Foordiceras ascetum, Korn & Hairapetian, 2025

Korn, Dieter & Hairapetian, Vachik, 2025, Late Permian nautiloids from Baghuk Mountain (Central Iran), European Journal of Taxonomy 1019, pp. 1-76 : 35-36

publication ID

https://doi.org/10.5852/ejt.2025.1019.3071

publication LSID

lsid:zoobank.org:pub:E24EBF4A-9FE2-47E4-A656-E1698F88BB41

DOI

https://doi.org/10.5281/zenodo.17278689

persistent identifier

https://treatment.plazi.org/id/03E487D4-FFF9-4923-FDAC-58DE81B9FB96

treatment provided by

Plazi

scientific name

Foordiceras ascetum
status

sp. nov.

Foordiceras ascetum sp. nov.

urn:lsid:zoobank.org:act:

Fig. 18 View Fig ; Table 12 View Table 12

Diagnosis

Species of Foordiceras with thinly discoidal, subevolute conch (ww/dm ~ 0.33; uw/dm ~0.43), nearly equidimensional whorl profile (ww/wh ~1.00) and high coiling rate (WER ~ 2.20) at a conch diameter of 60 mm. Whorl profile trapezoidal with weakly divergent, flattened flanks; venter flattened, umbilical margin incipient. Sculpture with about 10 coarse, blunt ventrolateral ribs per volution. Suture line with a very shallow external lobe and a very shallow, broadly rounded lateral lobe.

Etymology

From the Greek ‘ἀσκητός’= ‘decorated’; because of the sculpture.

Type material

Holotype

IRAN – Esfahan Province • Baghuk Mountain ; Hambast Formation, Vedioceras beds ( late Wuchiapingian); 2011; Korn et al. leg.; illustrated in Fig. 18 View Fig ; MB.C.32124 .

Description

Holotype MB.C.32124 is an internal mould with a diameter of 86 mm, but the last portion is poorly preserved ( Fig. 18B View Fig ). The conch is, at 62 mm diameter, thinly discoidal and subevolute (ww/dm=0.33; uw/dm = 0.43) with a high coiling rate (WER = 2.21). The whorl profile is weakly compressed (ww/ wh = 0.98) and rounded trapezoidal with a nearly flat venter and a broadly rounded ventrolateral shoulder. The weakly divergent flanks are flattened; an umbilical margin is only barely visible ( Fig. 18A View Fig ). The sculpture has five prominent conical nodes per half volution in the outer area of the flank; these nodes show a low extension on the flank towards the umbilicus. The nodes are narrower than their interspaces. The suture line shows shallow, broadly rounded lobes on venter and flanks ( Fig. 18C View Fig ). The last half volution of the phragmocone has about 16 chambers (CLI=11).

Remarks

Foordiceras ascetum sp. nov. differs from F. eicosacanthum sp. nov. and F. decacanthum sp. nov. in the nearly equidimensional whorl profile (ww/wh =1.00), which is depressed in the other two species (ww/ wh= 1.75 in F. eicosacanthum and = 1.25 in F. decacanthum ). Another criterion to separate F. ascetum from the rather similar F. decacanthum is in the width of the nodes; in F. ascetum they are only half as wide as their interspaces, while they are wider than the interspaces in F. decacanthum .

Table 12. Conch dimensions (in mm) and ratios of Foordiceras ascetum sp. nov. from Baghuk Mountain.

Nr. dm ww wh uw ah ww/dm ww/wh uw/dm WER IZR
MB.C.32124 61.6 20.5 21 26.5 20.2 0.33 0.98 0.43 2.21 0.04
MB

Universidade de Lisboa, Museu Bocage

Kingdom

Animalia

Phylum

Mollusca

Class

Cephalopoda

SubClass

Nautiloidea

Order

Nautilida

SubOrder

Tainoceratina

SuperFamily

Pleuronautiloidea

Family

Koninckioceratidae

Genus

Foordiceras

GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF