Goniatites crenistria Phillips, 1836

Goniatites crenistria Phillips, 1836 View in CoL

Goniatites crenistria Phillips, 1836: 234 View in CoL , pl. 19 figs 7–9.

Goniatites crenistria dinckleyense Bisat, 1928: 132 , pl. 6a fig. 1.

Glyphioceras crenistria – Schmidt 1925: 565, pl. 21 fig. 3.

Goniatites crenistria View in CoL – Nicolaus 1963: 96, text-figs 30a, 32. — Korn 1988: 83, pl. 17 figs 1–4, pl. 18 figs 1–11, text-figs 30–34 (for more synonymy). — Korn & Ebbighausen 2008: 97, text-figs 16–21. — Nikolaeva 2008: 51, pl. 7 figs 1–4, pl. 8 figs 1–2, 4, pl. 9 figs 1–4, 6, text-figs 1.1–4, 34.

non Goniatites crenistria View in CoL – Delépine 1941: 66, pl. 4 figs 2–3. — Nikolaeva 2008: pl. 9 figs 5, 7, pl. 17 fig. 6.

Diagnosis (from Korn & Ebbighausen 2008, emended)

Species of Goniatites reaching a conch diameter of 70 mm. Conch globular at 10 mm diameter (ww/ dm ~ 0.90–1.00), pachyconic at 30 mm diameter (ww/dm ~ 0.65–0.75) and thickly discoidal to thinly pachyconic at 50 mm diameter (ww/dm ~ 0.55–0.65). Umbilicus very narrow in all stages larger than 10 mm dm (uw/dm ~ 0.05–0.10), slightly opening in the adult stage; umbilical wall rounded. Coiling rate in the adult stage moderately high (WER ~ 1.75–1.90). Ornamentation with crenulated biconvex and rectiradiate growth lines with low dorsolateral projection and higher ventrolateral projection; external sinus deep. Without spiral lines. Suture line with a V-shaped, moderately narrow external lobe (0.50 of the external lobe depth, 0.90–1.00 of the adventive lobe width) and a moderately high median saddle (0.40 of the external lobe depth). Flanks of the external lobe almost straight, ventrolateral saddle acute, adventive lobe V-shaped with almost straight flanks.

Type material

Lectotype

UNITED KINGDOM – Lancashire • ‘ Bolland’; ‘ Mountain Limestone’ ( Late Viséan ); Gilbertson Coll.; NHM c282 ; illustrated by Phillips (1836: pl. 19 figs 7–9), Korn & Ebbighausen (2008: text-fig. 16) and Nikolaeva (2008: pl. 9 fig. 1).

Remarks

The specimens from the Jerada Basin assigned to Goniatites crenistria by Korn & Ebbighausen (2008) do not belong to this species, based on the knowledge of the ontogeny of specimens from Sidi Amar. Therefore, a confirmed record of G. crenistria from North Africa does not exist. For comparison with the new species Goniatites amarensis sp. nov., an emended diagnosis of G. crenistria is presented here.