Weyerella Bockwinkel & Ebbighausen, 2006

Korn, Dieter & Weyer, Dieter, 2023, The ammonoids from the Gattendorfia Limestone of Oberrödinghausen (Early Carboniferous; Rhenish Mountains, Germany), European Journal of Taxonomy 882, pp. 1-230 : 152-153

Genus Weyerella Bockwinkel & Ebbighausen, 2006

Type species

Weyerella protecta Bockwinkel & Ebbighausen, 2006: 117 ; original designation.

Genus diagnosis

Genus of the Gattendorfiinae with a small, thinly discoidal to pachyconic conch with low coiling rate (WER = 1.50–1.75); inner whorls evolute, adult stage subinvolute or subevolute, sometimes strongly overlapping the umbilicus. Ornament with fine to coarse, convex or slightly biconvex, rursiradiate growth lines, shell surface often with constrictions. Suture line with deep, lanceolate or V-shaped external lobe that is as deep as the adventive lobe.

Genus composition

Central Europe ( Vöhringer 1960): Gattendorfia molaris Vöhringer, 1960 ; Gattendorfia reticulum Vöhringer, 1960 ; Weyerella lenis sp. nov.

North Africa( Bockwinkel & Ebbighausen 2006): Weyerella protecta Bockwinkel & Ebbighausen, 2006 ; Weyerella minor Bockwinkel & Ebbighausen, 2006 .

NW China ( Sheng 1984; Liang & Wang 1991; Ruan 1995): Gattendorfia parapplanata Sheng, 1984 ; Gattendorfia angularia Liang & Wang, 1991 ; Gattendorfia acricula Ruan, 1995 ; Gattendorfia artilobata Ruan, 1995 ; Gattendorfia compressa Ruan, 1995 ; Gattendorfia hoboksarica Ruan, 1995 ; Gattendorfia lanceolata Ruan, 1995 ; Gattendorfia latalobata Ruan, 1995 ; Gattendorfia umbilicata Ruan, 1995 ; Gattendorfia cuneata Ruan, 1995 .

South China ( Ruan 1981): Gattendorfia discoides Ruan, 1981 ; Gattendorfia mimica Ruan, 1981 ; Gattendorfia popanoides Ruan, 1981 .

Remarks

Weyerella is easily distinguished from the genus Gattendorfia by its small conch, which has a maximum diameter of about 30 mm, whereas specimensof Gattendorfia can reach 80 mm or more. Another difference is the simpler ontogeny of the conch in Weyerella , where the distinct phases, for instance seen in Gattendorfia schmidti sp. nov., are not developed. In Weyerella , the ww/dm and ww/wh trajectories are nearly monophasic with an almost continuous decrease.

On the one hand, Weyerella may be seen as the phylogenetic descendant of Gattenpleura with G. concava that develops a dorsolateral groove but does not possess the radial ribs of the other Gattenpleura species, being the intermediate form. Weyerella can, on the other hand, be seen as the ancestor of Paprothites , which has a conch morphology similar to Weyerella but possesses well-developed ribs.