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

Genus Coilopoceras Hyatt, 1903

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

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.

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 Genus Turrilites Lamarck, 1801 Subgenus Turrilites (Turrilites) Lamarck, 1801

Turrilites (Turrilites) costatus Lamarck, 1801 ( Fig. 4 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.

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 Order BELEMNITIDA von Zittel, 1895 Suborder PACHYBELEMNOPSEINA Riegraf in Riegraf, Janssen & Schmitt-Riegraf, 1998 Family Duvaliidae Pavlow, 1914 Genus Duvalia Bayle, 1878

Figures

FIG. 4. — Cretaceous ammonites and belemnites of the d’Orbigny Collection of the National Museum of Natural History and Science (Museu Nacional de História Natural e da Ciência):A-C, Coilopoceras requienianus (d’Orbigny,1840) in lateral (A) and ventral (B) views,and original label (C): Nº 518/Ammonites Requienianus (d’Orb),Andar 21º [corrected] Turoniense,Terreno Cretaceo,Localidade Uchaux (Vanduse);D-F, Turrilites (Turrilites) costatus Lamarck,1801 in lateral (D) and basal (E) views,and original label (F):Nº 466/Turrilites costatus (Lamarck),Andar 20º Cenomaniense,Terreno Cretaceo,Localidade Rouen (Seine inf.re);G-J, Duvalia dilatata (de Blainville,1827) in dorsal view (G),section (H), lateral view (I),and original label (J):Nº 351/Belemnites dilatatus (Blainville),Andar 17º Neocomiense,Terreno Cretaceo,Localidade Cheiron perto de [near of] Castellanne (Basses Alpes);K-N,Hibolithes subfusiformis(Raspail,1829) in dorsal view (K),section (L),ventral view (M),and original label (N):Nº 352/Belemnitessubfusiformis (Raspail),Andar 17º Neocomiense, Terreno Cretaceo,Localidade Cheiron (Basses Alpes); O-R, Belemnitella mucronata (von Schlotheim, 1813) in dorsal view (O), section (P), ventral view (Q), and original label (R): Nº 556/Belemnitella mucronata (d’Orb),Andar 22º Senoniense,Terreno Cretaceo,Localidade Epernay (Marne).Scale bar:2 cm.