Pleuroceras solare trapezoidiforme ( Maubeuge, 1951 )

Bardin, Jérémie, Rouget, Isabelle & Cecca, Fabrizio, 2013, Late Pliensbachian (Early Jurassic) ammonites from Lac de Charmes (Haute-Marne, France): Systematic, biostratigraphy and palaeobiogeography, Geodiversitas 35 (2), pp. 309-334 : 327-328

Pleuroceras solare trapezoidiforme ( Maubeuge, 1951)

( Fig. 7F, G ; Table 3)

Paltopleuroceras trapezoidiformis Maubeuge, 1951: 5 , pl. 1, fig. 4a-c.

Pleuroceras solare var. trapezoidiforme – Howarth 1958: 30, pl. 5, figs 8, 9. — Bourdenet 1964: pl. 1, fig. 4.

TYPE MATERIAL. — Ľe holotype is the specimen figured by Maubeuge (1951: 5, pl. 1, fig. 4a-c).

SPECIMENS AVAILABLE. — UPMC-191, 202.

STRATIGRAPHICAL DISTRIBUTION. — Upper Apyrenum subchronozone. Haute-Marne: bed 13 to 16a.

GEOGRAPHIC DISTRIBUTION. — Eastern France, Franche- Comté ( Bourdenet 1964) and Haute-Marne (this work); North-West Germany ( Jordan 1971); England ( Howarth 1958); Belgium, Ardennes ( Maubeuge 1951); Italy, Lombardy Basin ( Wiendenmayer 1980).

DESCRIPTION

Evolute shell, with whorl section higher than large. Ľe development of the ventro-lateral edge can occur late in the ontogeny and be slightly pronounced. Whorl section is trapezoid, breadth on ventro-lateral edges inferior to dorso-ventral edges. Sometimes, small tubercles up to a diameter of 20 mm. Ribs are sharp-raised.

Pleuroceras spinatum ( Bruguière, 1789) ( Figs 7A ; 8 A-E; Table 3)

Ammonites spinata Bruguière, 1789: 40 .

Ammonites franconicus Schlotheim, 1813: 101 .

Nautilus franconicus Reinecke, 1818: 87 , pl. 9, figs 68, 69.

Ammonites costatus Schlotheim, 1820: 68.

Ammonites spinatus – d’Orbigny 1844:209, pl. 52, figs 1-3.

Ammonites costatus spinatus Quenstedt, 1849: 95, pl. 5, fig. 10a, b.

Pleuroceras costatum – Hyatt 1867: 89.

Pleuroceras pseudospinatum Hyatt, 1867: 90 (nom. nov. for Quenstedt, 1849: pl. 5, fig. 10; 1856: pl. 21, figs 1-3).

Ammonites amaltheus spinatus Quenstedt, 1885: 333, 335, pl. 42, figs 17, 18, 25, 27.

Ammonites costatus nudus Quenstedt, 1885: 335, pl. 42, fig. 26.

Paltopleuroceras spinatum – Arkell 1933: 604, pl. 31, fig. 1.

Pleuroceras spinatum – Howarth 1958: 37, pl. 7, figs 2-6. — Tintant et al. 1961: pl. 1, fig. 9. — Bourdenet 1964: pl. 1, figs 9-11. — Meister 1988: pl. 8, figs 5, 6, 10, pl. 9, figs 1, 2.

TYPE MATERIAL. — Ľe neotype (Sedgwick Museum of Earth Sciences, SM. J35923 ) has been designated by Howarth (1958: pl. VII, fig. 2).

SPECIMENS AVAILABLE. — UPMC-189, 201, 208, 209, 211, 217, 219, 220.

STRATIGRAPHICAL DISTRIBUTION. — Upper Apyrenum subchronozone to Hawskerense subchronozone. Haute- Marne: bed 13 (first outcrop) and bed 20 to 32 (second outcrop).

GEOGRAPHIC DISTRIBUTION. — South-East France ( Monestier 1913, 1916, 1928; Mattéi 1985; Meister 1989; Morard 2004); eastern France, Burgundy ( Tintant et al. 1961; Lablanche et al. 1997), Franche-Comté

( Bourdenet 1964) and Haute-Marne (this work); North- West Germany ( Jordan 1971); South-West Germany ( Frentzen 1934); South-East Germany (Hoffman et al. 2007); Switzerland, Prealps (Dommmergues et al. 1990); England ( Howarth 1958); Spain, Betic Range (Comas- Rengifo et al. 2010); Portugal ( Mouterde 1967); Italy, Lombardy Basin ( Wiendenmayer 1980); Georgia ( Topchishvili 1998);

DESCRIPTION

Evolute forms with quadrilateral and massive whorls. Adult size can reach 30 cm. Ribs are strong, straight on the flank and sharp-topped and projected forward on the ventral area. Rib density is weak. Ľe keel is high. A tubercle develops on each rib slightly dorsal than the sharp-topped part.

Figures

FIG. 7. — Pleuroceras spinatum (Bruguière, 1789): A, specimen UPMC-189, Outcrop 1, bed 13. Pleuroceras solare (Phillips, 1829); B, C, specimen UPMC-190, Outcrop 1, bed 13; D, E, specimen UPMC-200, Outcrop 1, bed 16. Pleuroceras solare trapezoidiforme (Maubeuge, 1951);F, G, specimen UPMC-202,Outcrop 1, bed 16. Pleuroceras cf. spinatum (Bruguière,1789);H, I, specimen UPMC- 201, Outcrop 1, bed 16. Scale bar: 1 cm. The arrows indicate the beginning of the body chamber.

FIG. 8. – Pleuroceras spinatum (Bruguière,1789):A, B, specimen UPMC-209,Outcrop 1, bed 20; C, specimen UPMC-208;D, E, speci- men UPMC-220, Outcrop 1, bed 20. Scale bar: 1 cm.