Szabó János szerk.: Fragmenta Mineralogica Et Palaentologica 19. 2001. (Budapest, 2001)

Middle Miocene (Badenian) Polyplacophora from Szokolya 41 76.7-91.1 m: grey clayey marl 111 .2-115.3 m: grey marly clay 91.1-102.2 m: grey marly sandstone 115.3-118.3 m: grey sandy marl 102.2-104.7 m: grey sandy clay 118.3-120 m: limestone 104.7-111.2 m: grey marly sandstone 120-140 m: andésite Material The fine, small-sized sandy marls and marly sandstones are full of fossils. The most diverse group is the molluscs, including lots of micromolluscs. The dominant fossils are gastropods and bivalves, but several other groups are also represented in the accompanying fauna (including bryozoans, decapods, otoliths, etc.). The polyplacophorans are accessorical elements. Five determinable specimens were found: four of them from 92.7-93 m interval and one specimen from 109-111.2 m interval. The accompanying fauna contains diverse mollusc and bryozoan remains. The bivalves (Myrtea spinifera MONTAGU, Venus sp., Corbula sp.) belong to the suspension feeding infauna. The gastropods contain browsing (Alvania partschi HÖRNES, Cerithiella kostejana BOETTGER, Rissoa acuticosta SACCO), carnivore (Hinia hoernesi MAYER) and ectoparasite (Odostomia sp., Pyramidella sp.) epifaunal elements. The bryozoan fauna consists of lunulitiform (Cupuladria cavernosa CADÉE, Lunulites androsaces MANZONI) and cellariiform (Cellaria salicornioides LAMOUROUX, Pleuronea pertusa (REUSS), Escharoides coccinea (ABILGAARDJ, Calpensia sp., Canda sp.) elements. The chitons were examined by scanning electron microscopy at the Scanning Laboratory of Hungarian Geological Institute. The specimens are deposited in the collection of the Department of Geology and Palaeontology of the Hungarian Natural History Museum, Budapest (inventory numbers: M.99.109— M.99.113). Systematics Phylum Mollusca Class Polyplacophora DE BLAINVILLE, 1816 Order Ischnochitonida BERGENHAYN, 1930 Family Ischnochitonidae DALL, 1889 Genus Lepidochitona GRAY, 1821 Lepidochitona lepida (REUSS, 1860) (Plate I: 1-6) 1860 Chiton kpidus n. sp. — REUSS, p. 259, pi. 8, figs. 12-13. 1897 Lepidopleurus cf. marginatus (PENN.) — SACCO, p. 90, pi. 7, fig. 32. 1934 Middendorfta lepida (REUSS) — §ULC, pp. 10-11, pl. 1, figs. 13-15. 1950 Chiton lepidus REUSS — CSEPREGHY-MEZNERICS, p. 15. 1971 Lepidochitona lepida (REUSS) — BALUK, pp. 459^60, pi. 4, figs. 6-12. 1984 Lepidochitona lepida (REUSS) — BALUK, pp. 288-289, pi. 7, figs. 1-3. 1988 Lepidochitona (Lepidochitona) lepida (REUSS) — SlUDENCKA & STUDENCKI, pp. 39-40, pi. 2, figs. 1 and 3. 1988 Lepidochitona lepida (REUSS) — MACIOSZCZYK, p. 53. Material — 2 intermediate valves (borehole Szokolya-2, 92.7-93 m and 109-111.2 m) (M.99.109 and M.99.110). Measurements (mm): length width M.99.109 1.3 2.46 M.99.110 1.26 1.76 (fragmentary) Description — The valves are broad. Fine granules ornament the surface of the entire tegmentum. The flattened oval granules are regularly distributed, forming two intersecting systems of rows on the first specimen (Pl I: 1—3). The granules are arranged in longitudinal rows on the jugal areas and in roughly radiated transversal rows on the lateral areas on the second specimen (Pl I: 4—6). The lateral areas are marked by a slight ridge. On the lateral areas the nodes are closely spaced, arranged one near another, but they are rarer on jugal areas. Sutural plates are wide and rounded. There are several pores on the nodes and along the nodes. There is a larger sized pore at the centre of the nodes, and there are several (7-10) smaller ones around the central pore. Remarks — Although one of the specimens is a fragmentary intermediate valve, both of them well correspond with the published specimens (see SULC 1934, pi. 1, fig. 14; BALUK 1971, pi. 4, figs. 7., 9 and 10; BALUK 1984, pi. 7, fig 2). The specimens previously determined under the name of Lepidochitona lepida (REUSS) were interpreted as Lepidochitona dnerea (LINNAEUS) or Middendorfta caprearum (SCACCHI) by