Cyrtospiriferidae Termier and Termier, 1949

Sokiran, Elena V., 2006, Early-Middle Frasnian cyrtospiriferid brachiopods from the East European Platform, Acta Palaeontologica Polonica 51 (4), pp. 759-772 : 761-762

Family Cyrtospiriferidae Termier and Termier, 1949 Subfamily Uchtospiriferinae Ljaschenko, 1973

[nom. transl. Carter et al. 1994: 335 (ex Uchtospiriferidae Ljaschenko, 1973 : 87)]

Emended diagnosis.— Cyrtospiriferidae with short hinge line and rounded cardinal extremities; deltidium without penetrating foramen; triangular pedicle opening at the base of delthyrium; radial ornament costate with flattened costae separated by narrow interspaces; costae on dorsal fold and ventral sulcus variably developed or absent; micro−ornament with distinct sub−radial capillae converging anteriorly on top of costae, and tubercles; delthyrial plate variably developed. Differs from Cyrtospiriferinae by having a narrow interarea and rounded cardinal extremities. From Cyrtiopsinae differs by having a rounded cardinal extremities, non−perforate deltidium and variably developed delthyrial plate (emended after Ljaschenko 1972).

Remarks.—Carter at al. (1994) considered the Family Uchtospiriferidae Ljaschenko, 1973 as a junior synonym of the Subfamily Cyrtiopsinae Ivanova, 1972 that was recognized as Cyrtospiriferidae with a narrow interarea and rounded cardinal extremities. This point of view was followed by Oleneva (2003, 2004) and Johnson (2006). However, according to Ma and Day (1999) the type species of Cyrtiopsis Grabau, 1923 , i.e., Cyrtiopsis davidsoni Grabau, 1923 has acute cardinal extremities, deltidium penetrated by a foramen close to the apex, and lacks a delthyrial plate. Thus, there is inconsistency in description of cardinal extremities in diagnosis of Cyrtiopsinae given by Johnson (2006) and Cyrtiopsis davidsoni in Ma and Day (1999). Because of that uncertainty and differences between Uchtospirifer and Cyrtiopsis , we here consider Uchtospiriferinae as a separate taxon within the family Cyrtospiriferidae .

Genera assigned.— Uchtospirifer Ljaschenko, 1957 .