The Early Carboniferous (Mississippian) ammonoids from the Chebket el Hamra (Jerada Basin, Morocco)

Abstract

Five Late Viséan ammonoid assemblages of North Variscan provenance are described from the locality Chebket el Hamra (Jerada Basin, north‐eastern Morocco). These assemblages are composed of 27 species of the genera Eoglyphioceras, Girtyoceras, Sulcogirtyoceras, Metadimorphoceras, Goniatites, Arnsbergites, Hibernicoceras, Paraglyphioceras, Lusitanoceras, Sudeticeras, Neoglyphioceras, Lusitanites, Ferganoceras, Praedaraelites, and Pronorites. The new subfamily Arnsbergitinae is described, as well as the thirteen new species Eoglyphioceras minutum n. sp., Girtyoceras ibnkhaldouni n. sp., Metadimorphoceras anguinosum n. sp., Arnsbergites ferrus n. sp., Arnsbergites proiecturus n. sp., Arnsbergites rufus n. sp., Hibernicoceras touissitense n. sp., Hibernicoceras artilobatum n. sp., Paraglyphioceras celeris n. sp., Lusitanoceras zirari n. sp., Sudeticeras ibnbajjahi n. sp., Sudeticeras horoni n. sp., and Pronorites owodenkoi n. sp. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Quantitative analysis of suture lines in Carboniferous ammonoids

“…Stratigraphic distribution of the genera in the superfamily Goniatitoidea analysed in this study. Relative lengths of the ammonoid zones after Korn and Kaufmann (2009), conodont stratigraphy after Meischner and Nemyrovska (1999) and Wang et al (2018).…”

The ammonoids from the Dalle àMerocanitesof Timimoun (Late Tournaisian-Early Viséan; Gourara, Algeria)

“…Differences in the composition of the assemblages may be caused by the different age of the faunas. It can be stated, however, that the interval around the Tournaisian-Vis an boundary is, in contrast to the Late Vis an (Korn 1997;Korn et al 2005;Korn & Ebbighausen 2008), a time of ammonoid cosmopolitanism. The wide geographic range of many of the genera, which compose similar communities is suggestive of such a situation.…”

The ammonoids from the Argiles de Teguentour of Oued Temertasset (early Late Tournaisian; Mouydir, Algeria)

“…Discussion. The members of the subfamily differ from the subfamilies Goniatitinae and Arnsbergitinae in the simple juvenile conch ontogeny (Korn 1988;Klug et al 2006;Korn & Ebbighausen 2008). While the other two subfamilies show a narrowing of the conch at 2-3 mm dm followed by an intermediate thickening and a subsequent narrowing, the ww/dm ratio is stable in the Progoniatitinae.…”

“…While Early Tournaisian (Ebbighausen et al 2004;Bockwinkel & Ebbighausen 2006;) and Late Visan (Korn et al 1999(Korn et al , 2007Klug et al 2006;Korn & Ebbighausen 2008) ammonoid Faunas from North Africa have been outlined in several monographs, the state of knowledge of middle or early Late Tournaisian ammonoids from that region is still limited. A rich early Late Tournaisian fauna was recently described by Korn et al (2003aKorn et al ( , 2005Korn et al ( , 2007 from Bouhamed and Jdaid in the Anti-Atlas of Morocco, being with twelve species the most diverse assemblage known so far from this time unit with the genera Irinoceras, Triimitoceras, Pericyclus, Orthocyclus, Helicocyclus, Jerania, Muensteroceras, Mouydiria, Progoniatites, Becanites, and Merocanites.…”