Temnocheilus imazighenorum, Korn & Klug, 2023

Korn, Dieter & Klug, Christian, 2023, Early Carboniferous coiled nautiloids from the Anti-Atlas (Morocco), European Journal of Taxonomy 885, pp. 156-194 : 163-164

Temnocheilus imazighenorum sp. nov.

urn:lsid:zoobank.org:act:84E662FC-B0AB-4F6C-A69D-FD82103B2127

Fig. 6 ; Table 1

Diagnosis

Species of Temnocheilus with thinly pachyconic, subevolute conch (ww/dm ~0.65; uw/dm ~0.38); whorl profile moderately depressed, trapezoidal (ww/wh ~1.85), venter flattened, ventrolateral shoulder angular with elongated longitudinal nodes. Whorls very weakly embracing. Shell surface almost smooth.

Etymology

Named after the Imazighen, the ethnic group indigenous to the Maghreb region of North Africa.

Material examined

Holotype

MOROCCO • Anti-Atlas, east of Gara el Itima, 36 km east-northeast of Taouz ; uppermost Zrigat Formation; Ebbighausen & Korn 2004 Coll.; illustrated in Fig. 6 ; MB.C.31291 .

Description

Holotype MB.C.31291 is a somewhat weathered specimen 105 mm in diameter, allowing the study of two whorls ( Fig. 6 ). The conch is barrel-shaped, thinly pachyconic and subevolute (ww/dm=0.64; uw/ dm =0.38) with a very high coiling rate (WER= 2.28) and weakly embracing whorls. The whorl profile is trapezoidal with a flattened venter, an angular ventrolateral shoulder and flattened flanks plus umbilical wall. On the penultimate whorl, the ventrolateral shoulder bears eight longitudinally elongate nodes per half volution; they are much weaker on the last volution. The shell surface appears to be smooth.

Remarks

Temnocheilus imazighenorum sp. nov. is similar to T. coronatus but differs in the more compressed conch (ww/dm ~ 0.65 in T. imazighenorum but ~ 0.75 in T. coronatus ), in the less depressed whorl profile (ww/wh ~ 1.85 in T. imazighenorum but ~ 2.25 in T. coronatus ) and in the more flattened venter, which is broadly arched in T. coronatus . Temnocheilus coronatiformae differs in the slightly convex venter.

Figures

Fig. 6. Temnocheilus imazighenorum sp. nov., holotype MB.C.31291 (Ebbighausen & Korn 2004 Coll.) from E of Gara el Itima; lateral view and reconstruction of apertural view. Scale bar units =1 mm.