reasonable,
we cannot agree with his first decision because the ventral
nodes of specimen no. 149 vanish in the adoral shell; thisdiagnosis is not known from any previously named speciesof Tainoceras. Thus, this specimen (Carnegie Museum cat.
no. 149) probably represents a new species. In addition,
Tucker (1976) synonymized T. murrayi Miller and Unklesbay,
1942b, with T. monilifer. This taxonomic treatment is also
unacceptable. Tainoceras murrayi is well differentiated fromT. monilifer by the absence of nodes at umbilical angles.

Pennsylvanian coiled nautiloids from Texas

3

Figure 2. Tainoceras monilifer Miller, Dunbar and Condra, 1933. A, G. AMNH 6023: A, lateral view; G, partial
enlargement of A to show embryonic to early juvenile shell morphologies. B, C. AMNH 6038: B, lateral view; C, ventralapertural view. D, E. AMNH 6068, shell wall mostly exfoliated: D, lateral view; E, ventral view. F, I. AMNH 6007: F, ventral
view; I, septal view, venter up. H. AMNH 6060, septal view, venter up. J. AMNH 6077, ventral view. Scale bar is 30 mm in A–F,
J; 6 mm in G; 20 mm in H, I.

4Shuji Niko, Royal H. Mapes and Barbara Seuss

Genus Metacoceras Hyatt, 1883
Type species.―Nautilus (Discus) sangamonensis Meek
and Worthen, 1860.
Metacoceras quadratum sp. nov.
Figure 3
Metacoceras sp., Mapes and Chaffin, 2003, fig. 4E;
McKinzie and McLeod, 2003, p. 88, fig. 4-31.
Diagnosis.―Small species of Metacoceras withwhorl sections of depressed subtrapezoidal in adoralphragmocones and depressed subquadrate shape in bodychamber; width/height ratios of whorls usually 1.4–1.9;
concavities of impressed area shallow to very shallow;
nodes strongly protruded, possess weak bulla-like extension.
Description.―Conchs small, discoidal and evolutewith gradual whorl expansion; umbilicus perforated; theholotype (largest specimen) represents an imperfect bodychamber with the last septum and is 40 mm in length,
24 mm in maximum whorl width and 16 mm in maximum
whorl height; reconstructed conch diameter from theholotype is approximately 60 mm; apex and peristome
are not preserved; whorl sections in juvenile shells facing
umbilical perforation are subcircular with a very shallow
median groove at venter, then their profiles shift towards
depressed subtrapezoidal shape with weakly inflated venter,rounded ventrolateral shoulders, nearly straight flanks that
acutely converse to dorsum, nearly straight umbilical zones
that obtusely converse to dorsum, and shallowly rounded
impressed area; furthermore, shapes of whorl sections inbody chamber shift to depressed subquadrate, where venter
becomes nearly flat, flanks weakly inflated, and concavity
of impressed area becomes very shallow; umbilical angles
rounded; median ventral groove disappears in adoralphragmocone and body chamber; width/height ratios ofwhorls are 1.4–1.9 in adoral phragmocone and 1.4–1.5
in body chamber. Juvenile shell surface ornamented by
distinct lirae that form V-shaped sinueses at venter, carinae
at ventrolateral shoulders and rounded sinueses at dorsum;
in more adoral shells, lirae become accentuated growthlines and strongly protruded and spine-like nodes developeon the position of ventrolateral shoulders; nodes possess
weak bulla-like extension on their dorsal side; peristome
shape can be reconstructed by growth lines as lingulate
ventral (hyponomic) and shallow lateral (ocular) sinuses.
Septa very shallow; sutures composed by broadly roundedventral lobes, rounded ventrolateral saddles, shallow laterallobes, and subtriangular dorsal lobes; siphuncle situatesnear halfway between conch center and ventral margin injuvenile, and subcentral position in more adoral shells; ratiosof distance between ventral shell surface and central axis ofsiphuncle per whorl height at dorsoventral plane are 0.31–
0.44.
Material examined.―Holotype, AMNH 6159. Paratypes,
AMNH 6102, 6108–6111, 6118, 6130, 6134, 6147–6149,
6472. In addition, 61 specimens (AMNH 6091–6101,
6103–6107, 6112, 6115–6117, 6119–6129, 6131–6133,
6135–6146, 6150–6158, 6160–6163, 6473) are assigned to
Metacoceras quadratum sp. nov.
Occurrence.―TXV-34 (AMNH 6092–6099), TXV-56(AMNH 6091, 6100–6112, 6473), TXV-120 (AMNH 6115),
TXV-200 (AMNH 6116–6163, 6472). All previous records ofthe new species as Metacoceras sp. by Mapes and Chaffin(2003) and McKinzie and McLeod (2003) are from the Finis
Shale Member in Texas.
Etymology.―The specific name is derived from the Latin,
quadratus (= quadrangular), referring to its whorl section
shapes in the body chamber.
Discussion.―In its gross conch form of the adoral shells
and ornament, Metacoceras quadratum sp. nov. is mostsimilar to M. cornutum Girty (1911, p. 145, 146; 1915,
p. 240–242, pl. 29, figs. 4, 4a, 4b, 5, 5a, 5b), which was
described from the Desmoinesian (Middle Pennsylvanian) of
Oklahoma. However, the impressed area of this new species
is shallower than that of M. cornutum and the subtrapezoidal
profiles developed in the phragmocones are not recognizedin M. cornutum. A Virgilian species, Metacoceras copei
Tucker (1976, p. 61, 62, pl. 1, fig. 6, pl. 3, figs. 1, 2, pl. 4.
fig. 3) from the Mattoon Formation of Illinois, also resembles
M. quadratum, but it possesses a median ventral groovein the adoral shells and the knob-like distal ends of nodes
exclude it from M. quadratum. Metacoceras clinocostatum
Sturgeon, Windle, Mapes and Hoare (1982, p. 1455, 1457,
1458, pl. 1, figs. 4, 8; 1997, p. 34, 35, pl. 1-8, figs. 4–9),
from the Desmoinesian Allegheny Group and the Missourian(Late Pennsylvanian) part of the Conemaugh Group of Ohio,
differs from M. quadratum by having strongly elongatednodes attaining the umbilical angles.
Family Koninckioceratidae Hyatt in Zittle, 1900
Genus Endolobus Meek and Worthen, 1865
Type species.―Nautilus spectabilis Meek and Worthen,
1860.
Endolobus sturgeoni sp. nov.
Figure 4
Diagnosis.―Species of Endolobus with 1.4–2.0 in
width/height ratios of adoral whorls; flanks narrowly
rounded; impressed area deeply concaved; nodes low anddorsoventrally elongated.
Description.―Conchs thick discoidal, evolute; whorl
expansion rapid in phragmocone, but it becomes gradual inPennsylvanian coiled nautiloids from Texas

5

Figure 3. Metacoceras quadratum sp. nov. A, B, E–G. paratype, AMNH 6118: A, lateral view of juvenile shell; B, septal viewof juvenile shell, venter up; E, ventral view; F, lateral view; G, septal view, venter up. C, D. paratype, AMNH 6472, juvenile shell: C,
ventral view; D, lateral view. H. paratype, AMNH 6130, septal view, venter up. I. paratype, AMNH 6134, dorsal view. J. paratype,
AMNH 6102, lateral view. K. paratype, AMNH 6147, septal view, venter up. L, M, P, Q. holotype, AMNH 6159: L, lateral view; M,
cross sectional view, venter up; P, ventral view; Q, dorsal view. N. paratype, AMNH 6110, ventral view, showing details of surface
ornamentation. O. paratype, AMNH 6111, lateral view. Scale bar is 6 mm in A–D; 12 mm in E–H, J, N; 15 mm in I, K–M, O–Q.

6

Shuji Niko, Royal H. Mapes and Barbara Seuss

Figure 4. Endolobus sturgeoni sp. nov. A–C. paratype, AMNH 6081, shell wall mostly exfoliated: A, lateral view; B,
cross sectional view, venter up; C, partial enlargement of A to show details of juvenile shell. D. paratype, AMNH 6082, septal
view, venter up. E, F, L. paratype, AMNH 6085: E, lateral view; F, dorsal view; L, ventral view. G. paratype, AMNH 6087, shellwall mostly exfoliated, lateral view. H, J, M, N. holotype, AMNH 6086: H, lateral view; J, cross sectional view, venter up; M,
ventral view; N, dorsal view. I, K. paratype, AMNH 6084, shell wall mostly exfoliated: I, lateral view; K, cross sectional view,
venter up. Scale bar is 15 mm in A, B; 6 mm in C; 20 mm in D–N.

Pennsylvanian coiled nautiloids from Texas
body chamber; umbilicus perforated; the holotype represents
an imperfect body chamber with the last septum and is 47
mm in length, 34 mm in maximum whorl width, and 18 mm
in maximum whorl height; the largest specimen (paratype,
AMNH 6089) has 41 mm in whorl width and 21 mm(imperfect) in whorl height; reconstructed conch diameter ofthe holotype is approximately 60 mm; apex not preserved;
whorl sections are circular in juvenile shells facing umbilicalperforation, then they shift towards depressed subellipticalshapes, whose profiles consist of broadly rounded venterto ventrolateral shoulders, narrowly rounded flanks (=umbilical angles), weakly inflated umbilical zones androunded impressed area; width/height ratios of whorls are
1.4–1.6 in adoral phragmocone, these ratios increase to 2.0
in body chamber. Shell surface marked by dorsoventrally
elongated low nodes on flanks; except for nodes, surface
ornamentation absent; no peristome is preserved, but
presence of deep lingulate ventral (hyponomic) and very
shallow lateral (ocular) sinuses can be reconstructed by
growth line shapes. Septal curvature moderate; sutures
roughly straight, but some sutures have shallow laterallobes, directly transverse in juvenile shell and strongly incline
towards venter in adoral shell; siphuncle supracentral withweak to moderate dorsum wards shifting; ratios of distance
between ventral shell surface and central axis of siphuncle
per whorl height at dorsoventral plane are 0.54–0.72.
Material examined.―Holotype, AMNH 6086. Paratypes,
AMNH 6081–6085, 6087–6089.
Occurrence.―TXV-34 (AMNH 6081–6086), TXV-200(AMNH 6087–6089).
Etymology.―The specific name is in honor of the late
Myron T. Sturgeon in recognition of his contributions topaleontological studies of Pennsylvanian nautiloids andconodonts.
Discussion.―Endolobus schucherti Miller (1932, p.
64–66, pl. 12, figs. 12, 13) from the Upper Pennsylvaniansandstone of New Mexico has similar node shapes as E.
sturgeoni sp. nov., but it differs in its shallower impressed
area. In addition, a median longitudinal ridge on the venterof E. schucherti is not developed in the new species.
Superfamily Trigonoceratoidea Hyatt, 1884
Family Grypoceratidae Hyatt in Zittle, 1900
Genus Domatoceras Hyatt, 1891
Type species.―Domatoceras umbilicatum Hyatt, 1891.
Domatoceras tuckeri sp. nov.
Figure 5
Domatoceras sp., Mapes and Chaffin, 2003, figs. 4C, 4G, 4I;
McKinzie and McLeod, 2003, p. 88, fig. 4-29.

7

Diagnosis.―Species of Domatoceras having whorl
sections of compressed subtrapezoidal with concave venterin adoral phragmocone and compressed subrectangular inbody chamber; width/height ratios of whorls 0.8–1.1; weakly
waved carinae developed at ventral angles.
Description.―Conchs moderate in size, lenticular andevolute with relatively rapid whorl expansion; umbilicus
perforated; the holotype of fragmentary phragmocone
consisting of three volutions is 67 mm in maximum length,
37 mm in maximum whorl width, and 41 mm in maximum
whorl height; the largest specimen (paratype, AMNH 6227)
of imperfect body chamber attains 42 mm in whorl width(reconstructed from half width), 51 mm in whorl height andapproximately 160 mm in reconstructed conch diameter;
apex and peristome are not preserved; whorl sections are
subcircular in juvenile shell facing umbilical perforation,
subtrapezoidal to compressed subtrapezoidal in more adoralphragmocone, and compressed subrectangular in bodychamber; profiles of whorl sections in adoral phragmocones
consist of shallowly concave venter as ventral groove, nearlystraight ventrolateral shoulders that acutely converge toventer, straight flanks that very acutely converge to venter,straight umbilical zones that obtusely converge to dorsum,
and quadrate impressed area; in body chamber, venter
becomes flat, shoulders and flanks integrate; umbilicalangles bluntly pointed; width/height ratios of whorls are 0.9–
1.1 in adoral phragmocone and 0.8–0.9 in body chamber.
Surface of juvenile shell marked by sinuous lirae thatpersist in body chamber at ventral side, but are replacedby growth lines in other parts of more adoral shells; strong
carina having weakly waved margin and frill-like appearance
developed at ventral angle with bilateral symmetry in adoralshells; lirae and growth lines suggest peristome shapewith V-shaped ventral (hyponomic) and shallow lateral(ocular) sinuses. Septal curvatures are relatively weak;sutures indicate shallow ventral and broadly rounded laterallobes. Siphuncle is subcentral in position; ratios of distance
between ventral shell surface and central axis of siphuncle
per whorl height at dorsoventral plane are 0.48–0.52.
Material examined.―Holotype, AMNH 6278. Paratypes,
AMNH 6181, 6186, 6208, 6209, 6227–6230, 6255, 6256,
6279–6281. In addition, 95 specimens (AMNH 6173–6180,
6182–6185, 6187–6207, 6210–6226, 6231–6254, 6257–
6277) are assigned to Domatoceras tuckeri sp. nov.
Occurrence.―TXV-34 (AMNH 6173–6185), TXV55 (AMNH 6186), TXV-56 (AMNH 6187–6227), TXV200 (AMNH 6228–6281). All previous records of the new
species as Domatoceras sp. by Mapes and Chaffin (2003)
and McKinzie and McLeod (2003) are from the Finis Shale
Member in Texas.
Etymology.―The specific name is to honor the late John K.
Tucker in recognition of his contributions to paleontological8Shuji Niko, Royal H. Mapes and Barbara Seuss

Figure 5. Domatoceras tuckeri sp. nov. A–F. holotype, AMNH 6278: A, lateral view; B, cross sectional view, venterup; C, ventral view; D, dorsal view; E, lateral view of juvenile shell; F, partial enlargement of C to shew details of surface
ornamentation. H. paratype, AMNH 6281, lateral view. G, I. paratype, AMNH 6208, shell wall exfoliated: G, ventral view; I,lateral view. J, K. paratype, AMNH 6227: J, cross sectional view, venter up; K, lateral view. Scale bar is 30 mm in A–D, I–K; 6mm in E; 10 mm in F; 20 mm in G; 37.5 mm in H.

Pennsylvanian coiled nautiloids from Texas

9

Figure 6. Titanoceras sp., IGPS coll. cat. no. 112545. A. ventral view. B. lateral view. C. cross sectional view, venter up.
Scale bar is 100 mm in A, B; 75 mm in C.
studies of Pennsylvanian nautiloids.
Discussion.―This new species most closely resembles
Domatoceras oreskovichi Sturgeon, Windle, Mapes andHoare (1982, p. 1468, 1469, pl. 2, figs. 6, 7, 9, pl. 3, fig.
2; 1997, p. 60, 61, pl. 1-23, figs. 6, 7, pl. 1-24, figs. 2, 3,
pl. 1-26, figs. 1, 2, pl. 1-27, figs. 1–6, text-fig. 1-8A), fromthe Desmoinesian Allegheny Group of Ohio, by having
compressed subquadrate whorl sections with a concaved
venter. However, larger amplitude of the waved carinae
distinguishes it from Domatoceras tuckeri sp. nov. A
concaved venter is also developed in D. texanum Tucker
and Mapes (1978, p. 597, pl. 2, figs. 4, 5, pl. 3, fig. 6)
from the Missourian Wolf Mountain Shale of Texas. The
differences between D. texanum and D. tuckeri are its
subtrapezoidal whorl sections remain in the body chambers
and morphological shifting from carinae to nodes as shell
grows.
Genus Titanoceras Hyatt, 1884
Type species.―Nautilus ponderosus Meek, 1872.
Titanoceras sp.
Figure 6

Titanoceras sp., McKinzie and McLeod, 2003, p. 91, fig.
4-33.
Description.―A single very large specimen of fragmentarybody chamber is available for study; it is 352 mm in length,225–232 mm in whorl width and 137 mm in whorl height;
whorl sections are strongly depressed, subquadrate withwidth/height ratios of approximately 1.6 and consists ofbroadly concave venter and weakly inflated flanks; mostof umbilical zone is missing, but preserved part indicatesshallow concavity. Shell surface smooth; ventrolateral andumbilical angles are carinated; longitudinally elongatednodes occur on carina at ventrolateral angles.
Material examined.―IGPS coll. cat. no. 112545.
Occurrence.―TXV-200. Previous record of the species
by McKinzie and McLeod (2003) is from the Finis Shale
Member in Texas.
Discussion.―Its depressed subquadrate whorl sections
with a broadly concaved venter suggest the genericassignment of this specimen to Titanoceras rather than
Latitemnocheilus Sturgeon, Windle, Mapes and Hoare(1982; type species, Nautilus (Temnocheilus) latus Meek
and Worthen, 1870) and Temnocheilus M’Coy (1844; typespecies, Nautilus (Temnocheilus) coronatus M’Coy, 1844).

10

Shuji Niko, Royal H. Mapes and Barbara Seuss

General shape of the venter of Latitemnocheilus is weakly
convex and the whorl section of Temnocheilus indicatessubtrapezoidal profile.
The present Titanoceras sp. is well differentiated fromother species assigned to the genus by having a larger
width/height ratio of the whorl. However, erection of new
species is not possible due to lacking information about thephragmocone.
Superfamily Aipoceratoidea Hyatt, 1883
Family Solenochilidae Hyatt, 1893
Genus Solenochilus Meek and Worthen, 1870
Type species.―Nautilus (Cryptoceras) springeri Whiteand St. John, 1868.
Solenochilus jackense sp. nov.
Figure 7
Diagnosis.―Species of Solenochilus with subelliptical
whorl sections, whose width/height ratios are 1.4–1.5;
venter broadly rounded; ventrolateral shoulders rounded;flanks weakly inflated to straight; umbilical angles carinated;umbilical zones weakly concaved; impressed area
moderately concaved; camerae relatively long; except for
relatively deep ventral sinus, sutures roughly transverse.
Description.―Conchs large, subglobose with rapid whorl
expansion; inner whorls are narrowly evolute with narrowumbilical area, then coiling becomes loose in more adoralphragmocone; apex not observable; the holotype (largest
specimen) is fragmentary whorl of mature phragmocone
having 58 mm in whorl length, 52 mm in maximum whorl
width (reconstructed from half width, exfoliated lateral shallwall), and 36 mm in maximum whorl height (exfoliatedventral shall wall); a paratype (AMNH 6167) representing
immature phragmocone is 45 mm in diameter, 40 mm in
maximum whorl width (reconstructed from half width), 27
mm in maximum whorl height, and 0.2 in approximate ratioof umbilical diameter per conch diameter; whorl sections
are depressed and subelliptical; profiles of whorl sections in
immature phragmocone consist of broadly rounded venter,rounded ventrolateral shoulders, weakly inflated flanks,
weakly concaved umbilical zones and shallowly rounded
impressed area; in mature phragmocone, flanks becomestraight and acutely converge to venter; umbilical angles
carinated; width/height ratios of whorls are 1.4–1.5; nobody chamber preserved. Shell surface is mostly smooth
except for umbilical carinae that are marked by longitudinallirae; umbilical spine not preserved. Septa are shallowly
concaved; sutures are roughly transverse with narrow but
relatively deep ventral sinus, weak ventrolateral saddles,and nearly straight at lateral to dorsolateral portions;cameral lengths are relatively long for the genus, 17–20 mm

at ventral margin in the holotype. Siphuncle is at the ventral
margin; septal necks are suborthochoanitic in immature andorthochanitic in mature phragmocones.
Material examined.―Holotype, AMNH 6168. Paratypes,
AMNH 6166, 6167. In addition, two specimens (AMNH
6164, 6165) are assigned to Solenochilus jackense sp. nov.
Occurrence.―TXV-34 (AMNH 6164), TXV-200 (AMNH
6165–6168).
Etymology.―The specific name is derived from JackCounty, from which all examined specimens including thetype series were collected.
Discussion.―Solenochilus missouriensis Miller, Laneand Unklesbay (1947, p. 10, pl. 4, figs. 3, 4), from theMiddle Pennsylvanian Winterset Limestone of Missouri,
most closely resembles the new species, by its subelliptical
whorl sections with a width/height ratio of approximately
1.5 and relatively long camerae. However, this species
has more strongly fluted sutures especially at the lateral
to dorsolateral portions than those of S. jackense sp. nov.
Solenochilus greenensis Sturgeon (1946, p. 33–35, pl. 8,
fig. 6, pl. 9, fig. 3, text-fig. 3A; Sturgeon et al., 1997, p. 71,
72, pl. 1-31, figs. 1, 2, pl. 1-32, fig. 2, pl. 1-33, fig. 3, pl. 1-34,
figs. 1–3, text-fig. 1-11B), described from the Desmoinesian
Hamden Limestone, Ohio also resembles S. jackense, but
its dorsal part of the flanks is strongly concave. Solenochilus
mcfarlandi Sturgeon, Windle, Mapes and Hoare (1982,
p. 1469, 1471, 1472, pl. 5, figs. 3, 4; 1997, p. 73, 74, pl.
1-35, fig. 2, pl. 1-37, figs. 2, 3, text-fig. 1-12A) from theMissourian part of the Conemaugh Group of Ohio differsfrom S. jackense in having more depressed whorl sections
exceeding 1.8 in a width/height ratio and shorter camerae.
Other comparable species, including S. brammeri Miller,
Dunbar and Condra (1933, p. 234–236, pl. 22, figs. 6, 7,
pl. 23, fig. 1, pl. 24. fig. 1) from the Missourian Argentine
Limestone of Nebraska and S. springeri (White and St. John,
1868, p. 124, 125, fig. 10; Kummel, 1964, figs. 319, 320,1,
321; Mikesh and Glenister, 1966, p. 273–277, figs. 1A, 1B)
from the Middle Pennsylvanian of Iowa and Arkansas, arewell differentiated from S. jackense by the presence of a
mid-ventral groove in their mature phragmocones.
Superfamily Clydonautiloidea Hyatt in Zittel, 1900
Family Liroceratidae Miller and Youngquist, 1949
Genus Liroceras Teichert, 1940
Type species.―Coloceras liratum Girty, 1911.
Liroceras liratum (Girty, 1911)
Figure 8
Coloceras liratum Girty, 1911, p. 144, 145; 1915, p. 237,
238, pl. 28, figs. 2, 2a, b, 3, 3a, b, 4, 4a, 5, 6, 6a; Miller etal., 1933, p. 132–134, pl. 6, figs. 1–8.

Pennsylvanian coiled nautiloids from Texas

11

Figure 7. Solenochilus jackense sp. nov. A, B, E, F. paratype, AMNH 6167: A lateral view; B, ventral-apertural view;E, ventral view; F, ventral view, showing details of siphuncle. C, D, G. holotype, AMNH 6168, shell wall mostly exfoliated: C,
septal view, venter up; D, lateral view; G, ventral view, showing details of siphuncle. Scale bar is 20 mm in A–E; 6 mm in F, G.

Coloceras liratum obsoletum Girty, 1911, p. 145; 1915, p.
238, 239, pl. 29, figs. 1, 1a, b, 2, 2a, 3, 3a.
Coloceras obsoletum Girty. Miller et al., 1933, p. 134–136,
pl. 7, figs. 4–7.
Coloceras liratum? Girty. Miller and Cline, 1934, p. 173–175,
pl. 28, figs. 24–26.
Liroceras liratum (Girty). Teichert, 1940, p. 590; Young,
1942, p. 122; Sturgeon, 1946, p. 19–21, pl. 4, figs. 6–9;
Miller and Youngquist, 1949, pl. 53, figs. 3–6; Unklesbay
and Palmer, 1958, p. 1073, pl. 138, figs. 1–3; Unklesbay,
1962, p. 45–47, pl. 5, figs. 6–8, pl. 6, figs. 5, 6, text-fig. 1;
Kummel, 1964, figs. 324,3a, b; Murphy, 1970, p. 203, 204,

pl. 36, fig. 9; Tucker, 1976, p. 67, 68, pl. 3, fig. 4; Sturgeon
et al., 1997, p. 78, 79, pl. 1-44, figs. 1, 3–12; Seuß et al,
2009, p. 627.
Liroceras cf. liratum (Girty). Young, 1942, p. 122.
Liroceras sp., Miller and Unklesbay, 1942a, p. 137, 138, pl. 1,
fig. 13, text-fig. 1A; Sturgeon and Miller, 1948, p. 76, 77;
Mapes and Chaffin, 2003, fig. 4B; McKinzie and McLeod,
2003, p. 88, fig. 4-30.
Description.―Conchs small, having 70 mm inreconstructed diameter, subglobose, involute with moderate
whorl expansion; whorl sections are depressed and reniform12

Shuji Niko, Royal H. Mapes and Barbara Seuss

Figure 8. Liroceras liratum (Girty, 1911). A, B, F. AMNH 6305: A, lateral view; B, ventral-apertural view; F, lateral view,
showing details of surface ornamentation. C. AMNH 6348, shell wall mostly exfoliated, ventral view. D. AMNH 6310, septal
view, venter up. E. AMNH 6354, septal view, venter up. G. AMNH 6352, dorsal view. H. AMNH 6345, shell wall exfoliated,
lateral view. I. AMNH 6360, septal view, venter up. J. AMNH 6355, lateral view. K, L. AMNH 6357: K, dorsal view; L, ventral
view. Scale bar is 20 mm in A–E, G–L; 6 mm in F.

Pennsylvanian coiled nautiloids from Texas
consisting of rounded venter, ventrolateral shoulders toflanks, broadly rounded umbilical zones and rounded
impressed area; umbilical angles narrowly rounded; width/height ratios of whorls are 1.2–1.7. Shell surface is smooth,
except for portion of umbilical angles to umbilical zones in
inner volutions, where reticulate ornamentation is developed;
growth lines exhibit shallow ventral (hyponomic) and lateral(ocular) sinuses. Septa relatively deep; sutures are directlytransverse. Siphuncle is subcentral.
Material examined.―AMNH 6298–6471.
Occurrence.―The syntypes were collected from the
Desmoinesian Wewoka Formation of Oklahoma (Girty,
1911). Except for the type stratum, specimens of this species
are widely known from the Middle to Upper Pennsylvanianof the North American Midcontinent including the Allegheny
and Conemaugh Formations in Pennsylvania (Miller andUnklesbay, 1942a), the Pottsville, Allegheny and Conemaugh
Formations in Ohio (Sturgeon, 1946), the Mattoon Formationin Illinois (Tucker, 1976), the Burgner Formation in Missouri(Unklesbay and Palmer, 1958), the Weston Shale in Kansas(Miller et al., 1933), the Atoka, Pumpkin Creek, Boggy,
Stuart, Senora, Wetumka, Holdenville, Nellie Bly, Wann,
Vamoosa and Kanwaka Formations in Oklahoma (Miller etal., 1933), the Jacksboro Limestone and the Finis Shale
Member in Texas (Miller et al., 1933), and the Magdalena
Group in New Mexico (Young, 1942).
Localities of each examined specimen in this study are as
follows; TXV-34 (AMNH 6298–6302), TXV-36 (AMNH 6303),
TXV-54, (AMNH 6304), TXV-56 (AMNH 6305–6341), TXV120 (AMNH 6342–6347), TXV-200 (AMNH 6348–6471).
Discussion.―Unklesbay (1962) considered thatdifferences between Liroceras liratum and L. obsoletum,
especially in their surface ornamentations are intraspecificvariations and synonymized them. We agree with his
proposal. Liroceras liratum is the most abundant nautiloid
species in the Finis Shale Member.
Genus Peripetoceras Hyatt, 1894
Type species.―Nautilus freieslebeni Geinitz, 1843.
Peripetoceras bridgeportense Tucker and Mapes, 1978
Figure 9
Peripetoceras bridgeportense Tucker and Mapes, 1978, p.
598, 600, 603, pl. 1, figs. 1–3, pl. 2, figs. 1, 2, pl. 3, fig. 7.
Peripetoceras sp., Wani et al., 2012, fig. 3D.
Description.―Conchs small, having 50 mm inreconstructed diameter, subglobose, involute with rapid whorl
expansion; whorl sections depressed, reniform in apicaland subtrapezoidal in adoral shells; profiles of apical whorls
consist of rounded venter, ventrolateral shoulders to flanks,

13

narrowly rounded umbilical zones and rounded impressed
zone; in adoral whorls, subquadrate ventral angles appear
and following profiles indicate nearly flat venter, nearlyflat ventrolateral shoulders to flanks converging acutely
to venter, narrowly rounded umbilical zones, and deeply
rounded and wide impressed zone; umbilical angles broadly
rounded throughout; width/height rations of whorls range
from 1.5 to1.7. Shell surface is smooth; growth lines exhibit
narrowly rounded ventral (=hyponomic) sinus, broadly
rounded ventrolateral lobes, very shallow lateral (= ocular)
sinus; sutures are transverse and roughly straight; siphuncle
is supracentral in position and slightly off to dorsum.
Material examined.―AMNH 6282–6297.
Occurrence.―The holotype and all paratypes ofPeripetoceras bridgeportense were collected from theMissourian (early Late Pennsylvanian) Wolf Mountain Shale,
Texas (Tucker and Mapes, 1978).
Localities of each examined specimen in this study are as
follows; TXV-34 (AMNH 6282–6287), TXV-54 (AMNH 6288),
TXV-56 (AMNH 6289–6292), TXV-200 (AMNH 6293–6297).
Previous record of the species by Wani et al. (2012) is fromthe Finis Shale Member in Texas.
Discussion.―We assign the present specimens to
Peripetoceras bridgeportense on the basis of similarities
with the holotype in their whorl section shapes, ratios ofconch expansion, and siphuncular position. It is possible thatan unfigured species, Peripetoceras sp., recorded from theFinis Shale Member by McKinzie and McLeod (2003) also isconspecific with P. bridgeportense.
Family Ephippioceratidae Miller and Youngquist, 1949
Genus Ephippioceras Hyatt, 1884
Type species.―Nautilus ferratus Cox, 1858.
Ephippioceras ferratum (Cox, 1858)
Figure 10
Nautilus ferratus Cox, 1858, p. 574, 575, pl. 10, figs. 2, 2a.
Ephippioceras ferratum (Cox). Hyatt, 1884, p. 290; 1894,
p. 539, pl. 10, figs. 23–26; Miller et al., 1933, p. 114–118,
pl. 3, figs. 14–17; Miller and Owen, 1934, p. 209–211, pl.
12, figs. 3, 4, text-figs. 1A, B; Smith, 1938, p. 10, 11, pl.
1, fig. 17; Miller and Unklesbay, 1942a, p. 136, pl. 1, figs.
14, 15; Sturgeon, 1946, p. 18, 19, pl. 4, figs. 2–4; Miller
and Unklesbay, 1947, p. 320, pl. 1, figs. 7, 8; Miller et al.,1947, p. 6, pl. 2, figs. 7–10; Miller and Youngquist, 1949, p.
129, pl. 53, figs. 7, 8; Unklesbay, 1962, p. 50–52, pl. 4, fig.
3; Kummel, 1963, p. 357, pl. 15, figs. 4–7; 1964, fig. 326,
2; Sturgeon et al., 1997, p. 81, 82, pl. 1-46, figs. 1–5, 7, 9.
Ephippioceras (Nautilus) ferratum (Cox). Hyatt, 1891, p.
352.
[not] Ephippioceras ferratum (Cox). Gordon, 1964, p. 162,

14

Shuji Niko, Royal H. Mapes and Barbara Seuss

Figure 9. Peripetoceras bridgeportense Tucker and Mapes, 1978. A, B, F, K. AMNH 6289: A, septal view, venter up;
B, ventral view; F, lateral view; K, partial enlargement of B to show details of surface ornamentation. C, I, J. AMNH 6283:
C, ventral view; I, lateral view; J, septal view, venter up. D, G. AMNH 6292: D, ventral view; G, dorsal view. E. AMNH 6295,
septal view, venter up. H. AMNH 6297, lateral view. Scale bar is 20 mm in A–J; 12 mm in K.

Pennsylvanian coiled nautiloids from Texas

15

Figure 10. Ephippioceras ferratum (Cox, 1858). A–C. AMNH 6169, shell wall mostly exfoliated: A, ventral view; B, crosssectional view, venter up; C, lateral view. D–F. AMNH 6170, shell wall mostly exfoliated: D, ventral view; E, lateral view;
F, ventral-apertural view. G, H. AMNH 6171: G, septal view, venter up; H, ventral view. I, J. AMNH 6172, shell wall mostly
exfoliated: I, lateral view; J, ventral view. Scale bar is 15 mm.

163, pl. 16, figs. 1–3, text-fig. 31 [= E. sp. nov.].
Eohippioceras [sic.] ferratum (Cox). Seuß et al, 2009, p.
627.
Description.―Conchs small, subglobose and involutewith relatively rapid whorl expansion; a well-preserved
specimen (AMNH 6172) has 29 mm in conch diameter;whorl sections are strongly depressed, reniform consistingof rounded venter, ventrolateral shoulders to franks, weakly
inflated umbilical zones and deeply rounded impressed
area; umbilical angles bluntly pointed; width/height ratios ofwhorls are 1.6–1.8; mid-ventral conchal furrow developed.
Shell surface smooth. Cameral length short; sutures exhibit
distinct flutings indicating V-shaped and very prominent

16

Shuji Niko, Royal H. Mapes and Barbara Seuss

Figure 11. Paleogeographic reconstruction of the distribution of common Late Pennsylvanian coiled nautiloid species
with the Finis Shale assemblage (arrow). Map based on and modified from Algeo and Heckel (2008). 1, Liroceras liratumand Ephippioceras ferratum in the Conemaugh Formation, Pennsylvania; 2, L. liratum and E. ferratum in the Conemaugh
Formation, Ohio; 3, L. liratum in the Mattoon Formation, Illinois; 4, E. ferratum in the South Bend Formation, Nebraska; 5,
Tainoceras monilifer in the Iatan Limestone, Nebraska; 6, E. ferratum in the Dennis and Westerville limestones, Missouri;
7, L. liratum in the Weston Shale, Kansas;8, T. monilifer in the Lawrence Shale and Kereford and Burlingame Limestones,
Kansas; 9, T. monilifer in the Vamoosa Formation and L. liratum in the Nellie Bly, Wann, Vamoosa and Kanwaka Formations,Oklahoma; 10, Peripetoceras bridgeportense in the Wolf Mountain Shale, Texas; 11, L. liratum in the Magdalena Group, New
Mexico.
ventral saddle, broadly rounded lateral lobes and low
umbilical saddle. Siphuncle central to slightly supracentral in
position.
Material examined.―AMNH 6169–6172.
Occurrence.―The holotype of Ephippioceras ferratum
was collected from the Pennsylvanian (specific stratigraphic
setting unknown) of Kentucky (Cox, 1858). Specimensof this species are also known from the Middle toUpper Pennsylvanian of the Conemaugh Formation in
Pennsylvania (Miller and Unklesbay, 1942a), the Pottsville,
Allegheny and Conemaugh Formations in Ohio (Sturgeon,1946), the Cherokee Formation and the Dennis andWesterville Limestones in Missouri (Miller et al., 1933), theSouth Bend Formation in Nebraska (Miller et al., 1933), andthe Boggy Formation in Oklahoma (Smith, 1938).
Localities of each examined specimen in this study are as
follows; TXV-34 (AMNH 6169–6171), TXV-56 (AMNH 6172).
Discussion.―Gordon (1964) assigned a single Morrowan(Early Pennsylvanian) specimen from the Hale Formation,

Arkansas to Ephippioceras ferratum and stated that it is theearliest record of this species. However, we cannot agreewith his point of view because the ventral saddle in the
suture of this Morrowan specimen is much lower than that of
the typical ones of E. ferratum. We think that this specimen
probably represents a new species and the chronologicalrange of E. ferratum is, therefore, constrained exclusively in
Middle to Late Pennsylvanian time.

Coiled Nautiloid Assemblage
The Late Pennsylvanian coiled nautiloid assemblage fromthe Finis Shale Member is composed by Tainoceras monilifer
Miller, Dunbar and Condra, Metacoceras quadratum sp.
nov., Endolobus sturgeoni sp. nov., Domatoceras tuckeri
sp. nov., Titanoceras sp., Solenochilus jackense sp. nov.,
Liroceras liratum (Girty), Peripetoceras bridgeportense
Tucker and Mapes, and Ephippioceras ferratum (Cox).
In our previous studies concerning fossil cephalopods

17

Pennsylvanian coiled nautiloids from Texas
in the Midcontinent of North America, Niko et al. (2018)
examined the Middle Pennsylvanian orthoconic cephalopod
assemblage in the Buckhorn Asphalt Quarry, located ca.
150 km northeast of Jacksboro, and concluded that itdemonstrates provincialism. In contrast to this assemblage,
the Finis Shale assemblage indicates cosmopolitanism
and is characterized by the absence of endemic genera
and presence of common, widely occurring species to highdegree. Most of the area of Midcontinent North America,
situated in the low latitudes at this time, was flooded dueto the rise of the sea level forced by melting Gondwanan
ice sheets and submergence in the shelf sea (i.e., the Late
Pennsylvanian Midcontinent Sea (LPMS); Heckel, 1994).
The LPMS included the Appalachian Basin, the Illinois
Basin, the Midcontinent Shelf and the Willistone Basin,
and was connected to the Panthalassic Ocean through the
Marginal Sea (Algeo and Heckel, 2008; Algeo et al., 2008;
Algeo and Herrmann, 2017).
As obvious from the proceeding systematic part, Late
Pennsylvanian occurrences of the previously known four
species from outside the Finis Shale Member are as follows:
T. monilifer (Nebraska, Kansas, Oklahoma), L. liratum(Pennsylvania, Ohio, Illinois, Oklahoma, New Mexico), P.
bridgeportense (Texas), and E. ferratum (Pennsylvania,
Ohio, Missouri, Nebraska, Oklahoma). Among these, alllocalities in Texas (including the Finis Shale) and New
Mexico belong to the Marginal Sea while others are in the
LPMS; more particularly they belong to the Appalachian
Basin (Pennsylvania, Ohio), the Illinois Basin (Illinois)
and the Midcontinent Shelf (Missouri, Nebraska, Kansas,
Oklahoma), whose areas represent the southern partof the sea (Figure 11). Niko et al. (2018) suggested thatthe Buckhorn Asphalt was deposited in the restricted
epeiric sea during a cool episode. Differences of abovementioned composition between these two assemblages
can be referred to sea level change triggered by forming
and melting of ice sheets. We can conclude that the coiled
nautiloid assemblage from the Finis Shale inhabited the
Marginal Sea that was open to the Panthalassic Ocean
at that time and thus, had strong biotic linkage with thesouthern LPMS including the Appalachian Basin, the Illinois
Basin, and the Midcontinent Shelf.

Acknowledgements
We thank G. Mapes, A. Pradel and I. Kruta for theirsupports in our field trips. Many thanks also go to themembers of the Dallas Paleontological Society forassistance and collecting specimens during field work at
the TXV-200 section by BS (DFG-project SE 2283/2-1). The
helpful reviews by M. Ehiro improved this paper.

References
Agassiz, L., 1847, An Introduction to the Study of Natural History,
in a Series of Lectures Delivered in the Hall of the College ofPhysicians and Surgeons, 58 p. Greeley and McElrath, NewYork.
Algeo, T. J. and Heckel, P. H., 2008, The Late Pennsylvanian
Midcontinent Sea of North America: A review. Palaeogeography,
Palaeoclimatology, Palaeoecology, vol. 268, p. 205−221.
Algeo, T. J. and Herrmann, A. D., 2017, An ancient estuarinecirculation nutrient trap: The Late Pennsylvanian Midcontinent
Sea of North America. Geology, vol. 46, p. 143−146.
Algeo, T. J., Rowe, H., Hower, J. C., Schwark, L., Herrmann, A.
and Heckel, P. H., 2008, Changes in ocean denitrification
during Late Carboniferous glacial-interglacial cycles. Nature
Geoscience, vol. 1, p. 709−714.
Barnes, V. E., Hentz, T. F., Brown, L. F., Cleaves, A. W., Kier, R. S.,
McGowen, J. H., Parrish, W. C., Ramsey, J. W., Long, T. F.,
Reutinger, C. A., Caran, S. C., Henry, C. D. and Kaiser, W. R.,
1987, Geologic Atlas of Texas, Wichita Falls-Lawton Sheet.
Annual Report, Bureau of Economic Geology, The University ofTexas at Austin.
Boardman, D. R. II, Work, D. M., Mapes, R. H. and Barrick, J.
E., 1994, Biostratigraphy of Middle and Late Pennsylvanian(Desmoinesian-Virgilian) ammonoids. Kansas Geological
Survey, Bulletin, no. 232, p. 1−121.
Cox, E. T., 1858, Palaeontological report of Coal Measure Mollusca.
Kentucky Geological Survey, vol. 3, p. 557−576, pls. 7−10.
Doguzhaeva, L. A., Mapes, R. H. and Dunca, E., 2006, A Late
Carboniferous adolescent cephalopod from Texas (USA), witha short rostrum and a long body chamber. Acta Universitatis
Carolinae, Geologica, vol. 49, p. 55−68.
Doguzhaeva, L. A., Mapes, R. H. and Mutvei, H., 1999, A Late
Carboniferous spirulid coleoid from the southern Mid-continent(USA), shell wall ultrastructure and evolutionary implications.
In, Olóriz F. and Rodríguez-Tovar, F. J. eds., Advancing
Research on Living and Fossil Cephalopods, p. 47−57. Kluwer
Academic/Plenum Publishers, New York, Boston, Dordrecht,
London and Moscow.
Furnish, W. M., Glenister, B. F. and Hansman, R. H., 1962,
Brachycycloceratidae, novum, deciduous Pennsylvanian
nautiloids. Journal of Paleontology, vol. 36, p. 1341‒1356, pls.
176‒180.
Geinitz, H. B., 1843, Gäa von Sachsen. Einleitung in die Floravon Sachsen von Dr. und Prof. Ludwig Reichenbach, 235 p.
Dresden and Leipzig.
Girty, G. H., 1911, On some new genera and species ofPennsylvanian fossils from the Wewoka Formation of
Oklahoma. Annals of the New York Academy of Science, vol.
21, p. 119‒156.
Girty, G. H., 1915, Fauna of the Wewoka Formation of Oklahoma.
United States Geological Survey, Bulletin, no. 544, p. 1‒353.
Gordon, M. Jr., 1964, Carboniferous cephalopods of Arkansas.
United States Geological Survey Professional Paper, no. 460,
p. 1‒322, pls. 1‒30.
Hansman, R. H., 1965, Brachycycloceras? from the Pennsylvanianof Texas. Journal of Paleontology, vol. 39, p. 729−730.
Heckel, P. H., 1994, Evaluation of evidence for glacial-eustatic
control over marine Pennsylvanian cyclothems in North
America and consideration of possible tectonic effects. In,
Dennison, J. M. and Ettensohn, F. R. eds., Tectonic andEustatic Controls on Sedimentary Cycles, p. 65−87. SEPM

18

Shuji Niko, Royal H. Mapes and Barbara Seuss(Society for Sedimentary Geology), Concepts in Sedimentology
and Paleontology, vol. 4, Tulsa.
Hyatt, A., 1883‒1884, Genera of fossil cephalopods. Proceedings ofthe Boston Society of Natural History, vol. 22, p. 253‒338.
Hyatt, A., 1891, Carboniferous cephalopods. Geological Survey ofTexas, Second Annual Report, 1890, p. 327‒356.
Hyatt, A., 1893, Carboniferous cephalopods. Second paper.
Geological Survey of Texas, Fourth Annual Report, 1892, p.
377‒474.
Hyatt, A., 1894, Phylogeny of acquired characteristics. Proceedingsof the American Philosophical Society, vol. 32, p. 349‒647, pls.
1‒14.
Kummel, B., 1963, Miscellaneous nautilid type species of Alpheus
Hyatt. Bulletin of the Museum of Comparative Zoology, vol.
128, p. 325‒368, pls. 1‒30.
Kummel, B., 1964, Nautiloidea―Nautilida. In, Teichert, C.,
Kummel, B., Sweet, W. C., Stenzel, H. B., Furnish, W. M.,
Glenister, B. F., Erben, H. K., Moore, R. C. and Nodine Zeller,
D. E. eds., Treatise on Invertebrate Paleontology, Part K,
Mollusca 3 (Cephalopoda. General Features, Endoceratoidea‒
Actinoceratoidea, Nautiloidea, Bactritoidea), p. K383‒K457.
Geological Society of America, New York, and University of
Kansas Press, Lawrence.
Mapes, R. H., 1979, Carboniferous and Permian Bactritoidea(Cephalopoda) in North America. The University of Kansas
Paleontological Contributions, Article 64, p. 1‒75, pls. 1‒41.
Mapes, R. H., 1987, Upper Paleozoic cephalopod mandibles:
Frequency of occurrence, modes of preservation, andpaleoecological implications. Journal of Paleontology, vol. 61, p.
521–538.
Mapes, R. H. and Chaffin, D. T., 2003, Predation on cephalopods,a general overview with a case study from the Upper
Carboniferous of Texas. In, Kelley, P. H., Kowalewski, M. andHansen, T. A. eds., Predator-Prey Interactions in the Fossil
Record, p. 177‒213. Kluwer Academic/Plenum Publishers,
New York, Boston, Dordrecht, London and Moscow.
Mapes, R. H., Sims, M. S. and Boardman, D. R. II, 1995, Predationon the Pennsylvanian ammonoid Gonioloboceras and its
implications for allochthonous vs. autochthonous accumulationsof Goniatites and other ammonoids. Journal of Paleontology,
vol. 69, p. 441–446.
McChesney, J. H., 1859, Descriptions of new species of fossils, fromthe Palaeozoic rocks of the western states. Extra Transactions,
Chicago Academy of Sciences, vol. 1, p. 1‒76.
McKinzie, M. and McLeod, J., 2003, Pennsylvanian fossils ofnorth Texas. Occasional Papers of the Dallas PaleontologicalSociety, vol. 6, p. 1–145.
McGowen, J. H., Proctor, C. V., Haenggi, W. T., Reaser, D. F. andBarnes, V. E., 1972, Geologic Atlas of Texas, Dallas Sheet.
Bureau of Economic Geology, The University of Texas atAustin.
M'Coy, F., 1844, A Synopsis of the Characters of the Carboniferous
Limestone Fossils of Ireland, 274 p. Privately published.
(reissued by Williams and Norgate, London, 1862)
Meek, F. B., 1872, Part II. Paleontology. Report on the paleontologyof eastern Nebraska, with some remarks on the Carboniferous
rocks of that district. In, Final Report of the United States
Geological Survey of Nebraska and Portions of the AdjacentTerritories, Made Under the Direction of the Commissioner of
the General Land Office, p. 83‒236, pls. 1‒11. Government
Printing Office, Washington, D.C.
Meek, F. B. and Worthen, A. H., 1860, Descriptions of new

Carboniferous fossils from Illinois and other westernstates. Proceedings of the Academy of Natural Sciences ofPhiladelphia, 1860, p. 447‒472.
Meek, F. B. and Worthen, A. H., 1865, Contributions to thepalaeontology of Illinois and other western states. Proceedingsof the Academy of Natural Sciences of Philadelphia, 1865, p.
245‒273.
Meek, F. B. and Worthen, A. H., 1870, Descriptions of new species
and genera of fossils from the Palaeozoic rocks of the westernstates. Proceedings of the Academy of Natural Sciences ofPhiladelphia, 1870, p. 22‒56.
Mikesh, D. L. and Glenister, B. F., 1966, Solenochilus springeri(White & St. John, 1868) from the Pennsylvanian of southern
Iowa. Proceedings of the Iowa Academy of Science, vol. 73, p.
269–278.
Miller, A. K., 1932, A Pennsylvanian cephalopod fauna from southcentral New Mexico. Journal of Paleontology, vol. 6, p. 59–93,
pls. 12, 13.
Miller, A. K. and Cline, L. M., 1934, The cephalopod fauna of thePennsylvanian Nellie Bly Formation of Oklahoma. Journal of
Paleontology, vol. 8, p. 171–185, pl. 28.
Miller, A. K. and Downs, R. H., 1950, Ammonoids of thePennsylvanian Finis Shale of Texas. Journal of Paleontology,
vol. 24, p. 185–218, pls. 31–35.
Miller, A. K., Dunbar, C. O. and Condra, G. E., 1933, The nautiloid
cephalopods of the Pennsylvanian System in the Mid-Continent
region. Nebraska Geological Survey, Bulletin, no. 9, p. 1‒240,
pls. 1‒24.
Miller, A. K., Lane, J. H. and Unklesbay, A. G., 1947, A nautiloid
cephalopod fauna from the Pennsylvanian Winterset
Limestone of Jackson County, Missouri. University of Kansas
Paleontological Contributions, Mollusca, Article 2, p. 1‒11, pls.
1‒5.
Miller, A. K. and Owen, J. B., 1934, Cherokee nautiloids of thenorthern Mid-Continent region. University of Iowa Studies in
Natural History, vol. 16, p. 185‒272, pls. 8‒19.
Miller, A. K. and Unklesbay, A. G., 1942a, The cephalopod faunaof the Conemaugh Series in western Pennsylvania. Annals of
the Carnegie Museum, vol. 29, p. 127‒174, pls. 1‒8.
Miller, A. K. and Unklesbay, A. G., 1942b, Permian nautiloids fromwestern United States. Journal of Paleontology, vol. 16, p.
719‒738, pls. 111‒117.
Miller, A. K. and Unklesbay, A. G., 1947, The cephalopod fauna of
the Conemaugh Series in western Pennsylvania: Supplement.
Annals of the Carnegie Museum, vol. 30, p. 319‒330, pls. 1, 2.
Miller A. K. and Youngquist, W., 1949, American Permian nautiloids.
The Geological Society of America Memoir, no. 41, p. 1‒218,
pls. 1‒59.
Murphy, J. L., 1970, Coiled nautiloid cephalopods from the Brush
Creek Limestone (Conemaugh) of eastern Ohio and western
Pennsylvania. Journal of Paleontology, vol. 44, p. 195‒205,
pls. 35, 36.
Mutvei, H. and Mapes, R. H., 2018, Carboniferous coleoids with
mixed coleoid-orthocerid characteristics: a new light on
cephalopod evolution. GFF, A Scandinavian Journal of Earth
Science, vol. 140, p. 11‒24.
Mutvei, H., Mapes, R. H. and Doguzhaeva, L. A., 2012, Shellstructure in Carboniferous bactritid-like coleoids (Cephalopoda)
from South Central UAS. GFF, A Scandinavian Journal of Earth
Science, vol. 134, p. 201‒216.
Niko, S. and Mapes, R. H., 2010, Reevaluation of the Late
Carboniferous cephalopod, Brachycycloceras? spectrum

Pennsylvanian coiled nautiloids from Texas
Hansman, 1965 from Texas, USA. Paleontological Research,
vol. 14, p. 227‒232.
N i k o , S . a n d M a p e s , R . H . , 2 0 11 , Te x a n o c e r a s , a n e w
neptunoceratid cephalopod genus from the Upper
Pennsylvanian Graham and Caddo Creek formations in northcentral Texas. Journal of Paleontology, vol. 85, p. 519‒523.
Niko, S., Seuss, B. and Mapes, R. H., 2018, Desmoinesian (Middle
Pennsylvanian) orthocerid cephalopods from the Buckhorn
Asphalt Lagerstätte in Oklahoma, Midcontinent North America.
Paleontological Research, vol. 22, p. 20‒36.
Plummer F. B. and Hornberger, J. Jr., 1936, Geology of Palo Pinto
County, Texas. University of Texas Bulletin, no. 3534, p. 1‒240.
Plummer, F. B. and Moore, R. C., 1922, Stratigraphy of thePennsylvanian formations of north-central Texas. University ofTexas Bulletin, no. 2132, p. 1‒237, pls. 1‒27.
Plummer, F. B. and Scott, G., 1937, Upper Paleozoic ammonites
in Texas. The University of Texas Bulletin, no. 3701, p. 1‒516,
pls. 1‒41.
Seuß, B., Nützel, A., Mapes, R. H. and Yancey, T. E., 2009, Facies
and fauna of the Pennsylvanian Buckhorn Asphalt Quarry
deposits: A review and new data on an important Palaeozoic
fossil Lagerstätte with aragonite preservation. Facies, vol. 55, p.
609‒645.
Smith, H. J., 1938, The cephalopod Fauna of the Buckhorn Asphalt,
40 p. The University of Chicago Libraries, Chicago, Illinois.
Sturgeon, M. T., 1946, Allegheny fossil invertebrates from eastern
Ohio— Nautiloidea. Journal of Paleontology, vol. 20, p. 8‒37,
pls. 3‒9.
Sturgeon, M. T. and Miller, A. K., 1948, Some additional
cephalopods from the Pennsylvanian of Ohio. Journal of
Paleontology, vol. 22, p. 57‒80, pls. 18, 19.
Sturgeon, M. T., Windle, D. L., Mapes, R. H. and Hoare, R. D.,
1982, New and revised taxa of Pennsylvanian cephalopods
in Ohio and west Virginia. Journal of Paleontology, vol. 56, p.
1453‒1479, pls. 1‒5.

19

Sturgeon, M. T., Windle, D. L., Mapes, R. H. and Hoare, R. D.,
1997, Pennsylvanian cephalopods of Ohio. Part 1. Nautiloid
and bactritoid cephalopods. Ohio Division of Geological Survey,
Bulletin, no. 71, p. 1‒191.
Teichert, C., 1940, Contributions to nautiloid nomenclature. Journalof Paleontology, vol. 14, p. 590‒597.
Tucker, J. K., 1976, A coiled nautiloid fauna from the Mattoon
Formation (Pennsylvanian) of Illinois. Transactions of theIllinois State Academy of Sciences, vol. 69, p. 57‒77.
Tucker, J. K. and Mapes, R. H., 1978, Coiled nautiloid cephalopods
from the Wolf Mountain Shale (Pennsylvanian), north-central
Texas. Journal of Paleontology, vol. 52, p. 596‒604, pls. 1‒3.
Unklesbay, A. G., 1962, Pennsylvanian cephalopods of Oklahoma.
Oklahoma Geological Survey, Bulletin, no. 96, p. 1‒150, pls.
1‒19.
Unklesbay, A. G. and Palmer, E. J., 1958, Cephalopods from the
Burgner Formation in Missouri. Journal of Paleontology, vol.
32, p. 1071‒1075, pl. 138.
Wani, R., Jenkins, R. G. and Mapes, R. H., 2012, Preferential
predatory peeling: Ammonoid vs. nautiloid shells from theUpper Carboniferous of Texas, USA. Geobios, vol. 45, p.
129‒137.
White, C. A. and St. John, O. H., 1868, Descriptions of new
Subcarboniferous and Coal Measure fossils collected upon
the Geological Survey of Iowa; together with a notice of new
generic characters observed in two species of brachiopods.
Transactions of the Chicago Academy of Sciences, vol. 1, p.
115‒127.
Yo u n g , J . A . J r. , 1 9 4 2 , P e n n s y l v a n i a n S c a p h o p o d a a n d
Cephalopoda from New Mexico. Journal of Paleontology, vol.
16, p. 120‒125, pl. 20.
Zittel, K. A. von, 1900, Text-book of Palaeontology (translated andedited by Eastman, C. R.), vol. 1, 706 p. Macmillan, London
and New York.