The overall exoskeletal architecture and hypostomal morphology of Silurian Dalmanites and Lower Devonian Odontochile, Reussiana and Zlichovaspis are compared and discussed. All four genera were benthic. However, a gradual shift from predator-scavenger to a scavenging feeding habit is inferred from the evolution of these dalmanitids in the Upper Silurian and Lower Devonian. In the more conservative, probable predator-scavenger Dalmanites, the posterior hypostomal doublure has a group of robust denticles: these would have been effective shredding structures, enabling milling or cutting of food into smaller particles, and allowing Dalmanites to deal with mechanically relatively robust prey. Lower Devonian dalmanitids from the Prague Basin possess a comparable denticulate structure on the posterior hypostomal doublure. However, although overall exoskeletal dimensions are larger, the denticles are significantly finer and denser. The whole exoskeleton of these younger dalmanitids, with a large multi-segmented pygidium, is considered well adapted for close approximation to the sediment surface. Shallow burrowing in a soft substrate, and scavenging with opportunistic predation, is therefore considered to be their main feeding habit. Odontochile, Reussiana and Zlichovaspis characteristically occur in micritic limestone facies, where the sediment surface is likely to have been soft. The shift from a more predatory to a dominantly scavenging mode of life may have occurred independently in several unrelated dalmanitid groups, with “odontochilid” characteristics developing at different stratigraphical levels. • Key words: Dalmanitidae, trilobite, mode of life, body morphology, hypostomes.

BUDIL, P., THOMAS, A.T. & HÖRBINGER, F. 2008. Exoskeletal architecture, hypostomal morphology and mode of life of Silurian and Lower Devonian dalmanitid trilobites. Bulletin of Geosciences 83(1), 1–10 (5 figures). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received August 23, 2007; accepted in revised form December 4, 2007; issued March 31, 2008.

Petr Budil, Czech Geological Survey, Klárov 3, 118 21 Praha 1, Czech Republic; budil@cgu.cz • Alan Trevor Thomas, Earth Sciences (GEES), University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom; a.t.thomas@bham.ac.uk • Frantisek Hörbinger, Ke Zdravotnímu støedisku 120, 155 00 Praha 5, Czech Republic; Frantisek.Hörbinger@cuzk.cz

A new lingulate brachiopod assemblage has been found in the early Middle Cambrian Týøovice Greywackes of the Skryje-Týøovice area (Central Bohemia, Czech Republic). A new species, Lingulella agaue sp. n., a minute indeterminable lingulid, a ceratretid Almohadella braunae Streng, 1999, and an acrotretid Treptotreta? sp. have been ascertained in the fauna. Four species in one bed is the most diverse lingulate fauna in the area. Associated faunas indicate a shallow marine nearshore environment with a simple trophic structure dominated by an eoorthid Pompeckium kuthani (Pompeckj, 1896), and a few other epibenthic low suspension feeders, as well as uncommon scavengers and browsers. The presence of Almohadella braunae Streng, 1999 is the first incidence of a ceratretid within territory of the Perunica terrane. • Key words: Brachiopoda, Lingulata, Ceratretida, taxonomy, palaeoecology, Middle Cambrian, Skryje-Týøovice area, Czech Republic

MERGL, M. & KORDULE, V. 2008. New Middle Cambrian lingulate brachiopods from the Skryje-Týøovice area (Central Bohemia, Czech Republic). Bulletin of Geosciences 83(1), 11–22 (10 figures). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received November 28, 2007; accepted in revised form January 17, 2008; issued March 31, 2008.

Michal Mergl, Department of Biology, Faculty of Education, University of West Bohemia in Plzeò, Klatovská 51, 30619 Plzeò, Czech Republic; mmergl@kbi.zcu.cz • Vratislav Kordule, Dlouhá 104, 26101 Pøíbram III, Czech Republic

Five named species of the helcionelloid mollusc genus Yochelcionella Runnegar&Pojeta, 1974 are recognized from the lower Cambrian (Cambrian Series 2) of North America: Yochelcionella erecta (Walcott, 1891), Y. americana Runnegar &Pojeta, 1980, Y. chinensis Pei, 1985, Y. greenlandica Atkins&Peel, 2004 and Y. gracilis Atkins&Peel, 2004, linking lower Cambrian outcrops along the present north-eastern seaboard. Yochelcionella erecta, an Avalonian species, is described for the first time; other species are derived from Laurentia. A revised concept of the Chinese species, Y. chinensis, is based mainly on a large sample from the Forteau Formation of western Newfoundland and the species may have stratigraphic utility between Cambrian palaeocontinents. • Key words: Yochelcionella, Helcionelloida, Mollusca, lower Cambrian (Cambrian Series 2), North America.

ATKINS, C.J. & PEEL, J.S. 2008. Yochelcionella (Mollusca, Helcionelloida) from the lower Cambrian of North America. Bulletin of Geosciences 83(1), 23–38 (8 figures). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received September 26, 2007; accepted in revised form January, 10, 2008; issued March 31, 2008.

Christian J. Atkins, Department of Earth Sciences (Palaeobiology), Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden; Christian.Atkins@geo.uu.se • John S. Peel, Department of Earth Sciences (Palaeobiology) and Museum of Evolution, Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden; John.Peel@pal.uu.se

Phragmoceras and Tubiferoceras are discosorid nautiloid genera with endogastric cyrtoconic to orthoconic breviconic shells possessing a contracted aperture. Because of the constricted aperture phragmoceratids have usually been considered as microphages. The constriction of the aperture appears during the late ephebic stage. Preceding ontogenetic stages possessed a brevicone shell with an open aperture, usually considered to be indicative of nectobenthic predatory lifestyle. The apertural constriction probably improved hydrodynamic control and served as protection for the soft body. Attachment sites for distinct retractor muscles suggest evidence of potentially fast movement of the head-arm complex out of the aperture with consequent capture of larger prey. Phragmoceratids are a characteristic component of Silurian nautiloid faunas, which inhabited the mainly tropical carbonate platforms of Baltica and Laurentia. Phragmoceratids closely related to those of the Baltic and Avalonia occasionally appeared in the Prague Basin, which was located in the temperate zone at the northern margin of peri-Gondwana. The distribution pattern of phragmoceratids suggests that immigration into the Prague Basin occurred in three stages: (1) first appeared stray immigrants (or occasional visitors) from warmer seas, this stage of immigration reflecting activation of sea currents after the early Silurian widespread anoxia in peri-Gondwana (latest Llandovery-early Wenlock); (2) appearance of small endemic palaeo-populations of migrants (with evidence of local hatching of phragmocerids) that persisted only briefly during the early Homerian and early Gorstian low stands; (3) stable palaeo-populations appeared in the Early Ludfordian, with occurrence of endemic taxa related to the forms known from Baltica-Avalonia, suggesting stable conditions for nautiloid evolution. The Middle Ludfordian Kozlowskii Event caused the extinction of the last phragmocerid taxa in the Prague Basin as elsewhere. Nautiloid immigration to the Prague Basin (Perunica microplate) indicates that Perunica, in contrast to peri-Gondwanan areas, was within reach of the South Tropical Current since the latest Llandovery. Many other nautiloid families show a similar migration pattern although timing of the immigrations do not necessarily correlate. Thus the nautiloids provide useful data for palaeobiogeographic and climate reconstruction, such analysis can be made precise by comparison of nautiloid clades. • Key words: Silurian, Nautiloidea, Phragmoceras, migration, palaeoecology, peri-Gondwana, Perunica, Prague Basin.

MANDA, Š. 2008. Palaeoecology and palaeogeographic relations of the Silurian phragmoceratids (Nautiloidea, Cephalopoda) of the Prague Basin (Bohemia). Bulletin of Geosciences 83(1), 39–62. Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received November 7, 2007; accepted in revised form February 26, 2008, issued March 31, 2008.

Štìpán Manda, Czech Geological Survey, P.O.B. 85, Praha 011, 118 21, Czech Republic; stepan.manda@geology.cz

A marine sedimentary sequence of the Pakhiammos section that crops out in the Ierapetra Basin (eastern Crete, Greece) is described here in detail for the first time. Diverse and abundant foraminifera have been recovered from the Pakhiammos section. Planktonic species indicate that sediments span the interval from Zone MPL1 to above the MPL1/MPL2 boundary (Zanclean, early Pliocene). R-mode cluster analysis identified three benthic foraminiferal assemblages named by their dominant taxa: Bolivina spathulata, Cibicidoides pseudoungerianus, and Siphonina reticulata assemblages respectively. Palaeoenvironmental implications of each assemblage and their stratigraphic distribution allow the recognition of two fossil associations: a well-diversified Association A, representative of a stable marine ecosystem, and a less diversified Association B, representative of a sapropel-like event. The deposition of the sapropel-like interval suggests that sapropels resulted from the interaction between sea surface temperature variations, productivity increases and reduced bottom water ventilation. This study represents the first report of early Pliocene marine sediments in the Ierapetra Basin and contributes to the understanding of the evolution of the Neogene basins in eastern Crete. • Key words: biostratigraphy, foraminifera, palaeoenvironment, Early Pliocene, eastern Crete.

DRINIA, H., ANTONARAKOU, A. & KONTAKIOTIS, G. 2008. On the occurrence of Early Pliocene marine deposits in the Ierapetra Basin, Eastern Crete, Greece. Bulletin of Geosciences 83(1), 63–78 (10 figures, 2 tables). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received January 23, 2007; accepted in revised form June 14, 2007; issued January 31, 2008.

Hara Drinia, National and Kapodistrian University of Athens, Faculty of Geology and Geoenvironment, Department of Historical Geology and Palaeontology, Panepistimiopolis 157 84 Athens, Greece; cntrinia@geol.uoa.gr

Algerina gen. nov. (Bivalvia, Spanilidae Køíž, 2007), with its type species Algerina algena sp. nov., is described from the Silurian (lower Ludlow) of Algeria, western Hoggar Mountains, Ahnet Massif and the Ougarta Range. The new genus is also known from the upper Wenlock of France, the Montagne Noire [Algerina chaubetae (Køíž, 1996)], and from the lower Ludlow of Italy, the Carnic Alps [Algerina cocco (Køíž, 1999)]. Algerina rebellis (Barrande, 1881) is known from the lower Ludlow and Algerina faba (Barrande, 1881) from the middle Ludlow of Bohemia, Prague Basin. Algerina faba is also known from the lower Ludlow of the Tajmyr Basin, Russia. • Key words: Bivalvia, Nepiomorphia, new taxa, Silurian, Algeria, France, Italy, Bohemia, Tajmyr (Russia).

KØÍŽ, J. 2008. Algerina gen. nov. (Bivalvia, Nepiomorphia) from the Silurian of the North Gondwana margin (Algeria), peri-Gondwanan Europe (France, Italy), Perunica (Prague Basin, Bohemia) and the Siberian Plate (Tajmyr Basin, Russia). Bulletin of Geosciences 83(1), 79–84 (1 figure). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received November 11, 2007; accepted in revised form December 11, 2007; issued March 31, 2008.

Jiøí Køíž, Czech Geological Survey, Klárov 3, P.O. Box 85, 118 21 Praha 1, Czech Republic; jiri.kriz@geology.cz

Well preserved and varied sphaeromorphs, filamentous trichomes and synaploid organic-walled microfossils occur in fine-grained clastics in the Mìnín-1 borehole. Thirty genera with 40 species have been identified, previously known from Meso- and Neoproterozoic sediments. The Proterozoic microfossils are excellently preserved, not affected by post-diagenetic thermal alteration. The Vendian age is documented by the presence of the taxa Bavlinella faveolata (Shepeleva) Vidal, 1976, Chabiosphaera bohemica Drábek, 1972, Obruchevella valdaica (Shepeleva ex Aseeva) Jankauskas et al., 1989, Podolina minuta Hermann in Timofeev et al., 1976, and Primoflagella speciosa Gnilovskaya, 1983. The palynological residuum contained no acritarch species of Early Cambrian age, although the basal Cambrian Asteridium tornatum–Comasphaeridium velvetum palynozone was ascertained from 266 m below the level with acritarchs. Thin sections from the Mìnín-1 borehole suggest a possible presence of more than 600 m of Vendian sediments. Irrespective of the possible secondary origin of the recovered microfossils, the existence of extensive Proterozoic marine sedimentation within the southern part of the Brunovistulicum is clearly demonstrated. Sediments from the Precambrian-Cambrian transition were not subjected to Cadomian or younger metamorphic processes. • Key words:Vendian, acritarchs, basal clastics, southern Moravia.

VAVRDOVÁ, M. 2008. Proterozoic acritarchs from the Precambrian-Cambrian transition in southern Moravia. Bulletin of Geosciences 83(1), 85–92 (4 figures). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received May 15, 2007; accepted in revised form January 17, 2008; issued March 31, 2008.

Milada Vavrdová, Academy of Sciences of the Czech Republic, Institute of Geology v.v.i., Rozvojová 269, 165 02 Praha 6, Czech Republic; vavrdova@gli.cas.cz

A new palaeozygopleurid gastropod, Palaeozygopleura vaneki sp. nov., is described from the Emsian Chýnice Limestone (Novakia elegans Zone, upper part of the Zlíchov Formation; late Early Devonian) of the Prague Basin (Bohemia). The phylogeny of the superfamily Loxonematoidea and the origin of planktotrophy are briefly discussed. It is suggested that the large protoconchs of the Palaeozygopleuridae and Loxonematidae might represent a grade before the inception of planktotrophy. • Key words: Mollusca, Loxonematoidea, Palaeozygopleuridae, Gastropoda, planktotrophy, Emsian, Bohemia.

FRÝDA, J., FERROVÁ, L., BERKYOVÁ, S. & FRÝDOVÁ, B. 2008. A new Early Devonian palaeozygopleurid gastropod from the Prague Basin (Bohemia) with notes on the phylogeny of the Loxonematoidea. Bulletin of Geosciences 83(1), 93–100 (1 figure). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received December 28, 2007; accepted in revised form January 15, 2008, issued March 31, 2008.

Jiøí Frýda, Czech Geological Survey, P.O.B. 85, 118 21 Prague 1, and Faculty of Environmental Sciences, CULS, 165 21 Prague 6, Czech Republic, fryda@cgu.cz • Lenka Ferrová and Stanislava Berkyová, Czech Geological Survey, P.O.B. 85, Praha 011, 118 21, Czech Republic; lenka.ferrova@geology.cz, berkyova@cgu.cz • Barbora Frýdová, VÚRV v.v.i., Research Institute, Drnovská 507, 161 06 Prague – Ruzynì, Czech Republic; frydova@vurv.cz

New palynostratigraphical studies have been undertaken to elucidate the complex stratigraphy of the Carboniferous succession of the southwestern Poland. Rocks from wells Paproæ 29, Katarzynin 2, Marcinki IG 1, Siciny IG 1, Dymek IG 1, Dankowice IG 1, Kalisz IG 1, Wrzeœnia IG 1 and Objezierze IG 1 were studied. Results of these studies facilitate a new interpretation of the stratigraphy and partly clarify timing of Carboniferous deposition and deformation. Stratigraphical interpretation of miospore assemblages proves the presence of Namurian-Westphalian (Pendleian-Alportian and Duckmantian-Asturian) or even younger rocks in the investigated intervals. During that time older rocks, the source of abundant contained miospores and faunal macrofossils, were subject of erosion and the fossils became reworked components in the studied rocks. Repetition of both dated sequences in some sections indicates that inversion of this foreland basin took place after the Bolsovian. • Key words: Carboniferous, Poland, palynostratigraphy, reworked fossils, repetition of stratigraphic sequences.

GÓRECKA-NOWAK, A. 2008. New interpretations of the Carboniferous stratigraphy of SW Poland based on miospore data. Bulletin of Geosciences 83(1), 101–116 (9 figures, 1 table). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received June 15, 2007; accepted in revised form November 30, 2007; issued March 31, 2008.

Anna Górecka-Nowak, Institute of Geological Sciences, University of Wroc³aw, ul. Cybulskiego 30, 50 205 Wroc³aw, Poland; agor@ing.uni.wroc.pl

The taxonomic position of sea bass fishes of the family Moronidae from Upper Eocene (Palaeogene) diatomite deposits of Kuèlín near Bílina, Czech Republic, is discussed. Although the fossil skeletons are incomplete, Morone sp. is characterised by skull elements, fin formula, caudal skeleton and specific ctenoid scales. The morphology of certain skull elements typifies the family. Data on moronid fishes from the northern Bohemian Palaeogene is reviewed. • Key words: fish, Teleostei, Perciformes, Moronidae, Czech Republic, Eocene, Priabonian.

PØIKRYL, T. 2008. Sea bass fish Morone sp. (Teleostei) from the north Bohemian Paleogene (Tertiary, Czech Republic). Bulletin of Geosciences 83(1), 117–122 (4 figures, 2 tables). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received May 2, 2007; accepted in revised form September 3, 2007; issued January 31, 2008.

Tomáš Pøikryl, Charles University, Faculty of Science, Institute of Geology and Palaeontology, Albertov 6, 128 43 Praha 2, Czech Republic; Prikryl.T@seznam.cz