Ouaoufilalites ouaoufilalensis, Korn & Bockwinkel & Ebbighausen & Klug, 2003

Korn, Dieter, Bockwinkel, Jürgen, Ebbighausen, Volker & Klug, Christian, 2003, Palaeobiogeographic and evolutionary meaning of an early Late Tournaisian ammonoid fauna from the Tafilalt of Morocco, Acta Palaeontologica Polonica 48 (1), pp. 71-92 : 84

publication ID	https://doi.org/ 10.5281/zenodo.13272527
persistent identifier	https://treatment.plazi.org/id/03BE87DE-5A7D-FFCA-FFB2-FA9E72C2FB01
treatment provided by	Felipe
scientific name	Ouaoufilalites ouaoufilalensis
status	sp. nov.

Treatment

Ouaoufilalites ouaoufilalensis View in CoL sp. nov.

Figs. 21 View Fig , 22 View Fig , 23A, B.

Derivation of name: After Jebel Ouaoufilal, where the specimens came from.

Holotype: Specimen MB.C.3954 (coll. Ebbighausen), Fig. 23A.

Type locality and horizon: Taouz, Jebel Ouaoufilal, locality A east of Ksar Bouhamed (Tafilalt, Morocco); Oued Znaïgui Formation, early Late Tournaisian.

Material.— 109 specimens, 4 to 15 mm in diameter.

Diagnosis.— Ouaoufilalites with conch thickly pachyconic at 8 mm diameter (ww/dm 0.75 to 0.85), becoming less pachyconic by 15 mm diameter (ww/dm 0.60 to 0.70). Umbilicus at 8 mm conch diameter narrow (uw/dm 0.20) and moderately wide at 15 mm diameter (uw/dm 0.35). Umbilical margin rounded. Steinkerns with three or four constrictions. Suture line with deep, parallel−sided external lobe, moderate median saddle, and asymmetrical adventive lobe.

Description.—The conch dimensions and ratios show little variability within the population ( Fig. 21 View Fig ). Juvenile conchs are wider (ww/dm> 0.80), and specimens over 10 mm diameter show a ratio of less than 0.70. The umbilicus opens remarkably during ontogeny, the uw/dm ratio increases from 0.20 at 6 mm diameter to almost 0.40 at 14 mm. The umbilical margin is rounded in all stages.

The steinkerns are smooth except for three or four constrictions which are linear across flanks and venter.

In specimen MB.C.3955, the external lobe has parallel, slightly sinuous flanks ( Fig. 22 View Fig ). The median saddle has a moderate height (0.40 of external lobe depth). The V−shaped adventivelobeisasymmetricalwithalinearventralflankand a sinuous dorsal flank. It is deeper than the external lobe.

Dimensions.—(in mm). Comparisons.— Ouaoufilalites ouaoufilalensis sp. nov. resemblessomespeciesof Dzhaprakoceras Popov,1965 ,butis clearly separable because of its rather wide umbilicus. In all species of Dzhaprakoceras , the umbilicus is less than one fifth of the conch diameter. The most similar species is D. djaprakense ( Librovitch, 1927) , with a similar whorl width/ conch diameter ratios, but the umbilicus is narrower (one fourth of the conch diameter).

With its pachyconic conch, O. ouaoufilalensis sp. nov. resembles species of Bollandites Bisat, 1934 , but these always show divergent flanks of the external lobe, in contrast to the parallel flanks in Ouaoufilalites .