bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hurricane effects on shallow-water cryptic reef molluscs, Fiji Islands
Authors: Kobluk David R. , Lysenko Mary A. 
Published: August 2016

An assemblage of 343 species of cryptic, shelled molluscs was identified in three large samples from shallow subtidal and intertidal shelter habitats under rubble and corals at Malololailai Fiji in 1983, 1984, and 1985. One species was a polyplacophoran, 273 were gastropods (38 families), and 69 were bivalves (21 families). Cryptic gastropods were more abundant than bivalves, but showed a reduction in abundance relative to bivalves from 1983 to 1985. The abundances of many cryptic molluscs show dramatic adjustments from 1983 to 1985, chiefly due to hurricanes in 1983 and 1985, showing a decrease in equitability with increased physical disturbance. The abundance and diversity of molluscan predators in the crypts means that predation in these habitats may be substantial.The gastropod sample diversity showed the greatest change during the 1984 post-hurricane recovery period. The 1985 hurricanes affected the sample diversity by shifting the gastropod diversity closer to what it was after the 1983 hurricane. The bivalves underwent a similar shift in sample diversity, although larger numbers of individuals in proportionately more species survived the hurricanes.The cryptic bivalves exploited space in new crypts, while maintaining their rate of increase in abundance in the recovery period after the 1983 hurricane and through the two hurricanes in 1985. The gastropods declined in abundance after the 1983 hurricane. They recovered after the 1985 hurricanes by doubling their abundance, showing that they could exploit new resources in crypts. This increase in the gastropod population was not proportional to the increase in available cryptic space. This may mean they were still recovering in August 1985, or they may have been unable to capture their portion of cryptic space in competition with other organisms during recovery.The 1985 hurricanes did not have much effect on the overall molluscan diversity, a possible result of pruning by the 1983 hurricane of molluscs unable to survive storms. Because there was only a short interval between the hurricanes, many molluscs that survived the 1983 event were still in the population, so that the cryptic molluscs probably were better able to deal with the effects of the 1985 hurricanes than they would have been before the 1983 hurricane. The result was that the sample diversity after the 1983 hurricane increased during the recovery period but did not decline later even though the population was devastated by hurricanes in 1985. This lends support to intermediate disturbance models linking increasing or stable diversity with disturbances spaced at intervals allowing recovery.
The Pandorinellina? boucoti lineage (Lochkovian, Devonian, conodonts)
Authors: Murphy Michael A. 
Published: August 2016

Pandorinellina? boucoti (Klapper) is based on material from the Lochkovian–Pragian (Devonian) section at Royal Creek, Yukon Territory, Canada, where it is found with species of the pesavis and sulcatus Zones. The species is also a rare element in the late Lochkovian–early Pragian faunas in the Toquima Range, central Nevada, where it is found within the same zones. Pandorinellina? boucoti has been recovered from 17 beds in sequence at the IK IV section in the McMonnigal Limestone and shows a morphologic change from a Pa element with a simple blade, small lateral lobes, and an enlarged triangular anterior denticle to a Pa element with ornamented pillars surmounting both platform lobes. The simple blade form is present in beds IK IV 21–16. The next overlying bed yields specimens with a single pillar-like enlargement of the larger platform lobe and a slight swelling on the smaller platform lobe. The following beds (IK IV 14–6) have only morphotypes with the pillar-like enlargement on both platform lobes.This morphologic change effectively divides the upper pesavis Zone into two segments in the IK IV section. The rarity of this species, however, will probably limit the usefulness of the lineage in refined biostratigraphy and the sequence of morphotypes needs to be verified in other areas. Nevertheless, where present, P.? boucoti should improve the accuracy of correlation in the late Lochkovian and early Pragian.
Epizoans on Flexicalymene (Trilobita) and implications for trilobite paleoecology
Authors: Brandt Danita S. 
Published: August 2016

Epibionts on specimens of Flexicalymene (Late Ordovician, Cincinnati Arch region, U.S.A.) that were encrusted while alive show an apparent preference for attachment along the relatively elevated sagittal axis of the exoskeleton (glabella, axial rings of thorax and pygidium) or the medial portion of the cephalic doublure. This site-specificity supports an interpretation of a semi-infaunal habit for this trilobite and may indicate a commensal relationship between the epizoan and host (e.g., epizoan bryozoans exploiting the trilobite exoskeleton as a hard substrate and perhaps benefitting from feeding currents generated by the trilobite). Epizoans are found only on larger individuals of this trilobite, suggesting a terminal molt stage for Flexicalymene.Although the number of previously reported encrusted trilobites is small, a survey of the literature suggests the following hypotheses concerning the relationships between trilobite life habit and susceptibility to epizoan colonization: 1) infaunal (burrow dwelling) trilobites were generally free of epizoans; 2) a small proportion of shallow-burrowing (semi-infaunal or “ploughing”) trilobites were suitable hosts for epizoans, but the epizoans preferentially colonized the elevated or anterior portions of the exoskeleton; 3) epifaunal (and some pelagic?) trilobites were more susceptible to encrustation.
Crinoid plate circlet homologies
Authors: Ausich William I. 
Published: August 2016

A model for crinoid plate circlet homologies is proposed based on a tricyclic (four-circlet) aboral cup, withAethocrinusthe characteristic tricyclic crinoid. The plate circlets in the aboral cup ofAethocrinus,from bottom to top, are lintels (named herein), infrabasals, basals, and radials. In this model, traditional interpretation is maintained for the aboral cup plates of most crinoids. Cladids, flexibles, articulates (primitively), and diplobathrid camerates are dicyclic and are composed of infrabasal, basal, and radial circlets. Monobathrid camerates are monocyclic, and they have basal and radial circlets. Disparid plate circlet homologies are reinterpreted. Among disparids, “basals” are lintels, “inferradials” and “radials” are infrabasals, and “superradials” are radials.The “Law of Wachsmuth and Springer” is judged to be a relationship that has most fidelity applied to lumen angles. This “law” is considered to be only a consequence of development and not an invariable basis by which to determine plate homologies. In the model presented here, plates cannot be shifted around after the juvenile calyx is sutured, and arms may grow on either radials or infrabasals, whichever plates are at the top of the cup when arms begin to grow.
Conodonts from the Prout Dolomite of north-central Ohio and Givetian (upper Middle Devonian) correlation problems
Authors: Sparling Dale R. 
Published: August 2016

The Prout Dolomite of north-central Ohio lies disconformably above the lowest Givetian (upper Middle Devonian) Plum Brook Shale and below the lowest Famennian (upper Upper Devonian) Ohio Shale. A sample from its base yielded over 4,000 diverse conodont specimens. Included isPolygnathus ansatusZiegler and Klapper, 1976, the index species for the MiddlevarcusSubzone, which is not reported from strata of this age in Ontario and Indiana, a fact that long caused their miscorrelation with the LowervarcusSubzone. Also present isP. rhenanusKlapper, Philip, and Jackson, 1970, considered to be also indicative of the MiddlevarcusSubzone in North America, andP. ovatinodosusZiegler and Klapper, 1976. Lowest occurrences of the latter are in the middle part of this subzone; its presence indicates correlation with the lower Tully Limestone of New York, the basal unit of the Taghanic Series. The Prout and equivalent strata in the region therefore represent a long unrecognized continuous time-rock unit created by Johnson's (1970) Taghanic onlap. The collection includes a new species ofAncyrolepis, A. huntleyi; a new species ofPolygnathusis left in open nomenclature, as are nine specimens assigned toTortodusbut of otherwise uncertain taxonomic status.Givetian conodont correlation between North America and the Global Stratotype Section and Point established by the Subcommission on Devonian Stratigraphy (SDS) in Morocco is extremely problematical because of relatively erratic distribution (probably owing to limited ecologic adaptability) ofP. ansatusandP. hemiansatusBultynck, considered herein to be an early morphotype ofP. ansatus.The base of the Givetian Stage has been defined by the SDS as coinciding with the lowest occurrence ofP. hemiansatus.The only possible evidence for the SDS'shemiansatusZone in North America involves reported occurrence of that morphotype in the uppermost Arkona Shale of Ontario, a position above the top of the Plum Brook Shale, which has been considered to be of Givetian age for decades. Also it appears that the interval between the Eifelian (lower Middle Devonian)kockelianusZone and thehemiansatusZone at the SDS's global-stratotype section in Morocco is of questionable age and probably too thin to represent continuous sedimentation. Adoption of a widely recognized faunal break at the base of strata deposited during the If T-R cycle of North America and Europe as the base of the Givetian could provide a sound alternative.
A microsaur from the Mississippian of illinois and a standard format for morphological characters
Authors: Lombard R. Eric , Bolt John R. 
Published: August 2016

The oldest known microsaur is preserved in a nodule from the Kinkaid Formation (Mississippian; Elvirian) collected near Goreville, Illinois. At least eight individuals are represented: three by partial skulls plus vertebral column segments with associated limb elements, and five by postcrania only. Skulls are crushed, incomplete, and exposed mainly in palatal view. Palatal bones are denticulate and the palatine has in addition a single large tooth. The basipterygoid process is laterally directed and the basipterygoid joint is open. The atlas carries large articulating facets for proatlantes, a pair of which are identifiable in one specimen. These features have not been found previously in a microsaur. All vertebral segments are dominated by a biconcave pleurocentrum; sutures between the pleurocentrum and neural arch are visible in presacral vertebrae. Distinctive microsaurian intercentra occur between all presacral pleurocentra. Their presence reinforces the hypothesis that microsaur intercentra are homologous with those of other early tetrapods. Caudal vertebrae retain separate haemal arches and some have ribs.Observed microsaur synapomorphies include: atlas with large median odontoid; atlas with concave lateral facets for occipital condyle; paired occipital condyles that are broad and concave; and thin, straplike intercentra. No observed features support a sister-group relationship with any other microsaur species, or placement within any higher level microsaur group. Because significant portions of the skeleton are missing or inaccessible, the Goreville microsaur is not formally named. A standardized, hierarchical format for skeletal characters is introduced that facilitates data sharing and comparison and fosters rapid archiving and retrieval.
Conodont biostratigraphy and paleoecology of Middle Ordovician rocks in eastern Oklahoma
Authors: Bauer Jeffrey A. 
Published: August 2016

Conodonts from the upper Burgen, Tyner, and Fite Formations (Middle Ordovician) of eastern Oklahoma include two new species,Phragmodus harrisiandPlectodina tynerensis. The conodont fauna indicates that the upper Burgen through middle Tyner is Whiterockian (pre- to earliest Chazyan) and that the upper Tyner–Fite is probably Kirkfieldian in age.The Whiterockian Burgen–Tyner preserves a regressive succession of shoreface, lagoonal, and intertidal deposits. That change is reflected by the conodont succession, which shows replacement of a fauna dominated by species ofNeomultioistodus, Scandodus?, andParaprioniodusby one dominated by species ofPhragmodus, Plectodina, andErismodus.Carbonate deposits of the Kirkfieldian(?) upper Tyner and Fite Formations follow a major hiatus and reflect shallow, subtidal to intertidal conditions. The conodont fauna is composed of species ofAphelognathus, Plectodina, Curtognathus, Erismodus, andOulodus, among others.
Bivalves (Mollusca) from the Imo Formation (Mississippian, Chesterian) of north-central Arkansas
Authors: Hoare R. D. , Heaney M. J. , Mapes R. H. 
Published: August 2016

The Chesterian Imo Formation in north-central Arkansas contains an abundant and diverse bivalve fauna which is dominated in numbers by nuculoids. The pterioids, pholadomyoids, and nuculoids show the greatest, and nearly equal, species diversity. Ecologically, on a generic level, the fauna is dominated by infaunal, burrowing, suspension feeders with attached suspension feeders a close second.Among the 40 taxa identified, the following new taxa are proposed: Economolopsis gordoni n. gen. and sp.; Spathelopsis browni n. gen. and sp.; Paleyoldia angustia n. sp.; P. bruta n. sp.; Phestia corrugata n. sp.; P. wortheni n. sp.; P. obtusa n. sp.; Imoella obscura n. gen. and sp.; Prothyris (Lophoprothyris) crista n. subgen. and sp.; Ectogrammysia crassatis n. gen. and sp.; Asketomorpha grandis n. gen. and sp.; and Sphenotus pisinnus n. sp.On the basis of ammonoids, the upper portion of the Imo Formation falls within the Elvirian Stage, E2b–c undifferentiated. Foraminifera place the formation in Mamet zone 19. The bivalve fauna discussed herein was collected from the E2b–c portion of the Imo.
Paleoecology of a well-preserved nautiloid assemblage from a Late Ordovician shale unit, southwestern Ohio
Authors: Frey Robert C. 
Published: August 2016

A diverse, well-preserved assemblage of nautiloid cephalopods was collected from theTreptoceras duserishale, a 1.5-m-thick claystone within the Waynesville Formation (Late Ordovician, early Richmondian) exposed in southwest Ohio. The strata, the enclosed fauna, and its taphonomy indicate deposition in a low-energy, mud-bottom marine environment, in water depths of 20–25 m, below wave base but within the zone of storm-current reworking.Nautiloid specimens consist of complete conchs that have been replaced by calcite. Twelve species of nautiloids, belonging to eight genera, representative of four orders, have been collected from the shale in southwest Ohio. Longiconic orthocones are clearly the dominant nautiloid morphotype present, with the assemblage dominated by three species of the longiconic orthoceridTreptocerasand with fewer numbers of the endoceridCamerocerasand the slender orthoceridIsorthoceras?, the cyrtoconic oncoceridsOncocerasandManitoulinoceras, and rare specimens of the orthoceridGorbyoceras, the oncoceridZittelloceras, and the ascoceridSchuchertoceras.Nautiloid taphonomy, the diversity of nautiloid taxa present, the lack of postmortem buoyancy in the shells of the more common taxa, the recurrent nature of this assemblage, and the restricted distribution of thisTreptoceras–Camerocerasfauna to portions of eastern North America in the Late Ordovician suggest that this nautiloid assemblage represents an in-situ accumulation of nautiloids representative of a living assemblage. These nautiloids were important elements associated with benthic communities in these epeiric sea mud-bottom environments and not simply assemblages of drifted, necroplanktonic shells.
New Paleogene Fimbria (Mollusca: Bivalvia) from the Pacific Coast of southwestern North America
Authors: Squires Richard L. 
Published: August 2016

The marine bivalve Fimbria susanensis n. sp. is reported from the uppermost Paleocene part of the “Meganos Stage” in the upper Santa Susana Formaton, Simi Hills, southern California.Fimbria pacifica n. sp. is reported from the middle lower Eocene “Capay Stage” strata of the Pacific coast of southwestern North America. The new species is present in the lower Bateque Formation, Baja California Sur, Mexico, and in the lower Juncal Formation, Whitaker Peak area and Santa Ynez Mountains, southern California.Fimbria susanensis n. sp. and F. pacifica n. sp. are the only fimbriids known from the Pacific coast of North America. Previously reported Pacific coast species, which gave a range of Late Cretaceous to late Eocene for this genus in this particular area, do not belong to Fimbria.
Fossil communities of the upper Trenton Group (Ordovician) of New York State
Authors: Titus Robert 
Published: August 2016

During the late Trentonian the New York State region experienced gentle crustal subsidence which preceded the onset of the Hudson Valley phase of the Taconic Orogeny. The lower and middle Steuben Limestone represents several shallow-water facies: a protected shoal, a wave dissipation zone and a shallow shelf. Overlying strata of the upper Steuben and the Hillier limestones represent progressively deeper water facies. After a short period of uplift, which produced a minor unconformity, black shales began to bury the Trenton carbonate platform.Three fossil communities are found in the upper Trenton Group. Each had been present on the Trenton bank since it first formed. The Liospira Community existed on the shallow protected shoal facies of the Steuben Limestone. Its assemblages are dominated by brachiopods, gastropods, bryozoans, and crinoids. The Encrinurus Community was found in the wave dissipation zone and on the shelf facies. This diverse community was dominated by brachiopods, bryozoans, and crinoids. The Trematis Community is found in the deeper shelf deposits of the Hillier Limestone. It was a very heterogeneous community with brachiopods, crinoids, gastropods, trilobites, and conodonts all represented.These communities have now been traced through a minimum of eight million years of their history and it is now possible to evaluate their patterns of community evolution. At the species level these communities were quite changeable. Between 45% and 55% of the species which were present in the lower Trenton Group were replaced by the late Trentonian. Despite this changeover, the communities maintained a remarkably familiar look because there was great stability at higher taxonomic levels and the same proportions of brachiopods, bryozoans, crinoids, etc., were maintained throughout the Trentonian. Community trophic group structure also seems to have been quite stable throughout the Trentonian. If these patterns are representative, then these invertebrate communities appear to be genuinely stable entities. Evolution changes the cast of characters but the play is the same!
New camerate crinoids of the suborder Glyptocrinina from the Lower Silurian Brassfield Formation (southwestern Ohio)
Authors: Ausich William I. 
Published: August 2016

Patelliocrinus planus n. sp. (Patelliocrinidae), Manticrinus exaitos n. gen., n. sp. (Marsupiocrinidae), and Clematocrinus ohioensis n. sp. (Hapalocrinidae) are described from southwestern Ohio. These new Early Silurian crinoids are from the upper lower or middle Llandoverian Brassfield Formation. Patelliocrinus planus is the oldest member of this genus. It was originally designated as Platycrinid(?) by Foerste (1919) and, subsequently, Brower (1973) placed it in the Hapalocrinidae. Manticrinus is placed in the Marsupiocrinidae, previously a monogeneric family, and is the oldest member of this family. Manticrinus is judged to have evolved from Macrostylocrinus.Species assignments are clarified between Clematocrinus and Hapalocrinus. These genera are distinguished by character of the arms, primibrachial number, and presence of cirri. Clematocrinus ohioensis is the oldest member of this genus and perhaps of the Hapalocrinidae.
Vertebrate paleontology, geology, and geochronology of the Tapera de López and Scarritt Pocket, Chubut Province, Argentina
Authors: Marshall Larry G. , Cifelli Richard L. , Drake Robert E. , Curtis Garniss H. 
Published: August 2016

Fossil land mammals were collected by G. G. Simpson in 1933–1934 at and near the Tapera de López in central Chubut Province, Patagonia, southern Argentina, from rocks now mapped as the Sarmiento Formation. These fossils are assigned to land mammal faunas of Casamayoran (Early Eocene), Mustersan (Middle Eocene), and Deseadan (late Early Oligocene through Early Miocene) age.40K-40Ar age determinations of eight basalt and two tuff units associated with the Deseadan age local fauna at Scarritt Pocket establish a geochronologic framework that calibrates the biostratigraphic record at this locality. The radioisotope dates obtained at Scarritt Pocket range from 23.4 Ma to about 21.0 Ma, and equate with earliest Miocene time. The Scarritt Pocket local fauna is the youngest dated Deseadan age fauna yet known in South America.Seven other localities have, or were reputed to have, local faunas of Deseadan age associated with dated volcanic units. Six of these localities are in Argentina (Gran Barranca, Cerro Blanco, Valle Hermoso, Pico Truncado, Cañadón Hondo, Quebrada Fiera de Malargüe) and one in Bolivia (Estratos Salla in the Salla-Luribay Basin). The stratigraphic relationships of the volcanic units with these local faunas is discussed, and the taxonomic content of each is reassessed.The Deseadan Land Mammal Age is defined by the earliest record of the land mammal genus Pyrotherium, which is from below a basalt dated at 33.6 Ma at Pico Truncado. Other early records of Pyrotherium occur below basalts dated at about 29 Ma at the Gran Barranca and Valle Hermoso, and from a 28.5 Ma level of the Estratos Salla. Thus, the lower boundary for Deseadan time is about 34 Ma.The youngest record of Pyrotherium is in the upper levels of the Estratos Salla dated at about 24 Ma. However, the Scarritt Pocket local fauna, which lacks Pyrotherium, permits placement of the upper boundary for Deseadan time at about 21.0 Ma. Late Deseadan time is surely, and the end of Deseadan time is apparently, marked by the last record of such groups as Proborhyaeninae (Proborhyaena), Rhynchippinae (Rhynchippus), Archaeohyracidae (Archaeohyrax), and the genera Platypittamys (Octodontidae), Scarrittia (Leontiniidae), Propachyrucos and Prohegetotherium (Hegetotheriidae), and Argyrohyrax (Interatheriidae), as these taxa are recorded in the Scarritt Pocket local fauna. Thus, Deseadan time extends from about 34.0 Ma to about 21.0 Ma, making it the Land Mammal Age with the longest known duration in South America.