New brachiopods from the Ordovician of northeastern Russia

New brachiopod taxa, Starnikoviella gen. nov., with the type species S. settedabanica sp. nov. (family Clitambonitidae), and Avdeevella gen. nov., with the type species A. mica sp. nov. (subfamily Glyptomeninae), from the Middle–Upper Ordovician boundary deposits of northeastern Russia are described.     

New Ordovician ostracodes from Himalaya and their palaeobiological and palaeogeographical implications

Silicified representatives of the ostracode orders Binodicopa, Palaeocopa and Podocopa have been recovered from the late Ordovician Pin Formation, Spiti, NW Himalaya area. Benthic binodicopes are distinctly more abundant than the palaeocope and podocope ostracodes. The binodicopes show biogeographical relations to Australia at the generic level, which supports the close palaeogeographic position of these continents. By contrast, the palaeocope and podocope taxa show close relations to Baltica and Bohemia even at the species level, which may suggest a pelagic or epipelagic mode of life since these regions are separated from each other by the broad and deep waters of Palaeotethys. New taxa are Vendona crassiplicata nov. sp., Glossomorphites himalayaensis nov. sp., Pilla pinensis nov. sp. and Pinpilla u-formis nov. gen. nov. sp.     

The oldest bryozoans of Baltoscandia from the lowermost Floian (Ordovician) of north-western Russia: two new rare,small and simple species of Revalotrypidae

We describe two new species of esthonioporate bryozoans, Revalotrypa inopinata sp. nov. and R. yugaensis sp. nov., from the Lower Ordovician, south-east of Lake Ladoga, north-western Russia. The colonies of the two species are very small and were extracted from limestone nodules found in the lower part of glauconitic sandstone in the Joa Member (lowermost Floian). Revalotrypa inopinata sp. nov. and R. yugaensis sp. nov. are the oldest known bryozoans from Baltoscandia. Study of the two species includes scanning electron microscopy (SEM) imaging and X-ray microtomography (micro-CT). The palaeogeographic distribution of the oldest known bryozoans from the Lower Ordovician and the advantages and disadvantages of micro-CT for the study of Palaeozoic bryozoans are discussed. The authorship of Revalotrypidae, which has been inconsistently allocated in the literature, is discussed.     

An Early Ordovician Trilobite assemblage from the Lashkarak Formation, Damghan area, northern Iran

A low diversity Lower Ordovician trilobite assemblage is described from the middle part of the Lashkarak Formation at Simeh-Kuh, northwest of Damghan, northern Iran. Co-occurrence with conodonts of the lowermost Paroistodusproteus Biozone suggests an uppermost Tremadocian age. This assemblage includes four taxa, including one new genus and two new species, Damghanampyxginteri nov. gen. nov. sp. and Asaphellusfecundus nov. sp. The third diagnosable species from the formation is Taihungshaniamiqueli (Bergeron, 1894) which has previously been reported from southern France and the Turkish Taurides, suggesting north Gondwanan faunal affinities.     

New species of stromatoporoidea from the Upper Ordovician and Silurian of the Subpolar Urals

Stromatoporoidea are widespread in the Upper Ordovician and Silurian beds of the Kozhim River (western slope of the Subpolar Urals). Five new species Cystostroma prodigiosum sp. nov., Stylostroma flabellatum sp. nov., Labechiina arguta sp. nov., Ecclimadictyon faveolatum sp. nov., and Araneosustroma astroplexum sp. nov. are described.     

Formation of cardinal process in Ordovician strophomenids

The cardinalia of strophomenids Lynnica fragilis gen. et sp. nov. and Sowerbyella (Sowerbyella) liliifera Öpik, 1930 from the Ordovician of the Leningrad Region are described in detail for different developmental stages. The study has revealed that the cardinal process of S. liliifera is bilobed unifid and the cardinal process of L. fragilis is bilobed trifid. L. fragilis gen. et sp. nov. is described.     

Discovery of rhombifera (Echinoderms) in the Ordovician of Mongolia

Two new rhombiferan species Echinosphaerites mongolicus sp. nov. and Stichocystis altaicus sp. nov., described from a recently discovered Upper Ordovician locality in the Mongolian Altai, on the Chegertei River, suggest possible biogeographic links between this region and Gondwana and Baltica in the Ordovician. In the Upper Ordovician beds in the East Gobi Depression near Saishand Well, we identified the crinoid Ristnacrinus, previously recorded from the Ordovician of Estonia and Central Asia.     

A new genus of the Arenigian bryozoans, <Emphasis Type="Italic">Lynnopora</Emphasis>, and its systematic position in the family Revalotrypidae Gorjunova, 1988

A new genus Lynnopora gen. nov. with the type species L. lunata sp. nov. and a new species Revalotrypa krestensis Koromyslova sp. nov. from the Arenigian Stage (Latorp and Volkhov horizons) of the Ordovician of the Leningrad Region are described. The positions of the genus Revalotrypa Bassler, 1952 and the family Revalotrypidae Gorjunova, 1988 in the order Cystoporida are substantiated. The problems of biogeography and ecological adaptations of bryozoans of the family Revalotrypidae are discussed.     

A new orthoceratoid cephalopod from the Ordovician (Caradoc) of east-central Iran

Orthoconic cephalopods from the Ordovician Katkoyeh Formation at Banestan, Kerman Province, Iran, comprise a single species named as Sactorthoceras banestanensis Evans nov. sp. Associated faunas suggest close palaeobiogeographical linkage with other regions of north peri-Gondwana, notably Morocco and Bohemia (Perunica), while Sactorthoceras itself is also indicative of relationships with Baltica and the Sino-Korean Plate.     

Discosorids and Oncocerids (Cephalopoda) of the Middle Ordovician Kunda and Aseri Regional Stages of Baltoscandia and the early evolution of these groups

Discosorid and oncocerid cephalopods of the Kunda and Aseri Regional Stage (Darriwilian, Middle Ordovician) from Öland Island, Sweden and North Estonia are described for the first time. We demonstrate that a high generic and specific diversity of Oncocerida was already established in the earliest Darriwilian. The new oncocerid species Neumatoceras borense nov. sp., N. breviborense nov. sp., Paramiamoceras breviventrum nov. sp., Richardsonoceras gastroscopium nov. sp., R. gerhardi nov. sp., R. goldmanni nov. sp., R. haelluddenense nov. sp., Richardsonoceroides kingi nov. sp., R. oelandense nov. sp., and R. rhytium nov. sp. are erected; Richardsonoceroides schiefferdeckeri (Dewitz) is revised. The new graciloceratid Kundoceras evansi nov. gen., nov. sp. is erected. A review of records of early oncocerids from China shows that Richardsonoceras Foerste is probably the most primitive oncocerid and supports the hypothesis that oncocerids evolved in the early Floian or latest Tremadocian from a Bassleroceras Ulrich and Foerste-like ancestor. The new discosorid genus Paldoceras nov. gen. and species Paldoceras paldiskense nov. sp. and P. neptunsakerense nov. sp. are erected. These discosorids record the morphological link between the late Darriwilian Ruedemannoceras Flower and the early Floian Apocrinoceras Teichert and Glenister, which is considered to be the earliest discosorid.     

Heckerocrinus, a new substitute generic name for fossil crinoid Bockia Hecker 1940 (Echinodermata: Crinoidea) non Reisinger 1924 (Vermes: Turbellaria)

Heckerocrinus nom. nov., a new generic name of fossil Ordovician crinoid, is proposed for preoccupied fossil generic name Bockia Hecker 1940 non Reisinger 1924 [Vermes: Turbellaria??Typhloplanidae-Protoplanellinae]. Illegitimate family name Bockiidae Ubaghs 1972 is replaced with a new valid family name Heckerocrinidae nom. nov.     

‘Cambrian’ demosponges in the Ordovician of Morocco: Insights into the early evolutionary history of sponges

Cambrian spicular sponge faunas are dominated by a distinctive assemblage of demosponges and hexactinellids that are known from Burgess shale-type faunas worldwide. Most of these are previously unknown outside the Lower-Middle Cambrian (and perhaps Tremadoc) and have no obvious close relatives in later sequences. This paper describes examples of Choia sp., Pirania auraeum sp. nov. and Hamptonia christi sp. nov. from the Arenig of Morocco, associated with isolated hexactinellid spicules. A summary of the stratigraphic ranges of the major Cambrian sponge lineages is provided. These indicate an environmental contrast in the Lower Palaeozoic evolution of hexactinellids and non-lithistid demosponges, with demosponges probably undergoing cryptic diversification in nearshore environments during the Upper Ordovician.     

Cryptostomid Bryozoans From The Sassito Formation,Upper Ordovician Cool‐Water Carbonates of the Argentinean Precordillera

Abstract: Two new bryozoan species are described from the Upper Ordovician Sassito Formation of the Argentinean Precordillera: Moyerella  spinata sp. nov. and Phylloporina  sassitoensis sp. nov. The bryozoans are found in cool‐water carbonates. The Silurian genus Moyerella is reported the first time in the Ordovician, showing palaeobiogeographic connections with Estonia and Siberia.     

New brachiopod subfamily Anechophragmiinae (Strophomenida) from the Ordovician of the Leningrad Region

A new strophomenid subfamily Anechophragmiidae is distinguished based on the peculiarities of cardinalia. The strophomenids of this subfamily lack cardinal process at all developmental stages; their socket ridges accrete and form a high plate, which closes the pedicle opening. Two genera are referred to the subfamily: Anechophragma Neuman, 1976 and Biseptata gen. nov. with new species B. briani sp. nov. from the Ordovician of the Leningrad Region. The shell structure, exterior, endoskeleton and ontogeny of A. rarum and B. briani were studied in detail due to the excellent preservation of the material. Two species are referred to Anechophragma: A. rarum Neuman, 1976 and A. alexandrae (Andreev, 1993).     

Morphogenesis,phylogenetic relationships,and distribution of the bryozoans of the genus <Emphasis Type="Italic">Orbipora</Emphasis> Eichwald, 1856 (order Trepostomida)

Five species of the genus Orbipora, including two new species, O. lynnensis sp. nov. and O. ukhakuensis sp. nov., are described from the Middle Ordovician of the Leningrad Region and Estonia. The colonies of the species O. acanthophora Bassler, 1911 and O. solida Bassler, 1911 are measured and figured for the first time. The stratigraphic range and geographic distribution of O. acanthophora are refined. A scheme of possible phylogenetic relationships and distribution maps of the species of the genus are presented.     

First procolophonid (Reptilia,Parareptilia) from the Lower Triassic of Madagascar

Lasasaurus beltanae nov. gen. nov. sp., a new procolophonid (Reptilia, Parareptilia) from the Lower Triassic of Madagascar, is represented by a single partial skeleton preserved in a ferro-calcareous nodule from the Middle Sakamena Formation, in the North of the island. This new taxon is unique in possessing peculiar, fine and dendritic crests running along the posterolateral side of the squamosal, widely spaced maxillary teeth, subparallel mesiodistal ridges connecting maxillary teeth to the tooth row, and a strongly acute anterior margin of the copula (hyoid bone). This well-preserved specimen belongs to a juvenile individual. The inclusion of L. beltanae nov. gen. nov. sp. in a phylogenetic analysis suggests that it is close to Theledectinae, Procolophoninae, and Leptopleurinae, though their respective relationships are uncertain. This specimen is the first procolophonid described from Madagascar and represents a minor terrestrial component of a coastal vertebrate assemblage dominated by amphibious to fully-aquatic taxa.     

Scotiadiscus nom. nov., a replacement name forActinodiscus Smith & Paul, 1982 (Cyclocystoidea), preoccupied byActinodiscus de Blainville, 1830 (Anthozoa)

A replacement name,Scotiadiscus nom. nov., is proposed for the Ordovician cyclocystoid genusActinodiscus Smith & Paul, 1982 (Echinodermata). The name was preoccupied byActinodiscus de Blainville, 1830 (Anthozoa).     

New data on osteostracans (Agnatha) from the Lower Devonian of the Severnaya Zemlya Archipelago

The osteostracans Reticulaspis menneri gen. et sp. nov. and Nucleaspis unica gen. et sp. nov. from the Lower Devonian Severnaya Zemlya Formation of October Revolution Island of the Severnaya Zemlya Archipelago are described. The perfect preservation of the exoskeleton structure of Reticulaspis menneri allows the design and growth mode of the exoskeleton, with a continuous reticular dental surface of the cephalothoracic shield to be characterized. Nucleaspis unica is represented by a juvenile stage, which is extremely scarce in this vertebrate group. The preoccupied generic name Ungulaspis Afanassieva et Karatajūt?-Talimaa, 1998 is replaced by Paraungulaspis.