bluuebunny/crossref_metadata_2025 huggingface dataset:
Catastrophic versus noncatastrophic extinction of the dinosaurs: testing, falsifiability, and the burden of proof
Authors: Williams Michael E.
Published: August 2016

In the dozen years since Alvarez et al. (1980) proposed their argument for dinosaur (and other) extinctions, lengthy debate has provided no consensus and the issue remains strongly polarized. The only test that has been proposed, that of additional fieldwork that sought to fill in the “gap” at the top of the Hell Creek Formation, recently has been conducted by Sheehan et al. (1991). Although the analysis found no indication of a gradual decline through the bulk of the formation, it did not produce the distribution Alvarez sought, a random distribution of remains clear through to the iridium. A second test based on the differing taphonomic predictions of catastrophic and noncatastrophic extinctions, and a comparison with the distribution of remains in the uppermost part of the formation, gives some credence to the latter and places considerable doubt on the former.
The calcareous nannofossil species Nephrolithus frequens Górka (1957) and its morphotypes
Authors: Ehrendorfer Thomas
Published: August 2016

A complete morphologic intergradation from biperforate to multiperforate specimens of Nephrolithus frequens Górka (1957) occurs in the uppermost Maastrichtian chalk at southern high-latitude ODP Holes 750A (Kerguelen Plateau, southern Indian Ocean) and 690C (Maud Rise, Weddell Sea). Previous workers have assigned taxonomic importance to the number of pores of the central area. Two subspecies, N. frequens subsp. frequens and N. frequens subsp. miniporus, were recently differentiated (Pospichal and Wise, 1990) based on this character (four or more pores and two pores, respectively). The observation of specimens of Nephrolithus frequens with three pores in the central area indicates that there is no “natural” breaking point in a progression from two to numerous pores and that specimens of N. frequens with different pore numbers should be considered morphotypes of a single species exhibiting a high intraspecific variability. In addition, our observations using the scanning electron microscope and light microscope illustrate that in well-preserved specimens each pore in the central area is surrounded by two cycles of elements. The margin consists of two cycles, with the elements of the inner cycle extending proximally about twice as far as the elements of the outer cycle.
New Middle Silurian hexactinellid sponge from the Mackenzie Mountains, Northwest Territories, Canada
Authors: Rigby J. Keith , Chatterton Brian D. E.
Published: August 2016

Several specimens of the small hexactinellid, Cyathophycus mackenziensis n. sp., were collected from pale brown, shaly mudstone of the Road River Formation. The sponges are of Wenlock age and were collected from near Avalanche Lake, Mackenzie Mountains, Northwest Territories, Canada. The small, steeply obconical sponges have skeletons in crudely ranked quadrules to at least third-order, with first-order openings generally 2 mm high and 1 mm wide. Successive orders decrease in stages approximately half that of larger elements. A moderately irregular dermal(?) layer with circular parietal gaps is suggested in some specimens. The new species is consistently finer textured than either the type species Cyathophycus reticulatus Walcott, 1879, or the later described Cyathophycus quebecensis Dawson, 1889.
Phylogenetic relationships of the Middle Ordovician trepostome bryozoansSonninoporaandBimuropora
Authors: Key Marcus M. , Judd Andrew B.
Published: August 2016

Bimuropora dendroidea, previously assigned to other genera, is described from Tennessee andB. winchelliis reported from Nevada. The occurrence ofB. winchelliin Nevada extends the geographic range of the Middle Ordovician trepostome genusBimuroporain North America. These two species share many derived characteristics with the halloporids, including a similar growth pattern and fluted zooecial walls in the endozone. This strengthens the hypothesis that the bimuroporids are a sister group to the halloporids.Sonninopora, a monospecific genus, contains these same features, and because of the presence of acanthostyles it is removed from the family Halloporidae and assigned to the family Bimuroporidae.
Late Cretaceous-early Tertiary gastropods from southwestern Patagonia, Argentina
Authors: Griffin Miguel , Hünicken Mario A.
Published: August 2016

The continuous sequence of Maastrichtian to Paleocene sediments exposed in the Sierra Dorotea area in southwestern Santa Cruz (Argentina) contains a rich molluscan fauna with many elements characteristic of the Weddellian Faunistic Province. The presence in this fauna of genera such asTaioma, Heteroterma, Fyfea, Zemacies, andPriscaphandersuggests close affinities with faunas of similar age from New Zealand, further supporting the existence of continuous shallow-sea conditions along the southern margin of the Pacific Ocean during the end of the Cretaceous and beginning of the Tertiary. In this paper 25 species are described, of which six are new:Pseudofax costellatusn. sp.,Taioma patagonican. sp.,Heteroterma elegansn. sp.,Fyfea beuin. sp.,Priscaphander sanjosensisn. sp., andPriscaphander bracacciniin. sp.
Middle Tertiary marsupials (Mammalia) from North America
Authors: Korth William W.
Published: August 2016

All species of North American marsupials from the Chadronian through Hemingfordian are reviewed. Most North American species of didelphids previously referred toPeratheriumare allocated toHerpetotherium.Five species ofHerpetotheriumare recognized.

The ChadronianPeratherium donahoeiHough is synonymized withHerpetotherium valens(Lambe). The Orellan speciesHerpetotherium stevensoniCope is resurrected and referred, along with the ChadronianPeratherium titanelixMatthew, to a new genus,Copedelphys.BothCopedelphysandHerpetotheriumcan be derived from known Duchesnean species ofPeratheriumfrom North America.

Two genera of peradectids are recognized,NanodelphysMcGrew andDidelphidectesHough.Nanodelphys minutusis synonymized with“Herpetotherium” huntiCope and a second species ofNanodelphysis recognized from the Arikareean, though not named.
Fossil actinomycete in Eocene-Oligocene Dominican amber
Authors: Waggoner Benjamin M.
Published: August 2016

Actinomycetes are Gram-positive prokaryotes that tend to form branching and fragmenting filaments, which in some groups form a sizable mycelium. They make up a large and important part of modern terrestrial microfloras but are not known extensively as fossils, although they have a long fossil history. Actinomycete-like fossils appear several times in the Precambrian: in the middle Precambrian Gowganda Formation of Ontario (Jackson, 1967), in the 2.0 Ga Gunflint Chert of Ontario (Lanier, 1987), and possibly in a lichen-like symbiosis in the 2.8 Ga Witwatersrand rocks of South Africa (Hallbauer and Van Warmelo, 1974), among others. Direct fossil evidence of actinomycetes is very rare in the Phanerozoic, and some “fossil” actinomycetes may be later contaminants (Knoll, 1977; Smoot and Taylor, 1983). Hyphae identified as actinomycetes are known from rod-like bodies identified as nematodes inside a decaying scorpion from the lower Carboniferous of Scotland (Stoermer, 1964), and from the interior of fern phloem cells from the Pennsylvanian (Smoot and Taylor, 1983). UnmineralizedActinomyces-like cells are known from calcite in bituminous lake-bed sediments from the early Cretaceous of Nevada (Bradley, 1963), and similar, poorly preserved fossils of a form calledActinomyciteshave been reported from the Jurassic of Scotland (Ellis, 1915). Actinorhizal nodules, formed by actinomycetes symbiotic with plant roots, have been described from the late Pleistocene (Baker and Miller, 1980).
First report of Lercaritubus in North America, from the Permian Capitan Limestone, Guadalupe Mountains, New Mexico
Authors: Senowbari-Daryan Baba , Rigby J. Keith
Published: August 2016

Lercaritubus problematicus Flügel, Senowbari-Daryan, and Di Stefano, 1990, a problematic organism, was initially described from Lower and Middle Permian rocks of Sicily, was subsequently recognized in Upper Permian reefs of Oman and reefal limestones of the Tethyan realm. It is here described for the first time from North America, from the Middle Permian reefoidal Upper Capitan Limestone of the Guadalupe Mountains in New Mexico. Lercaritubus problematicus has a stratigraphic range of Lower to Upper Permian and occurs widely in Permian tropical reef deposits.
Late Eocene chemosynthetic? bivalves from suspect cold seeps, Wagonwheel Mountain, central California
Authors: Squires Richard L. , Gring Michael P.
Published: August 2016

An anomalous pair of small, isolated calcareous sandstone bodies in the middle member of the upper Eocene Wagonwheel Formation, Wagonwheel Mountain, of the San Joaquin Valley, California, contain numerous articulated specimens of soft-bottom-dwelling bivalves. The lucinid bivalve Epilucina washingtoniana (Clark, 1925) dominates the fauna, which also sparingly contains the thyasirid bivalve Conchocele bisecta (Conrad, 1849) and the vesicomyid bivalve Vesicomya (Vesicomya) aff. V. (V.) tschudi Olsson, 1931.

The fossils in the pair of calcareous sandstone bodies, which are surrounded by deep-water silty mudstone barren of megafossils, most likely represent cold-seep communities in the upper bathyal environment. These cold seeps apparently were formed by diffusive flow through coarse sand-fill material in submarine channels.

Epilucina washingtoniana was previously known only from upper Eocene rocks on the Olympic Peninsula, Washington, and in Santa Barbara County, southern California. This species, along with a late Eocene species from Colombia, South America, are the earliest representatives of Epilucina. The Wagonwheel Formation contains one of the earliest records of Conchocele bisecta, which is a widespread Cenozoic fossil and is extant in the north Pacific. The species of Vesicomya in the Wagonwheel Formation is the earliest record of Vesicomya s.s. and has close affinity to Vescicomya (Vesicomya) tschudi Olsson, 1931, from the upper Oligocene of northwestern Peru, South America. As in the case of Conchocele bisecta, Vesicomya s.s. has not been reported previously from the Eocene of California.
An Archimedes-like cyclostome bryozoan from the Eocene of North Carolina
Authors: Taylor Paul D. , McKinney Frank K.
Published: August 2016

A distinctive spiral unilaminate cyclostome bryozoan, recently discovered in the Eocene Castle Hayne Limestone Formation of eastern North Carolina, is described as Crisidmonea archimediformis new species. Colonies have a thickened spiral axis bearing systems of bifurcating branches. When worn and stripped of their branches, the resistant axes closely resemble the familiar screws of the Carboniferous to Permian fenestrate bryozoan genus Archimedes. However, the Eocene screws are shorter and become more loosely coiled with growth, corresponding to a helicospiral rather than a helical form. The paleoenvironment inhabited by C. archimediformis colonies is inferred to have been on the shallow (< 30 m depth) margin of an open marine, waveswept embayment. Autozooid distribution and the gradient of increasing apertural size from branch reverse to frontal sides in C. archimediformis resemble those of the living cyclostome Exidmonea atlantica and suggest colonial water currents that flowed upwards and inwards through the spiral colony. Polyascosoecia, a genus closely related to Crisidmonea, is shown to be an objective junior synonym of Reteporidea, and the new genus Polyascoeciella (type species Idmonea foraminosa Reuss) is introduced for species with exterior-walled gonozooids that were previously assigned to Polyascosoecia.
Genus Arctomelon (Gastropoda, Volutidae) in the Tertiary of the northwestern Pacific: Evolution and adaptations
Authors: Oleinik Anton E.
Published: August 2016

The fossil record of the volutid gastropod Arctomelon is represented by three species from the Koryak Upland and the Kamchatka Peninsula (Russian northeast), ranging in age from late middle Eocene to early Miocene. Although Recent Arctomelon stearnsii (Dall, 1872) from the northeastern Pacific is a cold-water species, paleontological data point to the origin of the genus in shallow, warm-water conditions that existed in high latitudes of the northwestern Pacific during Paleogene time. The fossil record also indicates survival of the genus during the climatic coolings through the Cenozoic. It is apparent that Arctomelon successfully adapted to the new cooler and deeper-water conditions. Despite this major change of life habit, shell morphology has remained fairly unchanged since the Eocene. Two new species of the genus Arctomelon, A. harasewychi sp. nov. and A. rateginense sp. nov., are described.
Early Cambrian palaeoscolecid cuticles from Shaanxi, China
Authors: Zhang Xi-Guang , Pratt Brian R.
Published: August 2016

Phosphatized, three-dimensional cuticle fragments of the palaeoscolecids Houscolex lepidotus new genus and new species, Houscolex species indeterminate, and an unidentified form are described from the Lower Cambrian Qiongzhusi Formation of Shaanxi, China. These segmented worms, characterized by regularly arranged simple plates and platelets, small circular pores and fine pits, and irregularly distributed nipplelike protuberances, are unique among known palaeoscolecids. The occurrence of such cuticles as seemingly persistent elements of phosphatized faunas suggests that wormlike organisms achieved a fairly high diversity and widespread geographic distribution during the Early and Middle Cambrian.
The “evolution” of Anomalocaris and its classification in the arthropod class Dinocarida (nov.) and order Radiodonta (nov.)
Authors: Collins Desmond
Published: August 2016

The remarkable “evolution” of the reconstructions of Anomalocaris, the extraordinary predator from the 515 million year old Middle Cambrian Burgess Shale of British Columbia, reflects the dramatic changes in our interpretation of early animal life on Earth over the past 100 years. Beginning in 1892 with a claw identified as the abdomen and tail of a phyllocarid crustacean, parts of Anomalocaris have been described variously as a jellyfish, a sea-cucumber, a polychaete worm, a composite of a jellyfish and sponge, or have been attached to other arthropods as appendages. Charles D. Walcott collected complete specimens of Anomalocaris nathorsti between 1911 and 1917, and a Geological Survey of Canada party collected an almost complete specimen of Anomalocaris canadensis in 1966 or 1967, but neither species was adequately described until 1985. At that time they were interpreted by Whittington and Briggs to be representatives of “a hitherto unknown phylum.”

Here, using recently collected specimens, the two species are newly reconstructed and described in the genera Anomalocaris and Laggania, and interpreted to be members of an extinct arthropod class, Dinocarida, and order Radiodonta, new to science. The long history of inaccurate reconstruction and mistaken identification of Anomalocaris and Laggania exemplifies our great difficulty in visualizing and classifying, from fossil remains, the many Cambrian animals with no apparent living descendants.
A new Tethyan migrant:Cretachlorodius enciensisn. gen., n. sp. (Crustacea, Decapoda), from the Maastrichtian type area
Authors: Fraaye René H. B.
Published: August 2016

A new genus and species of crab is described from the late Maastrichtian Meerssen Member of the Maastricht Formation at the type area of the Maastrichtian Stage, SE Netherlands. This new taxon could well be the ancestor of the xanthidProchlorodius-Chlorodiellagroup and its occurrence provides additional evidence of a late Cretaceous radiation among the decapod crustaceans.
An unusual new sinuitid mollusc (Bellerophontoidea, Gastropoda) from the Ordovician of Spain
Authors: Frýda Jiří , Gutiérrez-Marco Juan Carlos
Published: August 2016

Hispanosinuites peeli new genus and species from the Lower Oretan shales (Middle Ordovician) of central Spain is described and placed in the new subfamily Hispanosinuitinae of the family Sinuitidae. This new subfamily is considered to represent a highly specialized phylogenetic lineage, which probably separated from the morphological range of the genus Sinuites during the Early Ordovician. The outer shell surface of Hispanosinuites peeli is entirely covered by secondary shell layers, which are interpreted as perinductura, inductura and coinductura. The similarity of these shell deposits in Hispanosinuites peeli and species of Euphemites suggests that these layers were secreted by mantle flaps having the same form in both genera. Hispanosinuites peeli is interpreted as a mobile mollusc with an internal shell adapted to an infaunal mode of life. Discovery of this unusual mollusc reopens the question of the phylogenetic relations of the families Sinuitidae and Euphemitidae, which are often assigned to different molluscan classes.
Heliolitine corals of the upper Douro Formation (Upper Silurian), Canadian Arctic Islands
Authors: Dixon Owen A.
Published: August 2016

Heliolitine corals are closely associated with lithistid sponge-dominated reef mounds in Ludlow carbonate ramp facies on Somerset Island. The corals occur abundantly in argillaceous, fossiliferous wackestone immediately flanking and capping the reef mounds, less commonly in calcilutite mudstone within the reef mounds, and with sharply decreasing abundance in nodular argillaceous wackestone to mudstone away from the reef mounds. Exhaustive field collection, and systematic study that included biometric analysis of collected assemblages, indicates that ten heliolitine species are present, including the new species Heliolites furyi, H. garnieri, and H. greineri, and two unidentified species, Heliolites sp. A, and Podollites? sp. The occurrence of H. subdecipiens Klaamann, 1984, H. tchernyshevi Bondarenko, 1966, H. cf. H. rariformis Tchi, 1976, Stelliporella cf. S. podolica Bondarenko, 1971, and Squameolites anomalus Tchi, 1976 indicates an affinity with Eurasian rather than North American faunas of equivalent age. Many new species have been ascribed to Stelliporella since the mid-1970s; most lack the diagnostic axial structures of the genus and are more appropriately regarded as belonging to Heliolites. Newly defined structures termed septal florets occur commonly in H. garnieri and very rarely in three other species of Heliolites. Effective taxonomic use of septal development requires very careful study because of the degree of intraspecific and intracolony variation in some species.
Freshwater gastropods from Early Eocene Difunta Group, northeastern Mexico
Authors: Vega Francisco J. , del Carmen Perrilliat Maria
Published: August 2016

Three new species of freshwater gastropods are described from the lower Eocene Adjuntas Formation. Five more species are reported from the same fauna. This is the first report of Tertiary freshwater Mollusca of the Campanian–lower Eocene Difunta Group. The three new species (Hemisinus (Longiverena) reticulosus, Hemisinus (Longiverena) adjuntaensis, and Melanatria ypresiana) belong to the family Thiaridae, which today is a worldwide distributed group of freshwater gastropods of medical importance. Paleoenvironmental interpretation for red, green, and yellow beds of Adjuntas Formation suggests delta-plain deposits. Gastropods here described lived in swamps and marshes of this portion of the ancestral Gulf of Mexico.
Scanning Em study of the living cyrtocrinid Holopus rangii (Echinodermata, Crinoidea) and implications for its functional morphology
Authors: Donovan Stephen K.
Published: August 2016

The unusual extant crinoid Holopus rangii d'Orbigny lacks a column, cements directly to hard substrates, has a conical to tubular dorsal cup in which plate sutures cannot be discerned, and has 10 tapered arms that are able to enroll swiftly into a “fist-like” configuration when disturbed. The first SEM study of H. rangii is presented herein. The gross morphology and skeletal microstructure of this species display many characteristics that bear an obvious relationship to the functional morphology of the living animal. Dorsal cups show a range of morphologies, reminiscent of those found in acorn barnacles and other tubular encrusters. During arm enrollment, the adjacent arms abut and form an impervious seal. Of the two specimens dissected, one had a regenerating arm.
Systematics and biogeography of the “Metacryphaeus group” Calmoniidae (Trilobita, Devonian), with comments on adaptive radiations and the geological history of the Malvinokaffric Realm
Authors: Lieberman Bruce S.
Published: August 2016

Phylogenetic parsimony analysis was used to classify the Siegenian–Eifelian “Metacryphaeus group” of the family Calmoniidae. Thirty-eight exoskeletal characters for 16 taxa produced a shortest-length cladogram with a consistency index of 0.49. A classification based on retrieving the structure of this cladogram recognizes nine genera: Typhloniscus Salter, Plesioconvexa n. gen., Punillaspis Baldis and Longobucco, Eldredgeia n. gen., Clarkeaspis n. gen., Malvinocooperella n. gen., Wolfartaspis Cooper, Plesiomalvinella Lieberman, Edgecombe, and Eldredge (used to represent the malvinellid clade), and Metacryphaeus Reed. The malvinellid clade is most closely related to a revised monophyletic Metacryphaeus. Typhloniscus is the basal member of the “Metacryphaeus group,” and the monotypic Wolfartaspis is sister to the clade containing the malvinellids and Metacryphaeus. Six new species are diagnosed: Punillaspis n. sp. A, “Clarkeaspis” gouldi, Clarkeaspis padillaensis, Malvinocooperella pregiganteus, Metacryphaeus curvigena, and Metacryphaeus branisai. Primitively, this group has South African and Andean affinities, and its evolutionary history suggests rapid diversification. In addition, evolutionary patterns in this group, and the distribution of character reversals, call into question certain notions about the nature of adaptive radiations. The distributions of taxa may answer questions about the number of marine transgressive/regressive cycles in the Emsian–Eifelian of the Malvinokaffric Realm.
Response by Malcolm C. McKenna: For the Award of the Paleontological Society Medal 27 October 1992
Authors: McKenna Malcolm C.
Published: August 2016

President Kaesler, John Flynn, members of the Society, and guests, this has come as a very pleasant surprise. I am only sorry not to be here in person to blush at the remarks of my friend and former student. Or is it student and former friend? At the moment I'm in the hinterlands of China. In case John has said anything he shouldn't, rest assured that I'll get even!
Presentation of the Harrell L. Strimple Award of The Paleontological Society to Gerard R. Case
Authors: Schwimmer David R.
Published: August 2016

I have known Gerard R. Case for only twelve among his thirty-odd years of work in vertebrate paleontology, but from that relatively limited vantage point, I'd say this year's awardee is a phenomenon, in most of the literal meanings of that word. Jerry is simultaneously an amateur and the prime North American authority on Mesozoic and Paleogene shark taxonomy. That fact says much about Jerry's energies and dedication, and perhaps a bit about the state of our science; nevertheless, I am very pleased that The Paleontological Society has granted the award to him this year for many reasons, not the least of which is that Jerry will now stop asking me whether or not “they're going to give him the award while he's still alive.”
Microborings and growth in Late Ordovician halysitids and other corals
Authors: Elias Robert J. , Lee Dong-Jin
Published: August 2016

Microborings in the Late Ordovician tabulate coralsCatenipora rubra(a halysitid) andManipora amicarum(a cateniform nonhalysitid) and in an epizoic solitary rugose coral differ from nearly all of those previously reported in Paleozoic corals. These microborings were formed within the coralla by endolithic algae and fungi located beneath living polyps. Comparable structures in the Late Ordovician tabulateQuepora?agglomeratiformis(a halysitid) represent algal microborings, not spicules, and halysitids are corals, not sponges as suggested by Kaźmierczak (1989).

Endolithic algae in cateniform tabulates relied primarily on light entering through the outer walls of the ranks rather than through the polyps; lacunae within coralla permitted appropriate levels of light to reach many corallites. The direction of boring was determined by corallum microstructure and possibly also by the distribution of organic matter within the skeleton. There is an apparent inverse correlation between boring activity and coral growth rate.

The location and relative abundance of pyritized microborings within calcareous coralla can be established quantitatively and objectively from electron microprobe determinations of weight percent sulfur along appropriate traverses of the coral skeleton. The distribution of such microborings inCatenipora rubraandManipora amicarumis comparable to algal banding in modern corals; this is the first report of such banding in the interiors of Paleozoic corals. Change in the intensity of boring within each corallum was evidently a response to variation in the linear growth rate of the coral, or to fluctuation in an environmental factor (perhaps light intensity) that could control both algal activity and growth rate in these corals. Change in the algal boring intensity and linear growth rate of the coral was generally but not always seasonal and usually but not invariably associated with change in the density of coral skeletal deposition.

Cyclic bands of boring abundance maxima within fossil colonial corals provide a measure of annual linear growth comparable to the widely accepted method based on skeletal density bands. Algal bands are more sporadically developed than density bands within and among coralla, thus increasing the difficulty of interpretation. Fluctuations in the abundance of algal microborings apparently provide a detailed record of changes in the linear growth rate of colonies and of individuals within colonies. Combined analyses of microboring abundance and skeletal density will contribute significantly to our understanding of the biological and environmental factors involved in endolithic activity and coral growth.
Catastrophic death assemblage ofChelomophrynus bayi(Anura, Rhinophrynidae) from the Middle Eocene Wagon Bed Formation of central Wyoming
Authors: Henrici Amy C. , Fiorillo Anthony R.
Published: August 2016

A unique monospecific bonebed of rhinophrynid anurans was recently discovered in the Wagon Bed Formation (Middle Eocene, Uintan), Hot Springs County, Wyoming. The bonebed occurs on a single bedding plane within a thin sandstone layer. This unit is part of a nearshore facies of a calcium carbonate-rich lake in which the water was warm, shallow, and quiet at the site of the mortality layer.

A representative area of this bonebed, approximately 450 square centimeters in size, provides the basis for this taphonomic and paleoecologic study. This area contains approximately 600 bones and at least 19 individuals are represented. Skeletons are nearly completely disarticulated but somewhat associated, bone modification features are absent, a slight preferred orientation of the linear bones is present, and many of the lighter, less dense skeletal elements are underrepresented. Scavengers probably contributed to disarticulation of the skeletons. Bone depletion occurred by a combination of the action of scavengers, weak currents, and the sloughing off of body parts as the carcasses floated. The assemblage was not subjected to extensive winnowing by currents.

All of the specimens within this assemblage represent young adults. Because the frogs are all of the same ontogenetic age and the deposit shows no signs of time averaging, the assemblage is interpreted as the result of catastrophic death, possibly by disease, of one age class. Either a population of frogs inhabited the site where the mortality layer formed or the carcasses floated into it.
New specimen of Basilemys praeclara Hay and its bearing on the relationships of the Nanhsiungchelyidae (Reptilia: Testudines)
Authors: Brinkman Donald , Nicholls Elizabeth L.
Published: August 2016

A new specimen of the Cretaceous trionychoid turtle Basilemys praeclara Hay, from the Frenchman Formation (Upper Maastrichtian) of Saskatchewan, confirms the validity of the species, previously known only from the type specimen. Basilemys praeclara is considered the sister taxon of Basilemys sinuosa, and the restriction of this clade to the late Maastrichtian reinforces the distinctiveness of the Lancian chelonian fauna from the older Judithian chelonian fauna. Basilemys, Nanhsiungchelys, and Zangerlia comprise the family Nanhsiungchelyidae, with Basilemys and Nanhsiungchelys being sister taxa within the family.
A Lower Pennsylvanian encrusting tabulate coral from a rocky shore environment developed on the Mississippian—Pennsylvanian unconformity surface in northwestern Arkansas
Authors: Webb Gregory E.
Published: August 2016

Paleozoic corals are very rare in rocky shore settings. The only Paleozoic encrusting coral so far reported from this environment isFavositessp. from Ordovician rocky shore deposits in Manitoba, Canada (Johnson and Baarli, 1987). Reading and Poole (1961) reported corals and brachiopods that occur between, and “coating,” boulders from a Silurian rocky shore in England, but it appears that the corals and brachiopods only occur in the sediment enveloping the boulders, not as encrusters on the surfaces of the boulders. One reason for the sparse record of Paleozoic corals in rocky shore settings is the scarcity of described Paleozoic rocky shore deposits themselves. Johnson (1988) found only 20 examples of Paleozoic rocky shores in a compilation of references on ancient rocky shores from the literature. The paucity of described ancient rocky shores has been attributed to the prevalence in the past of epicontinental seas with little relief upon which to develop rocky shores and with higher wave attenuation farther from shore (Boucot, 1981; Harland and Pickerill, 1984). Johnson (1988) concluded that the major reason for the rarity of ancient rocky shores in the literature is the difficulty with which they are recognized and studied, owing to the relatively poor exposure of most unconformity surfaces. The rocky shore environment was also probably hostile to many Paleozoic coral genera. Recent scleractinian corals may serve as analogues because they are also not very abundant in rocky shore settings despite their great abundance in similar shallow-water, high-wave-energy reefal environments. Turbidity and relative substrate stability may be important limiting factors for corals in rocky shore environments. Many corals are known to be highly sensitive to sediment in the water column. Substrate stability (Wilson, 1987) and the scouring effects of sand in high-energy environments (Palmer and Palmer, 1977) also have been shown to affect the abundance and diversity of organisms encrusting cobbles and boulders.
New genus of Late Cambrian gastropod
Authors: Gunderson Gerald O.
Published: August 2016

Gastropods are rare fossils in the Cambrian of Wisconsin. They are usually small and flattened. During the summer of 1978, while collecting trilobites along the western side of the state, I discovered a new gastropod in the Crepicephalus zone (as defined by Twenhofel, Raasch, and Thwaites, 1935; Nelson, 1951). It is a three-dimensional fossil represented by external mold and steinkern. This was the only gastropod uncovered during the splitting of over 200 kilograms of sandstone, which also yielded hundreds of trilobite cranidia and pygidia.
New pteraspidid (Agnatha: Heterostraci) from the Lower Devonian Water Canyon Formation of Utah
Authors: Elliott David K.
Published: August 2016

The extensive fauna of vertebrates from the Lower Devonian Water Canyon Formation of Utah was initially reported and described by Branson and Mehl (1930, 1931), and subsequently described in detail by Denison (1952, 1953, 1958, 1967). A major part of the fauna consists of heterostracans, particularly pteraspidids (Denison, 1953, 1967), and to date six species are known from the Water Canyon Formation. This fauna comes from the upper Emsian and is similar in age to that of the Beartooth Butte Formation of Wyoming and Montana, and also to faunas recently reported from Nevada and California (Elliott, 1989; Ilyes and Elliott, 1991, 1992).
Benthic invertebrates of a modern carbonate ramp: a preliminary survey
Authors: Ivany Linda C. , Newton Cathryn R. , Mullins Henry T.
Published: August 2016

A preliminary survey of benthic invertebrates off central west Florida provides documentation of modern epifaunal communities on a low-gradient carbonate slope. Three large-scale biofacies occur in soft-sediment carbonate environments between 200 and 2,000 m: an Echinoderm biofacies (200–550 m) dominated by a diverse assemblage of echinoderms, gastropods, and decapod crustaceans; a Penaeid shrimp–conical mound biofacies (550–1,200 m) characterized by large bioturbation structures; and a Microbial mat biofacies (1,200–2,000 m) with only rare epifaunal invertebrates. A fourth, hard-substrate biofacies reflects the presence of localized Miocene and Pleistocene hardgrounds in water depths of 200–600 m. This illustrates that hard-substrate biofacies may be laterally correlative with soft-sediment biofacies in a slope setting, thus producing a mosaic of contrasting faunal associations. All four biofacies have low population densities, presumably as a consequence of relatively low surface productivity. All four biofacies also show biogeographic affinity with other faunas at intermediate depths in the Caribbean region. Depth-related faunal transitions on the west Florida slope correlate with substrate and current velocity. Decreasing species diversity and abundance and a biofacies transition from suspension-feeding to deposit-feeding assemblages correlate with increasing depth, a decrease in mean grain size, and an increase in organic content of the sediment. This biofacies model may provide a modern analogue for faunas of ancient low-gradient slopes such as those of Cretaceous “shelf-sea” chalks of northwestern Europe.
Revision of the type species ofAcrotretaand related lingulate brachiopods
Authors: Holmer Lars E. , Popov Leonid E.
Published: August 2016

The poorly known type species ofAcrotreta, A. subconicaKutorga, 1848 [=Spondylotreta facetaGorjansky, 1969], is redescribed and a neotype selected from the lower Arenig (Billingen Stage, Oeland Series) Päite beds in the environs of St. Petersburg (Tosna river), Russia.Acrotretais also the type of the lingulate brachiopod family Acrotretidae Schuchert, 1893, and order Acrotretida Kuhn, 1949. Four new species are described:A. korynevskiifrom the upper Tremadoc–lower Arenig, South Ural Mountains;A. tallinnensisfrom the upper Arenig (Volkhov Stage), Tallinn, northern Estonia;A. nobilisfrom the Llanvirn (Kunda Stage), Siljan district, Sweden;A. cooperifrom the Llandeilo, Alabama, USA.Acrotretahas many features in common withSpondylotretaCooper, 1956. The type species of the latter,S. concentricaCooper, 1956, from the Llandeilo Pratt Ferry beds at Pratt Ferry, Alabama, is refigured.
Ordovician (Whiterockian) gastropods of Nevada: Bellerophontoidea, Macluritoidea, and Euomphaloidea
Authors: Rohr David M.
Published: August 2016

Gastropods are abundant in the Middle Ordovician (Whiterockian) Antelope Valley Formation of Nevada. Because Whiterockian rocks are absent in much of central and eastern North America, these Nevada gastropods play a significant role in understanding the Early to Middle Ordovician transition of the class. The shell and operculum of a new genus and species of macluritoid,Monitorella auricula, is described. New euomphaloid taxa includeWalcottoma frydain. gen. and sp.,Rossospira harrisaen. gen. and sp.,Barnesella measuresaen. sp.,Helicotoma gubanovin. sp.,Lytospira yochelsonin. sp., andMalayaspira hintzein. sp.
A Wenlockian (Silurian) gastropod shell and operculum from Siberia
Authors: Gubanov Alexander P. , Yochelson Ellis L.
Published: August 2016

In a large collection of Wenlockian gastropods from north Siberia, a single small specimen shows the operculum in situ just within the aperture. In other morphologic features, particularly the presence of numerous spiral lirae on the shell, this species is similar to Silurian gastropods traditionally assigned to Oriostoma. Preservation of the operculum is far from perfect, but almost certainly it has paucispiral growth, rather than concentric or multispiral construction. This new species (Australonema varvarae n. sp.) is assigned to Australonema, previously known only from the Lower Devonian of Australia, primarily because of the form of the operculum. The material was obtained from just below a biostromal unit in a bed interpreted as an interreef lagoon in an area of locally relatively quiet water.
Ontogeny and relationships of Trinucleoidea (Trilobita)
Authors: Chatterton Brian D. E. , Edgecombe Gregory D. , Speyer Stephen E. , Hunt Allen S. , Fortey Richard A.
Published: August 2016

Protaspides and later growth stages are described and discussed for the Ordovician trinucleid trilobite Cryptolithus tesselatus Green and the raphiophorid Lonchodomas chaziensis Shaw. A small triangular rostral plate is described for a single protaspid instar in both Cryptolithus and Lonchodomas. The presence of this small sclerite in the ontogeny of these taxa supports the origin of the Trinucleoidea from the Ptychopariida through reduction in and then fusion or loss of the rostral plate. Earlier and later growth stages have fused ventral sclerites, with no signs of connective sutures. All members of the Trinucleoidea with known ontogenies share similar small, ovoid asaphoid protaspides, with distinct axes and varying numbers of sharp, conical to subtubular, submarginal spines on the dorsal exoskeleton and marginal spines on the hypostome. Two protaspid instars are identified in both Cryptolithus and Lonchodomas, sharing many characters that indicate homologous levels of development. A single origin for the median suture of the Asaphida is supported, with an anterior rostellum as its precursor.
Multielement reconstructions of Palmatolepis and Polygnathus (Upper Devonian, Famennian) from the Canning Basin, Australia, and Bactrian Mountain, Nevada
Authors: Metzger Ronald A.
Published: August 2016

Upper Devonian (Famennian) sequences were sampled at two sections in the Canning Basin, Western Australia, and a section at Bactrian Mountain, Nevada, over an interval ranging from the Upper crepida Zone into the Lower marginifera Zone of the standard conodont zonation for the Famennian. Over 30,000 conodont elements have been identified among 43 species and subspecies within six genera. New complete and partial multielement reconstructions are illustrated for: Palmatolepis falcata, P. glabra prima, P. loba, P. minuta minuta, P. perlobata perlobata, P. perlobata maxima, P. quadrantinodosalobata, P. rhomboidea, P. schindewolfi, P. subgracilis, P. wolskae, Polygnathus cf. P. diversus, P. glaber glaber, P. nodocostatus nodocostatus, P. subnormalis, and P. cf. P. triphyllatus. The reconstructions are based on stratigraphic occurrence, detailed morphologic similarities, and a few exceptional low-diversity faunas. Additionally, Palmatolepis adamantea n. sp. is proposed based on the Pa element.

A more precise understanding of the taxonomic boundaries of Palmatolepis is achieved through knowledge of the entire apparatus, rather than confined to the Pa elements. Reconstructions presented here provide a more comprehensive understanding of the range of morphologic variation that exists in Palmatolepis, and show that a single generalized elemental plan can be demonstrated for all members of the genus. The differences in the non-Pa elements can thus be used to refine taxonomy and increase understanding of phylogenetic relationships at the specific and subspecific level.
A new Middle Pennsylvanian (Westphalian) amphibian trackway from the Cross Mountain Formation, East Tennessee Cumberlands
Authors: Kohl Martin S. , Bryan Jonathan R.
Published: August 2016

An amphibian trackway collected in minespoil from the Cross Mountain Formation in the Cumberland Mountains of East Tennessee represents the first known Middle Pennsylvanian (Westphalian) amphibian trackway from the southeastern United States. The tracks are impressed onto the upper surface of a bed of fine-grained, cross-laminated sandstone and siltstone, deposited in an upper delta plain environment.

The trackway was made by an amphibian with a long glenoacetabular distance and low pace-angulation. The imprints show five digits on the pes and four on the manus. Average measurements for the trackway are: stride, 8.4 cm; pace angulation, 76.1° (manus), 63.1° (pes); track width, 5.5 cm (manus), 6.7 cm (pes); glenoacetabular distance, 16.7 cm. The manus impression averages 2.8 cm long by 3.1 cm wide, and the pes averages 3.8 cm long by 3.1 cm wide. A tail drag is conspicuous along the entire length of the trackway and has a minimum radius of curvature of 9 mm.

The trackway is assigned toMatthewichnus caudifern. ichnosp. on the basis of similarities to published material. The trackmaker was probably a temnospondyl labyrinthodont, considering the size of the animal (thus excluding lepospondyls) and the fact that it had a four-digit manus (thus excluding reptiles and anthracosaurian labyrinthodonts).
Well-preserved fungal spores from Jurassic rocks of Hells Canyon on the Idaho–Oregon border
Authors: Traverse Alfred , Ash Sidney R.
Published: August 2016

Palynoflorules containing sparse but regularly occurring chitinous-walled fungal, probably ascomycete, spores have been obtained from silty limestone nodules in the Jurassic Coon Hollow Formation in the Wallowa terrane in Hells Canyon, Idaho. The fungal spores are associated with moderately abundant embryophytic spores and pollen that suggest late Early Jurassic to early Middle Jurassic age, which agrees with dating provided by marine animals stratigraphically just above. The fungal spores constitute the most diverse such assemblage of robust-walled spores described from pre-Cretaceous rocks. Two new species of the fossil fungal spore form-genusDiporicellaesporites, D. idahoensisandD. serratulus, and one new species of form-genusFractisporonites, F. pittsburgensis, are described.
Palliseria(Middle Ordovician Gastropoda) from east-central Alaska and its stratigraphic and biogeographic significance
Authors: Rohr David M. , Blodgett Robert B.
Published: August 2016

Several unsilicified gastropod specimens were collected by John B. Mertie, Jr., on July 13, 1941, during a boat traverse along the Porcupine River of east-central Alaska. The specimens were originally deposited in the Ulrich (Cambrian and Ordovician) stratigraphic collections of the U.S. Geological Survey at the National Museum of Natural History, Washington, D.C. The collection contains one specimen ofPalliseriaand three specimens ofMaclurites, all of which are broken from the limestone. Despite the lack of much of the shell material, they are easily identified as to genus. One specimen identified asPalliseriais particularly significant.
Statistical pattern recognition in paleontology using SIMCA-MACUP
Authors: Wei Kuo-Yen
Published: August 2016

This paper describes a pattern recognition method, Soft Independent Modeling of Class Analogy-Modeling And Classification Using Partial least squares (SIMCA-MACUP), and demonstrates its application to two common paleontological problems—identification and prediction. SIMCA-MACUP performs statistical pattern recognition at four hierarchical levels. At level 1, SIMCA builds disjoint principal component models to characterize multivariate data patterns of several classes. At level 2, new, unknown objects are either classified into one of the classes, or recognized as outliers. At levels 3 and 4, the MACUP method models the relationship between external (dependent) variables and internal (independent) variables, and allows prediction of the values of external variables of new objects which are classified at level 2.

The applicability of the SIMCA-MACUP has been demonstrated in a case study of the Pliocene planktic foraminiferal cladeGloboconella.Two morphotypes of the cladeGloborotalia (Globoconella) puncticulataandGloborotalia (Globoconella) inflatawere characterized in a reference sample with SIMCA. Ancestral forms of the two morphotypes were traced through the early phylogenetic history of the clade, resulting in a reconstruction of the branching pattern of the divergence ofG. inflatafromG. puncticulata.The apertural height and apertural width of specimens in the ancestral stocks were then treated as if there were two “external” variables, and predicted using MACUP. The predicted values show slight discrepancy from the observed values. The deviation is size-dependent, indicating a decoupling of the apertural shape from the size of foraminifers during the branching process.
Quantitative stromatolitology
Authors: Hofmann H. J.
Published: August 2016

All aspects of stromatolites can be quantified, encompassing morphologic, dimensional, material, and positional attributes. Numerical data obtained by electronic image analysis or otherwise can facilitate taxonomy, classification, and studies of evolutionary tendencies in stromatolites, and bridge the language barriers as well. Consensus on basic attributes for recognizing taxa at different levels of hierarchy still needs to be developed; quantitative data can promote reduction or elimination of disagreements.
Well-preserved specimens of the spongesGondekia(Heteractinida) andPseudohydnoceras(Hexactinellida), Middle Devonian of New York State
Authors: Rigby J. Keith
Published: August 2016

Part and counterpart of a well-preserved specimen ofGondekia lancifer(Reimann, 1945a), and a well-preserved specimen ofPseudohydnoceras erraticumReimann, 1935, are described from the Wanakah Member of the Middle Devonian, Givetian, Ludlowville Formation, of western New York State. The specimen ofGondekiais only the second articulated specimen known and is more complete than the holotype. It has an intact skeleton of felted sexiradiates of three orders of spicules; the largest has rays approximately 2 mm long. The specimen ofPseudohydnocerashas preserved hexactine-based spicules in a dictyid skeleton, described for the species for the first time.
The oldest knownEospirifer(Brachiopoda) in the Changwu Formation (Late Ordovician) of western Zhejiang, East China, with a review of the earliest spiriferoids
Authors: Jia-Yu Rong , Ren-Bin Zhan , Nai-Ren Han
Published: August 2016

Eospirifer praecursorn. sp. is the oldest known eospiriferine, probably ancestral to the entireSpirifergroup. It is described here based on external and internal mold material from the uppermost part of the Changwu Formation (mid-Ashgill, Late Ordovician), Hejiashan, Jiangshan, western Zhejiang, East China. A study of the ontogeny ofE. praecursorn. sp. suggests that the cardinalia of early growth stages are more similar to those of early atrypoids rather than to those of the orthoids but the brachidia in these earliestEospiriferare still unknown. The possibility that eospiriferines were derived from an atrypoid stock cannot be excluded. All early eospiriferine species recorded from the Ashgill, Rhuddanian, and early Aeronian are reviewed for comparison. Their morphological diversification reveals early evolutionary experimentation. Based on the Ashgill occurrence ofEospirifer, it is likely that East Asia may be considered as one of the eospiriferine source areas.