Julfanautilus hairapetiani, Korn & Ghaderi, 2025

Korn, Dieter & Ghaderi, Abbas, 2025, Late Permian nautiloids from Julfa (NW Iran), European Journal of Taxonomy 1018, pp. 1-113 : 100-101

Julfanautilus hairapetiani gen. et sp. nov.

urn:lsid:zoobank.org:act:

Fig. 50 ; Table 30

Diagnosis

Species of Julfanautilus gen. nov. with a thinly pachyconic, involute conch (ww/dm ~ 0.65; uw/dm ~0.05), weakly depressed whorl profile (ww/wh ~1.15) and extremely high coiling rate (WER ~2.60) at a conch diameter of 80 mm. Whorl profile with a weakly concave venter, a pronounced ventrolateral shoulder, flatly convex and moderately convergent flanks, a narrowly rounded umbilical margin, a steep and flattened umbilical wall and a moderately deep imprint zone ( IZR ~ 0.30). Suture line with broadly rounded and shallow external lobe and broadly rounded lateral lobe.

Etymology

Named after Vachik Hairapetian ( Isfahan), to acknowledge his support in the research project on the Permian–Triassic boundary.

Type material

Holotype

IRAN – East Azerbaijan • Ali Bashi 4; Vedioceras Beds of the Julfa Formation ( late Wuchiapingian); 2010; Korn et al. leg.; illustrated in Fig. 50 ; MB.C.32096 .

Description

Holotype MB.C.32096 has a conch diameter of 83 mm and is fully chambered ( Fig. 50A ). It is thinly pachyconic (ww/dm= 0.63) with an almost closed umbilicus and an extremely high coiling rate (WER =2.58). The whorl profile shows that the preceding whorl is strongly embraced ( IZR =0.31). The conch is widest at the pronounced, narrowly rounded umbilical margin, from where a steep, broadly rounded umbilical wall approaches the umbilical seam. The flanks converge towards the broadly rounded ventrolateral shoulders; the venter is broadly rounded with a shallow and wide median depression. Shell remains are not preserved. The suture line has a shallow, broadly rounded external lobe and a much larger and broadly rounded lateral lobe, which is twice as deep as the external lobe ( Fig. 50C ).

Remarks

Julfanautilus hairapetiani gen. et sp. nov. differs from J. ashourii gen. et sp. nov. in the closed umbilicus (uw/dm = 0.24 in J. ashourii ) and the lower coiling rate (WER ~ 2.60 in J. hairapetiani but ~ 3.10 in J. ashourii ).

Figures

Fig. 50. Julfanautilus hairapetiani gen. et sp. nov., holotype MB.C.32096 (Korn et al. 2010 Coll.) from the Vedioceras Beds of the Julfa Formation at Ali Bashi 4. A. Lateral and apertural views. B. Reconstruction of apertural view. C. Suture line at dm = 70.5 mm, ww= 52.5 mm, wh = 44.5 mm. Scale bar units= 1 mm.

Tables

Table 30. Conch dimensions (in mm) and ratios of the holotype of Julfanautilus hairapetiani gen. et sp. nov.

Nr.	dm	ww	wh	uw	ah	ww/dm	ww/wh	uw/dm	WER	IZR
MB.C.32096	83.2	52.2	45.2	2.5	31.4	0.63	1.15	0.03	2.58	0.31