bluuebunny/crossref_metadata_2025 huggingface dataset:
Late Triassic thalamid sponges from Nevada
Authors: Senowbari-Daryan Baba , Stanley George D.
Published: August 2016

A study of Upper Triassic (Norian) thalamid sponges (“sphinctozoans”) from the Pilot Mountains, Garfield Hills, and East Range, Nevada, reveals an abundance of calcified sponges of the suborder Porata Seilacher. Two new species, Polycystocoelia silberlingi n. sp. and Neoguadalupia? norica n. sp., are added to our knowledge of five thalamid sponge taxa previously known from Nevada. All specimens have been neomorphically altered to calcite in a manner implying an original aragonite mineralogy.

At the species level, the sponges show a restricted distribution. Nevadathalamia cylindrica (Seilacher) is a species also occurring in Sonora, Mexico, and previously known from the Yukon of Canada, but all other species are endemic to west-central and northwestern Nevada. At the generic level, similarities exist with species known from the Tethyan Realm, the Yukon, and south China. The genus Polycystocoelia has been known previously only from Hubei, China, and from the Yukon Territory, Canada. Neoguadalupia was previously known only from the Lower and Upper Permian of China. The occurrence of this genus in Nevada constitutes the first record of the genus outside of the Permian System of China.
Yonginella, a new bivalve (Mollusca) from the Silurian of Gotland
Authors: Liljedahl Louis
Published: August 2016

A new bivalve, Yonginella amica n. gen. and sp., is described from the Silurian of Gotland. Although it has a straight hinge line with cardinal and lateral teeth indicating relationship with the Cyrtodontidae of the Arcoida, its external morphology (with a conspicuous diagonal ridge and sulcus) differs considerably from all previously described taxa of this group. Yonginella amica exhibits a shell shape suitable for soft muddy bottoms (“snowshoe” adaptation), and is interpreted to have been a nonsiphonate suspension feeder with a semi-infaunal, byssate mode of life.
Permian and Early(?) Triassic radiolarian faunas from the Grindstone terrane, central Oregon
Authors: Blome Charles D. , Reed K. M.
Published: August 2016

Moderately well preserved Permian (late Wolfcampian, Leonardian, Guadalupian, and Djulfian) and Early(?) Triassic radiolarian faunas from sedimentary mélange cherts of the Grindstone terrane in central Oregon are nearly identical to coeval chert faunas in Japan. These Permian faunas are similar to those used in constructing the radiolarian zonations for Japan and the Tethyan regions. Although several Oregon taxa have been reported from limestone sequences in the central United States, most of the Oregon forms have only been found in cherty rocks and nearly half have not previously been reported from North America. Forty-two taxa belonging to 19 genera (AlbaillellaDeflandre,DeflandrellaDe Wever and Caridroit,EntactiniaForeman,EntactinosphaeraForeman,FollicucullusOrmiston and Babcock,HaplentactiniaForeman,HegleriaNazarov and Ormiston,IshigaumDe Wever and Caridroit,KashiwaraSashida and Tonishi,LatentibifistulaNazarov and Ormiston,LatentifistulaNazarov and Ormiston,NazarovellaDe Wever and Caridroit,NeoalbaillellaTakemura and Nakaseko,ParentactiniaDumitrica,PraedeflandrellaKozur and Mostler,PseudoalbaillellaHoldsworth and Jones,PseudotormentusDe Wever and Caridroit,QuinqueremisNazarov and Ormiston, andTriplanospongosSashida and Tonishi) are systematically treated. Co-occurrences of some species in Oregon indicate that their ranges in North America may differ from those in Japan. This paper also contains the first illustrated record of Early(?) Triassic radiolarians from North America.
Two occurrences of the genusPictetia(Early Cretaceous, Albian, Ammonoidea) in California
Authors: Rodda Peter U. , Murphy Michael A.
Published: August 2016

Two specimens of the Cretaceous genusPictetiaUhlig, 1883, have been found in the Cottonwood District, northern California, the first record of this genus in North America. The larger specimen is a septate whorl fragment from theBrewericeras hulenensezone that is associated withDouvilleiceras mammillatum.It is identified asPictetiasp. The smaller specimen is a septate fragment of one and a half whorls from theOxytropidoceras packardizone associated withCleoniceras. It is identified with the type species,Pictetia astierianaOrbigny, 1842, previously recorded from Europe. A review of the genusPictetiasuggests that species assigned to the genus have an open coil with a rounded dorsum. The occurrences of these Tethyan elements in the Albian fauna of the Cottonwood District suggest easy communication for many Cretaceous taxa between northern California and the Tethyan realm of Europe, the Caucasus, and Madagascar.
Campanian ammonites from the Upper Cretaceous Gober Chalk of Lamar County, Texas
Authors: Cobban W. A. , Kennedy W. J.
Published: August 2016

The Roxton Limestone Member at the top of the Gober Chalk in northeast Texas yields a rich fauna, dominated byBaculites haresiReeside, 1927, andInoceramus balticusBoehm, 1909, with sparse occurrences ofPachydiscuscf.P. paulsoni(Young, 1963),Anapachydiscussp. juv.,Placenticeras placenta(DeKay, 1828),Hoplitoplacenticerasaff.H. plasticum(Paulcke, 1907),Menabites(Delawarella)delawarensis(Morton, 1830),M.(D.)danei(Young, 1963),M.(D.) aff.M.(D.)vanuxemi(Morton, 1830),Submortoniceras vandalinaenseYoung, 1963,Submortonicerassp.,Eubostrychocerassp., andScaphites hippocrepis(DeKay, 1828) III. The presence ofS. hippocrepisIII suggests a late early Campanian age assignment for the fauna. The assemblage includes species known from the Western Interior, Gulf Coast, Atlantic seaboard, and western Europe.
A new tube-builder hydractinian, symbiotic with hermit crabs, from the Cretaceous of Antarctica
Authors: Olivero Eduardo B. , Aguirre-Urreta Maria B.
Published: August 2016

An Upper Cretaceous (early Maastrichtian) tube-building hydractinian (Psammoactinia antarctica n. gen. and sp.) from Sanctuary Cliffs, Snow Hill Island, believed to live in association with hermit crabs, is described for the first time from Antarctica. Psammoactinia forms thick, concentric, globular colonies that encrust gastropod shells and extend the shell aperture by forming an open spiral tube. The colony consists of concentric layers with chambers and pillars made of silt and very fine sand grains agglutinated by collophane, which is interpreted as a diagenetic modification of an original chitinous phosphatic material. On the basis of the additional finding of isolated claws of pagurid crabs, assigned to Paguristes sp., the functional analysis of the hydractinian structure, and a comparison with modern and fossil analogous structures it is concluded that the peculiar hydractinian tube is a carcinoecium that housed a symbiotic hermit crab.

Paleoenvironmental and paleoecological inferences suggest that the Psammoactinia–Paguristes association is mainly controlled by a fine-grained substrate and by a lack of abundant gastropod shells of different sizes. These factors do not necessarily correlate with absolute water depth, and favorable environments could include either offshore, relatively deep water or shallow restricted depositional settings.
BranchingHeliophyllum(Devonian rugose corals) from New York and Ohio
Authors: Oliver William A. , Sorauf James E.
Published: August 2016

Solitary species ofHeliophyllumare the most common form of the genus but branching and massive colonies do occur, especially in Middle Devonian strata of eastern North America.Heliophyllum delicatumn. sp. offsets laterally and has a dendroid, broad bushy growth form. The species is known only from western and west-central New York and appears to be limited to the lower part of the Deep Run Shale Member of the Moscow Formation (middle Givetian); specimens are common within this restricted geographic and stratigraphic range. The skeleton ofH. delicatumwas poorly designed for the common coral environments of the Devonian, but seems to have been well adapted to muddy, carbonate-poor conditions where its thin skeletal elements required less calcium carbonate and its unsupported branches were not subject to vigorous water movement.

Heliophyllum stewartin. sp. is based on a single specimen from the Tenmile Creek Dolomite (middle Givetian) in northwestern Ohio. The colony is phaceloid but each branch is an astreoid cluster without walls between individual corallites. In addition, the apparent protocorallite is turbinate with a larger diameter than any of the ceratoid offsets although offset lengths are several times that of the protocorallite.
Arenig (Lower Ordovician) conodonts and biozonation in the eastern Siljan district, central Sweden
Authors: Löfgren Anita M.
Published: August 2016

Based on biostratigraphic investigations in the eastern Siljan district, central Sweden, and combined with earlier studies at Hunneberg, south-central Sweden, it is shown that the early post-Tremadoc-ageParoistodus proteusconodont Zone can be divided into four successive subzones. These are, in ascending order: theDrepanoistodusaff.D. amoenusSubzone; theTripodusSubzone; theParacordylodus gracilisSubzone; and theOelandodus elongatus-Acodus deltatus deltatusSubzone. The lowermost of the subzones is a concurrent range zone, with its reference section at Storeklev, Hunneberg, and the other three interval zones with the reference section at Sjurberg in the eastern Siljan district. Correlations between these two areas, as well as with the Flåsjö area, Jämtland, the Finngrundet core, and some other areas, are discussed, and it is concluded that theDrepanoistodusaff.D. amoenusSubzone and theTripodusSubzone together correspond to theMegistaspis(Ekeraspis)armatatrilobite Zone, and occur below theHunnegraptus copiosusgraptolite Zone. TheParacordylodus gracilisSubzone is equivalent with the lower part of theMegistaspis(Varvaspis)planilimbatatrilobite Zone, and may correspond to theHunnegraptus copiosusZone. The uppermost subzone, theOelandodus elongatus-Acodus deltatus deltatusSubzone, equals the upper part of theM.(V.)planilimbataZone, and the local base of theTetragraptus phyllograptoidesgraptolite Zone is close to the base of this conodont subzone. The last occurrences ofT. phyllograptoidesare close to the top of this conodont subzone. Also included in the investigation are the uppermost part of the uppermost TremadocPaltodus deltiferZone and the conodont zones overlying theP. proteusZone in the eastern Siljan district, thePrioniodus elegansZone and theOepikodus evaeZone; the latter zone corresponds to the trilobite zones ofMegalaspides(M.)dalecarlicusandMegistaspis(Varvaspis)estonica.A few samples from the superimposedBaltoniodus triangularis, B. navis, andParoistodus originalisZones have been investigated and are described as well. The correlation of these conodont zones and subzones with those of areas outside Baltoscandia, particularly North America, is also discussed.
Conodont paleoecology of the Lower Ordovician St. George Group, Port au Port Peninsula, western Newfoundland
Authors: Ji Zailiang , Barnes Christopher R.
Published: August 2016

The St. George Group in western Newfoundland is nearly 600 m thick and is subdivided into the Watts Bight, Boat Harbour, Catoche, and Aguathuna Formations. The group is a nearly complete Lower Ordovician succession representing about 15–20 m.y. The depositional environment of the St. George Group is represented by three main lithofacies (supratidal, peritidal, and subtidal), expressed as two first-order cycles and five second-order cycles.

In the study of St. George Group conodonts, over 70 multielement species are represented in 45,000 conodont specimens from 432 samples of 10 sections. Computer cluster analysis of most of those samples on the basis of similarity of conodont species was used to determine conodont community structure. Both the principal coordinate analysis (PCA) partitioning method and the agglomerative method (UPGMA with Bray-Curtis) were chosen for the statistical analysis. The four lithological formations and five secondary lithological cycles in the St. George Group emerge as distinct entities when the samples are clustered together on the basis of conodont data for analysis of first-order and second-order variations in community composition.

Two deeper water, five shallow-water, and five intermediate communities through this time interval are recognized. The majority of conodonts from these communities are of Midcontinent Realm affinities, but some species represent strong North Atlantic Realm influxes during the transgressive periods.
The conodont genus Ancyrodella in the middle Genesee Formation (lower Upper Devonian, Frasnian), western New York
Authors: Kralick James A.
Published: August 2016

Conodont faunas with species of Ancyrodella are described from the upper Penn Yan Shale (Crosby Sandstone) and Genundewa Limestone of the middle Genesee Formation between Keuka Lake and Lake Erie. Three established species and three new species in the early phylogeny of Ancyrodella are discussed: A. rotundiloba (Bryant) early form, A. rotundiloba late form, A. crosbiensis n. sp., A. recta n. sp., A. triangulata n. sp., A. rugosa Branson and Mehl, and A. alata? Glenister and Klapper. Standardization of the taxonomic concepts pertaining to these species (and others in the genus) is necessary to ensure their continued biostratigraphic usefulness. The sequence of faunas in New York correlates well with the lower Frasnian sequence and numbered conodont zones described by Klapper (1985, 1989) in the Montagne Noire, France. A fauna with the late form of Ancyrodella rotundiloba and A. crosbiensis n. sp. in the Crosby Sandstone of the upper Penn Yan Shale correlates with Zone 2 of Klapper (1989). The Crosby fauna succeeds a Zone 1 fauna with the early form of Ancyrodella rotundiloba in the lower Penn Yan Shale. The Crosby fauna is succeeded in turn by a fauna in the upper Genundewa Limestone with A. recta n. sp., A. triangulata n. sp., A. rugosa, and A. alata?, which is correlated with Zone 3 even though the zonal markers, A. alata sensu stricto and typical forms of A. rugosa, first occur in the lower part of the overlying West River Shale.
Phycosiphon incertum revisited: Anconichnus horizontalis is its junior subjective synonym
Authors: Wetzel Andreas , Bromley Richard G.
Published: August 2016

Comparisons between Phycosiphon incertum Fischer-Ooster (1858) and Anconichnus horizontalis Kern (1978) show that these two monotypic ichnogenera do not differ significantly in geometry, size, sediment fill, and environmental occurrence. Therefore, taxonomic priority has to be given to Phycosiphon and Anconichnus becomes a subjective junior synonym. The trace fossil is a small, highly lobed spreite structure produced by a zoned backfill consisting of a pale mantle and dark core. In a few cases, a meniscate structure is visible in the core. The spreite sediment is an extension of the mantle material; it commonly is poorly visible. The spreite-producing behavior may be locally interrupted, leaving a single tube of backfill. The spatial arrangement of the trace fossils seems to depend on the host sediment; in muddy and homogeneous material the lobes tend to be oriented randomly, including vertically, whereas in laminated sand and silty sediments they tend to lie parallel to bedding. This latter orientation is exaggerated by compaction. Textural differences between host sediment and spreite or mantle may be subtle and not always evident. Observations in modern sediments are in agreement with the type material of both ichnogenera.
The Carboniferous-Permian boundary and ammonoids from the Aidaralash section, southern Urals
Authors: Bogoslovskaya M. F. , Leonova T. B. , Shkolin A. A.
Published: August 2016

The stratigraphic section at Aidaralash Creek, northern Kazakhstan, provides a complete and well-developed succession of strata across the Carboniferous–Permian boundary. This section, containing abundant and well-preserved ammonoid, fusulinacean, and conodont faunas, can serve well as the Carboniferous–Permian boundary stratotype. A profound change in ammonoid faunas, which occurs at the Orenburgian–Asselian boundary and which has been recognized by previous workers (e.g., Ruzhencev, 1950, 1951, 1952; Bogoslovskaya and Popov, 1986a, 1986b; Furnish, 1973; Glenister and Furnish, 1981), occurs in the Aidaralash Creek section, at the boundary between beds 19 and 20, and serves to mark the Carboniferous–Permian boundary. Additionally, Lower Permian strata at Aidaralash Creek mark the first appearance of widespread Permian ammonoid taxa, including representatives of Svetlanoceras, Juresanites, Prostacheoceras, Tabantalites, and Kargalites, that are preceded by the extinction of characteristic Late Carboniferous genera such as Prouddenites, Uddenites, Shumardites, Vidrioceras, Schistoceras, and Subkargalites.
Aulacopleurine trilobites from the Llandovery of northwestern Canada
Authors: Adrain J. M. , Chatterton B. D. E.
Published: August 2016

Aulacopleurine trilobites from Llandovery strata of the Whittaker Formation in the central Mackenzie Mountains, Northwest Territories, Canada, includeAulacopleura andersonin. sp.,Aulacopleura?ranfordin. sp., andSongkania smithin. sp. The subfamily Aulacopleurinae consists of only the generaAulacopleuraHawle and Corda, 1847, andSongkaniaChang, 1974, characterized by smooth, broad early growth stages and holaspides having expanded frontal and genal areas, covered with dense caecal pits, but usually very subdued tuberculate sculpture. The relationship ofAulacopleura? ranfordiandA.? reediPřibyl, 1947, to the remainder of species assigned to the genus is ambiguous.
Fossil crabs (Crustacea: Decapoda) from the Late Cretaceous cárdenas Formation, east-central Mexico
Authors: Vega Francisco J. , Feldmann Rodney M. , Sour-Tovar Francisco
Published: August 2016

Twenty-four nearly complete carapace samples were collected at three different localities of the Maastrichtian (Late Cretaceous) Cárdenas Formation in San Luis Potosí, east-central Mexico. The material has been assigned to five families: the Callianassidae, Dakoticancridae, Carcineretidae, ?Majidae, and Retroplumidae. Two genera of callianassid shrimp are described,Cheramusfor the first time in the fossil record.Dakoticancer australisRathbun is reported as the most abundant crustacean element; one new genus and species of carcineretid crab,Branchiocarcinus cornatus, is erected, and a single, fragmentary specimen is questionably referred to the Majidae. The three localities reflect paleoenvironmental differences, exhibited by different lithologies, within marginal marine, lagoon environments. The record of dakoticancrid crabs in the Cardenas Formation extends the paleobiogeographic range of the family and the genusDakoticancer.Carcineretid crabs, although not abundant, seem to have been a persistent element of crustacean assemblages in clastic environments during the Late Cretaceous of the ancestral Gulf Coast of Mexico.
Ivanovia tebagaensiswas a cyathiform Permian codiacean membranous alga with dimorphic cortices
Authors: Torres Andrew M.
Published: August 2016

Species ofIvanovia(Codiaceae or Udoteaceae, Chlorophyta) have traditionally been characterized as phylloid or leaf-like. Extraordinarily well preserved specimens ofI. tebagaensisin limestone from the Upper Permian of southern Tunisia indicate that the thallus was cyathiform or cup-shaped, similar to the broadly conical codiaceanCalcipateraand to livingUdotea cyathiformis. Ivanoviaalso shared withCalcipaterathe same general membrane structure consisting of bilateral cortices with palisades of utricles, now filled with micrite, and a medulla of tubular coenocytes, now filled with sparry calcite mosaic. A cyathiform thallus would have had an inner and an outer cortex and those ofI. tebagaensiswere dimorphic. The utricular structure as usually seen in thin sections using transmitted light is much clearer when viewed on polished surfaces of hand specimens using reflected light. Commonly occurring fused membranes suggest that the thalli reproduced vegetatively by budding. The complexity and regularity of theI. tebagaensismembrane structure strongly suggest that a model which proposes thatIvanoviais simply a diagenetic stage in the fossilization of the red alga,Archeolithophyllum, is invalid.
Early Devonian (Pragian) gastropods from Kyrgyzstan (central Asia)
Authors: Gubanov Alexander P. , Blodgett Robert B. , Lytochkin Vladimir N.
Published: August 2016

A gastropod assemblage is described from the middle Lower Devonian (Pragian) of Alai Ridge, Kyrgyzstan. It includes eight species, six of which are new. Two new genera are established, Alaionema and Barroisocaulus. Newly named species belonging to the above genera include: Alaionema kyrgyzensis and Barroisocaulus oliveri. In addition, four new species belonging to extant genera are also described: Omphalocirrus kaukensis, Ruedemannia tienshanica, Oriostoma sarydalchaensis, and Goniasma? asiatica.
Upper Placentian—Branchian series of mainland Nova Scotia (middle-upper Lower Cambrian): Faunas, paleoenvironments, and stratigraphic revision
Authors: Landing Ed
Published: August 2016

Lithostratigraphy and depositional and epeirogenic history of the upper Placentian Series (Cuslett-Fosters Point Formations of the Bonavista Group) and Branchian Series (Brigus Formation) are identical in the northern Antigonish Highlands; Cape Breton Island; and eastern Placentia Bay, southeastern Newfoundland. Preliminary evidence suggests that the lower Middle Cambrian is present in the field area. A unified, uppermost Precambrian–Lower Cambrian, formation- and member-level nomenclature is appropriate to Avalonian North America, and the stratigraphic nomenclature of southeastern Newfoundland is applied in northern mainland Nova Scotia.

Latest Placentian shoaling and deposition of a peritidal carbonate lithosome and unconformable onlap of the trilobite-bearing Branchian Series occurred in shallow Avalonian shale basins from eastern Massachusetts to central England.

Uppermost Placentian Series faunas are very diverse in the Fosters Point Formation. Limited similarities with the South Australian Lower Cambrian are indicated by the presence ofCamenellasp. cf.C. reticulosa, Conotheca australiensis, andHyptiothecasp., but these forms do not contribute to highly resolved correlation.

Twenty-eight taxa are illustrated from the upper Placentian and Branchian Series.Caveacus rectusn. gen. and sp., a phosphatic problematicum, is limited to the upper Placentian Series. The oldest, skeletalized, macrophagous predators are the Pseudoconodontida and the later appearing Protoconodontida (n. orders). The Pseudoconodontida includes the Protohertzinacea n. superfamily and Strictocorniculacea n. superfamily (with the Rhombocorniculidae and Strictocorniculidae n. families).Strictocorniculum vanallerumn. gen. and sp. is described. The tommotiid family Sunnaginiidae emend. includesEccentrotheca, Sunnaginia, Kulparina, andJayceia deltiformisn. gen. and sp.
Jaws and radula of the Carboniferous ammonoid Cravenoceras
Authors: Tanabe Kazushige , Mapes Royal H.
Published: August 2016

A well-preserved mouth apparatus consisting of jaws and a radula was found in situ within the body chamber of the goniatite Cravenoceras fayettevillae Gordon, 1965 (Neoglyphiocerataceae: Cravenoceratidae), from the middle Chesterian (Upper Mississippian) of Arkansas. Both upper and lower jaws consist of a black material. The lower jaw is characterized by a widely opened larger outer lamella and a shorter inner lamella. The upper jaw is fragmental. The radula is preserved in the anterior portion of the buccal space and comprises a series of tooth elements. Each transverse tooth row consists of seven teeth (a rhachidian and pairs of two lateral and one marginal teeth), with a pair of marginal plates. This arrangement is typical of radulae of other ammonoids of Carboniferous to Cretaceous age, coleoids, and the orthoconic “nautiloid” Michelinoceras (Silurian, Michelinocerida), suggesting a phylogenetic affinity among them.
Silurian-Early Devonian ostracodes from South America (Argentina, Bolivia): Preliminary investigations
Authors: Vannier J. M. C. , Racheboeuf P. R. , Benedetto J. L.
Published: August 2016

Ostracodes are described from the “Cerro del Fuerte Section” and neighboring localities, all in the Precordillera de San Juan (northern Argentina, San Juan Province), and from sparse faunas in Bolivia (Chuquisaca, Tarabuco Province). Additional material comes from the collection of Thomas (1905). This preliminary study gives the first detailed description of ostracode assemblages in the Upper Silurian and Lower Devonian of the South American continent. Records of other abundant lower Paleozoic (Lower Ordovician to Lower Devonian) ostracodes in Argentina, Bolivia, Brazil, Peru, and Venezuela are also reviewed. Twelve different species, belonging to Palaeocopa (Beyrichiacea and Primitiopsacea) and to Binodicopa and Podocopa (Healdiacea, Thlip-suracea, Cypridacea) are described and a new genus is established (Australobollian. gen.). Ostracode distribution at Cerro del Fuerte attests to the presence of the Siluro-Devonian boundary within the upper Los Espejos Formation and confirms recent stratigraphical attributions mainly based on conodonts and brachiopods (Benedetto et al., 1992). The beyrichiaceanHemsiellaindicates a late Ludlow to Pridolian age for the lower part of upper Los Espejos Formation. The non-palaeocope“Thlipsurella-Phanasymmetria-Ranapeltis”assemblage found in the uppermost part of the formation indicates an Early Devonian (Lochkovian) age. The present study reveals the existence of faunal links at genus (Silurian) and probably species (Early Devonian) level between South America (Argentina, Bolivia), Laurentia, Avalonia-Baltica, and northern Gondwana. For example, close affinities (e.g.,Ranapeltissp. aff.rowlandiandThlipsurellasp. aff.ellipsoclefta)exist between the uppermost Los Espejos Formation (Argentina) and contemporaneous horizons in the North American Mid-Continent (e.g., Haragan Formation, Oklahoma; Shriver Formation, Pennsylvania). Two types of ostracode assemblages, “beyrichiacean-dominated” and “thlipsuracean-bairdiacean-cypridacean dominated,” are recognized in the Late Silurian–Early Devonian of Argentina and discussed relative to other assemblages known in Laurentia, Avalonia-Baltica, and northern Gondwana. Their paleoecological significance in relation to marine bathymetry is addressed.
Plating and pectinirhombs of the Ordovician rhombiferanPlethoschisma
Authors: Sumrall Colin D. , Sprinkle James
Published: August 2016

When first described,Plethoschisma grandiswas thought to have an unusual plating arrangement compared to other pleurocystitids, although the ventral surface was largely unknown. New specimens showing more of the ventral surface indicate thatPlethoschismahas very similar ventral plating toDeltacystisand that four of the original dorsal plate designations ofPlethoschismawere incorrect. A new subfamily, Deltacystinae, is erected to receive the two similarly plated genera. The pectinirhombs ofPlethoschismaare reinterpreted as confluent and in the B2/IL2 and IL3/L4 positions, and one of the new specimens has the largest pectinirhomb and greatest number of dichopores of any known glyptocystitid. A phylogenetic analysis of the Pleurocystitidae reveals that the Deltacystinae, new subfamily, is the sister group to the Pleurocystitinae, new subfamily, and that pectinirhombs apparently evolved independently in the Pleurocystitidae and the Cheirocrinidae.
A new Middle Pennsylvanian species of Petalaxis (Rugosa) from eastern California
Authors: Stevens Calvin H.
Published: August 2016

Colonial rugose corals are uncommon in Pennsylvanian rocks in North America and until now the only massive form known from rocks of this age south of the Arctic is an undescribed species of Petalaxis reported by Sutherland (1985) from Morrowan rocks in Oklahoma, Texas, and New Mexico. This report concerns a second species of Petalaxis recovered from Desmoinesian rocks immediately west of Death Valley, California. Although only a single colony has been found, it is profoundly different from all other described species of this genus and is significant from the standpoint of its presence during a very long time span when there was an apparent dearth of massive rugose corals in most of North America.
Five new genera of Late Ordovician-Early Silurian brachiopods from Anticosti Island, eastern Canada
Authors: Copper Paul
Published: August 2016

Uninterrupted, ~800 m thick, Ashgill through Llandovery carbonate strata from Anticosti Island (eastern Canada) reveal five new brachiopod genera, enhancing present knowledge about the early evolution of the spire-bearing order Atrypida, spanning some 10.2 million years of time, and a global mass extinction crisis. New taxa include smooth-shelled forms such as the Late Ordovician genusXysila, typeX. astacan. sp., and two new Early Silurian genera,Becscia, typeB. scissuran. sp., andCerasina, typeC. pycnatan. sp. New costate genera include the Early Silurian reef-dwelling formDihelictera, typeD. acrolophan. sp., and a deeper water inhabitant,Joviatrypa, typeJ. brabylan. sp. For comparison with these new taxa, the spiralia and jugal processes of the type species of the Llandovery generaProtatrypaandMeifodiaare illustrated and described for the first time.
Silurian and Devonian molluscan bivalves from precordillera region, western Argentina
Authors: Sanchez Teresa M. , Waisfeld Beatriz G. , Toro Blanca A.
Published: August 2016

Silurian and Devonian bivalves recovered from the Los Espejos (Silurian to Lower Devonian) and Talacasto (Devonian) Formations of the Northern Precordillera Mountain belt are described and illustrated. The fauna comprises some new nuculoidsDeceptrix (Devonodeceptrix) jachalensisn. subgen. and n. sp.,Nuculites argentinumn. sp., andAnthracoleda (Pseudoleda) minutan. subgen. and n. sp., as well as the new pterioidActinopteria modestan. sp. Additionally, many poorly known South American bivalves are redescribed and figured. Silurian–Devonian pelecypod faunas from some South American localities show differences both in diversity and in faunal composition. Causes for these differences are briefly discussed. Controls other than latitude are suggested in order to explain biogeographical affinities of the studied fauna.
A taxonomic revision of three mid-Telychian monoclimacids
Authors: Zalasiewicz Jan , Loydell David K. , Štorch Petr
Published: August 2016

The important mid-Telychian biozonal index speciesMonoclimacis griestoniensis(Nicol, 1850) is redescribed and distinguished from two new species:Monoclimacis directa(formerly the‘Monograptuscf.griestoniensis’of Elles and Wood, 1911), andMonoclimacis woodae.Stratigraphically,directaappears a little beforegriestoniensis, whilstwoodaeis from the lategriestoniensisto earlycrenulataBiozone.
Element morphology and taxonomic relationships of the Ordovician conodonts Phragmodus primus Branson and Mehl, 1933, the type species of Phragmodus Branson and Mehl, 1933, and Phragmodus undatus Branson and Mehl, 1933
Authors: Leslie Stephen A. , Bergström Stig M.
Published: August 2016

Rediscovery of Branson and Mehl's (1933b) classical outcrop of the Middle Ordovician Joachim Dolomite near Holstein in eastern Missouri, from which they described 32 new species and four new genera of conodonts, makes it possible to obtain the large topotype collections needed to interpret their taxa in terms of modern multielement taxonomy. Of special interest in their Holstein fauna is Phragmodus primus Branson and Mehl, 1933, by original designation the type species of Phragmodus Branson and Mehl, 1933, whose morphology and relationships have been very poorly understood. Study of topotype collections, as well as of Branson and Mehl's syntypes, has failed to reveal any notable morphological differences between the elements of P. primus and those of P. undatus Branson and Mehl, 1933, a very well known and widely distributed species in the Middle and Upper Ordovician Midcontinent Realm faunas. These species are herein considered to be synonymous. Because the original descriptions of P. primus and P. undatus were published simultaneously, neither name has priority over the other. However, P. undatus has figured far more prominently in the taxonomic and biostratigraphic conodont literature than P. primus and therefore we favor use of the former designation for this species. The recognition that P. primus and P. undatus are the same species extends the stratigraphic range of P. undatus downward to considerably below the Deicke K-bentonite, that is, well into the Blackriveran.
Biostratigraphy and evolution of Late Carboniferous and Early Permian smaller foraminifers from the Barents Sea (offshore Arctic Norway)
Authors: Groves John R. , Wahlman Gregory P.
Published: August 2016

Nearly continuous cores from a 500-meter interval of upper Moscovian through post-Artinskian carbonate strata on the Finnmark Platform have yielded rich assemblages of fusulinaceans and smaller foraminifers. The fusulinaceans provide an independent time framework for evaluating stratigraphic occurrences of associated smaller foraminifers. Information derived from this study has been integrated with that from previous investigations to produce a smaller foraminiferal biostratigraphic model for the High Arctic. Kasimovian strata are characterized by occurrences ofNodosinelloidesspp.,Protonodosariaspp. andHemigordius schlumbergeri.Overlying lower Gzhelian beds are identified by the appearances ofRaphconilia modificataandAmphoratheca iniqua. Tezaquina clivuliandCribrogenerina gigasfirst occur in upper Gzhelian strata, and Asselian rocks contain appearances ofGeinitzina postcarbonicaandPachyphloiaspp. Phylogenetic reconstructions suggest that the Late Carboniferous-Early Permian pseudovidalinids (Archaediscacea) derived from the Pseudoammidiscidae, as did the older group of predominantly Early Carboniferous archaediscaceans. The repeated development of similar morphologies within the two groups of archaediscaceans includes examples of both convergence and iterative evolution. The Protonodosariidae and Syzraniidae most likely evolved from an earlandiid ancestor. The syzraniids gave rise to the Geinitzinidae, which in turn gave rise to the Pachyphloiidae. As in the archaediscaceans, evolution within and among the Earlandiidae, Protonodosariidae, Syzraniidae, Geinitzinidae and Pachyphloiidae includes multiple examples of repeated patterns. Two key phenotypic developments seemingly led to bursts of diversification in different groups throughout late Paleozoic foraminiferal evolution. The acquisition of an outer hyaline or pseudofibrous wall layer was a morphologic breakthrough followed by taxonomic radiation in both groups of archaediscaceans and in theEarlandia-Syzranialineage. The second major event was the shift from an undivided tubular morphology to uniserial morphology in both the Earlandiidae-Protonodosariidae and Syzraniidae-Geinitzinidae lines.Nodosinelloides pinardaeis proposed as a new name forNodosaria grandisLipina, 1949 (preoccupied).
Mississippian coral latitudinal diversity gradients (western interior United States): Testing the limits of high resolution diversity data
Authors: Webb Gregory E. , Sando William J. , Raymond Anne
Published: August 2016

Analysis of high resolution diversity data for Mississippian corals in the western interior United States yielded mild latitudinal diversity gradients despite the small geographic area covered by samples and a large influence on diversity patterns by geographic sampling intensity (sample bias). Three competing plate tectonic reconstructions were tested using the diversity patterns. Although none could be forcefully rejected, one reconstruction proved less consistent with diversity patterns than the other two and additional coral diversity data from farther north in Canada would better discriminate the two equivalent reconstructions.

Despite the relatively high sampling intensity represented by the analyzed database, diversity patterns were greatly affected by sample abundance and distribution. Hence, some effort at recognizing and accounting for sample bias should be undertaken in any study of latitudinal diversity gradients. Small-scale geographic lumping of sample localities had only small effects on geographic diversity patterns. However, large-scale (e.g., regional) geographic lumping of diversity data may not yield latitudinally sensitive diversity patterns. Temporal changes in coral diversity in this region reflect changes in eustacy, local tectonism, and terrigenous sediment flux, far more than they do shifting latitude. Highest regional diversity occurred during the interval when the studied region occupied the highest latitude. Therefore, diversity data from different regions may not be comparable, in terms of latitudinal inference. Small-scale stratigraphic lumping of the data caused a nearly complete loss of the latitudinal diversity patterns apparent prior to lumping. Hence, the narrowest possible stratigraphic resolution should be maintained in analyzing latitudinal diversity gradients.
Illaenidae (Trilobita): Morphology of thorax, classification, and mode of life
Authors: Whittington Harry B.
Published: August 2016

The axial rings of the thorax of seven Ordovician species of Illaenidae, and of the type species of the SilurianCybantyx,all have the ring curved downward and forward, lacking the articulating furrow but traversed by a stout ventral ridge; the doublure similarly curves downward and forward. This type of axial ring is apparently unique among post-Cambrian trilobites. The axial ring in Scutelluidae is like that occurring in most post-Cambrian trilobites, having a convex ring, deep articulating furrow, and horizontal half ring and doublure. These and many other characters distinguish the Styginidae-Scutelluidae group from Illaenidae.Cybantyxis not an effaced scutelluid, but an illaenid. Upper Cambrian illaenid-like trilobites, which have the illaenid type of thoracic axial ring, deserve consideration as possible ancestors of post-Cambrian illaenids. The thorax is given considerable flexibility by the illaenid axial ring, enabling the body to have been flexed unusually strongly concavely dorsally, as well as to enroll. The musculature suggested omits dorsal longitudinal muscles. It is argued that many illaenids may have been vagrant benthos, particularly adapted for negotiating over irregular surfaces. The view that illaenids lived partly in a burrow is not supported by specimens preserved in such an attitude. The arrangement and varying strength of the terrace ridges on the exoskeleton ofCybantyxis consistent with their having had a sensory function; anastomosing caeca on the fixed cheek and the pleural region of the pygidium are described.
The youngest Ediacaran fossils from Southern Africa
Authors: Narbonne Guy M. , Saylor Beverly Z. , Grotzinger John P.
Published: August 2016

Discovery of fossils of the Ediacara biota near the top of the Spitzkopf Member at farm Swartpunt extends the known range of these remains in Namibia more than 600 m to near the sub-Cambrian unconformity. The fossiliferous beds occur approximately 100 m above a volcanic ash dated at 543 ± 1 Ma, and thus may be the youngest Proterozoic Ediacara-type fossils reported anywhere in the world. Fossils are preserved within and on the tops of dm-thick beds of storm-deposited sandstone at two stratigraphic levels; the environment is interpreted as open marine, generally calm but with episodic disruptions by storm waves, and probably within the euphotic zone. The presence of Pteridinium carolinaense (St. Jean), which is also known from the classic sections in Ediacara and the White Sea among others, reinforces evidence from geochronology and chemostratigraphy that the Swartpunt section is terminal Neoproterozoic in age. The new genus and species Swartpuntia germsi is a large, multifoliate frond that exhibits at least three quilted petaloids. Macroscopically, Swartpuntia resembles Pteridinium and Ediacara-type fronds such as Charniodiscus traditionally interpreted as Cnidaria, whereas microscopically it exhibits segmentation that is remarkably similar to that of the putative worm Dickinsonia. Combination of diagnostic characters of these supposedly disparate groups in a single species suggests that many species of quilted Ediacaran organisms were more similar to each other than they were to any modern groups, and provides support for the concept of the “Vendobionta” as a late Neoproterozoic group of mainly multifoliate organisms with a distinctive quilted segmentation.
Review ofEohiodon(Teleostei: Osteoglossomorpha) from western North America, with a phylogenetic reassessment of Hiodontidae
Authors: Guo-Qing Li , Wilson Mark V. H. , Grande Lance
Published: August 2016

Review of recently collected material ofEohiodonfrom North America suggests that there are two valid species,E. rosei(Hussakof) andE. woodroffiWilson.Eohiodon falcatusGrande is identical toE. woodruffiin known skeletal features and nearly all meristic features and is treated as a junior synonym of the latter. The fossil genusEohiodonCavender differs fromHiodonLesueur, which is known from both fossil and extant species, in numerous meristic and osteological features. The caudal skeleton inEohiodonis nearly identical to that inHiodon.

The traditionally accepted Notopteroidei, containing Lycopteridae, Hiodontidae, and Notopteridae, is a polypheletic group. The Asian fossil family Lycopteridae is not more closely related to Hiodontidae than it is to other taxa in the Osteoglossomorpha, but is sister to all other Osteoglossomorpha. The Hiodontiformes sensu stricto, including only the family Hiodontidae, is the sister-group of the Osteoglossiformes. This family is not more closely related to notopterids than to other taxa in Osteoglossiformes. The Notopteridae are most closely related to the Mormyroidea; together they and the fossil family Ostariostomidae constitute the sister-group of the Osteoglossoidei.

Fossil records of Hiodontiformes sensu stricto and Notopteroidei indicate a widespread pre-Neogene biogeographic range of these freshwater teleosts, suggesting that extinction must have been involved in the Cenozoic evolution of these two osteoglossomorph sublineages.
The Archosauria from the Woodbine Formation (Cenomanian) in Texas
Authors: Lee Yuong-Nam
Published: August 2016

The archosaur fauna from the Woodbine Formation (Cenomanian), Tarrant County, Texas includes crocodiles, theropod, nodosaurid, and hadrosaurid dinosaurs. A new neosuchian crocodile,Woodbinesuchus byersmauriceinew genus and species, appears to be a longirostrine goniopholid. Isolated theropod teeth include morphotypes similar toRichardoestesia.Nodosaurid premaxillary teeth are unique among early nodosaurids in having no marginal cusps. Hadrosaurid remains represent the oldest hadrosaurs east of the Western Interior Seaway.
Latest Cretaceous/earliest Tertiary transition on Seymour Island, Antarctica
Authors: Zinsmeister William J. , Feldmann Rodney M. , Woodburne Michael O. , Elliot David H.
Published: August 2016

Seymour Island, Antarctica (64°17'S), offers the first opportunity to examine the crisis at the end of the Cretaceous from the high southern latitudes. The K/T boundary sequence on Seymour Island consists of a nearly continuous sequence of siliciclastic sediments deposited in a mid-shelf environment. The faunal changes across the boundary occur through a 30-m interval with no single extinction horizon, in contrast to other well-studied K/T boundary sections. The “expanded” nature of the Seymour Island section makes placement of the K/T boundary difficult because boundary indicators such as planktic foraminifera, ammonites, and dinocysts disappear at different levels within the section.
Triassic corals and spongiomorphs from Hells Canyon, Wallowa terrane, Oregon
Authors: Stanley George D. , Whalen Michael T.
Published: August 2016

Twenty-one species of corals and three species of spongiomorphs occur in a series of richly fossiliferous, molluscan-dominated beds with silicified bioclasts in the Upper Triassic Martin Bridge Limestone of Hells Canyon, Oregon. Two of these,Maeandrostylis grandiseptusandRecticostastraea wallowaensisare new species.Recticostastraeais designated as a new genus.

The fauna is early Norian and occurs in the island arc Wallowa terrane, one of many tectonostratigraphic terranes in western North America. Like other examples, it appears to have developed independently of the North American craton and to have links with Wrangellia. The fossil corals and spongiomorphs are para-autochthonous, occurring in a series of tempestite beds. They are interpreted to have inhabited a shallow-water carbonate platform that developed around a tropical island arc following cessation of volcanic activity. The corals and spongiomorphs are associated with abundant gastropods and a diverse epifaunal suspension-feeding bivalve fauna. Relative to the corals, branching spongiomorphs,Spongiomorpha ramosa, are more abundant and occur with relatively common branching, sheet to plate-like, colonial corals. Solitary corals are relatively rare. The associated bedded limestone includes a variety of shallow-water microfacies but throughout the Hells Canyon sequence, reef structure is absent.

Together, the 24 coral and spongiomorph taxa show mixed paleogeographic affinities with Upper Triassic faunas known only from alpine regions of the western Tethys (five species), the Pamir Mountains, U.S.S.R. (two species), and the island of Timor (one species). Five additional species are pan-Tethyan and exceptionally cosmopolitan, but 11 species (45.8%) occur only in displaced terranes. Of these, a significant component (six species) is endemic to the Wallowa terrane. At least four Hells Canyon taxa, previously thought endemic to North American terranes, have recently been reported from the high-latitude Koryak terrane of northeastern U.S.S.R., a displaced tropical volcanic terrane of the northwestern Pacific. For Triassic corals, this is the first example of a clear link between western Pacific and eastern Pacific terranes. Less similarity exists with the Wrangell Mountains, Alaska, where identical age lower Norian silicified corals and spongiomorphs are known.
Species definition in heliolitine corals of the lower Douro Formation (Upper Silurian), Canadian Arctic
Authors: Dixon Owen A.
Published: August 2016

Specimens representingHeliolites diligensBondarenko, 1966,H.aff.H. luxarboreusYang, 1978, andH. tchernysheviBondarenko, 1966, are common andHeliolitessp. andStelliporellasp. are rare in diverse coral assemblages associated with lithistid sponge reefs in deep shelf or ramp limestone facies of the Douro Formation.Heliolites diligens, a more widely adapted, possibly “opportunist” species, occurs abundantly in lower diversity stromatoporoid/coral assemblages from nonreefal, shallower shelf limestone facies. Detailed systematic study of approximately contemporaneous populations of these Ludlovian heliolitid species shows that all are morphologically variable; assessment of this variability qualitatively and quantitatively is critical to species definition and recognition.Heliolites diligensis the most variable, with wide intercolony variation in septal development, corallite wall configuration, and spacing of horizontal skeletal elements. This apparently represents morphological plasticity rather than differences that can be ascribed to distinct species. Conspecificity of the more extreme and dissimilar variants can be inferred from study of large assemblages of coeval specimens. The other species, with more narrowly defined, discrete variation fields, are more readily distinguished from each other.