Coilopoceras Hyatt, 1903

Barroso-Barcenilla, Fernando, Antunes, Miguel Telles, Brandão, José Manuel, Callapez, Pedro Miguel, Santos, Vanda Faria dos & Segura, Manuel, 2018, The d’Orbigny Palaeontological Collection of the National Museum of Natural History and Science, Lisbon, Portugal: Historical perspective and revision of Cretaceous Cephalopoda, Geodiversitas 40 (20), pp. 505-519 : 512-514

publication ID

https://doi.org/ 10.5252/geodiversitas2018v40a20

publication LSID

urn:lsid:zoobank.org:pub:ED6A1495-51C7-4586-91FF-111E2DBF4267

persistent identifier

https://treatment.plazi.org/id/03D28793-F615-FFB5-99DF-FD265D42F9EC

treatment provided by

Marcus

scientific name

Coilopoceras Hyatt, 1903
status

 

Genus Coilopoceras Hyatt, 1903 View in CoL

Coilopoceras requienianum (d’Orbigny, 1840) ( Fig. 4A, B View FIG )

MATERIAL. — Two partly silicified internal moulds with glued indications (518). Original label: Nº 518/ Ammonites Requienianus (d’Orb), Andar 21º [corrected] Turoniense, Terreno Cretaceo, Localidade Uchaux (Vanduse) [sic]. See Figs 1D; 4C. View FIG

DESCRIPTION

Medium-sized and involute oxycones, with sublanceolate compressed section, whose maximum width occurs close to the inner third of the flanks. Sharp venter, arched flanks and very narrow umbilici. They have large siphuncle and weak ornamentation, with juvenile whorls showing very tenuous and clavate umbilical tubercles that become feeble and projected falcoid ribs, and adult spires exhibiting smooth surfaces. Suture lines with shallow and dentate external lobes and saddles of similar height, and numerous lateral elements.

DISCUSSION

The specimen of d’Orbigny (1840: pl. 93, figs 1-2), originally collected in Uchaux, and nowadays belonging to the Requien Collection of the MHNA, has been designated by Kennedy & Wright (1984) as the lectotype. This species was firstly reported in Uchaux (Vaucluse), France, by d’Orbigny (1850, p. 189). Cobban & Hook (1980) suggested that many of the forms assigned to the genus Coilopoceras must be considered as mere synonyms of C. requienianum . In their detailed revision of this upper Turonian species, Kennedy & Wright (1984) included Coilopoceras ? grossouvrei Hyatt, 1903, within the wide morphological variability of C. requienianum , and proposed the existence in the same species of sexual dimorphism formed by smooth and ribbed forms. Some other species of Coilopoceras include the type of the genus, C. colleti Hyatt, 1903 , C. springeri Hyatt, 1903 , and C. inflatum Cobban & Hook, 1980 , usually with wider and less deeply incised suture lines. In the last years, C. requienianum has been studied by Meister & Rhalmi (2002), Fischer & Gauthier (2006), Nagm et al. (2010), Ayoub-Hannaa & Fürsich (2012), Nagm & Wilmsen (2012) andRobaszynski et al. (2014), among others.

Suborder ANCYLOCERATINA Wiedmann, 1966 Family TURRILITIDAE Gill, 1871 View in CoL Genus Turrilites Lamarck, 1801 View in CoL Subgenus Turrilites (Turrilites) Lamarck, 1801 View in CoL

Turrilites (Turrilites) costatus Lamarck, 1801 View in CoL ( Fig. 4 View FIG D-E)

MATERIAL. — Four phosphatised internal moulds without written or glued indications. Original label: Nº 466/ Turrilites costatus (Lamarck) , Andar 20º Cenomaniense, Terreno Cretaceo, Localidade Rouen (Seine inf.re). See Figs 1D; 4F. View FIG

DESCRIPTION

Medium-sized turrilitid ammonites with subpoligonal whorl sections. Deeply incised inter-whorl junction and highly acute apical angle. Ornamentation formed by approximately 20 coarse oblique ribs per whorl, located on the exposed face, and obliterated in their lower part by a wide spiral groove. The ribs exhibit a row of strong and elongated tubercles below the groove, and two rows of tenuous tubercles above it. Nearly unobservable suture lines.

DISCUSSION

According to d’Orbigny (1840: 600), specimens of this species, characteristic of the “craie chloritée moyenne”, were collected in Rouen ( France) by him and by Brongniart, Passy, d’Archiac, de Vibraye and Largilliert.This middle Cenomanian heteromorph ammonite, type of the genus, has been recently studied by some authors, such as Wright & Kennedy (1996), Matsumoto & Takahashi (2001), Fischer & Gauthier (2006), Wilmsen & Nagm (2014), Robaszynski et al. (2014) and Meister & Piuz (2015). Some other morphologically close forms of the genus are T. scheuchzerianus Bosc, 1801 , with coarse entire ribs at the later growth stages and lack of tubercles, and T. acutus Passy, 1832 , with more depressed and less ornamented whorls.

Subclass COLEOIDEA Bather, 1888 View in CoL Order BELEMNITIDA von Zittel, 1895 View in CoL Suborder PACHYBELEMNOPSEINA Riegraf in Riegraf, Janssen & Schmitt-Riegraf, 1998 Family Duvaliidae Pavlow, 1914 View in CoL Genus Duvalia Bayle, 1878 View in CoL

Kingdom

Animalia

Phylum

Mollusca

Class

Cephalopoda

Order

Ammonoidea

Family

Coilopoceratidae

Loc

Coilopoceras Hyatt, 1903

Barroso-Barcenilla, Fernando, Antunes, Miguel Telles, Brandão, José Manuel, Callapez, Pedro Miguel, Santos, Vanda Faria dos & Segura, Manuel 2018
2018
Loc

PACHYBELEMNOPSEINA

Riegraf 1998
1998
Loc

ANCYLOCERATINA

Wiedmann 1966
1966
Loc

Duvaliidae

Pavlow 1914
1914
Loc

BELEMNITIDA

von Zittel 1895
1895
Loc

COLEOIDEA

Bather 1888
1888
Loc

Duvalia

Bayle 1878
1878
Loc

TURRILITIDAE

Gill 1871
1871
Loc

Turrilites

Lamarck 1801
1801
Loc

Turrilites (Turrilites)

Lamarck 1801
1801
Loc

Turrilites (Turrilites) costatus

Lamarck 1801
1801
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