ANNALES HISTORICO-NATURALES MUSEI NATIONALIS HUNGARICI Tomus 87. Budapest, 1995 p. 35-54 Middle Miocene (Badenian) lunulitiform Bryozoa from Szob (Börzsöny Mts., Hungary) by A. DULAI, Budapest DULAI, A. (1995): Middle Miocene (Badenian) lunulitiform Bryozoa from Szob (Börzsöny Mts., Hungary). - Annls hist.-nat. Mus. natu. hung. 87: 35-54 Abstract - Szob is very famous for its mollusc fauna, however, several other fossil groups can be found in the yellowish-grey sand, which are hardly known. The free-living, so-called lunulitiform Bryozoa are represented by two species at Szob: Cupuladria vindobonensis BALUK et RADWANSKI and Reussirella haidingeri (REUSS). Up to now, lunulitiform Bryozoa have only been mentioned in fauna-lists at numerous localities in Hungary. The way of life and the ecological characters of lunulitiform Bryozoa are well known from studies on the recent representatives of free-living Bryo­ zoa. Thus this group is suitable for the reconstruction of the paleoenvironment of Szob. Lunulitiform Bryozoa choose small-particle sand bottom below the wave base and they live in normal or slightly reduced salt water in tropical or subtropical climate. Lunulitiform species adapted themselves to life on soft sediments, where they may be the dominant elements among Bryozoa. With 28 figures and 7 tables. INTRODUCTION The research of Bryozoa is a very neglected area of Hungarian paleontology. This fact holds especially true for the Miocene Bryozoa of Hungary, although important data have been lost because of the lack of such studies, as Bryozoa are excellent environment indica­ tors. The aim of this paper is to show the free-living, so-called lunulitiform Bryozoa of the famous Szob locality. Bryozoa are generally fixed marine animals. The special feature of the examined group is its free-living habitude. "Lunulitiform" is an old-established term derived from the name of Lunulites. However, sometimes it had different meanings in the works of different authors. This paper follows BALUK & RADWANSKI'S (1984a) classification in which three families belong to lunulitiform Bryozoa (Cupuladriidae, Discoporellidae, Lunulitidae). Lunulitiform Bryozoa appeared in the Late Cretaceous and live up to now. The way of life and the ecological characters of lunulitiform Bryozoa are well known from studies on their recent representatives. The type species of genus Cupuladria, C. canadensis (BUSK), is one of the most minutely examined Bryozoa species. Lunulitiform Bryozoa were studied extensively in the last few decades by European speci­ alists. The family Cupuladriidae was defined by LAGAAU (1952). The vertical distribution of lunulitiform Bryozoa in the Tertiary of the Netherlands was examined by LAGAAU (1953). A very accurate biological and ecological study was made by LAGAAU (1963) on recent Cupu­ ladria canadensis (BUSK). ANNOSCIA (1963) mentioned three lunulitiform species from the Miocene deposits of Italy. The external morphological characters of Cupuladriidae have been discussed in detail by COOK (1965a, b). Lunulitiform Bryozoa species were divided into four groups by COOK (Cupuladria canadensis group, Cupuladria guineensis group, Cupuladria owenii group, Discoporella umbellata group). HAKANSSON (1973) examined the internal morphology of Cupuladria biporosa CANU et BASSLER by orientated thin sections and a very regular internal structure was found with the repetition of a few basic elements. Miocene Bryozoa (of which 5 species belong to lunulitiform Bryozoa) of NW Germany were described by BUGE (1973). CADÉE (1975) described seven recent lunulitiform Bryozoa from the Guyana shelf, from which two were new. Three Miocene species were mentioned by CADÉE (1977) from West Germany. Miocene Bryozoa of Austria were summarized by VÁVRA (1977, 1979). Cupulad­ ria canadensis was divided into three subspecies by CADÉE (1979, 1981). Badenian (Middle Miocene) lunulitiform Bryozoa of Korytnica Basin and Vienna Basin were examined by BALUK & RADWANSKI (1977b, 1984a, b). In their later work a new family (Discoporellidae), a new genus (Reussirella) and a new species {Cupuladria vindobonensis) were described. A SEM atlas of type and figured material from LAGAAU (1952) was presented by BISHOP & HAYWARD (1989). Five lunulitiform species were mentioned from the Pliocene deposits of SW Spain by REGUANT (1993). LOCALITY The locality is situated at the SW slopes of the Börzsöny Mountains, N Hungary. The old sandpit is NW of Szob on the left bank of Ipoly river, where the Damásd stream crosses the high road between the villages Szob and Ipolydamásd (Fig. 1). In the older literature this locality was mentioned as "Szob, Nagyfeltárás" (big outcrop). The fossils of the yellowish-grey sand were already studied from the mid-nineteenth century owing to its rich mollusc fauna. After many smaller papers the mollusc fauna was examined monographically by CSEPREGHY-MEZNERICS (1956). A short list is given in her work about the foraminifers of the locality. MÜLLER (1984) wrote about some decapods from Szob. MAN- ZONI (1877) mentioned Cupularia haidingeri Bryozoa species from the locality. In the same way as in the publications, mollusc centralisation is a characteristic feature of the the collection of the Department of Geology and Paleontology of the Hungarian Natural History Museum, where molluscs form more than 90 per cent of the material of Szob. MATERIAL AND METHODS The examined material is derived from the coarse fraction (>2 mm) of 10-12 kg washed sand of Szob. The composition of the more than 10,000 specimens is the following (Fig. 2a): bivalves are the most frequent (46.57%), gastropods are significant (25.82%), but more than one-quarter of the fossils are composed of the other groups (27.6%). Taking the other fossil groups into consideration (Fig. 2b) it can be seen that worm tubes are the most frequent (45.4%). Bryozoa (27.92%) and vertebrates (otoliths, fish-teeth and bones: 19.46%) are also significant, but decapods (4.41%) and scaphopods (2.75%) are less important. Within Bryozoa (Fig. 2c) the number of lunulitiform Bryozoa is more than three times larger than that of all the other Bryozoa. Two lunulitiform species can be found in the Szob material: Cupuladria vindobonensis BALUK et RADWANSKI and Reussirella liaidingeri (REUSS). The specimens are deposited in the Department of Geology and Paleontology of the Hungarian Natural History Museum in Budapest (inventory numbers: M.94.154.-M.94.175.). Measurements of Bryozoa were taken according to COOK'S (1965a) methods. The length of zooecia was measured from the distal edge of the aperture to the distal edge of the next succeeding radial zooecial aperture, including the vibraculum. Mean, range and standard deviation of 50 measurements are given (5 zooecia of 10 specimens) for both species (Tables 1-2). One hundred measurements of the number of basal pores are given for Cupuladria vindobo­ nensis BALUK et RADWANSKI (10 basal sectors of 10 specimens) (Table 3). For Bryozoa terminology BASSLER (1953) and COOK (1965a, b) are followed. SYSTEMATIC DESCRIPTIONS Class: Bryozoa EHRENBERG, 1831 Subclass: Gymnolaemata ALLMAN, 1856 Order: Cheilostomata BUSK, 1852 Family: Cupuladriidae LAGAAD, 1952 Genus: Cupuladria CANU et BASSLER, 1919 Cupuladria vindobonensis BALUK et RADWANSKI, 1984 (Figs 4-10, 23, 27-28) Cupularia canadensis BUSK: MANZONI 1877: 72, PI. 17, Figs 56a-c. Cupuladria canariensis (BUSK): LAGAAIJ 1952: 33, PI. 2, Figs la-b; LAGAAIJ 1953: 15, Pl. 1, Figs la-b; BUGE 1957: 139, Pl. 9, Fig. 5, Pl. 10, Fig. 3; LAGAAIJ 1963: 172, Pl. 25, Figs la-b, 3-5; ANNOSCIA 1963: 225, Pl. 9, Fig. 1, Pl. 10, Fig. 1, Pl. 11, Figs la-b, Pl. 12, Figs la-b; CHEETHAM & SANDBERG 1964: 1021, Figs 11, 13; COOK 1965b: 197, Figs la-f, Pl. 3, Fig. 4; BUGE 1973: 36, Pl. 6, Figs 1-2; CADÉE 1975: 323, Pl. 3d; BALUK & RADWANSKI 1977b: 143, Pl. 1, Figs 1-6, Pl. 2, Figs 1-5, Pl. 3, Figs. 1-2; CADÉE 1977: 45, Pl. 1, Fig. 3 Cupuladria canariensis canariensis (BUSK): CADÉE 1979: 446, Figs lc-d. Cupuladria canariensis cavernosa CADÉE 1979: 445, Figs le-g, Fig. 4; BISHOP & HAYWARD 1989: 8, Figs 18-21. Cupuladria vindobonensis BALUK & RADWANSKI 1984a: 22, Pis 2-3, PI. 9, Figs 1-2; BALUK & RADWANSKI 1984b: 243, Pis 1-4; REGUANT 1993: p.127. Material: Numerous fragmentary specimens. Dimensions: length of zooecia 0.637±0.0324 mm (range: 0.59-0.70 mm), width of zooecia 0.276+0.013 mm (range: 0.22-0.31 mm), length of vibracular opesia 0.206+0.01 mm (range: 0.18-0.27 mm), number of pores per basal sectors 8.56± 2.99 (range: 2-17) (see details in Tables 1 and 3). Description: The discoidal, flattened cone-shaped zoaria are free in adult stages. Zooecia form a single layer, in which vibracula alternate with zooecia in the same radial series. The asymmetrical vibracula aie distal to each zooecia. The shape of zooecia is rounded rectangular. Central zooecia arc open, without closures by a calcareous lamina. Vestibular arch is not developed. The cryptocyst is simple, without any denticles. Ovicells are absent. Opesia are deprimed laterally. The number of basal kenozoidal chambers are between 1-5. The kenozoecial layer is about as thick as the zooecial layer. The basal surface of the colony is sectored by radial and tangential grooves. The majority of the basal sectors are long, with pores ranging usually between 5-13 and their maximum range observed 2 to 17 in a sector. Remarks: The family Cupuladriidae was described by LAGAAIJ (1952) to include only the type genus Cupuladria. Later Discoporella also was classified to family Cupuladriidae by CHEETHAM & SANDBERG (1964), COOK (1965a) and BUGE (1973) but recently BALUK & RADWANSKI (1984a) returned to the original interpretation and Discoporella was placed into a new family (Discoporellidae BALUK et RADWANSKI). According to COOK (1965a) three species belong to her Cupuladria canariensis group, i.e. C. canariensis (BUSK), C. monotreinata (BUSK) and C. biporosa CANU et BASSLER). This group was supplemented by CADÉE (1975) and BALUK & RADWANSKI (1984a, b) with two later described species (C.