bluuebunny/crossref_metadata_2025_split huggingface dataset:
Systematic revisions toAorocrinus, Dorycrinus, Macrocrinus, Paradichocrinus, Strotocrinus, andUperocrinus: Mississippian camerate crinoids (Echinodermata) from the stratotype region
Authors: Ausich William I. , Kammer Thomas W. 
Published: August 2016

Systematic revisions and revised stratigraphic occurrences are made toAorocrinus, Dorycrinus, Macrocrinus, Paradichocrinus, Strotocrinus, andUperocrinusfrom the Osagean and Meramecian stratotype region in Iowa and Missouri. Systematic revisions include the assignment ofBatocrinus procerusMiller and Gurley as a junior synonym ofMacrocrinus mundulus. Batocrinus heteroclitusMiller and Gurley,B. vicinusMiller and Gurley, andB. stelliformisMiller and Gurley are assigned toUperocrinus heteroclitusn. comb. The concept ofAorocrinus spinosulus(Hall) did not match characteristics of the holotype. Consequently, the appropriate name for this concept isAorocrinus kelloggi(Worthen) n. comb., andA. spinosulusis assigned toDorycrinus mississippiensisas a junior synonym.Batocrinus strenuusis assigned toAorocrinus strenuusn. comb.?; andStrotocrinus glyptusis regarded as the valid name for the only species recognized in this genus.These systematic revisions result in the restriction ofStrotocrinus glyptusto the middle Osagean Burlington Limestone, and extension ofAorocrinus, Dorycrinus, Macrocrinus, andUperocrinusinto the Meramecian upper Warsaw Formation.
Vogelgnathus Norby and Rexroad (Conodonta): new species from the Lower Carboniferous of Atlantic Canada and northern England
Authors: Purnell Mark A. , von Bitter Peter H. 
Published: August 2016

Four new species are assigned to Vogelgnathus Norby and Rexroad because of the close similarity of their Pb and ramiform elements to those of the type species, V. campbelli (Rexroad). Recognition of the four new species requires that the generic diagnosis, based almost exclusively on the morphology of V. campbelli, be modified, chiefly to accommodate greater variation in Pa element morphology. Vogelgnathus dhindsai n. sp., V. gladiolus n. sp., V. kyphus n. sp., and V. pesaquidi n. sp. all possess abbreviated, carminiscaphate Pa elements. Spathognathodus postcampbelli Austin and Husri is reassigned to the genus.The origins of Vogelgnathus are uncertain but V. gladiolus first appeared in the early Viséan and gave rise to V. pesaquidi. The latter species appears to represent the rootstock from which V. kyphus, V. campbelli, and V. dhindsai evolved. Vogelgnathus postcampbelli evolved from V. campbelli during the late Viséan.Vogelgnathus campbelli and, to a lesser extent, V. postcampbelli have a wide geographic distribution; the four new species, however, are currently known only from Atlantic Canada, northern England, and southwest Scotland.
Advanced cladid crinoids from the Middle Mississippian of the east-central United States: primitive-grade calyces
Authors: Kammer Thomas W. , Ausich William I. 
Published: August 2016

Species of the late Osagean and early Meramecian advanced cladid crinoid genera (suborder Poteriocrinina)Armenocrinus, Bollandocrinus, Corythocrinus, Cosmetocrinus, Culmicrinus, Cydrocrinus, Histocrinus, Hypselocrinus, Lebetocrinus, Ophiurocrinus, Poteriocrinites, Scytalocrinus, Springericrinus, andUlrichicrinusfrom Illinois, Indiana, Iowa, and Missouri are redescribed and redefined from study of type material. Nomenclatural and systematic acts include the following: 1)Poteriocrinus tenuidactylusWorthen, 1882, is a senior synonym ofScaphiocrinus obscurusWachsmuth and Springer, 1886, and is assigned toArmenocrinus; 2)P. verusMiller and Gurley, 1890, is assigned toCulmicrinus; 3)P. mammaeformisWortheninMiller, 1889, is questionably assigned toCulmicrinus; 4)Cydrocrinus coxanus(Worthen, 1882) is a junior synonym ofC. concinnus(Meek and Worthen, 1870); 5)Decadocrinus stellatusLane and Howell, 1986, is questionably assigned toHistocrinus; 6)P. crawfordsvillensisMiller and Gurley, 1890, is a junior synonym ofHypselocrinus hoveyi(WortheninWorthen and Meek, 1875); 7)Hypselocrinus boonvillensis(Miller, 1891) andH. neglectus(Miller and Gurley, 1896) are junior synonyms ofH. arcanus(Miller and Gurley, 1890); 8)Hypselocrinus vansantin. sp. is described; 9)Hypselocrinus indianensis(Meek and Worthen, 1865) is a nomem dubium; 10)Poteriocrinus arachnaeformisWorthen, 1882, is a valid species ofPoteriocrinites; 11)P. cantonensisMiller and Gurley, 1890, is assigned toScytalocrinus; 12)Ulrichicrinus coryphaeus(Miller, 1891),P. amoenusMiller, 1891, andP. brittsiMiller, 1891, are junior synonyms ofU. agnatus(Miller, 1891); and 13)P. illinoisensisWorthen, 1882, is questionably assigned toUlrichicrinus.Bollandocrinus? sp. from the Keokuk Limestone might represent the first report of the genus from North America, being previously known only from the lower Carboniferous of Great Britain.Ophiurocrinussp. from the Keokuk Limestone is the first report of this genus from the Osagean, being previously known only from the Chesterian of North America and the upper Carboniferous of Europe.
Causality and Cope's Rule: evidence from the planktonic foraminifera
Authors: Arnold Anthony J. , Kelly D. C. , Parker W. C. 
Published: August 2016

A literature-based compilation of phylogenetic relationships and biometric measurements of 342 Cenozoic planktonic foraminiferal species suggests that the group shows a net increase in size through the Cenozoic, thus appearing to follow Cope's Rule of phyletic size increase. However, when the data are corrected for size-related biases, they do not support the hypothesis that this apparent trend is driven by an organismal adaptive advantage of larger size.When the planktonic foraminifera return to their “primitive” globigerine morphology during the Eocene-Oligocene transition, there is no indication of size-dependent origination or extinction; however, when the extinction signal is decomposed into pseudoextinctions and true lineage terminations, a differential pulse of pseudoextinction is observed among the smaller forms. This observation suggests that smaller bodied species, rather than surviving stressful times with static morphologies, may evolve their way through times of crisis and go on to found lineages which, by virtue of their initial small size, are stochastically likely to increase in mean size during subsequent diversification. Thus, one general explanation for Cope's Rule might be that smaller bodied species are more adaptively responsive due to their tendency to have shorter generation times. During times of stress, this adaptive responsiveness may give them an advantage that is correlated with, but causally unrelated to, their size.
Revision of the Middle Cambrian trilobiteAgnostus acadicusHartt
Authors: Robison Richard A. 
Published: August 2016

Agnostus acadicusHartt (inDawson, 1868) was the first agnostoid trilobite to be described from Middle Cambrian strata in North America. It was later designated the type species ofAcadagnostusKobayashi, 1939. The original description ofA. acadicuswas based on two specimens, a cephalon and a pygidium, which are illustrated for the first time with photographs. These are interpreted to represent separate species, each belonging to a different genus. The holotype cephalon is reassigned asPeronopsis acadica, which is judged to be a subjective senior synonym ofAgnostus fallaxLinnarsson, 1869, and several other species-group taxa. Consequently,Acadagnostusis suppressed as a subjective junior synonym ofPeronopsis. Agnostus fallaxis the type species ofAxagnostusLaurie, 1990, which also is suppressed as a subjective junior synonym ofPeronopsis.The pygidium on which the original description ofA. acadicuswas based is reassigned toHypagnostus parvifrons(Linnarsson, 1869).Peronopsis acadica, as emended, is a common, cosmopolitan agnostoid in open-marine lithofacies. It has an observed stratigraphic range from thePtychagnostus praecurrensInterval-zone to thePtychagnostus punctuosusInterval-zone.
Taxonomy, evolution, and biostratigraphy of theOrthograptus quadrimucronatusspecies group (Ordovician, Graptolithina)
Authors: Goldman Daniel 
Published: August 2016

TheOrthograptus quadrimucronatusspecies group currently comprises 22 taxa, which, with the exception ofO. ruedemanni, are distinguished from other orthograptids by the presence of paired apertural spines on their thecae. A detailed morphometric analysis of this group indicates that these taxa comprise four basic morphotypes that actually represent only six distinct species:O. pageanus, O. quadrimucronatus, O. spinigerus, O. ruedemanni, O. eucharis, andO. rivai.Specimens ofOrthograptus pageanushave a rapidly widening rhabdosome with elongated spines on the first two or four thecae.Orthograptus pageanusis divided into two chronological subspecies, an older, smaller form,O. pageanus pageanus, and a younger, larger form,O. pageanus maximusn. subsp. Specimens ofO. spinigerushave elongated spines on one or two thecal pairs between the sixth and thirteenth thecal pairs, a very narrow proximal end, and a rapidly widening rhabdosome. Specimens ofO. quadrimucronatushave a more parallel-sided shape and no unusually long spines. The subspeciesO. quadrimucronatus richmondensisis differentiated by the absence of both a median septum and a th 12spine.Orthograptus ruedemanni, O. rivai, andO. eucharisare all dwarf forms.Within a chronostratigraphic framework based on K-bentonite bed correlations the pattern and process of evolutionary change in the members of theO. quadrimucronatusspecies group is examined. Morphometrically, each species remains a coherent entity through time, occupying its own distinct morphospace. Each speciation event probably occurred rapidly, precluding the preservation of intermediates, and the new species retained their basic morphology throughout their existence. Within these lineages, phyletic changes were either absent or encompassed only changes in size, even when accumulated for much longer intervals than would be expected for speciation events. These patterns appear to be consistent with the evolutionary model of punctuated equilibrium.
Dendrocrinid crinoids from the Ordovician of northern Iowa and southern Minnesota
Authors: Brower James C. 
Published: August 2016

Plicodendrocrinusn. gen. is erected for dendrocrinids with solid pentalobate columns, strong stellate ridges on the aboral cup plates, and highly plicate anal sac plates. Five species are assigned: Middle Ordovician;P. proboscidiatus(E. Billings, not W. R. Billings) n. comb., from the Trenton of Canada and the Dunleith of Iowa and Minnesota. Upper Ordovician;P. casei(Meek) n. comb., from the Richmond and Gamachian of the midcontinent;P. rugocyathus(Ramsbottom) n. comb., from the Ashgill of England;P. collapsus(Donovan) n. comb.; andP. granditubus(Ramsbottom) n. comb., from the Ashgill of Scotland.The Middle Ordovician dendrocrinids from the Dunleith Formation (Trentonian) of northern Iowa and southern Minnesota areP. proboscidiatus(E. Billings),Dendrocrinus acutidactylusE. Billings, andQuienquecaudex springeri(Kolata). All species are also known from the Middle Ordovician of Ontario and Quebec. In addition,O. springeri(Kolata) is recorded from the Platteville Group of Illinois. Biogeographically, the Dunleith dendrocrinids are most similar to those of the northern Appalachians.Plicodendrocrinus casei(Meek) ranges widely in the midcontinent and has been obtained from the Maysvillian and Richmondian Maquoketa Formation of Iowa and Minnesota, several Richmondian units in the Cincinnati area, and the Gamachian Girardeau Limestone of Illinois and Missouri.A quantitative cladistic analysis of Ordovician cladid and flexible crinoids produces five groups: primitive forms includingAethocrinus, Compagicrinus, Ottawacrinus, andGrenprisia; cyathocrinids withCarabocrinus, Palaeocrinus, Illemocrinus, andPorocrinus; merocrinids withArchaetaxocrinus, Merocrinus, Praecupulocrinus, Polycrinus, andAithriocrinus; dendrocrinids withEsthonocrinus, Eoparisocrinus, Dendrocrinus, Quienquecaudex, Plicodendrocrinusand perhapsEopinnacrinus; andCupulocrinusand the flexibles,Protaxocrinus, Clidochirus, andProanisocrinus.These groups are not consistent with the present taxonomy and several suggestions for restructuring are presented, notably grouping flexibles with cladids and adjusting the taxonomic level of cyathocrinids. The cladograms for early cladids and flexibles are poorly correlated with stratigraphic position because of numerous unfilled range zones for the taxa or their ancestors. Thus, the cladograms generate predictions that can be tested by later finds in the Lower and the lower part of the Middle Ordovician. The overall evolutionary trends are highly mosaic with numerous parallelisms and reversals.
The Placentian Series: appearance of the oldest skeletalized faunas in southeastern Newfoundland
Authors: Landing Ed , Myrow Paul , Benus Alison P. , Narbonne Guy M. 
Published: August 2016

The lowest Cambrian of Avalon, or Placentian Series, is a relatively thick sequence (1,400 m) in southeastern Newfoundland. A newly proposed body fossil zonation supplements an existing trace fossil zonation of the lower part of the Placentian Series and includes strata to the top of the sub-trilobitic Lower Cambrian.TheSabellidites cambriensisZone brackets the Precambrian–Cambrian boundary and comprises peritidal and wave-influenced subtidal facies deposited during deepening through the lower part of the Chapel Island Formation. Younger “Ladatheca”cylindricaZone strata include the deepest facies of the Chapel Island Formation. The base of the overlyingWatsonella crosbyiZone (a post-Nemakit Daldyn and pre-Tommotian equivalent) is significantly diachronous because the diagnostic mollusks were preferentially preserved in pyritiferous offshore muds rather than in coeval nearshore muds. High diversity, upperWatsonella crosbyiZone faunas (18 species) are limited to peritidal limestones of member 4 and are dominated by calcareous small shelly fossils. A thick interval (ca. 430 m) without body fossils and an important episode of block faulting that led to 750 m of differential erosion preceded deposition of the lower part of the Bonavista Group (=Sunnaginia imbricataZone, an interval considered to be largely older than the Tommotian). Although much Early Cambrian time may be lost as a result of erosion at Random Formation–Bonavista Group unconformities, manyWatsonella crosbyiZone species reappear in theSunnaginia imbricataZone. Shoaling accompanied the immigration event defining the base of theCamenella balticaZone, and an unconformity following regional offlap marks the top of the Placentian Series.Calcareous, and not phosphatic, composition is most common in earliest Cambrian shelly remains. Little evidence suggests that a global, Precambrian–Cambrian boundary interval “phosphogenic” event either resulted in deposition of local phosphate deposits in the Tethyan region or had a role in the appearance of mineralized skeletons.Twenty metazoans and problematica and an alga are illustrated from the Chapel Island Formation.Bemella?vonbitteriLanding n. sp. andHalkieria stoneiLanding n. sp. are described. The monoplacophoranArchaeospira?avalonensisLanding n. sp. has right-and left-handed conchs comparable to those ofArchaeospira(=Yangtzespira) from China.Anabaritesis the senior generic synonym ofTiksitheca.
Taxonomy and paleoecology of Devonian rostroconch mollusks from Ohio
Authors: Hoare R. D. 
Published: August 2016

Rostroconchs are a common faunal component in the Devonian rocks of Ohio, particularly in the Columbus and Dundee Limestones. Hippocardia cunea (Conrad) is the most abundant species. Also present are H. monroica (Grabau), H. ohioense (Meek), H. curta n. sp., and Bransonia? sibleyense (La Rocque).Growth series of Hippocardia cunea show that the large hood and the rostrum begin to develop early in ontogeny. The rates of increase in the number of comarginal growth increments on the posterior or rostral face and radial ribs on the body of the shell are slow; most size increase of the shell occurred in the increasing widths of the ribs and the interspaces. The length/height ratio increases from young to juvenile specimens and then decreases in adult specimens. However, the length/width and height/width ratios show a general decrease from young to adult specimens. Considerable variation in shell lateral profile is present in H. cunea.Three specimens of Hippocardia cunea show borings entering the posterior rostral portion of the shell, presumably made by Trypanites, a polychaete worm. In one instance, a boring caused disfiguration of the shell material indicating that the host was alive at the time of the boring. The orientation and location of the borings and the presence of one specimen believed to be preserved in life position provides the base for interpreting H. cunea as an infaunal deposit feeder.
Error-weighted maximum likelihood (EWML): a new statistically based method to cluster quantitative micropaleontological data
Authors: Fishbein Evan , Patterson R. Timothy 
Published: August 2016

The advent of readily available computer-based clustering packages has created some controversy in the micropaleontological community concerning the use and interpretation of computer-based biofacies discrimination. This is because dramatically different results can be obtained depending on methodology. The analysis of various clustering techniques reveals that, in most instances, no statistical hypothesis is contained in the clustering model and no basis exists for accepting one biofacies partitioning over another. Furthermore, most techniques do not consider standard error in species abundances and generate results that are not statistically relevant. When many rare species are present, statistically insignificant differences in rare species can accumulate and overshadow the significant differences in the major species, leading to biofacies containing members having little in common.A statistically based “error-weighted maximum likelihood” (EWML) clustering method is described that determines biofacies by assuming that samples from a common biofacies are normally distributed. Species variability is weighted to be inversely proportional to measurement uncertainty. The method has been applied to samples collected from the Fraser River Delta marsh and shows that five distinct biofacies can be resolved in the data. Similar results were obtained from readily available packages when the data set was preprocessed to reduce the number of degrees of freedom. Based on the sample results from the new algorithm, and on tests using a representative micropaleontological data set, a more conventional iterative processing method is recommended. This method, although not statistical in nature, produces similar results to EWML (not commercially available yet) with readily available analysis packages. Finally, some of the more common clustering techniques are discussed and strategies for their proper utilization are recommended.
Calcareous algae from Cretaceous carbonates of Egypt, Sinai, and southern Jordan
Authors: Kuss J. , Conrad M.-A. 
Published: August 2016

Calcareous algae are frequent constituents in the shallow-marine limestone intercalations of late Aptian–Maastrichtian strata of the Eastern Desert of Egypt, the Sinai, and southern Jordan. A total of 18 species of green algae (among them 16 dasycladaceans withPraturlonella hammudain. comb. andPraturlonella jordanican. sp., two udoteaceans) and eight species of red algae (among them two gymnocodiaceans, three solenoporaceans, and one squamariacean) are described and compared with algae from several Tethyan occurrences. The stratigraphic distribution is calibrated by 10 assemblage-zones based on the associated foraminiferids and compared with 10 ammonite assemblage-zones.The algal contents vary within the different strata: their total contents and diversities increase from the late Aptian–Albian carbonates to the Cenomanian and decrease to the Turonian–Coniacian; no algae were proved in the Santonian–Campanian. The Maastrichtian occurrences are limited to one outcrop.
Devonian bryozoan diversity, extinctions, and originations
Authors: Horowitz Alan S. , Pachut Joseph F. , Anstey Robert L. 
Published: August 2016

Observed diversity of bryozoans within Devonian stages is not significantly different from range-through values for species because very few species have ranges longer than a single stage. Generic diversity differs significantly between observed stadial and stadial range-through values except for the diverse Givetian faunas. Among families, observed stadial and range-through comparisons differ significantly in the lower diversity Early and Late Devonian but are not significant in the taxonomically diverse Middle Devonian. The patterns of Devonian generic and familial diversity are apparently robust proxies for specific diversity.Givetian specific and generic extinctions, based on generated bootstrap distributions, are significantly higher than the other six Devonian stages even when modifications for different stage durations are considered. Based on present data, we conclude that a major change in Devonian diversity occurred between the Givetian and the Frasnian stages. Givetian specific and generic extinctions are not “smeared” with respect to adjacent stages and should qualify as a mass extinction among bryozoans pending more accurate data on bryozoan ranges and more precision in radiometric dating of Devonian stadial boundaries. Devonian bryozoan familial extinctions are not numerous and do not exhibit a significant number of extinctions for any stage. The Givetian extinction, which for the time being ranks as the largest bryozoan extinction in the Phanerozoic, is a global event with a marked local effect in the Hamilton-Tully fauna of New York, Pennsylvania, and Ontario.Givetian specific originations are significantly higher than bootstrap distributions for both raw data and data modified for stadial durations. A Givetian generic high in originations for raw data is not significant when modified for stadial durations and only Eifelian familial originations are significantly higher than bootstrapped distributions.
Taxonomy and biostratigraphy of Coniacian through MaastrichtianAnchura(Gastropoda: Aporrhaiidae) of the North American Pacific Slope
Authors: Elder William P. , Saul L. R. 
Published: August 2016

North American Pacific Slope deposits of Coniacian to Maastrichtian age have yielded eight biostratigraphically useful species ofAnchura: A. (Helicaulax?) popenoeinew species, Coniacian;A. halberdopsisnew species, early Campanian;A. callosaWhiteaves, 1903, early Campanian;A. falciformis(Gabb, 1864), late early to middle Campanian;A. phabanew species, middle to late Campanian;A. ainiktanew species, middle to late Campanian;A. gibberaWebster, 1983, late Campanian to early Maastrichtian;A. baptosnew species, late Maastrichtian to early Danian. In addition, two other possible species areA. nanaimoensis(Whiteaves, 1879), middle to late Campanian, andAnchura?new species, late Maastrichtian. These species together with two additional Turonian species,A. (Helicaulax) tricosaSaul and Popenoe, 1993, andA. (H.) condonianaAnderson, 1902, allow the definition at least eight Late CretaceousAnchurazones for the Pacific Slope. These zones have durations of 1.5 m.y. to 4 m.y.Anchura (H.?) popenoeifrom northern California appears most closely related toA. (Helicaulax) tricosaSaul and Popenoe, 1993, of Turonian age from southern California.Anchura callosa, A. falciformis, A. nanaimoensis, andA. phabaappear to be closely related based on sculptural elements, as doesA. gibberadespite having an anterior spur on the wing. However, these species appear to belong to two latitudinally differentiated faunal provinces. Species having a northern range includeA. callosa, A. falciformis, andA. nanaimoensis, whereasA. phabaandA. gibberaare from more southern deposits, as are alsoA. halberdopsis, A. ainikta, andA. baptos.