Postclymenia calceola, Klein & Korn, 2014

Klein, C. & Korn, D., 2014, A morphometric approach to conch ontogeny of Cymaclymenia and related genera (Ammonoidea, Late Devonian), Fossil Record 17 (1), pp. 1-32 : 24-26

Postclymenia calceola n. sp.

Figures 27 and 28

2004 Postclymenia evoluta . – Korn et al., p. 315, fig. 6A–D, 8. 2007 Postclymenia evoluta . – Korn et al., p. 137, fig. 8.

Derivation of name: After Lat. calceolus (noun) = little boot; because of the shape of the lateral lobe.

Holotype: Specimen MB.C.22662.1 (Ebbighausen 2005 Coll.); illustrated here in Fig. 27b .

Type locality and horizon: Lalla Mimouna (Anti-Atlas); latest Famennian.

Material: 119 specimens with a maximum phragmocone diameter of 60 mm.

Diagnosis: Species of Postclymenia with thinly discoidal conch in the adult stage (ww / dm = 0.25–0.30); whorl cross section weakly compressed (ww / wh = 0.70). Suture line with strongly asymmetric, pouched boot-shaped lateral lobe.

Discussion: Postclymenia evoluta has a very similar or nearly identical conch but differs from the new species in the suture line, which possesses a smaller adventive lobe with a vertical ventral side of the adventive lobe, as figured by Schmidt (1924, pl. 8, fig. 19) and Price and Korn (1989, fig. 11A). For a detailed description and discussion of the new species, see Korn et al. (2004) and Korn et al. (2007).

Acknowledgements. We are indebted to the Moroccan authorities for their permission for us to undertake field work. We greatly acknowledge the late Volker Ebbighausen (deceased 2011), Raimund Feist (Montpellier), Jürgen Kullmann (Tübingen), Martin Rücklin (Leiden), Jobst Wendt (Tübingen) and Dieter Weyer (Berlin) for providing specimens. Evelin Stenzel (Berlin) cleaned the specimens from the matrix. Jonas Jahn (Berlin) is acknowledged for taking the photographs, and Sonny A. Walton (Potsdam) revised the language of the manuscript. We acknowledge the reviews of the article by Jürgen Bockwinkel (Leverkusen), Claude Monnet (Lille) and Alan L. Titus (Kanab, Utah).

Edited by: F. Witzmann

Reviewed by: J. Bockwinkel, C. Monnet, and A. Titus

Figures

Figure 27. Postclymenia calceola n. sp. from Lalla Mimouna (Anti-Atlas of Morocco); all × 1.0. (A) Paratype MB.C.22662.2 (Ebbighausen 2005 Coll.). (B) Holotype MB.C.22662.1 (Ebbighausen 2005 Coll.). (C) Paratype MB.C.22662.3 (Ebbighausen 2005 Coll.). (D) Paratype MB.C.22663.1 (Korn 2005 Coll.). (E) Paratype MB.C.22663.2 (Korn 2005 Coll.).

Figure 28. Cross sections (A–D; all × 1.5) and ontogenetic trajectories (E–H) of Postclymenia calceola n. sp. from Lalla Mimouna (Anti-Atlas of Morocco). (A) Paratype MB.C.9302.2 (Ebbighausen 2005 Coll.). (B) Paratype MB.C.9302.1 (Ebbighausen 2005 Coll.). (C) Paratype MB.C.9302.3 (Ebbighausen 2005 Coll.). (D) Paratype MB.C.9302.4 (Ebbighausen 2005 Coll.). (E) Conch width index (ww /dm). (F) Umbilical width index (ww/ wh). (G) Whorl width index (uw / dm). (H) Whorl expansion rate (WER).