Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 90. (Budapest 1998)

Dulai, A.: Early Jurassic brachiopods from the basal layers of the Pisznice Limestone of Lábatlan (Gerecse Mts, Hungary)

Calcirhynchia plicatissima (QUENSTEDT) - This is one of the most frequent species of these localities, found in all layers. C. plicatissima is well-known from Hettangian (DULAI 1993/;), Sinemurian and Lower Pliensbachian localities (VÖRÖS 1997) of the Transdanubian Central Range. A wide range of sizes occurs from small-sized juvenile to large-sized adult specimens (Fig. 15), pointing to a more or less autochthonous assemblage without significant transportation and size selection. The outline of the juvenile specimens is more circular than that of the adult ones. This species was figured and described in detail (including the internal characters, on the basis of serial sections) from Hettangian and Early Sinemurian localities of the Bakony Mts (DULAI 1992: 44 and 1993b: 29). Calcirhynchia cf. laevicosta (STUR in GEYER) - Only one flat, fragmentary specimen occurs in the lowermost layer of Póckő. This species is also known from other Sinemurian localities in the Bakony and the Gerecse Mts (VÖRÖS 1997). Calcirhynchia fascicostata (UHLIG) - A small-sized juvenile specimen was found in layer 3 of Póckő and a larger adult one is present in the collection of the Hungarian Geological Institution. This species was mentioned from Pliensbachian localities of the Transdanubian Central Range (VÖRÖS 1997). Salgirella alberti (OPPEL) - Only one small-sized specimen was found in the lowermost layer of Póckő. This species occurs in the Hettangian Kardosrét Limestone (DULAI 1993b) as well as in the Upper Sinemurian of the Bakony Mts (VÖRÖS 1997). The specimen is slightly flat, similar to GEYER's figured specimen (1889, Plate 5, Fig. 16). S. alberti was described in detail from Lókút Hill by DULAI (1993/;: 30). Prionorhynchia cf. greppini (OPPEL) - Several fragmentary specimens were found in the basal layers of Póckő. The planareas are not as well-developed as at other localities (for example at Lókút Hill, DULAI 1992). The beak of the pedicular valve is erect, similar to GEYER'S figured specimen (1889, Plate 6, Figs 5 and 7). A detailed description of P. greppini is given by DULAI (1992: 47). Prionorhynchia pseudopolyptycha (BÖCKH) - A single, relatively small-sized specimen occurs in the collection of the Hungarian Geological Institution. This species, which was originally described by BöCKH (1874) from the southern Bakony, is known from several localities of the Bakony and the Gerecse Mts in Hungary (VÖRÖS 1997), but it has not been reported from other countries. P. pseudopolyptycha was figured and described in detail from Lókút Hill by DULAI (1992: 50). Prionorhynchia sp. - Four fragmentary specimens were found at Póckő. The determination is based on the features of the shell and the ribbing. Cuneirhynchia cartieri (OPPEL) - It is a common species at both examined localities. All specimens are small or medium-sized and flat in appearance. The almost globular morphotype, which was found in the lower layers of the Lókút Hill in the Bakony Mts (DULAI 1990), is absent at Lábatlan localities. C. cartieri is well-known from several Sinemurian localities of the Transdanubian Central Range (VÖRÖS 1997). This species was figured and described in detail (including the internal characters) from Lókút Hill by DULAI (1992: 52). Cuneirhynchia fraasi (OPPEL) - Some fragmentary specimens occur in layer 3 of Póckő and in the collection of the Hungarian Geological Institution. This species was reported from several Sinemurian localities of the Transdanubian Central Range (VÖRÖS 1997). "Rhynchonella" triquetra GEMMELLARO - Some very small-sized specimens were found at the upper part of the Póckő locality. This species has never been mentioned from Hungary in the literature, but it was also found in the Vöröshíd quarry at Tardos. Serial sections were made on a Vöröshíd specimen, but the generic classification of this species is not solved yet. ALMÉRAS (1964) mentioned "R". triquetra only from the Pliensbachian. Liospiriferina alpina (OPPEL) - Several specimens occur at both localities. A significant part of Póckő specimens are not disintegrated, i.e. the two valves remained together during lbssilization, which is not very frequent at spiriferids, because of their hinge structure. This suggest a lack of significant transportation. L. alpina is a very common species in the Hungarian Liassic (Hettangian to Annls iiist.-nul. Mus. natn. hung. 90, 199S