bluuebunny/crossref_metadata_2025_split huggingface dataset:
Substrate preferences of Late Eocene (Priabonian/Jacksonian) echinoids of the eastern Gulf Coast
Authors: Carter B. D. , Beisel T. H. , Branch W. B. , Mashburn C. M. 
Published: August 2016

Thin sections and acetate peels of the sediment within, and adhering to the outsides of, tests of Late Eocene echinoids from the southeastern United States have proven to be useful checks on inferences from test morphology concerning substrate preference. Previous characterizations of species' sediment preferences have concentrated primarily on the functional morphology of spatangoids, and relied particularly heavily upon Recent relatives of nonspatangoids. Reassessment of the preferences of spatangoids has led to a few discrepancies between interpretations herein and those of previous workers. In addition, this study attempts a more thorough assessment of functional morphology of nonspatangoid irregular echinoids than has previously been tried.Carbonate sand-dwelling species from the Ocala Limestone (thin sections are clean grainstones) include Oligopygus, Echinolampas, Rhyncholampas, fibulariids, Durhamella, Neolaganum, Agassizia, Macropneustes, some species of Plagiobrissus and Periarchus, and most species of Eupatagus. All these have been interpreted previously as preferring clean sand. Species that preferred, or at least tolerated, significant carbonate mud in the substrate (thin sections are poorly washed grainstones and packstones) include all the regular echinoids and the irregular echinoids Schizaster, Ditremaster, Brissopsis, Brissopatagus, Amblypygus, Eurhodia, Weisbordella, Wythella, Paraster, some species of Periarchus and Plagiobrissus, and perhaps some species of Eupatagus. The last seven of these have previously been interpreted as sand-dwellers.In general, species preferring mud-rich sands are found in the upper Ocala of peninsular Florida and in the middle to upper Ocala equivalents in the rest of the Gulf Coast. Sand-dwellers are most often found in the lower Ocala strata of both regions and up into the middle Ocala in Florida. These generalizations are consistent with existing paleoenvironmental models for the region.
Apparent cannibalism by Chesapeake Group naticid gastropods: a predictable result of selective predation
Authors: Kelley Patricia H. 
Published: August 2016

Naticid gastropods of the Chesapeake Group of Maryland, like extant naticids, apparently were cannibalistic. This cannibalism did not result from the absence of bivalve prey or from the ineptitude of the predator, as some previous authors have suggested. Instead, predation on Chesapeake Group naticids was a predictable result of prey selection to maximize energy gain per foraging time.This study examines predation on Lunatia heros (530 specimens) and Polinices duplicatus (340 specimens) from the St. Marys Formation of the Chesapeake Group. Predation on naticids displayed the same characteristics as predation on bivalve prey, including selectivity of prey size and drillhole site. The two naticid species were differentially attacked, based on their relative cost-benefit ratios and escape sizes. Cannibalism is not anomalous; it is the expected result of selective predation, and is inhibited primarily by the high mobility of naticid prey.
Permian trilobites from West Texas
Authors: Brezinski David K. 
Published: August 2016

Trilobites occur in two generically distinct faunas in the Permian strata of West Texas. The stratigraphically lower fauna, composed ofDitomopyge decurtata(Gheyselinck),Ditomopygesp.,Triproetus angustusn. sp.,Triproetus tumidusn. sp.,Triproetus altasulcusn. sp., is present in Wolfcampian and early Leonardian strata. The stratigraphically upper fauna, present in late Leonardian and Guadalupian strata, is comprised ofDelaria antiqua(Girty),Delaria grantin. sp.,Delaria brevisn. sp.,Delaria westexensisn. sp.,Delaria chinatiensisn. sp.,Novoameura vitrumonsn. sp.,Anisopyge perannulata(Shumard), andAnisopyge cooperin. sp.The lower fauna originated in the late Pennsylvanian, inhabited shallow-water environments, was relatively pandemic, and is interpreted to have become extinct as a result of marine regression during the early to middle Leonardian. The endemic upper fauna originated in deep waters of the Marfa and Delaware Basins during the late Leonardian, and, concurrent with sea level rise, migrated and diversified into the shelf-margin reefs of the late Leonardian and Guadalupian. Regression during the Late Permian resulted in extinction of this second Permian trilobite fauna.
Mabou Mines Section: biostratigraphy and correlation (Pennsylvanian Pictou Group, Nova Scotia, Canada)
Authors: Zodrow Erwin L. , Vasey Gary M. 
Published: August 2016

The floras and the faunas encountered in the Mabou Mines Section of Cape Breton Island, Nova Scotia, are not greatly diversified. The floras are composed mainly of medullosean (seed) ferns referable to neuropterids and reticulopterids. Infrequently encountered are lycopod, pecopterid, mariopterid, alethopterid, fortopterid, sphenopterid, sphenophylls and cordaitean fossils. The fauna is characterized by Anthraconauta phillipsii, Carbonita spp., Leaia spp. and rare Gutschickia bretonensis representing a fresh-water, lacustrine paleoenvironment in a fluviatite regime. Shells possibly referable to Anthraconauta tenuis s.l. are rare.In European chronostratigraphy (i.e., Heerlen), the age of the Mabou Mines Section encompasses middle to late Westphalian C to early Westphalian D. Correlation of the fauna with British chronozones is not without difficulty and a phillipsii Chronozone assignment is proposed which is somewhat lower (Westphalian C) than the floral correlation, an expected result.
Middle Ordovician agglutinated foraminifera including Reophax from the Mifflin Formation, Platteville Group of Illinois
Authors: Gutschick Raymond C. 
Published: August 2016

Agglutinated siliceous foraminifera occur in the Middle Ordovician (Blackriveran) Mifflin Formation of the Platteville Group in northern Illinois. The fauna consists of globular saccamminids and a new form Reophax blackriveranus n. sp. which records the oldest validated representative of this genus. This marks the earliest known occurrence of agglutinated foraminifera with multichambered uniserial tests of progressively expanding chambers from the proloculus to the aperture. This early innovation of test morphology was probably developed to control unfavorable changes in the water chemistry of the environment.Mifflin lithofacies consist of light gray, thin, wavy-bedded, lithographic limestone and fine-grained dolomite with green shale interbeds, thin calcarenite layers with graded bedding, a K-bentonite ash layer and hardground corrosion bedding surfaces. Mifflin biofacies include the foraminiferan fauna, brachiopods and molluscan shelly faunas, bryozoans, trilobites, ostracodes, echinoderms, solitary corals, conodonts, chitinozoans, scolecodonts, sponges and trace fossils particularly Chondrites.The Mifflin strata were deposited on an exceedingly gentle slope off the Pecatonica carbonate platform which flanked the Wisconsin Arch. Thin Mifflin clinothem limestone beds wedge out into shales in the moderately deep (<200 m) aerobic starved basin in eastern Iowa. This occurred in south tropical seas during a eustatic rise in sealevel and major marine transgression. Reophax is associated with saccamminids in the benthos of the marine upper foreslope. Apparently slope-dwelling Reophax foraminifera of the Ordovician were displaced downslope into the basin by the rapid development and expansion of hyperamminids which occupy the lower and middle foreslope in the Mississippian.
The polyplacophoran“Chiton” carbonariusStevens, 1858, in North America and new related species
Authors: Hoare R. D. , Mapes R. H. 
Published: August 2016

“Chiton” carbonariusStevens, 1858, is reassigned as the type species toGlaphurochitonRaymond, 1910. This species evolved from an unknown Mississippian ancestor, and spread rapidly into the Midcontinent region, Eastern Interior, and Appalachian basins during the Morrowan.Glaphurochiton carbonariusserved as the root stock for development of several species:G. concinnus(Richardson) during the Desmoinesian andG. subcircularisn. sp. during the Virgilian in the Eastern Interior basin andG. elimatusn. sp. in the Appalachian basin and possiblyG.?riddlei(Frederickson) in the Midcontinent region during the Missourian.Glaphurochitonis believed to have been essentially restricted to a mud bottom based upon its occurrence and relative abundance. Commonly the only taxon present, often abundantly, in black and gray shales,Glaphurochitonis rare to absent in limestones, algal limestones, reefs, and shales with an abundance of crustose calcareous algae. The latter lithologies commonly support a diverse polyplacophoran fauna essentially lackingGlaphurochiton.
Sponges and chancelloriids from the Cambrian of western Argentina
Authors: Beresi Matilde S. , Rigby J. Keith 
Published: August 2016

Anthaspidellid sponges are reported from the La Laja Formation in the Chica de Zonda Range in the Precordillera Oriental, Argentina. These are generically unidentifiable fragments of trabs and more or less well-defined dendroclone spicules. They occur as skeletal elements in small transported fragments and are the only Cambrian occurrence of anthaspidellids known thus far from South America.Walcott (1920) proposed to include an array of dissociated spicules, including triradiate prodiaenes, hexactines, and probable monactine spicules, in the genus Kiwetinokia. Assemblages tentatively identified as Kiwetinokia utahensis? Walcott, 1920, are reported from the Estancia San Martin Formation, of latest Early Cambrian and early Middle Cambrian age from San Isidro Gulch near Mendoza. Similar spicule assemblages occur in the La Laja Formation from the Chica de Zonda Range, in the Precordillera Oriental near San Juan, and in the Los Sombreros Formation in the Tontal Range of the Precordillera Occidental.Sclerites of the sponge-like Chancelloria eros Walcott, 1920, are described from the upper Lower to lower Middle Cambrian La Laja Formation. Chancelloria sclerites are also reported here from rocks of the Middle Cambrian Glossopleura Zone in the San Isidro Formation in Empozada Gulch in the San Isidro area of the Precordillera Austral, west of Mendoza, in Mendoza Province. Sponges and chancelloriids from the Cambrian of Argentina are known basically from dissociated skeletal elements.
Carabocrinid crinoids from the Ordovician of northern Iowa and southern Minnesota
Authors: Brower James C. 
Published: August 2016

Four species of carabocrinids from the Ordovician of northern Iowa and southern Minnesota are described, namelyCarabocrinus radiatusE. Billings,C. vancortlandtiE. Billings,C. magnificusSardeson from the Middle Ordovician Dunleith Formation andC. slocomiFoerste from the Upper Ordovician Maquoketa Formation.Carabocrinus radiatusandC. vancortlandtiare also known from the Middle Ordovician of Ontario and Quebec. In addition,C. magnificusandC. vancortlandtiare recorded from the Decorah of the Twin Cities area and the Curdsville Limestone of Kentucky, respectively. Biogeographically, the Middle Ordovician carabocrinids from Iowa and Minnesota are most similar to those from rocks of similar age in the northern Appalachians.Development of the cup and its component plates inC. slocomiis almost entirely isometric so that the its shape is largely constant regardless of size. This species exhibits ridge canals on the shoulders of the radial plates in the cup. The ridge canals probably served for respiration. As expected, the number of ridge canals and their length increase with positive allometry compared to the size and volume of the cup. Growth of the ridge canals restricts the width of the radial facets.
Oldest shelly fossils from the Taconic Allochthon and late Early Cambrian sea-levels in eastern Laurentia
Authors: Landing Ed , Bartowski Kenneth E. 
Published: August 2016

Continental slope facies in eastern New York have the most diverse small shelly faunas known in Laurentian late Early Cambrian strata. Diversity of a lowerElliptocephala asaphoidesassemblage, the oldest body fauna in the Taconic allochthon, reflects turbidity current exhumation, transport, and deposition of phosphatized fossil hash in a proximal facies of the Browns Pond Formation. Phosphatization is linked to the first of twoOlenellusChron intervals with a thickened dysaerobic water mass on the slope. This interval of increased rate of sea-level rise corresponds to development of extensive carbonate belts and onlap of dark shales (e.g., Forteau and lower Kinzers formations) on the east Laurentian shelf.The assemblage includes two trilobites, archaeocyathan fragments, echinoderm debris, the first edrioasteriod from east Laurentia, and 26 small shelly fossil species. New taxa areAsperconellanew genus andStenotheca taconicanew species (helcionellids);Mackinnonia obliquanew species (pararostroconch);Conotheca laurentiensisnew species,Insolitothecanew genus, andPetasotheca minutanew genus and species (hyoliths); andPlinthokonion?psamminonnew species (agglutinated problematicum).
Siliceous microfossils from the warm Late Cretaceous and early Cenozoic Arctic Ocean
Authors: Dell'Agnese Daniel J. , Clark David L. 
Published: August 2016

More than 40 species of siliceous microfossils are present in both T-3 core Fl-437 (Cretaceous) and in core Fl-422 (Eocene) from the central Arctic Ocean. Previous identifications of the silicoflagellates were the basis of the ages for these cores, but diatoms of the two cores, previously unidentified, suggest that Fl-437 could be as old as Campanian rather than middle to late Maastrichtian and that Fl-422 may be early to middle Eocene rather than middle to late Eocene. Identification of archaeomonads and ebridians completes the cataloging of the known biosiliceous assemblages of the older Arctic Ocean.Strong seasonality for the Late Cretaceous and early Cenozoic Arctic Ocean is suggested from alternating layers of vegetative cells and resting spores in both cores. The abundance of fossils is interpreted as evidence for seasonal upwelling in a nutrient-rich and much warmer Arctic Ocean. No evidence of seasonal ice or of ice-rafting is present. The profound climate change from the warmer older Arctic Ocean to the ice-covered condition of the present occurred after deposition of the sediment of Fl-422.
Ostracodes and chronostratigraphic position of the Upper Cretaceous Arkadelphia Formation of Arkansas
Authors: Pitakpaivan Kasana , Hazel Joseph E. 
Published: August 2016

The ostracode assemblage of the Arkadelphia Formation, upper Maastrichtian, of southwestern Arkansas is characterized by a well-preserved, relatively diverse, and abundant fauna representing 36 podocopid species and an undetermined number of species of the platycopid genus Cytherella. Thirteen of these account for 85 percent of the fauna. The dominant forms are Cytherella spp., Brachycythere rhomboidalis (Berry, 1925), Haplocytheridea renfroensis Crane, 1965, Haplocytheridea bruceclarki (Israelsky, 1929), and Brachycythere ovata (Berry, 1925), which account for about 57 percent of the specimens found. Other species that are less common, but are characteristic of the Arkadelphia, are Antibythocypris macropora (Alexander, 1929), Ascetoleberis hazardi (Israelsky, 1929), Aversovalva fossata (Skinner, 1956), Brachycythere ledaforma (Israelsky, 1929), Curfsina communis (Israelsky, 1929), Cytheromorpha arbenzi (Skinner, 1956), Escharacytheridea micropunctata (Alexander, 1929), and Veenia arachoides (Berry, 1925). The ostracode assemblage indicates that the Arkadelphia was deposited in the inner sublittoral zone.The species Veenia parallelopora (Alexander, 1929) and Brachycythere foraminosa Alexander, 1934, are restricted to the Arkadelphia Formation and allow correlation with other Gulf Coastal Plain Upper Cretaceous units. A new ostracode interval zone, the Veenia parallelopora Zone, is proposed. This zone divides the Platycosta lixula Zone.Calcareous planktic microfossils reported from the Arkadelphia and its correlatives in the Veenia parallelopora Zone indicate that these deposits are late Maastrichtian in age, not middle Maastrichtian as some authors have thought.
The environment, biogeography, and origin of the southern African Recent brachiopod fauna
Authors: Hiller Norton 
Published: August 2016

The brachiopod fauna that presently lives in the seas off the coasts of Namibia, South Africa, and southern Moçambique comprises 35 named plus seven unnamed species belonging to 26 genera, making it one of the most diverse in the world. Within the fauna are some species that are confined to the warm waters of the east coast, some that are restricted to the cold west coast waters, and others that enjoy a more widespread distribution. The geographic distribution of species is believed to be controlled by the two major oceanographic systems operating off southern Africa, namely, the Agulhas Current on the east and the Benguela Upwelling System on the west.Among the species that live off the west and south coasts are many that appear to have evolved in situ during times of pronounced environmental stress since the late Miocene. The fauna living off the east coast shows strong similarity with others in the Indian Ocean and it is inferred that many of the species migrated into the South African region by way of the ocean current systems that were established by the mid-Pliocene.Descriptions ofXenobrochus naudeiand the previously undescribedArgyrothecasp. andAmphithyriscf.A. richardsonaeare provided.
Late Ordovician nearshore faunas and depositional environments, northwestern Maine
Authors: Pollock Stephen G. , Harper David A. T. , Rohr David 
Published: August 2016

The Little East Lake Formation represents a spectrum of Late Ordovician (Ashgill) nearshore environments. These physical environments are characterized by a variety of quartz- and feldspar-rich sandstone and slate. Depositional environments include neritic nearshore, beach, tidal flat, and alluvial(?). The beach and neritic nearshore environments contain a variety of fossil invertebrates. The majority of the brachiopod fauna is confined to two taxa:Eodinobolus rotundusHarper, 1984, andDalmanella testudinaria ripaeMitchell, 1978(inCocks, 1978). Some of the specimens have been broken and abraded suggesting transport within the beach swash zone. Gastropods includeLophospiracf.L. milleri(Hall),Lophospira(?),Trochonemellacf.T. notabilis(Ulrich and Scofield), andDaidia cerithioides(Salter). Tidal-flat environment contains the trace fossilsPalaeophycusandPlanolites.The Late Ordovician (Caradoc and Ashgill) sedimentary basins developed subsequent to the collisional Taconian orogeny, wherein an arc accreted to the eastern Laurentian margin. Prior paleomagnetic reconstructions place the southeastern continental margin of Laurentia at approximately 25° south latitude during the Late Ordovician. Using these reconstructions, the siliciclastic Ashgill rocks discussed here would have been deposited in an elongated, northeast-trending basin on the southeastern Laurentian margin. The fauna developed along this margin, but in contrast to possibly adjacent Irish and Scottish assemblages, was located in much shallower water.
The H. A. Nicholson Collection of Paleozoic stenolaemate bryozoans: comparison of cladistic and phenetic classifications
Authors: Pachut Joseph F. , Anstey Robert L. , Horowitz Alan S. 
Published: August 2016

Until the late 1960's, most of Nicholson's types of Paleozoic bryozoans were not available for study. We present a set of coded characters of many of Nicholson's types, which should assist in bringing his species into conformity with current taxonomic standards so that his species can be consistently recognized and used in biostratigraphic, paleobiogeographic, and evolutionary studies.Cladistic and phenetic analyses of these species permit comparisons between inferred phylogenies of Nicholson specimens, adaptive morphospace, and treatise-based systematic relationships. Specimen-based cladistic and phenetic analyses of Nicholson's species both produce clusters that are congruent with existing family-level taxonomic assignments of species in the collection. However, cladistic analysis more fully retrieves the pattern of branching, or degree of relatedness, among higher taxa. Phenetic clusters represent adaptive peaks in morphospace for these specimens, but higher level “phenons” are strongly affected by multiple evolution of the same character states.
The phylogenetic position of the Tyrannosauridae: implications for theropod systematics
Authors: Holtz Thomas R. 
Published: August 2016

Tyrannosaurids are a well-supported clade of very large predatory dinosaurs of Late Cretaceous Asiamerica. Traditional dinosaurian systematics place these animals within the infraorder Carnosauria with the other large theropods (allosaurids, megalosaurids). A new cladistic analysis indicates that the tyrannosaurs were in fact derived members of the Coelurosauria, a group of otherwise small theropods. Despite certain gross cranial similarities with the large predators of the Jurassic and Early Cretaceous, the Late Cretaceous tyrannosaurids are shown to be the sister group to ornithomimids and troodontids, which share a derived condition of the metatarsus. This clade is found to be nested within Maniraptora, which is a more inclusive taxon than previously recognized. The atrophied carpal structure found in tyrannosaurids and ornithomimids is derived from a maniraptoran condition with a large semilunate carpal, rather than from the plesiomorphic theropod morphology.The taxa “Carnosauria” and “Deinonychosauria” (Dromaeosauridae plus Troodontidae) are shown to be polyphyletic, and the Late Jurassic African formElaphrosaurusis found to be the sister taxon to Abelisauridae rather than a primitive ornithomimosaur. Purported allosaurid-tyrannosaurid synapomorphies are seen to be largely size-related, present in the larger members of both clades, but absent in smaller members of the Tyrannosauridae. The remaining giant tetanurine theropods(MegalosaurusandTorvosaurus)were found to be progressively distant outgroups to an allosaurid-coelurosaur clade. The inclusion of the Tyrannosauridae within Maniraptora suggests a major adaptive radiation of coelurosaurs within Cretaceous Asiamerica comparable to contemporaneous radiations in various herbivorous dinosaurian clades.
Baiotomeus, a new ptilodontid multituberculate (Mammalia) from the middle Paleocene of western North America
Authors: Krause David W. 
Published: August 2016

Baiotomeus is a new genus of ptilodontid multituberculate from the late Torrejonian Land-Mammal Age (late middle Paleocene) of western North America. Baiotomeus douglassi (Simpson), the type species, has been assigned, at one time or another, to Ptilodus, Mimetodon, and Neoplagiaulax. In addition, a second, new species, B. lamberti, from three localities in the Medicine Rocks area of southeastern Montana is reported here. The Medicine Rocks localities are tentatively assigned a latest Torrejonian age, younger than localities yielding B. douglassi and younger than previously suggested on the basis of plesiadapid primates.Multituberculates appear to have attained their highest species richness during the Torrejonian Land-Mammal Age, but the discovery of B. lamberti illustrates that our knowledge of multituberculate diversity is incomplete from even that interval of time.