Metaconularia, Sinclair, 1952

Sendino, Consuelo, Taylor, Paul D. & Iten, Heyo Van, 2012, Metaconularia? pyramidata (Bronn, 1837): a scyphozoan from the Ordovician of Normandy, France, recorded for the first time as a reworked fossil in the Triassic of Devon, England, Geodiversitas 34 (2), pp. 283-296 : 288-293

Metaconularia ? pyramidata (Bronn, 1837) ( Figs 4 ; 5 ; 6A, B , E-K, M-O)

Conulaire ondulée (var.) – Deslongchamps 1825: pl. 20, figs 6a-c, 7a-b.

“ Conularia pyramidata ” – Bronn 1830: 228. — De la Beche 1832: 535.

Conularia pyramidata Bronn, 1835 -1838: 1284, pl. 1, fig.12. — d’Orbigny 1850: 10. — Roemer 1857: 437, pl. 1, fig. 12a, b. — Barrande 1867: 50, pl. 2, figs 1-6. — Tromelin 1877: 29. — Lapparent 1886: pl. 3, fig. 9. — Lamouche 1925: 13, pl. 4, fig. 3.1a, b. — Bouček 1928: 79, 80, pl. 4, figs 11, 12.

Conularia curvata – Sandberger 1847: 23, pl. 1, fig. 14.

Conularia pyramidata Hoeninghaus [n.n.] – Sherborn 1930: 5335.

Conularia pyramidata Hoeninghaus – Kowalski 1935: pl. 12, figs 3-6. — Kiderlen 1937: 119, figs 2, 3. — Termier & Termier 1953: 1006, fig. 1.

Exoconularia pyramidata (Hoeninghaus) – Moore & Harrington 1956: F62, fig. 24.1. — Fischer 1980: 19, pl. 2, fig. 1.

Metaconularia pyramidata (Hoeninghaus) – Pillet & Beaulieu 1998: 35, 36, figs 1-5.

TYPE MATERIAL. — Lectotype, MCZ 16028, Harvard, Bronn Collection ( Fig. 4 ).

TYPE LOCALITY. — May-sur-Orne, Calvados, Normandy, France.

TYPE HORIZON. — Ordovician, Caradocian (Sandbian or Katian), Grès de May, Grand May Formation.

TOPOTYPES. — Muséum national d’Histoire naturelle, Paris, collection de paléontologie: MNHN.F.A00023, d’Orbigny Collection no. 25, specimens (a), (b) and (c); NHMUK PI C3407, NHMUK PI C3408a-f, NHMUK PI C3409a-b, NHMUK PI PG4465-4466 and NHMUK PI CL1000 ( Figs 5 ; 6 ).

MATERIAL EXAMINED. — France. Grès de May (Ordovician, Caradocian), May-sur-Orne, Normandy: NHMUK PI C3407, Pratt Collection 1857; NHMUK PI C3408af, Ward Collection 1869; NHMUK PI C3409a-b, no collection details. NHMUK PI PG4465-6, Geological Society of London Collection 1911; NHMUK PI CL1000, Deyrolle Collection.

England. Budleigh Salterton Pebble Beds Formation (Lower Triassic, as reworkedfossils), Budleigh Salterton, Devon: NHMUK PI G15288, NHMUK PI G15293, NHMUK PI G15294, Vicary Collection 1903. In addition, the following specimens from the same locality are indeterminate or juvenile conulariids, the latter possibly of M.? pyramidata: NHMUK PI G 15287, G15289- G15292, G15295.

STRATIGRAPHICAL DISTRIBUTION. — Stratigraphical: Middle-Upper Ordovician. Recorded from arkoses of the Dobrotivá and Bohdalec formations (Middle to Upper Ordovician) and the Letná and Libeñ formations (Upper Ordovician) of Bohemia, and the Grès de May (Upper Ordovician) of Normandy.

GEOGRAPHICAL DISTRIBUTION. — May and Jurques, Calvados, Normandy, France; Ille-et-Vilaine, Normandy; Saint-Germain, Normandy; Mt Ded (= Mt Drabov), Bohemia, Czech Republic; Budleigh Salterton, Devon, England.

DESCRIPTION

Conulariidae with tetrameral symmetry and straight pyramidal exoskeleton, usually found incomplete and preserved as a steinkern. Incomplete specimens up to 230 mm long by 50 mm wide, complete specimens probably as much as 300 mm long. Length/ width ratio varies from about 4 to 6. Cross-sectional shape square, rectangular or rhomboidal. Apical angle ranging from 8 to 13° in the best preserved specimens, although in specimen NHMUK PI C3409b it is 19° due to deformation and crushing. Corner sulcus narrow and shallow, approximately 0.5 mm wide. Edges blunt. Faces slightly convex. Midline grooved, about 1 mm wide. Secondary lines seemingly present in specimen NHMUK PI G15288, but accessory lines have not been observed in other specimens.Transverse corrugations observed in some BSPBF specimens ( NHMUK PI G15293 and G15294), with a density ranging from three to four per 5 mm, regular, weak. Transverse ribs formed by tubercles (seen in specimens NHMUK PI G15288 and G15293), with a density of 15-19 per 5 mm, apparently coalescing at midline and corner sulcus; tubercle density of 50 per 5 mm. Aperture preserved in a specimen from the Grès de May ( NHMUK PI C3408d), showing apparently very long, triangular, lappet-like ends juxtaposed to form a pyramid opposed to the rest of the exoskeleton, comprising 41% of total exoskeleton length. Apex blunt, preserved in a few specimens ( NHMUK PI C3408d, C3409b, PG4465).

REMARKS

The authorship of this species is problematical. It was first figured by Deslongchamps (1825, pl. 20, figs 6-7; Fig.1 herein) as “Conulaire ondulée (var.)”, that is, a corrugated variety of a conulariid.The trivial name “pyramidata” was introduced by Hoeninghaus (1830) as “ C. pyramidata Grès quartz. micacé. May bei Caen”. The lack of an author’s name suggests that Hoeninghaus’ intention was to describe it as a new species (many other species listed in his work are suffixed by an author’s name). However, C. pyramidata Hoeninghaus, 1830 is not an available name as it fails to satisfy the criteria of an indication ( ICZN: art. 12) for names published before 1931. De la Beche (1832) and Bronn (1837) both attributed C. pyramidata to Hoeninghaus but it was Bronn (1835 -1838: 1284) who first made the name formally available by describing it thus:“ pyramidata HOENINGHAUS,GOLDF. bei DECH. 535, und scheint sich rücksichtlich ihres Vorkommens auf den Übergans-Sandstein von May in Calvados zu beschränken.” By mentioning an earlier bibliographical reference (Hoeninghaus) that refers to Deslongchamps, as well as a distinguishing occurrence of the species (sandstone from May in Calvados), Bronn was the first to make “ pyramidata ” available in a nomenclatural sense. Therefore, the authorship of Conularia pyramidata should be attributed to Bronn (1837).

The synonymy for this species lists Metaconularia pyramidata of Pillet & Beaulieu (1998) preceded by a “p.” (pro partim) according to the terminology of Matthews (1973), because Pillet & Beaulieu (1998) included Conularia consobrina and C. rugulosa as synonyms of M. pyramidata .

We have questionably assigned this species to the genus Metaconularia Foerste, 1928 . Unfortunately, all of our material consists of steinkerns from which diagnostic features such as secondary lines are absent or difficult to see. However, the deep grooves in the steinkerns may represent the positions of strong internal midline carinae which distinguish Metaconularia from Exoconularia Sinclair, 1952 according to the author of the latter genus.

It is usually difficult to observe all of the characteristics of this species in the steinkerns from the Grès de May Formation and the BSPBF.Traverse ribs and tubercles may be scarcely visible, the grain of the sandstone being coarser than these structures. Four specimens from the BSPBF could be juvenile specimens of M.? pyramidata but there are not enough characteristics to affirm this. These specimens are up to about 100 mm long by 30 mm wide, with a length/width ratio varying from 3.65-5.80 (Fig. 7).

Figures

FIG. 4. — Metaconularia? pyramidata (Bronn, 1837) from the Upper Ordovician Grès de May of May-sur-Orne, Normandy: Harvard, Bronn collection: A-D, lectotype, MCZ16028; E-H, plaster cast, MCZ16029; I, J, plaster cast MCZ (no number). Scale bars: 10 mm.

FIG. 5. — Metaconularia? pyramidata (Bronn, 1837) from the Upper Ordovician Grès de May of May-sur-Orne, Normandy: A, NHMUK PI PG4465; B, NHMUK PI C3409a; C, NHMUK PI CL1000; D, NHMUK PI C3408d; E, NHMUK PI C3407; F, NHMUK PI 3408b; G-L, MNHN.F, d’Orbigny collection no. 25; G, H, specimen MNHN.F.A00023 (a); I, J, specimen MNHN.F.A00023 (b); K, L, specimen MNHN.F.A00023 (c). Scale bars: 10 mm.

FIG. 6. — Reworked Ordovician conulariids from the Triassic Budleigh Salterton Pebble Beds Formation, Devon: A, B, Metaconularia? pyramidata (Bronn, 1837) (NHMUK PI G15294); C, D, conulariid indet. (NHMUK PI G15295); E, F, part and counterpart of conulariid indet., probably a juvenile individual of M.? pyramidata (NHMUK PI G15287); G, fragment of M.? pyramidata (NHMUK PI G15288); H, I, conulariid indet., probably a juvenile individual of M.? pyramidata (NHMUK PI G15289); J, K, conulariid indet., probably a juvenile individual of M.? pyramidata (NHMUK PI G15290); L, conulariid indet. (NHMUK PI G15291); M, conulariid indet., probably a juvenile individual of M.? pyramidata (NHMUK PI G15292); N, O, M.? pyramidata (Bronn, 1837) (NHMUK PI G15293). Scale bars: 10 mm.

FIG. 1. — Reproduction of a part of plate 20 of Deslongchamps (1825), showing conulariids referred to as “Conulaire ondulée (var.)” (figs 6a-c; 7a, b) and “Conulaire acutangle” (fig. 8). The former is the large conulariid characteristic of the Ordovician Grand May For- mation of May-sur-Orne, here revised as Metaconularia? pyramidata (Bronn, 1837).