Temnocheilus aubrechtovae, 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 : 165-166

Temnocheilus aubrechtovae sp. nov.

urn:lsid:zoobank.org:act:51FDC5C3-01AA-47F6-B678-F67E2C360F4A

Fig. 7 ; Table 2

Diagnosis

Species of Temnocheilus with thickly pachyconic, subevolute conch (ww/dm ~0.80; uw/dm ~0.35); whorl profile strongly depressed, rounded-trapezoidal (ww/wh ~ 2.05), venter broadly rounded, ventrolateral shoulder angular with large, elongated longitudinal nodes (about 10 per whorl). Whorls weakly embracing. Shell surface almost smooth.

Etymology

Named after Martina Aubrechtová, in honour of her studies on Palaeozoic nautiloids.

Material examined

Holotype MOROCCO • Anti-Atlas, region south-west of Rissani ; basal Mougoui Ayoun Formation; Karaoui Coll.; illustrated in Fig. 7 ; PIMUZ 39511 .

Description

Holotype PIMUZ 93511 is a slightly deformed but otherwise rather well-preserved specimen with a conch diameter of 54 mm ( Fig. 7 ). The last quarter of the last preserved whorl belongs to the body chamber. The conch is thickly pachyconic to cadiconic and subevolute with a high coiling rate (WER =2.04–2.21). The whorl profile is broadly trapezoidal (ww/wh 1.88 to 2.14) with a very broadly and continuously rounded venter; the ventrolateral shoulder is narrowly rounded. The nodes are about twice as long as they are wide and their spacing is equal to their length. There are ten such nodes on the last whorl, giving the ventrolateral shoulder a conspicuous coronate appearance.

Remarks

Temnocheilus aubrechtovae sp. nov. differs from the other Early Carboniferous species of the genus in the shape of the venter, which is either nearly flat (e.g., T. coronatus , T. imazighenorum sp. nov.) or slightly concave (e.g., T. ventroconcavum ). Temnocheilus coronatiformae has a similar conch shape but differs from T. aubrechtovae in the much smaller and more numerous ventrolateral nodes (about 15 per volution).

Figures

Fig. 7. Temnocheilus aubrechtovae sp. nov.; holotype PIMUZ 39511 (Karaoui Coll.) from south-east of Rissani; reconstruction of apertural view, dorsal, lateral and ventral views. Scale bar units =1 mm.