bluuebunny/crossref_metadata_2025_split huggingface dataset:
Taxonomic revision of lower and middle Paleozoic Orthothecida (Hyolitha) from North America and China
Authors: Malinky John Mark 
Published: August 2016

North American and Chinese lower and middle Paleozoic representatives of the hyolith order Orthothecida are here placed in the families Orthothecidae Syssoiev, Novitatidae Syssoiev, Decorithecidae Syssoiev, Chelsonellidae n. fam., ?Isitithecidae Syssoiev, and ?Tchuranithecidae Syssoiev. The Orthothecidae is redefined, and the Decorithecidae is in part synonymized with the Novitatidae.Re-examination of type specimens of some species formerly included in the order Hyolithida requires placement of these species in the order Orthothecida. The type suite ofHyolithes newsomensisFoerste from the Middle Silurian of Tennessee is divided into two species, and is used as a basis for the new genusFoersteotheca; the speciesF. merryiis new.Hyolithes richardiClarke from the Lower Devonian of New York is designated as the type species of the new genusDevoniotheca. Orthotheca cyreneWalcott from the Middle Cambrian of China is now included underDecoritheca. Foersteotheca, Devoniotheca, andDecorithecaare here placed in the redefined family Novitatidae.Hyolithes vanuxemiWalcott is assigned to the new genusChelsonellain the new family Chelsonellidae. The types ofHyolithes newtoniWalcott from the Upper Cambrian of South Dakota andHyolithes canalisfrom the Middle Cambrian of China are both included underDecorithecawith question.Recognition of orthothecid hyoliths in the Cambrian of North America and China provides a more accurate record of the geographic and stratigraphic distribution of this group. The discovery ofFoersteothecaandDevoniothecaconstitutes the first known middle Paleozoic orthothecid occurrences from North America. In addition, reports of Tchuranithecidae and Isitithecidae in North America, if authentic, are the first occurrences of these forms in North America. The discovery in North America of hyolith taxa previously known only from the Soviet Union and China raises the possibility of intercontinental correlation using these fossils.
Revision, distribution, and extinction of the Middle and early Late Devonian archaeogastropod genera Floyda and Turbonopsis
Authors: Day Jed 
Published: August 2016

Large palaeotrochid gastropods of the genera Floyda Webster (1905a) and Turbonopsis Grabau and Shimer (1909) occur in the late Frasnian Lime Creek Formation of Iowa. Floyda concentrica was designated as the type species of Floyda by earlier workers (Webster, 1905a; Knight, 1941), but is a junior synonym of F. gigantea (Hall and Whitfield, 1873). Three of five species and subspecies of Floyda described from the Lime Creek (Floyda concentrica, F. concentrica multisinuata, and F. gigantea depressa) are considered synonyms of the type species F. gigantea; the fifth species, F. gigantea hackberryensis, is here reassigned to the closely related genus Turbonopsis. Both F. gigantea and T. hackberryensis are redescribed using the original types and additional hypotype material from the collections of Charles Belanski.Floyda, first known from late Givetian rocks of the Rhenish Slate Mountains in Germany, is widespread in the United States Midcontinent and western North America by early Late Devonian time. Turbonopsis was endemic to the Appohimchi Subregion of the Eastern Americas Realm prior to the Taghanic Onlap, and appears to have remained so until late Frasnian time when it migrated to western North America.Eustatic sea-level highstands during the Middle and Late Devonian are thought to have breached barriers to migration, allowing both Floyda and Turbonopsis to disperse by prevailing oceanic currents from the United States Midcontinent into western North America during the late Frasnian. The expected oceanic current patterns of the Middle and Late Devonian paleogeographic reconstructions of Heckel and Witzke (1979, figs. 3, 5) adequately account for the known distribution and dispersal of Devonian palaeotrochid gastropods.The Palaeotrochidae underwent extinction prior to the latest Frasnian. Floyda, Turbonopsis, and Westerna became extinct during the onset of the last eustatic deepening event prior to the close of the Frasnian. The extinction of the palaeotrochid gastropods as well as other invertebrate groups may have been the result of restriction or near elimination of shallow warm-water, well-oxygenated shelf habitats by the onlap of cold anoxic bottom waters prior to latest Frasnian time.
The origin ofChubutolithesIhering, ichnofossils from the Eocene and Oligocene of Chubut Province, Argentina
Authors: Bown Thomas M. , Ratcliffe Brett C. 
Published: August 2016

The distinctive trace fossilChubutolithes gaimanensisn. ichnosp. occurs in Casamayoran (early Eocene) and Colhuéhaupian (late Oligocene) alluvial rocks of the Sarmiento Formation in eastern Chubut Province, Argentina. Though known for nearly 70 years, its origin has remained obscure. Examination of new specimens and comparisons with modern analogs demonstrate that specimens ofChubutolithesrepresent the fossil nests of a mud-dauber (Hymenoptera: Sphecidae). Virtually identical nests are constructed today by mud-daubers in areas as disparate as southern Santa Cruz Province, Argentina, and Nebraska, confirming that quite similar trace fossils can be produced by several different taxa in a higher taxonomic clade. No satisfactory ethological term exists for trace fossils that, likeChubutolithes,were constructed by organisms above, rather than within, a substrate or medium. The new termaedificichniais proposed.Chubutolithesoccurs in alluvial paleosols and is associated with a large terrestrial ichnofauna. These trace fossils include the nests of scarab beetles, compound nests of social insects, and burrows of earthworms.
Articulate brachiopods from the Richmondian of Tennessee
Authors: Howe Herbert J. 
Published: August 2016

The Richmondian (Upper Ordovician) strata in the Central Basin of Tennessee yield an abundant and diverse fauna of brachiopods. The section consists in ascending and conformable order of the “Arnheim” and Fernvale Formations.The following species are described: Austinella kankakensis (McChesney), Diceromyonia tersa Wang, Glyptorthis insculpta maquoketensis Ladd, Hebertella occidentalis (Hall), Onniella meeki (Miller), Paucicrura quadrata (Wang), Pionodema alberstadti n. sp., Plaesiomys bellistriatus Wang, P. proavita (Winchell and Schuchert), Platystrophia acutilirata (Conrad), P. ponderosa Foerste, Rafinesquina sp., Retrorsirostra carleyi (Hall), Strophomena planumbona (Hall), Tetraphalerella neglecta (James), Thaerodonta recedens (Sardeson), and Zygospira modesta (Hall).Faunal comparisons confirm correlations with the Cape Limestone of southeastern Missouri, the Maquoketa Formation of Iowa, the upper part of the Viola Formation of Oklahoma, the Aleman and Cutter Formations in West Texas, and the standard Richmond section. The fauna in Tennessee connects the provincial Richmond in the Ohio Valley with the western faunas.
Late Cretaceous Kossmaticeratidae (Ammonoidea) from the Magallanes Basin, Chile
Authors: Macellari Carlos Enrique 
Published: August 2016

Even though ammonites are not very abundant in Patagonia, a large number of specimens were collected by geologists from the Empresa Nacional del Petroleo (ENAP), Chile, during the course of several years of field work in the Magallanes Basin. This study describes the ammonite family Kossmaticeratidae present in that collection, which is a typical element of most southern hemisphere Late Cretaceous assemblages. The species described include: Kossmaticeras (Kossmaticeras?) fasciculatum n. sp., K. (Karapadites) constrictus n. sp., K. (Natalites) cecioni n. sp., K. (Natalites) hauthali (Paulcke), K. (Natalites) sp., Neograhamites kiliani Spath, N. taylori Spath, Gunnarites elegans n. sp., G. bhavaniformis (Kilian and Reboul), Grossouvrites gemmatus (Huppe), and Maorites densicostatus (Kilian and Reboul).The stratigraphic information on this fauna indicates that it is distributed in four assemblages. The oldest (assemblage A), possibly late Santonian to early Campanian in age, includes the species Kossmaticeras (Kossmaticeras?) fasciculatum, Neograhamites taylori, and possibly N. kiliani. This is followed by assemblage B (possibly middle to late Campanian), with K. (Karapadites) constrictus, K. (Karapadites) centinelaense (Blasco, Nullo, and Proserpio), K. (Natalites) hauthali, K. (Natalites) cecioni, Neograhamites morenoi Riccardi, N. taylori, N. kiliani, K. (Natalites) sp., Gunnarites elegans, G. bhavaniformis, and possibly Pseudokossmaticeras paulckei Collignon. The third assemblage (C), possibly late Campanian to early Maastrichtian in age, contains G. elegans, G. bhavaniformis, Grossouvrites gemmatus, and K. (Natalites) hauthali. The youngest assemblage (D) is possibly late Maastrichtian in age and is composed of the species Maorites densicostatus and Grossouvrites gemmatus.
Ontogeny and phylogeny in primitive calceocrinid crinoids
Authors: Brower James C. 
Published: August 2016

The evolution of primitive calceocrinids with four arm-bearing rays, here termed cremacrinids, has been examined for 13 species ofCremacrinus, Paracremacrinus, andAnulocrinususing numerical cladistics. The lineage was reconstructed from a Wagner tree of a Manhattan distance matrix. The characters were polarized by outgroup comparison. The Calceocrinidae originated from the Homocrinidae by development of the hinge, recumbent stem, loss of the BC interray basal and the C ray arm, and reorganization of the dorsal cup plates. The main evolutionary trends within cremacrinids consist of differentiation of the B and E ray arms from those of the lateral rays, increase or decrease in the number of branches and size of all arms, reduction of the B ray arm relative to those of the A and D rays, acquistion of additional main axils in the lateral rays, fusion of the infer- and superradials in the B and C rays, development of elongate brachials, and changes in adult body size.Relatively complete growth sequences are known for six species of cremacrinids and these are analyzed with allometric equations for the dorsal cup, hinge, and arms. The relationships between ontogeny and phylogeny for the links in the evolutionary sequence and the number of examples of each are listed in order of decreasing frequency and importance: 1) unclassified divergences (for example, changes in the number of branches in the E ray and the formation of elongate brachials), 12 examples; 2) 10 cases of paedomorphosis; 3) no significant differences between ancestors and descendants, seven instances; 4) five links where the dorsal cup plates are rearranged; and 5) a single change by recapitulation. Some phyletic links are characterized by several patterns whereas others only exhibit one or two kinds of transitions.
Early Permian conodont assemblages from the Wolfcamp Shale, Midland Basin, West Texas
Authors: Ritter Scott M. , Baesemann John F. 
Published: August 2016

Nine assemblages of conodont elements have been found on bedding surfaces of the “Wolfcamp Shale’ from the Midland Basin, Texas. Four of these assemblages have Pa elements assigned to Sweetognathus cf. S. inornatus. The assemblages are classified taphonomically as apparatus (remains or partial remains of a single individual) or coprolitic associations. The two apparatus assemblages indicate that Sweetognathus cf. S. inornatus possessed a seximembrate apparatus comprised of Pa, Pb, M, Sa, Sb, and Sc elements. Five of the seven coprolitic associations contain numerous elements (50–100) and/or multiple pairs of Pa elements representing the presumably ingested remains of two or more conodonts.The “Wolfcamp Shale’ assemblages are significant because 1) they confirm the polygnathacean affinity of the family Sweetognathidae, 2) they represent the youngest polygnathacean assemblages currently known, and 3) they permit comparison of multielement Sweetognathus with homologous elements of coeval genera such as Hindeodus, Adetognathus, Streptognathodus, and Neostreptognathodus.
Trilobites, biostratigraphy, and lithostratigraphy of the Crepicephalus and Aphelaspis zones, lower Deadwood Formation (Marjuman and Steptoean stages, Upper Cambrian), Black Hills, South Dakota
Authors: Stitt James H. , Perfetta Patrick J. 
Published: August 2016

Trilobites assigned to 25 genera and 39 species are reported from the Crepicephalus Zone (Marjuman Stage) and Aphelaspis Zone (Steptoean Stage) in the lower part of the Deadwood Formation in the Black Hills of South Dakota. Six taxa are left in open nomenclature, and one new species, Glaphyraspis newtoni, is described.Analysis of the lithologies for this interval from the best exposed measured sections on a southeast-northwest transect reveal a nearshore, shallow subtidal, siliciclastic dominated environment to the southeast, succeeded offshore by a shallow subtidal to lowest intertidal carbonate shoal environment, and then a transitional shaly limestone interval into a more shaly distal intrashelf basin to the northwest.Specimens of species of Coosia, Crepicephalus, Tricrepicephalus, Kingstonia, Pseudagnostina, and Coosina comprise more than 75 percent of the fauna of the Crepicephalus Zone. Coosina ariston, Crepicephalus snowyensis, Tricrepicephalus tripunctatus, Arcuolimbus convexus, and some species of Blountia had a strong preference for the shallow-water siliciclastic facies present in the southeastern sections closest to the paleoshoreline. Crepicephalus rectus, Tricrepicephalus coria, Agnostogonus, cf. A. incognitus and the genera Coosella and Uncaspis preferred the farther offshore, deeper-water, shaly intershelf basin located in the northern Black Hills. Trilobites from the Crepicephalus Zone are used to correlate the lower part of the Deadwood Formation with coeval strata elsewhere in North America.
Skeletal microstructure and mode of attachment inPalaeacisspecies (Anthozoa: Tabulata) from the Mississippian and Pennsylvanian of northeastern Oklahoma and northwestern Arkansas
Authors: Webb Gregory E. 
Published: August 2016

Three species of the Paleozoic coralPalaeacisare described from northeastern Oklahoma and northwestern Arkansas. Included are the Chesterian speciesP. carinataGirty andP. sniderin. nom., a replacement name for the junior homonymP. cuneataSnider, and the Desmoinesian? speciesP. erectan. sp. Coralla of each species exhibit two types of microstructure that characterize two skeletal zones. The outer skeletal zone is composed of numerous parallel trabeculae, mostly between 0.2 and 0.3 mm in diameter, that lie perpendicular to, and have their accretionary surfaces on, the exterior surface of the corallum. Trabeculae are closely spaced laterally and are not organized into rows except uncommonly on the distal portion of some coralla. Where trabeculae coalesce into parallel rows, ornamentation on the corallum exterior consists of parallel ridges or rows of small nodes. Where trabeculae are irregularly arranged, external ornamentation consists of irregularly disposed nodes. The inner skeletal zone consists of radially fibrous stereoplasm arranged into discrete septal spines that coalesce into irregularly developed septal ridges in each calice. InP. erecta, septal spines merge into continuous layers of fibro-normal stereoplasm in some places. On the basis of microstructure, corallum morphology, and external ornamentationP. carinataandP. sniderican be allied withP. axinoidesSmyth andP. robustaWebb.Palaeacis erectafalls within the same group on the basis of microstructure and ornament, but has a unique corallum morphology.Two distinct types of skeletal attachment occur in thesePalaeacisspecies.Palaeacis carinataandP. snideriexhibit an encrusting attachment surface that results in a prostrate growth habit wherein smaller substrates were entirely engulfed, producing free-living coralla.Palaeacis erectaexhibits a small, circular attachment surface and an erect growth habit wherein most skeletal accretion occurs perpendicular to, and away from, the substrate. The substrate is not engulfed and the corallum remains attached and sessile throughout astogeny.Palaeacis erectais, to date, the onlyPalaeacisspecies known to possess this erect, sessile growth form.
Spygoria zappanianew genus and species, aCloudina-like biohermal metazoan from the Lower Cambrian of central Nevada
Authors: Salak Marc , Lescinsky Halard L. 
Published: August 2016

A new enigmatic Lower Cambrian fossil,Spygoria zappania,is described From theNevadellazone (Botoman) of Lander County, central Nevada. In gross morphology,Spygoriafossils consist of stacks of small (5–10 mm in diameter) irregular calcified cups that are preserved in vertical, concave-up life orientation. Stacks are linked laterally into large monospecific bioherms which flourished in a shallow turbulent marine environment.TheSpygoriaorganism is interpreted as a metazoan which presumably inhabited the uppermost cup in each stack and periodically secreted new cups as it grew upward. Absence of holdfast structures suggest that the organism was held in place by sticky mud until opportunistically cementing to adjacent individuals. The affinity ofSpygoriaremains problematical, though we suggest that its stacked structure somewhat resembles the cone-in-cone structure ofCloudina,which formed similar dense thickets in shallow turbulent carbonate environments during the terminal Proterozoic.
Relationships between internal and external morphology in Paleofavosites (Tabulata): the unity of growth and growth form
Authors: Young Graham A. , Elias Robert J. 
Published: August 2016

During growth of colonial corals, the basic organization of skeletal elements was determined by inherent factors, but arrangement of corallites within a colony could be affected if environmental change induced a modified growth form. Comparisons of internal and external characters during colony development indicate how environmental and genetic factors determined growth form. The results of these comparisons have implications for understanding of colony integration, functional morphology, and systematics.This study is based on serially sectioned coralla of the cerioid tabulate Paleofavosites subelongus, from the uppermost Ordovician to lowermost Silurian of the east-central United States. Colony growth form resulted from changes in maximum growth angle of marginal corallites, and in the shape of the growth surface. These features were coordinated with corallite characters and were dependent on variation in corallite growth. At the same time that a colony became broader by expanding its maximum growth angle and developing a taller growth surface, its corallites became larger, more new corallites were initiated, and recently initiated corallites expanded more rapidly. When a colony's maximum growth angle was reduced and the growth surface became flatter, corallites also became smaller, fewer corallites were initiated, and those corallites that were recently initiated expanded slowly.Genetic constraint of growth is illustrated by consistent patterns of initial colony growth, and by relationships among characters of internal and external morphology. Frequent small-scale variations in growth angle and growth surface height:width during astogeny indicate fluctuating environmental factors. Sedimentation and subsidence of the colony were probably the major environmental controls on form.
The Late Devonian brachiopodCyrtiopsis davidsoniGrabau, 1923, and related forms from central Hunan of South China
Authors: Ma Xueping , Day Jed 
Published: August 2016

New specimens representing species ofCyrtiopsisGrabau, 1923, described by Grabau (1931a) were recovered in samples from the Late Devonian deposits of the Changlongjie Member of the Xikuangshan Formation in central Hunan Province of South China. Associated Famennian age conodonts and morphotypes of the rhynchonellid brachiopodYunnanellinalineage fix the ranges of species ofCyrtiopsisand related taxa in the Xikuangshan Formation within the interval of the MiddletriangularisZone through the LowercrepidaZone (early Famennian) in central Hunan Province.Detailed study and comparison of external and internal shell structures of the type species ofCyrtiopsisGrabau, 1923, and related species described in Grabau (1931a) shows thatCyrtiopsisfrom South China includes the type species,C. davidsoni(embodied by the holotype), andC graciosa.Both of these species are shown to lack a delthyrial plate. Grabau's paratypes ofC. davidsoniare considered to belong inCyrtiopsis intermediaGrabau, 1931. The speciesC. kayseriGrabau, 1931, andC. shensiensisGrabau, 1931, are also deemed synonyms ofC. davidsoniGrabau, 1923 (as restricted above).“Cyrtiopsis” intermediadiffers from other species ofCyrtiopsisby development of a short delthyrial plate and its systematic position remains uncertain.The genusPseudocyrtiopsisis proposed withCyrtiopsis spiriferoidesGrabau, 1931, as the type.Pseudocyrtiopsisnew genus is distinguished fromCyrtiopsisGrabau, 1923, by its alate hinge and development of a delthyrial plate. Comparisons of species ofCyrtiopsisfrom South China with cyrtospiriferid brachiopods identified asCyrtiopsisby Crickmay (1952) demonstrate that none of the early Famennian species from western Canada can be assigned to the genus as revised here, althoughC. mimetesCrickmay, 1952, is closely related to“C.” intermediaGrabau, 1931.
The first complete skeleton of Solnhofia parsonsi (Cryptodira, Eurysternidae) from the Upper Jurassic of Germany and its taxonomic implications
Authors: Joyce Walter G. 
Published: August 2016

A complete skeleton of Solnhofia parsonsi (Cryptodira, Eurysternidae) from the Kimmeridgian/Tithonian boundary of Schamhaupten, Germany provides the first complete understanding of the postcranial morphology of this genus. The here newly described postcranial characters are important in distinguishing Solnhofia from shell-based genera and thus help in resolving part of the parataxonomic conflict between shell-based and cranium-based turtle genera. This disparity originated during the last 150 years due to the history of fossil finds, preparation, and changing interests of researchers. Synonymies of Solnhofia with such turtle genera as Eurysternum, Idiochelys, Plesiochelys, Thalassemys, and Euryaspis can now be refuted. Similarities with Hydropelta are apparent, but not considered sufficient to support a synonymy. Newly observed or confirmed characters include the relatively large head (40 percent of the carapace length), the pentagonal carapace, the unique arrangement of bones and fontanelles in the pygal region, and the absence of mesoplastra, epiplastra, and an entoplastron.The carcass of the new specimen was embedded in finely laminated limestones and shows little sign of disintegration or scavenging, suggesting hostile bottom conditions with very low water energy during deposition. This taphonomy agrees with recent published models for the origin of the lithographic limestones of southern Germany. Tooth marks along the posterior margin of the carapace are evidence of predation by a broad-nosed crocodilian. This is the first clear example for this type of predatorial interaction from the Upper Jurassic of Germany.