Celeroliroceras Korn & Ghaderi, 2025, gen. nov.

Genus Celeroliroceras gen. nov. urn:lsid:zoobank.org:act: DDB55D63-9584-47C5-B8B4-BD69879FDB4F New genus G – Korn 2025: 66. Type species Celeroliroceras celere gen. et sp. nov. Diagnosis Genus of the family Liroceratidae with globular, involute or subinvolute conch. The conch is rapidly increasing in height with an extraordinarily high coiling rate (WER higher than 3.50). Whorls very weakly embracing with nearly circular profile. Adult ornament very weak. Septa without inflexions, slightly concave. Suture line simple, nearly straight to straight with shallow lobes. Etymology Combination of the Latin ‘ celere ’ (adjective, n.) =‘fast’ and Liroceras; because of the conch geometry with the extraordinarily high coiling rate. Included species NW Iran (this paper): Celeroliroceras celere gen. et sp. nov., Wuchiapingian. Remarks Celeroliroceras gen. nov. is a genus that differs from Liroceras in its extraordinarily high coiling rate of the conch. The type species has a whorl expansion rate of over 3.60, a value far above that of most species of Liroceras. The whorl expansion rate of liroceratids is usually around 2.50. The new species is therefore placed in its own genus. The conch of Celeroliroceras gen. nov. is very reminiscent of that of the genus Solenochilus Meek & Worthen, 1870, which is also characterised by an exceptionally high whorl expansion rate. However, the position of the siphuncle, central in Celeroliroceras and marginally ventral in Solenochilus, indicates that both genera belong to phylogenetically distant evolutionary lineages.