A Revision Of The Turonian Members Of The Ammonite Subfamily Collignoniceratinae From The United States Western Interior And Gulf Coast
Author
KENNEDY, W. JAMES
Author
COBBAN, WILLIAM A.
Author
LANDMAN, NEIL H.
text
Bulletin of the American Museum of Natural History
2001
2001-12-13
2001
267
1
148
http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1206%2F0003-0090(2001)267%3C0001%3AAROTTM%3E2.0.CO%3B2
journal article
10.1206/0003-0090(2001)267<0001:AROTTM>2.0.CO;2
0003-0090
5382148
Genus
Cibolaites
Cobban and Hook, 1983
TYPE
SPECIES:
Cibolaites molenaari
Cobban and Hook, 1983: 16
, pl. 2, figs. 1–9; pl. 3, figs. 3–8; pl. 8, figs. 6–8; pl. 13, figs. 1– 5; pl. 14; textfigs. 13, 14;
lower Turonian
Mammites nodosoides
Zone
, westcentral
New Mexico
.
DIAGNOSIS: A mediumsize genus, largest known adults
120 mm
in diameter; dimorphism not demonstrated. Coiling involute with small umbilicus, whorl section compressed to depressed, intercostal section with convergent sides and fastigiate venter, costal section markedly concave between tubercles. Strong conical umbilical bullae give rise to primary ribs singly or in pairs with shorter, intercalated ribs, all with ventrolateral and siphonal clavi on phragmocone. Umbilical bullae decline on the adult body chamber, which is flatsided with crowded weak primary and intercalated
Fig. 22.
Collignoniceras woollgari regulare
(Haas, 1946)
.
A–C
. USNM 498244, robust form from locality 8.
D, E
. USNM 498245;
F
. USNM 498246;
G, H.
USNM 498247, all robust forms from locality 7. All figures are ×1.
Fig. 23.
Collignoniceras woollgari regulare
(Haas, 1946)
.
A–C
. USNM 498226, gracile form from locality 8.
D, E
. USNM 252723, gracile form from locality 7. All figures are ×1.
Fig. 24.
Collignoniceras woollgari regulare
(Haas, 1946)
. USNM 420012, robust form from locality
62. Figures are ×0.80.
ribs; ventrolateral and siphonal tubercles decline progressively and the venter flattens towards the adult aperture.
Suture relatively simple with broad, littledivided saddles and narrower, rectangular lobes.
DISCUSSION: Coarse tuberculation and presence of only a single row of ventrolateral tubercles distinguishes
Cibolaites
from all other genera currently referred to the Collig noniceratinae.
Cibolaites
superficially resembles
Barroisiceras
de Grossouvre, 1894
, and
Subbarroisiceras
Basse, 1946
, of the upper Turonian–Coniacian
Barroisiceratinae
. However, they differ in sutural characteristics, while both are more involute than
Cibolaites
, with smaller umbilici and crenulate keels; in
Cibolaites
there is no continuous keel and the siphonal clavi are separated by smooth interspaces.
Fig. 25.
Collignoniceras woollgari regulare
(Haas, 1946)
. USNM 498248, robust form from locality
14. Figures are ×0.80.
Fig. 26.
Collignoniceras woollgari regulare
(Haas, 1946)
.
A, B
. Muséum National d’Histoire Naturelle, Paris, no. 6778 (
ex
d’Orbigny Collection), from the Middle Turonian of Ponce´, Sarthe, France.
C
. Faculté des Sciences, Rennes, no. C273, also from Ponce´.
D, E
. Same collection as A, B, no. W1, from ‘‘Le Mans, Sarthe,’’ France. All figures are ×1.
OCCURRENCE: Upper Cenomanian
Neocardioceras juddii
Zone
in
Devon
,
England
and Aube,
France
; lower Turonian
Mammites nodosoides
Zone
, immediately below first appearance of
C. woollgari woollgari
of the middle Turonian in westcentral New Mexico;
M. nodosoides
Zone, N.W.
Germany
; also recorded from northern
Spain
(Kaplan, 1988) and from
Tunisia
(Chancellor et al., 1994).
Fig. 27.
Collignoniceras woollgari regulare
(Haas, 1946)
.
A, B
. BMNH 4863, from ‘‘near Lewes,’’ Sussex, England (
ex
J. de C. Sowerby Collection).
C, D
. BMNH 4863a, from the same locality.
E
. paralectotype BMNH 5742b.
F
. Paralectotype BMNH 5742a, both from near Lewes, Sussex.
G
. BMNH C82268, from the Middle Turonian Middle Chalk, upper
Terebratulina lata
Zone, Mickleham Bypass
, Surrey, England. All figures are ×1.
Cibolaites molenaari
Cobban and Hook, 1983
Figures 5–8
Collignoniceras
sp.
Wright and Kennedy, 1981:
107, pl. 8, fig. 17.
Cibolaites molenaari
Cobban and Hook, 1983:
16, pl. 2, figs. 1–9; pl. 3, figs. 3–8; pl. 8, figs.
6–8; pl. 13, figs. 1–5; pl. 14; textfigs. 13, 14.
Cibolaites molenaari
Cobban and Hook. Kennedy
et al., 1986: 209, textfig. 5i, j, k, l.