genus F

Korn, Dieter & Ghaderi, Abbas, 2025, Late Permian nautiloids from Julfa (NW Iran), European Journal of Taxonomy 1018, pp. 1-113 : 102

New genus F Korn & Hairapetian (in press)

Type species

New species R to be described by Korn & Hairapetian (in press); original designation.

Diagnosis

Genus of the family Julfanautilidae fam. nov. with discoidal, involute conch. The conch is rapidly increasing in height with a very high to extremely high coiling rate (WER usually higher than 2.50). Whorls moderately strongly embracing, their profile ranges from compressed to weakly depressed. Adult ornament with extremely fine growth lines. Septa without inflexions, slightly concave. Suture line simple, nearly straight to straight with a low external saddle, broadly rounded internal lobe. The siphuncle has a dorsocentral position (from Korn & Hairapetian in press).

Included species

Central Iran ( Korn & Hairapetian in press): new species R to be described by Korn & Hairapetian (in press), Wuchiapingian.

Remarks

Korn & Hairapetian (in press) compared the new genus with other similar genera; in terms of conch morphology, the new genus shows some similarities to the genera Julfanautilus gen. nov. and the new genus E to be described by Korn & Hairapetian (in press). This is particularly true for the shape of the whorl profile with slightly flattened, converging flanks and the slightly flattened umbilical wall. However, the other two genera show a much higher coiling rate (WER above 3.00) than the new genus (WER around 2.50) and a much more pronounced subangular to angular umbilical margin.