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Cross-sections of conchs of species of Gracilitheca . A , Gracilitheca sp. sensu Kouchinsky et al . (2011, text-fig. 12F); B , Gracilitheca sp. sensu Malinky & Skovsted (2004, text-fig. 9A1); C , Gracilitheca ternata Sysoev, 1968 (after Val’kov 1987, pl. 10, fig. 18); D , Gracilitheca argasalairica Val’kov (1987, pl. 10, fig. 18); E , Gracilitheca mirabilis sp. nov. (after Marek 1967, Fig. 8b); F , Gracilitheca destombesi Marek et al . (1997, text-fig. 15); G , Gracilitheca triangularis sp. nov.; H , Gracilitheca sp.; I , Gracilitheca bayonet (Matthew, 1899) (after Landing 1988, fig. 7/7).
Source publication
VALENT, M., FATKA, O. & MAREK, L., iFirst article. Gracilitheca and Nephrotheca (Hyolitha, Orthothecida) in the Cambrian of the Barrandian area, Czech Republic. Alcheringa, 1–10. ISSN 0311-5518.Five orthothecid hyoliths, Gracilitheca mirabilis sp. nov., Gracilitheca triangularis sp. nov., Gracilitheca sp., Nephrotheca betula sp. nov. and Nephrothec...
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Present paper dealt with three species viz. Virgularia gustaviana, Virgularia mirabilis and Cavernularia pusilla under the order Pennatulacea reported from Andaman and Nicobar Islands are described and illustrated. They are new distributional recorded to Indian waters.
Citations
... The richly fossiliferous shales and greywackes with spatially restricted sandstone and conglomerate bodies are assigned to the middle Cambrian Buchava Formation in the Skryje-Týřovice Basin, and to the Jince Formation in the Příbram-Jince Basin (Text- fig. 1b). From both these units, abundant and exceptionally diverse hyoliths (both hyolithids and orthothecids) were described by Barrande (1867), Marek ( , 1980Marek ( , 1983, Valent (2004Valent ( , 2006, Valent et al. (2009Valent et al. ( , 2011Valent et al. ( , 2013Valent et al. ( , 2015Valent et al. ( , 2019. At several outcrops situated in numerous stratigraphic levels of both formations, articulated orthothecids with operculum preserved inside of conch as well as hyolithids with conch, operculum and rarely also with helens have been identified (e.g. ...
Hyoliths recorded from the middle Cambrian Jince Formation of the Barrandian area in the Czech Republic are reviewed and listed, based on various published papers printed since 1854. Up to now, only five species of hyolithids and three species of orthothecids have been reported, classified within seven genera. The reported material was collected from more than twenty small occasional outcrops and/or sections measuring up to several tens of meters in thickness, all situated exclusively in the area between the villages Felbabka and Čenkov in the Litavka River Valley. From the Paseky Shale member of the Holšiny-Hořice Formation at the Medalův mlýn locality, the first hyolith classified as “Hyolith genus and species indeterminate” is described. The new study of two specimens described and figured by Barrande in 1867 as Hyolithes primus made it possible to classify them as Jincelites vogeli and Jincelites sp. respectively.
... This extensive collection was transferred from the Academy of Science to the National Museum, Prague, in 1998. Here, the original hyolith material was newly sorted and specimens belonging to still-undescribed or poorly known taxa were selected for study, leading to the successful description of material from Marek's original collection (Valent et al. 2013(Valent et al. , 2017. ...
... Thanks to the monograph of Barrande (1867) and the more recent studies of Marek (1972Marek ( -1981, Cambrian hyoliths of the Barrandian area represent a classical repository of this group. The hyolith taxa first distinguished by Marek have since been completed by more recently collected specimens and published one by one (Valent et al. 2011(Valent et al. , 2012(Valent et al. , 2013(Valent et al. , 2015(Valent et al. , 2017. ...
The rare hyolith Alfaites romeo gen. et sp. nov. is described from the lower half of the middle Cambrian (Drumian) Buchava Formation of the Skryje-Týřovice Basin in the Barrandian area of the Czech Republic. This new taxon is based on excellently preserved external and internal moulds of three opercula and several conchs collected from carbonate nodules and shale. This rare species has been established at three separate outcrops in the lower part of the Biozone of Paradoxides (Eccaparadoxides) pusillus (Barrande 1846). Morphology of conch and both external and internal surface of operculum are well known. However, specific morphology excludes assignment to any predescribed hyolithid family.
... The specimens are also similar to species of the genus Decoritheca Sysoev, 1972. It is impossible, however, to decide on the precise generic affinity because species of both genera may have a shallow ventral furrow, longitudinal ornamentation and a small apical angle (13° in Nephrotheca sophia Valent et al. 2013).The absence of the apertural part, however, prevents a confident placement under this genus because it remains unclear whether this specimen belongs to order Hyolithida or Orthothecida. ...
The early middle Cambrian Tannenknock Formation of the Franconian Forest, traditionally subdivided into the Galgenberg and Wildenstein strata, yields a relatively diverse fauna. This fauna includes a number of molluscs, which portrays a fairly diverse assemblage that can be regarded as paradigmatic for the lower–middle Cambrian boundary interval in West Gondwana, with the helcionelloid genera Helcionella, “Bemella,” “Igorella,” Latouchella, Leptostega, Yochelcionella, the pelagiellid Pelagiella, a stenothecoid, and the Hyolithida Hyolithes?, Hexitheca?, Jincelites, Maxilites?, Aladraco, Cambrachelous, the Orthothecida Brevitheca?, Nephrotheca?, and a number of helcionelloid and hyolith forms dealt with under open nomenclature. New species include the helcionelloids Helcionella lemdadensis sp. nov. and Leptostega frankenwaldensis sp. nov. and the hyoliths Grantitheca? klani sp. nov. and Cambrachelous diploprosopus gen. et sp. nov. The stenothecoid discovered in the Wildenstein Member of the formation is the first report of the group from West Gondwana.
... The mid-Cambrian Jince Formation of the Příbram-Jince Basin and Buchava Formation of the Skryje-Týřovice Basin are globally renowned as classical repositories of a well-preserved skeletal marine fauna (Geyer et al. 2008), including exceptionally diverse and well preserved hyoliths (i.e. Barrande 1867;Marek 1972Marek , 1975Marek , 1981Valent et al. 2009Valent et al. , 2011Valent et al. , 2012Valent et al. , 2013Valent et al. , 2015Valent et al. , 2017. The highly diverse hyolith fauna of the Buchava Formation is quite well studied and comprises at least fifteen species (Valent et al. 2015). ...
... Some show exceptional preservation, particularly when the inner side of operculum is preserved both as the internal and external mould (Fig. 3E, F). Such preservation is outstanding because the inner side is usually preserved only as an external mould (Valent et al. 2009(Valent et al. , 2011(Valent et al. , 2012(Valent et al. , 2013(Valent et al. , 2015. The size distribution of this species in the Příbram-Jince Basin corresponds with the size distribution in the Skryje-Týřovice Basin (Valent 2004). ...
... The size the conch from the Jince Formation corresponds to the size of the conch of the Buchava Formation (see Valent et al. 2013). ...
The mid-Cambrian Jince Formation of the Barrandian area is globally renowned as a classical repository of exceptionally diverse and well preserved hyoliths. However, our knowledge about hyoliths of the mid-Cambrian Jince Formation of the Příbram-Jince Basin is quite incomplete and the locally abundant and well preserved hyolith specimens are not adequately studied. The hyolith association studied herein consists of three hyolithids and three orthothecids from the lower strati-graphic levels of the Jince Formation and constitutes a considerable increase of our knowledge. The studied material is preserved as internal and external moulds in calcareous nodules, fine greywackes and shales. Except for one taxon, Maxilites sp., the other five hyolith species, Oboedalites oboediens Marek, 1981, Slehoferites slehoferi Marek, 2011, Circotheca sp., Gracilitheca triangularis Valent et al., 2013, and Probactrotheca briketa Marek, 2012 are new for the Příbram-Jince Basin; previously these species have been known exclusively from the Buchava Formation of the Skryje-Týřovice Basin of the Barrandian area.
... The specimen is poorly preserved, which prevents precise taxonomic assignment. Martí Mus and Bergström (2005) described the best preserved hyolithid conchs with articulated helens and an operculum of Maxilites Marek, 1972 from the Cambrian Series 3 of the Czech Republic (Peel 2010;Valent et al. 2013). The Czech specimens are preserved as moulds and exquisite details of the musculature and internal structures can be observed. ...
... OCCURRENCE: Gracilitheca is known from Siberia (Sysoev 1968), North America (Landing 1988), Morocco (Marek et al. 1997;Malinky and Skovsted 2004), Czech Republic (Valent et al. 2013), and Germany (this report). ...
Atnisha, A. 2018. A middle Cambrian (Series 3, Stage 5) microfaunal assemblage from the Torgau-Doberlug Syncline (Central Germany) and its palaeogeographic implications for the configuration of West Gondwana. Acta Geologica Polonica, XX (x), 1−25. Warszawa. A microfauna of small shelly fossils (SSF) is reported here for the first time from middle Cambrian (Series 3, Stage 5) subsurface strata of the Torgau-Doberlug Syncline (TDS), Central Germany. Considering that this microfauna is strongly limited and poorly preserved the material is quite abundant and diverse. The assemblage consists of molluscs (pelagiellids, bivalves), coeloscleritophorans (chancelloriids, halkieriids), poriferids, pro-toconodonts, cambroclaves, hyoliths, brachiopods, and disarticulated echinoderm remains. Additionally, a probable pterobranch hemichordate is noted. The assemblage is dominated by epifaunal suspension feeders from mid-to outer shelf depositional settings. Stratigraphically it represents (together with rare trilobites) the oldest middle Cambrian (Series 3, Stage 5) fauna known from Central Germany and the entire Saxothuringian Zone. Regardless the taphonomic problems related to the SSF occurrence, close palaeobiogeographic relations are indicated with the Mediterranean shelf of West Gondwana (especially with the areas of southwestern Europe and Morocco). The reported microfauna coupled with recent trilobite and palynomorph research supports assumptions that the Cambrian succession in the TDS is by far more complete than hitherto suggested, emphasizing its importance as a region yielding Cambrian rocks in Central Europe.
... Despite more than 150 years of intensive investigation by both professional palaeontologists and amateur collectors, field work at exposures of the Buchava Formation continuously provides new species of trilobites, echinoderms, hyoliths and other skeletal fauna (e.g. Valent et al., 2013;Fatka and Kraft, 2014;. Recently, rare specimens of poorly to completely non-mineralised Burgess Shale-type metazoans were also described (Chlupáč and Kordule, 2002;Maletz et al., 2005;Fatka et al., 2011a;Mikuláš et al., 2012;Fatka et al., 2013;Fatka and Kozák, in press). ...
... Weakly articulated skeletons are represented by diverse ontogenetic stages of trilobites and agnostids documented by Barrande (1852Barrande ( ) andŠnajdr (1958, and make possible the application of quantitative methods in detailed study of larval morphology (Laibl et al., 2014(Laibl et al., , 2015. Similarly exceptionally preserved are hyolith conchs with operculum and with helenae in situ (Martí Mus and Bergström, 2005;Valent et al., 2011Valent et al., , 2013, and numerous echinoderm specimens with loosely connected ossicles (Barrande, 1887;Lefebvre and Fatka, 2003;Lefebvre, 2007 andZamora et al., 2013). Numerous articulated specimens of the small trilobite Skreiaspis spinosus ascertained inside of large hyolithid conchs represent the gardening strategy known in other Cambrian trilobites (Mikuláš, 2001;Fatka et al., 2008). ...
A fragment of a Burgess Shale-type fossil, bivalved arthropod Tuzoia Walcott, 1912, is described from shales of the mid-Cambrian Buchava Formation in the Skryje–Týřovice Basin, Central Bohemia, Czech Republic. It is the second recorded find of Tuzoia from West Gondwana. Uncrushed and uncoloured preservation of the tuzoiid valve is consistent with the very thin non-mineralised cuticle described for this taxon. This new occurrence of the genus Tuzoia, as well as the earlier described genera Wiwaxia and Hurdia, indicate the presence of a Burgess Shale-type fauna in several stratigraphical levels of Cambrian sequence of the Skryje–Týřovice Basin. Distribution of other exceptionally preserved specimens established in the Buchava Formation is briefly summarized and discussed.
Hyoliths are usually preserved as isolated skeletal elements consisting of conch, operculum, and helens. The occurrence of a conch associated with an operculum is ordinarily exceptional, and the co-occurrence of helens with other skeletal parts is a great rarity. The extraordinary finds of hyolithid conchs associated with opercula in situ are relatively abundant in the Cambrian and Ordovician clastic sediments of the Barrandian area in the Czech Republic. The platyclaviculate operculum with clavicles divided by longitudinal walls into channels characterizes members of the newly established family Slapylitidae fam. nov., which includes two genera: Slapylites Marek, 1980 known from the mid-Cambrian of West Gondwana and Baltica and Nevadalites Marek, 1976 documented from the Late Cambrian of Laurentia. To this family most probably belongs also an operculum from the Cambrian Series 2–Series 3 boundary of North Greenland and poorly known material from the Middle Devonian of Bolivia.
Two new endemic genera and species of extinct group of Hyolitha, Skryjelites auritus gen. et sp. nov. and Quasimolites quasimodo gen. et sp. nov. are described and illustrated from the Buchava Formation of the Barrandian area (Czech Republic).
Two conicaltubules from shales of the Skryje Member (Buchava Formation) at the Skryje-Luh and Týřovice -"Pod hruškou" localities, two of the key out crops of this stratigraphic unit in the Skryje-Týřovice Basin (Barrandian area, Czech Republic), are described. One specimen consists of a small, compressed tubule with a very low expansion angle and wide and flat thickenings. The second, larger specimen exhibits indications of very narrow thickenings of a more abruptly expanding shell. Both specimens are as signed to the genus Sphenothallus Hall, but the latter only provisionally. Sphenothallus shows a world wide distribution with numerous species, ranging from Cambrian to Permian in age. How ever, reported occurrences in the Cambrian are relatively sparse, in the form of rare specimens from the lower to middle Cambrian strata of Laurentia, Eastern Gondwana and European peri-Gondwana. According to accepted palaeogeographical reconstructions, Cambrian Sphenothallus occurred in low as well as in higher palaeolatitudes.
