bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biogeography of Ordovician sponges
Authors: Carrera Marcelo G. , Rigby J. Keith 
Published: August 2016

Sponges have an unrealized potential importance in biogeographic analysis. Biogeographic patterns determined from our analysis of all published data on distribution of Ordovician genera indicate Early Ordovician sponge faunas have relatively low diversity and are completely dominated by demosponges. Early Ordovician (Ibexian) faunas are characterized by the widespread co-occurrence ofArchaeoscyphiaand the problematicCalathium.This association is commonly found in biohermal structures. Middle Ordovician faunas show an increase in diversity, and two broad associations are differentiated: Appalachian faunas (including Southern China and the Argentine Precordillera) and Great Basin faunas.Late Ordovician faunas show important changes in diversity and provincialism. Hexactinellid and calcareous sponges became important and new demosponge families appeared. Four Mohawkian-Cincinnatian associations are recognized here, including: 1) Midcontinent faunas; 2) Baltic faunas; 3) New South Wales faunas; and 4) Western North American (California and Alaska) faunas. However, two separate biogeographic associations are differentiated based on faunal differences. These are a Pacific association (western North American and New South Wales) and an Atlantic association (Midcontinent Laurentia and Baltica).Distribution of sponge genera and migration patterns are utilized to consider paleogeographic dispositions of the different continental plates, climatic features, and oceanic currents. Such an analysis points to close paleogeographic affinities between the Argentine Precordillera and Laurentian Appalachian faunas. However, significant endemicity and the occurrence of extra-Laurentian genera suggest a relative isolation of the Precordillera terrane during the Late Ibexian-Whiterockian. The study also shows a faunal migration from the Appalachian region to South China during the Middle Ordovician and the migration of faunas from Baltica to Laurentia in the Late Ordovician. The occurrence of Laurentian migrants in New South Wales during the Late Ordovician could be related to inferred oceanic current circulation between these two areas, although other paleogeographic features may be involved.
Crinoids and stelleroids (Echinodermata) from the Broken Rib Member, Dyer Formation (Late Devonian, Famennian) of the White River Plateau, Colorado
Authors: Webster Gary D. , Hafley Daniel J. , Blake Daniel B. , Glass Alexander 
Published: August 2016

A crinoid and stelleroid fauna is described from the Famennian (Late Devonian) Broken Rib Member of the Dyer Formation of the White River Plateau, Colorado. The fauna postdates the Late Devonian extinction event. Six new crinoid species described, including the new genusTarassocrinus, are:Strimplecrinus dyerensis, Catactocrinus?torus, Hypselocrinus?bisonensis, Gilmocrinus?albus, Eireocrinus?coloradoensis, andTarassocrinus synchlydus.The cladid-dominated crinoid fauna is transitional between earlier Devonian and later Carboniferous faunas. It contains the first report ofCupressocrinites(a Famennian Lazarus taxon) andEireocrinus? in North America and extends ranges of several Carboniferous genera into the Late Devonian. A preliminary revision of the Rhenocrinidae is recommended. The family Glossocrinidae is recognized, and the Cupressocrinitidae are transferred to the Gasterocomacea.A new stelleroid genus and species,Pleiadeaster inceptus(Asteroidea; family unknown), and an ophiuroid,Ophiopolytretus aethus(Ophiuroidea; Lapworthuridae?) are named. In addition,Hudsonaster(Hudsonasteridae; Asteroidea) and two unassigned asteroids are present, and three further stelleroids cannot be assigned to the class level.PleiadeasterandHudsonasterare important because they suggest that the Late Devonian might have been a time of transition for asteroids.Ophiopolytretus aethusis an oegophiurid ophiuroid with distinctive respiratory? pores penetrating the disk plates.
Tabulaconus Handfield: microstructure and its implication in the taxonomy of primitive corals
Authors: Debrenne Francoise M. , Gangloff Roland A. , Lafuste Jean G. 
Published: August 2016

Numerous specimens of Tabulaconus Handfield, 1969, have been collected in carbonate buildups within the Adams Argillite (Early Cambrian, Tatonduk area, Alaska). The wall structure of this form has been investigated, along with contemporaneous archaeocyaths and algae, through the use of polished ultra-thin sections (2–3 μm thick) and scanning electron microscopy. The results of this microstructural comparison indicate that despite diagenetic alteration Tabulaconus has a skeleton that is unlike any presently known and is quite distinct from associated algae or archaeocyaths. It is more elaborate than that found in the archaeocyaths but has not reached the stage of complexity seen in the primitive coral Cothonion Jell and Jell, 1976. The presence of some elongated units may represent an initial step towards the fibrous skeleton typical of Paleozoic corals.This study shows that even though diagenesis alters the original microstructure of calcareous skeletons, the resultant fabrics and detailed structures can be useful in systematic descriptions.Tabulaconus is removed from the Gastroconidae Kordae due to the presence of rudimentary septa and constitution of the tabularium. A number of species assigned to the genus Bačatocyathus Vologdin and included within the Archaeocyatha appear to be examples of Tabulaconus or very close relatives. An emended description of Tabulaconus kordae, the type species, is proposed.
Gyrodiform gastropods from the Pacific Coast Cretaceous and Paleocene
Authors: Popenoe W. P. , Saul L. R. , Susuki Takeo 
Published: August 2016

Seven previously described and seven new taxa of gyrodiform naticoids from West Coast Late Cretaceous–Paleocene age strata are discussed. Gyrodes (Gyrodes) dowelli White of Turonian age is a typical Gyrodes; G. robustus Waring from the Paleocene has the shape of Gyrodes s.s. but lacks the crenulations. G. greeni Murphy and Rodda, G. yolensis n. sp., G. quercus n. sp., G. banites n. sp., G. canadensis Whiteaves, G. pacificus n. sp., and G. expansus Gabb comprise the new subgenus Sohlella, which thus ranges from Cenomanian through Maastrichtian. Gyrodes robsauli n. sp. resembles “Polinices” (Hypterita) helicoides (Gray), and Hypterita is reassigned to the Gyrodinae as a subgenus of Gyrodes. Gyrodes onensis n. sp. of Albian age is similar to the G. americanus group of Sohl (1960). Three texa—Natica allisoni (Murphy and Rodda) of Cenomanian age and N. conradiana Gabb and N. conradiana vacculae n. subsp. of Turonian age—which have all been previously considered to be Gyrodes are placed in Natica. Well marked relict color patterns on N. conradiana and N. conradiana vacculae suggest that these naticids from northern California and southern British Columbia were tropical forms.Diversity of taxa and size of specimens are reduced at the end of the Turonian, suggesting a change in West Coast marine conditions at that time.
Trace fossils and regional significance of a Middle Devonian (Givetian) disconformity in southwestern Ontario
Authors: Landing Ed , Brett Carlton E. 
Published: August 2016

The Hungry Hollow Formation on the southeastern margin of the Michigan Basin is interpreted as a composite stratigraphic unit representing the lateral equivalents of two depositional cycles in the northern Appalachian Basin. The basal beds (? = Pompey and upper Levanna transgressive hemicycle of the upper Skaneateles Formation in New York) are separated by disconformity surfaces both from the underlying Arkona Shale and from the upper part of the Hungry Hollow (= upper part of Centerfield Limestone Member). These basal beds were deposited on eroded, overcompacted claystones of the Arkona Shale, contain a diverse suite of remanie sediments, and fill deep, delicately sculpted furrows of Cruziana transversa n. ichnosp., C. reticulata n. ichnosp., and Rusophycus bilobatum (Vanuxem, 1842). This lower disconformity may be recognizable regionally over the Northern Midcontinent. Overlying beds feature the lowest local occurrence of an offshore-aspect conodont fauna of the lower Polygnathus varcus Subzone. The underlying Arkona Shale yields Icriodus-dominated (nearer-shore aspect) faunas apparently representing Polygnathus xylus ensensis Zone assemblages. The upper part of the Hungry Hollow Formation and overlying lower part of the Widder Formation represent an offlap-onlap cycle within the lower Polygnathus varcus Subzone that is comparable to that of the upper part of the Centerfield Limestone.Cruziana and Rusophycus from the Hungry Hollow were not originally produced as “under-tracks” but were formed at the sediment–water interface on erosion-resistant, overconsolidated muds. The producer of Cruziana reticulata n. ichnosp. appeared in the benthic community of the field area before the excavator of C. transversa n. ichnosp. and of Rusophycus bilobatum (possibly the trilobite Dipleura). The degree of limb swing required to produce the reticulate scratch patterns in C. reticulata n. ichnosp. suggests the evolution of specialized coxa-sternite and inter-podomere hinges that were not previously considered to be present in trilobites. Comparable reticulate scratch patterns occur as early as the earliest Cambrian and are apparently related to excavation on disconformity-related mud firmgrounds.
Brassfield Compsocrinina (Lower Silurian crinoids) from Ohio
Authors: Ausich William I. 
Published: August 2016

Four compsocrinine camerate crinoids are described from the Lower Silurian Brassfield Formation of southwestern Ohio. These late early or early middle Llandoverian crinoids are assigned to the Periechocrinidae and include Tirocrinus trochos n. gen. and sp., Ibanocrinus petalos n. gen. and sp., Acacocrinus anebos n. sp., and the taxon Dimerocrinites? vagans Foerste, herein referred to periechocrinid incertae sedis.These Brassfield forms are the oldest known members of the Periechocrinacea and Periechocrinidae. Diagnoses of these supergeneric concepts are broadened to include the morphologic variability embodied within the Brassfield forms but not otherwise present in later periechocrinaceans.
Impact of two sequential Pacific hurricanes on sub-rubble cryptic corals: the possible role of cryptic organisms in maintenance of coral reef communities
Authors: Kobluk David R. , Lysenko Mary A. 
Published: August 2016

The hermatypic scleractinian cryptic coral biota living under mobile rubble in the reef flat and back reef zones of a Fijian fringing reef was surveyed in detail in August of 1984; only 138 days later the reef was struck by the first of two sequential hurricanes (57 days apart). The same sample areas were re-studied in August 1985, thereby providing the first detailed census of pre- and post-hurricane cryptic reef coral populations, and allowing an assessment of hurricane impact on these populations.The 61 cryptic species (60 corals andMillepora) show 88 percent commonality with the intertidal and shallow subtidal reef surface coral population (68 species), and therefore are a good representation of the surface biota.A major effect of the hurricanes was a reduction of almost 50 percent in the number of boulders sheltering cryptic coral. However, among boulders that retained coral through the storms, there was only a 5 percent reduction in the mean number of corals per boulder, signifying that damage to the surviving population was minor. The composition of the surviving cryptic coral population is essentially unchanged from its pre-hurricane state (there are differences in absolute abundances), and the relative importance of the species does not show marked change in most cases. Coral morphologies show little change in their absolute and relative percent abundances after the hurricanes. In contrast to what is normally seen in reef surface habitats, therefore, coral colony form did not appear to be an important determinant in survivability for those living under boulders; primary selection by the storms seems to have been on boulder form rather than cryptic coral form.Cryptic sub-rubble coral populations may function as a preserve for elements of the pre-hurricane reef surface community. For example, delicately-branching forms that are commonly devastated in reef surface habitats during hurricanes may, in some cases, be preserved in great numbers under boulders or in other cryptic habitats. This provides a “recruitment pool” that can greatly accelerate their recovery and re-establishment on the post-hurricane reef surface, and dampen the potentially severe community dislocations arising from intense competition for space in “instantaneous” new reef substrate.
Blastoids from the late Osagean Fort Payne Formation (Kentucky and Tennessee)
Authors: Ausich William I. , Meyer David L. 
Published: August 2016

A largely new, Early Mississippian blastoid fauna is described from the Fort Payne Formation of south-central Kentucky and north-central Tennessee. The fauna consists of nine species assigned to eight genera, including four new genera and six new species. The fauna includes Hadroblastus breimeri n. sp., Granatocrinus granulatus (Roemer), Dentiblastus macurdai n. sp., Deliablastus cumberlandensis n. gen. and sp., D. tribulosus n. gen. and sp., Xyeleblastus magnificus n. gen. and sp., Perittoblastus liratus n. gen. and sp., Euryoblastus veryi (Rowley) n. gen., and an unidentifiable basal circlet that may represent a phaenoschismatidid. All spiraculates belong to the Granatocrinidae.The Fort Payne Formation has the most diverse blastoid fauna known between the middle Osagean blastoid extinction and the Permian. Diversification immediately after the middle Osagean extinction is recorded in the Fort Payne and is largely a diversification of the Granatocrinidae.Orbitremites grandis Rowley (1902) is an internal mold from the Fort Payne Formation. This specimen cannot be identified and is designated as a nomen dubium.
The genus Glyptospira (Gastropoda: Trochacea) from the Permian of the southwestern United States
Authors: Erwin Douglas H. 
Published: August 2016

Glyptospira is a small, highly ornamented, turriteliform gastropod found in the Lower Permian of the southwestern United States. Two species, Glyptospira cristulata Chronic and G. arelela Plas, have been previously described from the Kaibab Formation, Arizona, and the Bird Spring Group, Arrow Canyon Range, Nevada, respectively. The genus is most diverse in the Wolfcampian Hueco Formation of West Texas and southern New Mexico and the Colina Limestone of southeastern Arizona. This contribution describes four new species of Glyptospira from the southwestern United States: two bicarinate forms, G. huecoensis and G. turrita, and two tricarinate forms, G. tricostata and G. cingulata.A phylogenetic analysis of all known species of Glyptospira was performed using qualitative characters for which transformation series could be established and two quantitative characters for which transformation series could not be established. The phylogenetic results provided the best available hypothesis of the evolutionary history of the genus.
Uppermost Precambrian(?)–Lower Cambrian of mainland Nova Scotia: faunas, depositional environments, and stratigraphic revision
Authors: Landing Ed , Murphy J. Brendan 
Published: August 2016

The uppermost Precambrian(?)–Lower Cambrian of the Avalon Zone in the northern Antigonish Highlands is composed of two dissimilar sequences in thrust contact. These include the sandstones and slates of the Doctor's Brook allochthon and the volcanoclastic-rich Malignant Cove authochthon.Lithostratigraphy of the “Black John Formation” (designation abandoned) in the Doctor's Brook allochthon is comparable to the uppermost Precambrian–Lower Cambrian in eastern Placentia Bay, southeastern Newfoundland, and Cape Breton Island. A unified stratigraphic nomenclature is appropriate in these Avalonian areas. The lower part of the “Black John” is an unconformity-bounded depositional sequence with subaerial rift facies (Rencontre Formation, 178+ m), overlying marine siliciclastic mudstones and fine sandstones (Chapel Island Formation, 59 m), and a quartzite cap (Random Formation, 2.05 m). The Chapel Island Formation has the oldest faunas from mainland Nova Scotia (Watsonella crosbyiZone, lower Placentian Series). A post-Random unconformity known in Newfoundland and Cape Breton Island lies at the Random-Bonavista Group (Cuslett Formation) contact in the upper “Black John Formation.”Fossiliferous Lower Cambrian limestones and siliciclastic mudstones previously reported from the Malignant Cove autochthon are actually clasts in basalt pebble-dominated slope deposits of the Arbuckle Brook Formation. These clasts were eroded from shallow-marine facies comparable to those in the Doctor's Brook allochthon during local uplift associated with Middle Cambrian(?) extension and mafic volcanism.Eight species are illustrated from the Placentian and Branchian Series.AnabaritellusMissarzhevsky, 1974, emend. (=SelindeochreaValkov, 1982) is a Lower Cambrian calcareous tube-dwelling metazoan(?) known from tri- through multisulcate conchs that are morphologically intermediate betweenAnabaritesandColeoloides.
Three additional thalamid sponges from the Upper Permian reefs of Djebel Tebaga (Tunisia)
Authors: Senowbari-Daryan Baba , Rigby J. Keith 
Published: August 2016

Three more thalamid sponge species are described from Upper Permian reefs of Djebel Tebaga, Tunisia. Intrasporeocoelia hubeiensis Fan and Zhang, 1985, Rhabdactinia depressa Rigby, Fan, and Zhang, 1989, and Glomocystospongia gracilis Rigby, Fan, and Zhang, 1989, are now known from a few Tunisian specimens.Monaxon spicules are common within the rigid, diagenetically altered, aragonitic skeleton of Glomocystospongia gracilis Rigby, Fan, and Zhang, 1989. Spicules are common as vertical elements in walls of tubes between the vertical series of cyst-like chambers and less common in the chamber walls where they are parallel to the tube walls but project out into the chambers.Intrasporeocoelia has been reported from Permian rocks of the Sosio Valley in Sicily, and therefore from the Western Tethys. However, the species of Rhabdactinia and Glomocystospongia reported here have been known, until now, only from the Permian of China; thus, the Djebel Tebaga locality in southern Tunisia represents the first known occurrence of these latter sponges in the Western Tethyan realm.Two additional specimens of Tristratocoelia rhythmica Senowbari-Daryan and Rigby, 1988, have also been found. They allow further definition of characteristics of this sponge, which was initially described from a single specimen from Djebel Tebaga.
Automobility in Tabulata, Rugosa, and extant scleractinian analogues: Stratigraphic and paleogeographic distribution of Paleozoic mobile corals
Authors: Plusquellec Yves , Webb Gregory E. , Hoeksema Bert W. 
Published: August 2016

Freeliving corals capable of automobility (e.g., lateral migration) were rare during Paleozoic time, but some species within the tabulate generaProcterodictyum, Procteria(Granulidictyum),P.(Pachyprocteria),PalaeacisandSmythina, and the rugose generaCombophyllum, andBaryphyllum, have morphologic characters that suggest they were capable of such self-directed movement. The rugose coralsGymnophyllumandHadrophyllum, sensu stricto may have exhumed and righted themselves. No single morphological character is diagnostic for an automobile habit, but the following characters appear to be important indicators: 1) lack of an external attachment surface; 2) concentric skeletal accretion; 3) discoid corallum shape; 4) concavo-convex, plano-convex, and, less commonly, biconvex corallum profile; and 5) small, lightweight corallum. Additionally, the occurrence of corallites on the base of the corallum (hypocorallites) is a good indicator of automobility in freeliving corals, but the character is so far known only inProcterodictyum.All known fossil automobile taxa appear to have inhabited relatively quiet environments on muddy or silty, soft substrates.The earliest known automobile corals were early Emsian (Devonian)Procterodictyum.Paleozoic automobile corals were most abundant during Devonian time, withProcterodictyum, Procteria(Granulidictyum), andCombophyllumdistributed in a narrow longitudinal band in the southern hemisphere on both sides of the Rheic Ocean. Carboniferous and Permian automobile taxa (Palaeacispartim,SmythinaandBaryphyllum) were less diverse, but more cosmopolitan. Throughout Paleozoic time, the vast majority of automobile corals was confined to within 40 degrees of the paleoequator. However, additional research will be required before coral automobility can be used to constrain paleolatitude independently.
Redescription ofAlokistocare subcoronatum(Hall and Whitfield, 1877), the type species ofAlokistocare, and the status of Alokistocaridae Resser, 1939B (Ptychopariida: Trilobita, Middle Cambrian)
Authors: Sundberg Frederick A. 
Published: August 2016

Alokistocare subcoronatum(Hall and Whitfield, 1877) is the type species ofAlokistocareLorenz, 1906, the nominal genus for the diverse Middle Cambrian Alokistocaridae Resser, 1939b. New collections from theEhmaniellaBiozone contain cranidia, librigenae, hypostomes, rostral plates, thoracic segments, and pygidia, which allow a more complete understanding of the morphological range and character of this important species.Cladistic analyses using this new information aboutA. subcoronatumsuggest that: 1) Ehmaniellidae Sundberg, 1994, is synonymous with Alokistocaridae; 2) Alokistocaridae is a monophylectic clade and not synonymous with Papyriaspididae Whitehouse, 1939; 3)PseudoalokistocareSundberg, 1994, is synonymous withAlokistocare; and 4) Taxa previously assigned to the older“Alokistocare”/Amecephalusgroup (PlagiuratoGlossopleurabiochrons) form a separate clade and should not be included inAlokistocareor the Alokistocaridae. These older species are assigned toAmecephalusWalcott, 1924, which is restricted to the Delamaran Stage. Alokistocaridae as recognized here is restricted to the Marjuman Stage.A morphometric analysis ofAlokistocare subcoronatumshows minor but significant differences among collections, indicating population differences. In addition, the cranidium displays both positive and negative allometric growth as well as isometric growth. Allometric growth is present in both meraspid and holaspid stages. The pygidium shows only isometric growth.