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Silty noduliferous shales in the lower part of the Middle Ordovician (late Darriwilian 2) Taddrist Formation in the central Moroccan Anti-Atlas contain a unique assemblage of conulariids consisting of one species each of Archaeoconularia Bouček, 1939, Glyptoconularia Sinclair, 1952, and Pseudoconularia Bouček, 1939. Glyptoconularia antiatlasica new species, currently represented by a single three-dimensional specimen, is the first member of this extremely rare, highly autapomorphic genus to be described from outside of cratonic North America as well as the first Glyptoconularia from the Middle Ordovician. Pseudoconularia cf. P. grandissima (Barrande, 1867) and Archaeoconularia cf. A. exquisita (Barrande, 1867) most closely resemble species previously described from Middle and Upper Ordovician strata in the Prague Basin (Czech Republic), then located adjacent to North Africa. Anaconularia anomala (Barrande, 1867), previously known from the Upper Ordovician (Sandbian) Libeň and Letná formations in the Prague Basin, is documented for the first time from the Upper Ordovician (Katian) Upper Tioririne Formation of Morocco. In addition to extending the known stratigraphical and paleogeographical ranges of these conulariids, results of the present investigation add to the list of invertebrate taxa that appear to have originated during Early or Mid-Ordovician times in peri-Gondwana or south-polar Gondwana, and then migrated to the eastern margin of Laurentia, arriving there along with other cool-water taxa during the Sandbian-Katian transition. UUID: http://zoobank.org/9ea5051b-cff5-4911-861a-531db4f45883 [ABSTRACT FROM AUTHOR]

The record of Middle Ordovician (Oretanian, ca. Darriwilian 2) hyolithids from the Ossa Morena Zone of the Iberian Massif in southwestern Spain is increased with the recognition of Robardetlites sevillanus n. gen. n. sp., Andalucilites parvulus n. gen. n. sp., Pauxillites desolatus n. sp., Leolites malinkyi Marek and Gutiérrez-Marco n. sp., and Cavernolites sp. in that region. Andalucilites n. gen. and Robardetlites n. gen. are endemic whereas the other genera are known from coeval strata in the Barrandian region in central Europe, France, and Morocco, giving this assemblage a decidedly "Mediterranean province" character. The discovery of Pauxillites, Leolites, and Cavernolites in Iberia extends their geographic ranges to that region, and Leolites from this area extends its stratigraphic range downward, making its occurrence in Iberia the oldest known for that genus. UUID: http://zoobank.org/f5b29223-6dac-4c7e-8851-551e634da667 [ABSTRACT FROM AUTHOR]

Phragmolites lissoni new species is described from 11 specimens found in the Sandbian Calapuja Formation near Calapuja in Peru. The deposits are part of the Central Andean Basin. This is the hitherto only systematically described Ordovician gastropod from Peru. The species is from a brachiopod-dominated siliciclastic sequence and is associated with bryozoans. Most specimens are preserved as external molds, but latex casts yield excellent details of shell ornamentation and are used as a basis for evaluating this feature in the genus. The characteristic ornamentation of Phragmolites should be called corrugated lamellae, and the individual elements on these should be referred to as flutes. A descriptive terminology for these is suggested. The development and shape of the corrugated lamellae and flutes could be biomechanical process. A second component in lamellar formation is the alternation between regular incremental growth and formation of a lamella. Phragmolites is mainly found in shallow-water carbonate facies from tropical latitudes in the Sandbian and a mid-latitude presence in Peru is unexpected. Brachiopods from the same section in Calapuja show affinities with faunas of the Mediterranean margin of Gondwana but also weak links with Avalonia. Phragmolites is found abundantly in deeper-water facies in Laurentia, and a broad tolerance to facies and temperature and possible planktotrophy might have allowed a wide geographical dispersal of the genus. The scant record of Ordovician gastropods in the Central Andean Basin precludes comparison with the disparate record of the Ordovician gastropod taxa from the Precordillera, which do not include Phragmolites. UUID: http://zoobank.org/References/fbd7a43e-a610-42fd-a31d-b1a16fa69c9b [ABSTRACT FROM AUTHOR]

The order Intejocerida is an enigmatic, short-lived cephalopod taxon known previously only from Early–Middle Ordovician beds of Siberia and the United States. Here we report a new genus, Cabaneroceras, and a new species, C. aznari, from Middle Ordovician strata of central Spain. This finding widens the paleogeographic range of the order toward high-paleolatitudinal areas of peri-Gondwana. A curved conch, characteristic for the new genus, was previously unknown from members of the Intejocerida. UUID: http://zoobank.org/21f0a09c-5265-4d29-824b-6b105d36b791 [ABSTRACT FROM AUTHOR]

An Ordovician–Silurian boundary section marked by an uninterrupted, relatively high rate of black shale sedimentation and abundant, diverse graptolites is described from the south-central Pyrenees. The structurally simple Estana section comprises the uppermost part of the quartzite-dominated Bar Formation and overlying black shales of late Hirnantian and early Rhuddanian age, which have been dated by graptolites to the upper Metabolograptus persculptus and lower–middle Akidograptus ascensus–Parakidograptus acuminatus biozones. Due to the absence of M. persculptus , a Metabolograptus parvulus Biozone correlative with the upper part of the persculptus Biozone is recognized below the lowest occurrence of akidograptids, which indicate the base of the Silurian System. The graptolite fauna comprise 27 species including Normalograptus minor , N. lubricus , N. rhizinus , Hirsutograptus , Korenograptus bifurcus , K. bicaudatus, K. lanpherei and Nd. shanchongensis , most of which were formerly considered to be endemic to the low-latitude palaeobiogeographical province of China, Siberia and northern North America. Two new species, N. baridaensis and N. ednae , are described. The succession of graptolite assemblages in the Estana section, and occurrence of several cosmopolitan taxa in its parvulus and lower ascensus – acuminatus biozones that are unknown elsewhere in peri-Gondwanan Europe, suggest that strata immediately surrounding the Ordovician–Silurian boundary may be absent, highly condensed or oxic and barren of graptolites in other sections of northwestern peri-Gondwana. Common graptolite synrhabdosomes and abnormal rhabdosomes may indicate some environmental stress in the parvulus Biozone, although the rather uniform black shale lithology, total organic carbon content and δ 13Corg values suggest uninterrupted sedimentation under stable, anoxic conditions. [ABSTRACT FROM AUTHOR]

The end-Ordovician mass extinction, linked to a major glaciation, led to deep changes in Hirnantian–Rhuddanian biotas. The Hirnantia Fauna, the first of two Hirnantian survival brachiopod-dominated communities, characterizes the lower–mid Hirnantian deposits globally, and its distribution is essential to understand how the extinction took place. In this paper, we describe, illustrate, and discuss the first macrofossiliferous Hirnantia Fauna assemblage from Belgium, occurring in the Tihange Member of the Fosses Formation at Tihange (Huy), within the Central Condroz Inlier. Six fossiliferous beds have yielded a low-diversity, brachiopod-dominated association. In addition to the brachiopods (Eostropheodonta hirnantensis, Plectothyrella crassicosta, Hirnantia sp., and Trucizetina? sp.), one trilobite (Mucronaspis sp.), four pelmatozoans (Xenocrinus sp., Cyclocharax [col.] paucicrenulatus, Conspectocrinus [col.] celticus, and Pentagonocyclicus [col.] sp.), three graptolites (Cystograptus ancestralis, Normalograptus normalis, and ?Metabolograptus sp.), together with indeterminate machaeridians and bryozoans were identified. The graptolite assemblage, from the Akidograptus ascensus-Parakidograptus acuminatus Biozone, indicates an early Rhuddanian (Silurian) age, and thus, an unexpectedly late occurrence of a typical Hirnantia Fauna. This Belgian association may represent an additional example of relict Hirnantia Fauna in the Silurian, sharing characteristics with the only other known from Rhuddanian rocks at Yewdale Beck (Lake District, England), although reworking has not been completely ruled out. The survival of these Hirnantian taxa into the Silurian might be linked to delayed post-glacial effects of rising temperature and sea-level, which may have favored the establishment of refugia in these two particular regions that were paleogeographically close during the Late Ordovician–early Silurian. [ABSTRACT FROM AUTHOR]