Gypsobia Tausch 1886

Genus Gypsobia Tausch, 1886 Type species: Gypsobia cretacea Tausch, 1886; by monotypy. Remarks: Sitnikova & Vinarski in Sitnikova et al. (2023) established the new family Palaeobaicaliidae to host the genera Palaeobaicalia Martinson, 1961, Probaicalia Martinson, 1949, and Gypsobia. The family lacks synapomorphic traits and is “conchologically similar to the recent Baicaliidae and Pyrgulidae ” (Sitnikova et al. 2023) and was merely defined to distinguish Cretaceous to Palaeogene taxa from modern Baicaliidae (see also discussion in Zhang et al. 2024). The two only species of Palaeobaicalia described by Martinson (1961) from the Late Cretaceous of Mongolia are poorly preserved turriform, conical gastropods with few characters. Both species may be considered nomina dubia. Species of Probaicalia are slender, with highly convex whorls and typically spiral sculpture (Martinson 1949; Isaji 2023). Some species, such as Probaicalia katoensis (Suzuki, 1943) as reported by Isaji (2023), show a similarly shaped aperture as Gypsobia cretacea, indicating a potential relationship.Accordingly, but with hesitation due to the vast geographic distance between Gypsobia and other palaeobaicaliids as well as the ill-defined nature of the family, we preliminarily follow the concept of Sitnikova et al. (2023).