bluuebunny/crossref_metadata_2025 huggingface dataset:
Apparatus architecture of Belodina (Conodonta): Interpretations based on fused clusters of Belodina compressa (Branson and Mehl, 1933) from the Middle Ordovician (Turinian) Plattin Limestone of Missouri and Iowa
Authors: Leslie Stephen A.
Published: August 2016

Twelve fused clusters of conodont elements representing the apparatus of Belodina compressa (Branson and Mehl, 1933) were recovered from the Plattin Limestone (Turinian) near New London, Missouri, and Hanover, Iowa. These clusters show that the apparatus of B. compressa consisted of four morphologically distinct elements: eobelodiniform (M), compressiform (S1), grandiform (S2), and dispansiform (S3) elements. All four element types are also present in fused clusters of B. confluens Sweet, 1979, supporting the interpretation that Belodina had a quadrimembrate apparatus. The B. compressa clusters were recovered from pellet-rich wackestones that yielded relatively large and diverse conodont faunas, in which only the elements of B. compressa were fused. The elements of B. compressa present in the fused clusters may have been deposited in fecal pellets, where a higher concentration of calcium phosphate, combined with the relatively large surface area contacts between B. compressa elements, facilitated the fusing of these elements into clusters. These fused clusters provide the basis for interpretation of the apparatus architecture of Belodina.
The type species of the eurypterid genusAcutiramusRuedemann, 1935
Authors: Tollerton Victor P.
Published: August 2016

Current usage as to the name of the type species of the eurypterid genusAcutiramusRuedemann, 1935, violates Article 68 of the third edition of the International Code of Zoological Nomenclature (Ride et al., 1985; hereafter referred to as the Code). The history is recorded here, and the correct citation of the type species is given as the conclusion of this note. The pertinent sections of the Code are quoted for convenience of the reader.
Mobergellans from the Lower Cambrian of Mongolia, Sweden, and the United States: molluscs or opercula of incertae sedis?
Authors: Morris S. Conway , Chapman A.J.
Published: August 2016

Mobergellans are a distinctive group of Lower Cambrian breviconic shells with a prominent set of internal scars, presumably representing sites of former muscle attachment. Shells grew by accretion and appear to have secreted primary phosphate. Here a redescription is given of mobergellans, assigned toHippoklosmanew genus, from the Khairkhan Formation (Botomian-age equivalent) of southwest Mongolia.Hippoklosma mongolica(Missarzhevsky) is bilaterally symmetrical, with five pairs of radiating structures. These are presumably homologous with the muscle scars of other mobergellans, but in contrast consist of a series of disks (herein fibroplacodes) each containing a characteristic fibrous structure capped externally by a smooth lid. The apical region of the shell is domelike with transverse segmentation. A review of other mobergellans, including new data onMobergella holstifrom Sweden andDiscinella micansfrom New York, and possibly related taxa concludes that although their affinities are problematic, a relationship with the Mollusca may be the most plausible hypothesis on existing evidence.
Oryctocephalids (Corynexochida: Trilobita) of the Lower-Middle Cambrian boundary interval from California and Nevada
Authors: Sundberg Frederick A. , Mccollum Linda B.
Published: August 2016

Seven species of oryctocephalids occur in the Lower to Middle Cambrian boundary strata of the southern Great Basin. These includeOryctocephalites palmerin. sp. and an Oryctocephalinae species from the uppermost Lower Cambrian (upperOlenellusBiozone);Oryctocephalus indicus(Reed, 1910),Microryctocara nevadensisn. gen. and n. sp., andOryctocephalites rasettiin. sp. near the base of the Middle Cambrian (lowerPlagiuraBiozone); andOryctocephalus primusWalcott, 1886, andOryctocephalus nyensisPalmer, 1979, from slightly higher strata (upperPlagiuraBiozone).OryctocephalusandOryctocephalitesare emended based on a cladistic analysis of Oryctocephalinae Beecher, 1897.
New land snails (Archaeogastropoda, Helicinidae) from the Miocene (Early Barstovian) Flint Creek beds of western Montana
Authors: Pierce Harold G. , Rasmussen Donald L.
Published: August 2016

Waldemaria monticolaPierce n. sp. and “Hendersonia”validaPierce n. sp. are described from fluviatile sediments of the intermontane Flint Creek Basin of western Montana. The genusWaldemariawas previously known only from Japan. The presence of these two genera suggest a marked climatic cooling when compared with western North American Eocene–Oligocene faunas. The stratigraphy of the Flint Creek beds, and the associated vertebrate fauna, diagnostic of an early Barstovian age (17–15 Ma), is summarized.
Note on the Antarctic Tertiary brachiopods and museum registry of specimens described by E. F. Owen, 1980
Authors: Zinsmeister William J.
Published: August 2016

During the course of fieldwork by a joint Argentine-American expedition to Seymour Island (Elliot et al., 1975) during the austral summer of 1974-1975, a number of brachiopods were collected from the Late Eocene La Meseta Formation. A representative collection of these brachiopods was sent to E. F. Owen, Department of Palaeontology, British Museum (Natural History) for study. Owen (1980) published a revision of the brachiopods from Seymour and nearby Cockburn Islands. The study was based on material collected by W. N. Croft of the Faulkland Islands Dependencies Survey (now British Antarctic Survey) and the material which I sent.
Transfer of Devonian type specimens from New Brunswick
Authors: Miller Randall F.
Published: August 2016

Trace fossils and fish remains, representing three species described by Greiner from the Devonian of New Brunswick, have been transferred and reposited in the New Brunswick Museum. Holotype, paratype, and figured specimens originally at the University of New Brunswick are now located in the Palaeontology Type Collection of the New Brunswick Museum (NBMG). All specimens have been assigned new catalogue numbers.
Neogene paleoenvironments of the Bocas del Toro Basin, Panama
Authors: Collins Laurel S.
Published: August 2016

Outcrops of upper Miocene to upper Pliocene sediments in the Bocas del Toro Basin, Caribbean coast of western Panama, contain a record of the emergence of the southern Central American isthmus. Paleodepths and characteristics of past sedimentary regimes within the basin were determined from benthic foraminiferal species assemblages. The present Valiente Peninsula shallowed from upper bathyal depths of about 300–500 m to outer neritic depths of 150–200 m between latest Miocene (5.6–6.5 Ma) and middle Pliocene (3.5–3.6 Ma) times. Outer neritic assemblages from about 100–150 m paleodepth on the island of Escudo de Veraguas indicate negligible emergence through the late Pliocene, and their present sea-level altitude suggests rapid Quaternary shallowing. Middle neritic foraminiferal assemblages of Cayo Agua island shallowed from depths of about 40–80 m to 20–40 m between early (4.5–5.0 Ma) and middle (3.5–3.6 Ma) Pliocene times. Cayo Agua assemblages indicate establishment of a carbonate regime in the southwestern Caribbean region prior to complete closure of the Caribbean–East Pacific seaway around 3.5 Ma.
Ontogeny and variation in Glyptopleura costata (McCoy) (Ostracoda: Mississippian, Chesterian) from Ohio
Authors: Hoare R. D.
Published: August 2016

Large collections of Glyptopleura costata (McCoy, 1844) from the Maxville Limestone in central Ohio contain four instars and adults. The juveniles provide a basis for understanding the orderly development of the complex ornamentation of costae characteristic of Glyptopleura. Dimorphism is prominent with heteromorphs and adult tecnomorphs readily identifiable, primarily in adults. Progressive development of the ornamentation in juveniles, significant variation in adult ornamentation, and dimorphism has led to a proliferation of proposed taxa.
Ptychopleurites spinosa, a new trilobite species from the Upper Cambrian of Texas and South Dakota
Authors: Stitt James H. , Metcalf Wendy L.
Published: August 2016

During preparation of a manuscript on new collections of Upper Cambrian trilobites from the Threadgill Creek section in central Texas (Longacre, 1970, text-fig. 6), a new trilobite species Ptychopleurites spinosa was discovered that can be used to recognize a revised base to the Saukia Zone (Trempealeauan Stage) in central Texas. This species is represented in central Texas by numerous, well-preserved cranidia and librigenae, but no pygidia have been recovered. Recently Ptychopleurites spinosa was also identified in a collection of trilobites of the partly correlative Illaenurus Zone (= lower part of Saukia Zone) from the type section of the Deadwood Formation in the Black Hills of South Dakota. This work is part of a paper that will describe the latest Franconian and Trempealeauan trilobites from the Deadwood Formation, using collections made by Dr. Christina Lochman-Balk. Ptychopleurites spinosa is represented in the Black Hills by incompletely preserved cranidia and well-preserved librigenae. Because it is not known which of these two papers will be published first, it was decided to establish Ptychopleurites spinosa as a new species with one of the better Texas cranidia as the holotype and the Black Hills material as part of the suite of paratypes.
What is Mitrocrinus wetherbyi S. A. Miller and Gurley, 1894?
Authors: Ausich William I.
Published: August 2016

Phylogenetic classification is dependent upon confident ordering of character states that can be greatly facilitated if the earliest members of a clade are known and well understood. Unfortunately, one of the oldest known representatives of the camerate crinoid order Monobathrida is the problematic Mitrocrinus wetherbyi S. A. Miller and Gurley, 1894. It is problematic because it is a teratologic specimen with hexamerous symmetry and because its basic constructional design is more typical of middle to late Paleozoic monobathrids than of a Middle Ordovician monobathrid. A more advanced-looking construction does not preclude this crinoid from being the most primitive monobathrid a priori, but these two problems have relegated this taxon to an addendum in most classifications. Bather (1900, p. 203) included Mitrocrinus as an “incorrect or indeterminable name” by stating that it was “based on a six-rayed individual, probably abnormal, and a Periechocrinid or Carpocrinid” and Ubaghs (1978, p. T518) designated it as order, suborder, superfamily, and family uncertain.
The internal features of the Rhynchonellid brachiopod Propriopugnus Brunton, 1984, from the lower Carboniferous of England
Authors: Savage Norman M. , Corlett Risa M.
Published: August 2016

As part of the preparation for reviewing the Paleozoic rhynchonellids for the revised brachiopod treatise, one of us (NMS) requested help from Dr. Howard Brunton, of the Natural History Museum (British Museum, London) in obtaining type material of Propriopugnus pugnus (Martin) to further investigate the internal features. Dr. Brunton kindly sent a Natural History Museum specimen that he considers to be close to the lectotype. This specimen has been photographed and sectioned, and it is described below.
Phylogenetic taxonomy of the Coelurosauria (Dinosauria: Theropoda)
Authors: Holtz Thomas R.
Published: August 2016

Phylogenetic taxonomy, that component of phylogenetic systematics concerned with the verbal representation (rather than the reconstruction or estimation) of phylogenetic relationships, was developed by de Queiroz and Gauthier (1990, 1992, 1994). Under phylogenetic taxonomy, all taxon names are names of clades (i.e., an ancestor and all of that ancestor's descendants). De Queiroz and Gauthier (1990, 1992, 1994) described three possible ways of denning clade names within the phylogenetic taxonomic system: 1) node-based definitions (Figure 1.1), of the form “the most recent common ancestor of Taxon A and Taxon B, and all of that ancestor's descendants”; 2) stem-based definitions (Figure 1.2), of the form “Taxon A and all taxa sharing a more recent common ancestor with Taxon A than with Taxon B”; and 3) apomorphy-based definitions (Figure 1.3), of the form “the first taxon with derived character X and all of that ancestor's descendants.” Bryant (1994) noted that, while the first two definition types will always be stable, apomorphy-based definitions are potentially confusing if that derived character is found to occur in more than one lineage (i.e., is homoplastic). Under the phylogenetic system of taxonomy, definitions of taxon names are independent with respect to previous diagnosis (as particular character states may be found to occur in other lineages or in more inclusive clades) and composition (as particular member taxa may subsequently be found to lie outside the defined clade boundary). This paper is the initial work in an ongoing study by Holtz and Padian (1995, in preparation) to clarify the phylogenetic taxonomy of major clades of theropods and related taxa.
Isoxys(Arthropoda) from the Early Cambrian Sirius Passet Lagerstätte, North Greenland
Authors: Williams Mark , Siveter David J. , Peel John S.
Published: August 2016

The marine offshore shelf mudstones of the Early Cambrian Buen Formation at Sirius Passet, North Greenland, contain a rich Konservat-Lagerstätte which includes abundant well-preserved material of the bivalved arthropodIsoxys volucrisnew species. The new material confirmsIsoxysWalcott, 1890 as a component of the earliest arthropod faunas worldwide.Isoxysspecies are known from the Early Cambrian of Spain, Siberia, South Australia and Southwest China and also from the Early to Middle Cambrian of Laurentian North America.Isoxysoccurs in the Redlichiid, Bigotinid and Olenellid trilobite faunal realms but is restricted to within tropical/subtropical regions, attesting to possible paleolatitudinal controls on its distribution.Isoxysresembles some phyllocarid and bradoriid arthropods but without knowledge of its soft-parts the affinity of the genus remains uncertain.
The Eocene larger foraminifer Lepidocyclina ariana Cole and Ponton, from the so-called Polylepidina gardnerae horizon at Little Stave Creek, Alabama
Authors: Robinson Edward
Published: August 2016

Recent sampling for larger foraminifers in the so-called Polylepidina gardnerae horizon in the middle Eocene Lisbon Formation of the Little Stave Creek section, southwest Alabama, did not produce any examples of the lepidocyclinid foraminifer Polylepidina gardnerae Cole, but several specimens of the stratigraphically younger species, Lepidocyclina ariana Cole and Ponton, were recovered. Although the P. gardnerae horizon is named on nearly all figures of this important Gulf Coast section published since 1944, preliminary research has also failed to turn up a published basis for the identification of P. gardnerae at this locality. As L. ariana and P. gardnerae are not normally found together, it is the writer's opinion that true P. gardnerae probably has not been collected from any part of the Lisbon Formation at Little Stave Creek. If it does occur, it should be found at a lower horizon than that indicated in the literature.
The taphonomy and affinities of the problematic fossilMyoscolexfrom the Lower Cambrian Emu Bay Shale of South Australia
Authors: Briggs Derek E. G. , Nedin Christopher
Published: August 2016

Most of the specimens ofMyoscolex atelesGlaessner, 1979, the most abundant soft-bodied taxon in the Big Gully fauna from the Lower Cambrian Emu Bay Shale of South Australia, preserveonlythe phosphatized trunk muscles, in striking contrast to the organic residues that characterize other Burgess-Shale-type biotas. This is the oldest phosphatized muscle tissue and the first thus far reported from the Cambrian. The extent of phosphatization implies a source in addition to the animal itself, and this is reflected in high levels of phosphate in the Big Gully sequence compared to other shales. The apparent anomaly posed by the extensive preservation of labile muscle tissue as opposed to the more decay resistant cuticle is explained by the role of bacterial processes in the preservation of soft tissues. New specimens ofMyoscolexreveal a variable number of trunk somites with possible tergites, and flap-like appendages. There is evidence for at least three eyes on the head, and a proboscis may have been present. An annelid affinity is rejected andMyoscolexis reinterpreted as anOpabinia-likeanimal with possible affinities with the arachnomorph arthropods.
Review of the bivalve genusPlicatulafrom Cretaceous and lower Cenozoic strata of California and Baja California
Authors: Squires Richard L. , Saul Louella R.
Published: August 2016

The Cretaceous and early Cenozoic species of the shallow-marine, warm-water bivalvePlicatulafrom California (United States) and Baja California (Mexico) are reviewed, and three new species are named. All of these species are representatives ofPlicatulaand not of the closely related taxonHarpax,which is associated with high-latitude and cool-water regions. The earliestknown Cretaceous species ofPlicatulafrom the study area isP. variataGabb, 1864, from Lower Cretaceous (Hauterivian Stage) strata in northern California, and our studies show it to be conspecific withPlicatula onoensisAnderson, 1958.

Plicatula allisoninew species is from Lower Cretaceous (Albian Stage) strata in Baja California, Mexico.Plicatula modjeskaensisnew species is from Upper Cretaceous (Turonian Stage) strata in the Santa Ana Mountains, southern California. A possible new species from the same strata is also mentioned. A poorly preserved specimen ofPlicatula? sp. is known from Upper Cretaceous (upper Campanian to lower Maastrichtian) strata in northern California.

The only Paleocene species ofPlicatulafrom the study area isP. ostreiformisStanton, 1896, from lower Paleocene strata of Lake County, northern California, and our studies show it to be conspecific withOstrea buwaldanaDickerson, 1914. The only previously described Eocene species ofPlicatulafrom the study area isP. juncalensisSquires, 1987, from lower middle Eocene (“Capay Stage”) strata of Los Angeles County, southern California.Plicatula surensisnew species is from middle lower Eocene (“Capay Stage”) strata in Baja California Sur, Mexico. In addition, there is aPlicatula? sp. from Eocene strata of Baja California Sur, Mexico.

AlthoughPlicatulais of uncommon occurrence north of Baja California, its thermophilic trait makes it useful in recognizing periods of warm climate.
Evolution and classification of the Productellidae (Productida), upper Paleozoic brachiopods
Authors: Brunton C. H. C. , Lazarev S. S.
Published: August 2016

In the Lower Devonian the first productellids evolved from their chonetidine ancestors as the Productellinae. This subfamily was the stem group from which all the later Productidina evolved, yet three of its five subfamilies persisted to the end of the Permian. The main characters used in the new classification, here presented, for the Productellidae are described and reviewed, and the main changes seen during its evolution are discussed. Within this new classification five new genera are described: in the Overtoniinae are Barunkhuraya Lazarev from the latest Famennian, Onavia Lazarev from the Tournaisian, both from Mongolia, and Echinariella Lazarev (type species Krotovia jisuensiformis Sarycheva) from the late Permian of Transcaucasia; in the Marginiferinae there is Breileenia Brunton from the Visean of western Europe and in the Plicatiferinae is Maemia Lazarev from the mid and Upper Carboniferous on the coast of the Barents Sea. New species described in these genera are Barunkhuraya indrengynensis Lazarev, Onavia barunkhurensis Lazarev, Breileenia radiata Brunton, Maemia chaykensis Lazarev, and M. nana Lazarev.
Earliest Triassic origin of Isoetes and quillwort evolutionary radiation
Authors: Retallack Gregory J.
Published: August 2016

Isoetes beestonii new species is the most ancient known species of this living genus. In earliest Triassic shales of the Sydney and Bowen Basins of Australia it is locally abundant as circlets of transversely wrinkled leaves. It was heterosporous with megaspores of Maiturisporites rewanensis and microspores of Lundbladispora sp. cf. L. springsurensis.

Isoetes thus predates Pleuromeia from which it has been thought to have evolved. Australian Pleuromeia-like subarborescent lycopsids are here reviewed as whole plants, with names based on fertile structures, and include Cylostrobus sydneyensis Helby and Martin from the Sydney Basin, Pleuromeia dubia (Seward) Retallack from the Sydney and Canning Basins, and Cylostrobus indicus (Lele) new combination and Pleuromeia sternbergii (Münster) Corda for Germar, newly recorded from the Canning Basin.

There are in addition an array of cormose lycopsids that formed compact conelike plants when fertile, intermediate in stature between Isoetes and Pleuromeia. One of these is Tomiostrobus australis (Ash) Sadovnikov, formerly regarded as a cone, but here reinterpreted as a small pioneering plant of oligotrophic lakes and ponds, like Isoetes. Its megaspores are Horstisporites and its microspores are the stratigraphically important Aratrisporites tenuispinosus. Other similar forms are Tomiostrobus polaris (Lundblad) new combination from the early Triassic of Greenland, T. mirabilis (Snigirevskaya) new combination from the early Triassic of the Tunguska Basin of Siberia, T. taimyrica (Sadovnikov) new combination from the Early Triassic of the Taimyr region of Siberia, Lepacyclotes ermayinensis (Wang) new combination from the middle Triassic of China, L. convexus (Brik) new combination from the middle-late Triassic of Kazachstan, and L. zeilleri (Fliche) new combination from the middle Triassic of France and Germany.

The diversity of isoetaleans in early Triassic floras and the weak vascular system of permineralized Tomiostrobus and Pleuromeia contradict the traditional view that Isoetes evolved by reduction in size from Pleuromeia and that its opportunistic life style allowed it to avoid plant competition. It is now more likely that Isoetaceae were weedy survivors of Permian-Triassic extinctions. The adaptive radiation and decline of Triassic quillworts matches the recovery from near-extinction, then decline of therapsid reptiles, for which these plants may have been an important food.
Archosaur teeth from the Cretaceous of Morocco
Authors: Kellner Alexander W. A. , Mader Bryn J.
Published: August 2016

The newly organized Long Island Natural History Museum (LINHM) has assembled a small collection of fossil vertebrates from the Cretaceous of Morocco. Among the remains in this collection are two spinosaurid (Theropoda) teeth and one sauropod tooth that we refer to either the Diplodocidae or Titanosauridae. Because of the scarcity of spinosaurid and Cretaceous sauropod teeth, a short description of the material is presented here. In addition to the dinosaurian remains, the collection includes an unidentified crocodilian tooth and a tooth identified tentatively as that of a pterosaur, which we also describe briefly. Furthermore, there are other fossil reptile teeth from the Ksar es Souk Province in the collections of the LINHM. Some of these may represent groups of reptiles other than those discussed here, but the taxonomic identity of these teeth is still being determined.
A history of diversification, extinction, and invasion in tropical America as derived from species-level phylogenies of chionine genera (Family Veneridae)
Authors: Roopnarine Peter D.
Published: August 2016

Phylogenetic reconstructions of two tropical American venerid genera, Chione and Chionopsis (subfamily Chioninae) were attempted at the species-level. The purposes of the analyses were to provide historical reconstructions of origination and extinction events in the two clades, as well as patterns of invasion and diversification. The analyses were based entirely on conchological characters to facilitate the inclusion of a substantial number of fossil taxa, but difficulties were encountered due to the quality of preservation and availability of material. Nevertheless the two genera were established as monophyletic clades, and the reconstructions yielded considerable insight into their histories in tropical America. The analyses suggest that both genera originated in the tropical western Atlantic, Chionopsis by at least the early Oligocene, and Chione in the early Miocene. Various branches of both genera subsequently invaded the tropical eastern Pacific several times prior to Seaway closure, with only one possible reciprocal invasion of the western Atlantic. Pliocene extinction affected both genera more significantly in the western Atlantic relative to the eastern Pacific, and diversity is higher today in the latter region. These conclusions are not entirely consistent with the fossil records of the genera, but this incongruency highlights the need for much more extensive sampling of the eastern Pacific Cenozoic record.
A new species of Leptarctus (Carnivora, Mustelidae) from the Late Miocene of Texas
Authors: Lim Jong-Deock , Martin Larry D. , Wilson Robert W.
Published: August 2016

Leptarctus is a poorly known fossil carnivore that ranges through the Miocene of North America and Inner Mongolia, China (Lim, 1996; Zhai, 1964). Though it has been one of the least studied carnivores, more than 20 localities in North America have produced Leptarctus (Lim, 1999). The characters diagnosing Leptarctus as a mustelid include absence of M2, absence of a notch between the blades of the upper carnassial, and a reduced dentition with loss of PI and pi. Though Leptarctus is a mustelid, the teeth bear many similarities to those of procyonids, Procyon lotor and Nasua nasua and stand as a remarkable example of dental convergence (Leidy, 1856; Lim, 1999). Unlike other mustelids, Leptarctus has prominent double sagittal crests, heavy zygomatic arches, a prominent occipital crest, a well-developed hypocone on P4, labially curved upper canines, grooved lower canines, raccoon-like mandibles, elongated metatarsals, and unique bony projections on the tympanic bullae (Lim, 1999).
Namurian (Lower Carboniferous) gastropod assemblages from Ningxia, China
Authors: Huazhang Pan
Published: August 2016

The Namurian Tsingyuan Formation from Ningxia, China, is divided into three members. The remarkably well-preserved gastropods from the Tsingyuan Formation belong to three assemblages: the Angyomphalus longicostatus—Glabrocingulum tongxinensis assemblage from the Lower Member; an assemblage of some siliceous Bellerophon sp., and Naticopsis sp. from the Middle Member; and the Euphemites hindi—Turbonitella semisulcatus assemblage from the Upper Member. Based on the associated ammonoids and conodonts, these assemblages are considered equivalent to the Eumorphoceras, Homoceras2-Reticuloceras1 and Reticuloceras2 zones of West Europe respectively.
A new species of late Cretaceous crab (Brachyura: Carcineretidae) from Albion Island, Belize
Authors: Vega Francisco J. , Feldmann Rodney M. , Ocampo Adriana C. , Pope Kevin O.
Published: August 2016

A new species of carcineretid crab, Carcineretesplanetarius, is described from the Upper Cretaceous (lower Maastrichtian) Barton Creek Dolomite at Albion Island, Belize. The age is based on the stratigraphic range of associated nerineid gastropods and correlation with nannoplankton, benthic foraminifera, and the other known congeneric species of crab found in Jamaica. Confirmation of this age aids in constraining the timing of ejecta deposits of the Chicxulub impact found at the top of Barton Creek Dolomite exposed on Albion Island. Paleoenvironmental and paleoecological analyses suggest that these crabs were swimmers in lagoonal settings, capable of burrowing a few centimeters into the mud for protection.
Acritarchs and microfossils from the Mesoproterozoic Bangemall Group, northwestern Australia
Authors: Buick Roger , Knoll Andrew H.
Published: August 2016

Three microfossil assemblages occur in the Mesoproterozoic Bangemall Group (1625-1000 Ma) of northwestern Australia, each occupying a different environmental and taphonomic setting. In peritidal environments, benthic prokaryotic filaments and spheroids of matting habit and small size were permineralized by early diagenetic silicification of stromatolitic carbonates. In shallow subtidal environments, benthic filaments of large size and nonmatting habit and planktonic sphaeromorph acritarchs with thin walls and moderate dimensions were compressed in mildly kerogenous shale. In deeper subtidal environments, planktonic megasphaeromorph acritarchs with thick walls were initially entombed in concretionary nodules in highly kerogenous shale and then permineralized by silica during later diagenesis. Taxonomic diversity and numerical abundance evidently decrease offshore. The three assemblages have typical Mesoproterozoic aspects: peritidal benthic habitats were dominated by Siphonophycus-Sphaerophycus-Eosynechococcus-Myxococcoides-Palaeopleurocapsa, shallow subtidal settings were occupied by Siphonophycus-Leiosphaeridia-Pterospermopsimorpha-Satka, and offshore plankton consisted solely of very large chuarid acritarchs. Because of its taphonomic restriction to mid-intertidal stromatolites, the peritidal assemblage can be equated in microenvironment with a similar assemblage in the Neoproterozoic Draken Conglomerate, suggesting that ecological stasis at the community level can last for intervals up to 900 million years. In the deeper subtidal assemblage, the common chuarid has an unusual mode of preservation, in three dimensions in early diagenetic concretions, revealing that it possesses a thick multilamellate wall. Because of this distinctive ultrastructure, the new genus Crassicorium is erected for these fossils, which are among the oldest indubitable eukaryotes. Very large (34-55 μm in diameter) filaments from shallow subtidal habitats are assigned to the emended species Siphonophycus punctatum.
The optimal acetate buffered acetic acid technique for extracting phosphatic fossils
Authors: Jeppsson Lennart , Anehus Rikard , Fredholm Doris
Published: August 2016

When extracting or cleaning phosphatic fossils using acetic acid, the solutions must be buffered with calcium acetate to a pH greater than 3.6 for conodont and many fish taxa, and to a slightly greater pH for some conulariid, shark, and some fish taxa. Diagrams of the changes in pH and density during dissolution, rate of dissolution, and productivity per liter of acid provide a means for selecting the economically optimal process, monitoring the progress, and adjusting the composition of the solution when necessary.
Discoaster praebifax n. sp.: a possible ancestor of Discoaster bifax Bukry (Coccolithophoridae)
Authors: Wei Wuchang , Wise Sherwood W.
Published: August 2016

An investigation of middle Eocene calcareous nannofossils from Deep Sea Drilling Project Sites 162 and 361 has revealed a new species, Discoaster praebifax, and prompted the emendation of Discoaster bifax Bukry. Based on their morphologic similarities and stratigraphic relationship, D. praebifax is suggested to be the ancestor of D. bifax. Because the new species closely resembles D. bifax, the use of the latter as an index species for Subzone CP14a should be cautioned. The first occurrence of D. praebifax is, however, a potentially useful datum in Zone CP12.
A unique bivalve–algae life assemblage from the Bear Gulch Limestone (Upper Mississippian) of central Montana
Authors: McRoberts Christopher A. , Stanley George D.
Published: August 2016

A single limestone slab is described from the Mississippian Bear Gulch Limestone of central Montana containing more than 100 bivalves, including Caneyella sp. and ?Ptychopteria (Actinopteria) sp., attached in original life positions along an 80-cm-long ?brown alga. The assemblage provides clear evidence of life position and choice of substrate for these pterioids. The bivalves increase in size, and appear to be radially disposed in their attachment sites, along the loosely coiled “kelp-like” alga, indicating little postmortem transport and current activity. The bivalve population is interpreted as living on an algal thallus that was either planktonic or attached to the substrate. Observations and comparisons with modern bivalve—seaweed associations support either view. Evidence for local anoxic conditions and stagnant water help explain the superb preservation and confirm past interpretations of the Bear Gulch Limestone.
Cephalopods: biasing agents in the preservation of lobsters
Authors: Tshudy Dale M. , Feldmann Rodney M. , Ward Peter D.
Published: August 2016

Modern Nautilus, in natural and laboratory settings, scavenges both dead and molted decapod crustaceans. Ingestion of palinurid lobster exuviae by Nautilus follows a specific pattern in which the cephalopod consumes the exoskeleton beginning at the posteriormost part of the abdomen and continuing anteriorly. During the ingestion process, the cephalothorax is least likely to be consumed, either because the Nautilus may abandon the remains, or the cephalothorax may become separated from the abdomen at its weakest point, the articulation of the cephalothorax with the abdomen. Examination of 767 fossil lobster specimens from 50 formations, 41 of Cretaceous age, demonstrates that the fossil record of lobsters, the preponderance of which appear to be exuviae, is strongly biased in favor of cephalothoraxes. Observations on Nautilus suggest that anatomically selective scavenging by ancient cephalopods, both nautiloids and ammonoids, may explain, in part, the selective preservation of lobster cephalothoraxes over abdomens. Despite the range of variation in jaw morphologies among ammonoids, probably most could have fragmented and ingested decapod remains. Evidence for selective scavenging in the geologic past is purely circumstantial; no cephalopod bitemarks have been identified on fossil lobster exuviae. Pre-burial decomposition of connective tissues and subsequent disarticulation of the abdomen in the absence of scavenging may also have contributed significantly to the observed anatomical taphonomic bias.
Large heteromorph ammonites from the Upper Cretaceous of Seymour Island, Antarctica
Authors: Olivero Eduardo B. , Zinsmeister William J.
Published: August 2016

Two species of the heteromorph ammonite genus Diplomoceras Hyatt are described from the Upper Cretaceous of the James Ross–Seymour Islands area, Antarctica. The late Campanian–early Maastrichtian D. lambi Spath has a relatively high rib density, whereas D. maximum n. sp. has a lower rib density and is known only from the uppermost Maastrichtian of the Lopez de Bertodano Formation on Seymour Island. Both species attain an exceptionally large size with the body chamber of D. maximum n. sp. attaining a length in excess of one meter. The structure of the shell wall in Diplomoceras is characterized by the thickening of the nacreous layer below the ribs. The shell thickening results in an inner flat surface and a smooth phragmocone. Reconstruction of the shell suggests at least four parallel shafts and three U-connectives. Estimates of the total density, center of buoyancy, and center of mass in this reconstructed shell indicate a slightly positive buoyant shell with a relatively unstable floating position.
Morphology, taxonomy, and classification of the order Eurypterida Burmeister, 1843
Authors: Tollerton V. P.
Published: August 2016

Standards have been empirically developed to describe various morphological characters of eurypterids. The standards pertain to the following characters: 1) shape of the prosoma; 2) shape of the metastoma; 3) shape of the eyes; 4) position of the eyes; 5) types of prosomal appendages; 6) types of swimming leg paddles; 7) structure of the doublure; 8) differentiation of the opisthosoma; 9) structure of the genital appendages; 10) shape of the telson; and 11) types of ornamentation.

For the first time, a uniform, standardized taxonomy is proposed for classification and identification of most genera. The taxonomy is based on the observation that most higher taxonomic levels for arthropods are based on the structure and arrangement of the appendages. Details of the taxonomy rely on the morphological standards proposed here.

The order Eurypterida Burmeister, 1843, is here defined by the presence of only six pairs of prosomal appendages, the first pair being the chelicera, the next five pairs being the gnathobasic, uniramus legs. Suborders are characterized by the gross morphology of the chelicera. Superfamilies and families are characterized by the use of a single character complex, specifically the structure and arrangement of the second through sixth pairs of prosomal appendages. Genera are recognized by more specific standards.

A new classification of the order Eurypterida is proposed. Three new superfamilies, Kokomopteroidea, Megalograptoidea, and Brachyopterelloidea, and five new families, Brachyopterellidae, Adelophthalmidae, Lanarkopteridae, Erieopteridae, and Hardieopteridae, are proposed.
Illusioluidia teneryi n. gen. and sp. (Asteroidea: Echinodermata) from the Pennsylvanian of Texas, and its homeomorphy with the extant genus Luidia Forbes
Authors: Blake Daniel B. , Guensburg Thomas E.
Published: August 2016

Illusioluidia teneryi is a new genus and species of asteroid echinoderm described from the Missourian (Upper Pennsylvanian) Wolf Mountain Shale of Texas. Illusioluidia is important because it is strongly homeomorphic with modern Luidia; Luidia has been considered primitive among living asteroids by some authors. Illusioluidia, however, is not ancestral to Luidia or any other modern genus; similarities are convergent. Luidia is a predator, largely on active invertebrates (other echinoderms, mollusks), whereas Illusioluidia is inferred to have been a small-particle feeder. Homeomorphy reflects neither descent nor feeding habits; environmental controls are suggested.
Notoschizaea Graham is a synonym of Corynepteris Baily (Coenopteridales; Carboniferous)
Authors: Mickle James E.
Published: August 2016

Notoschizaea was described by Graham in 1934 but has not been generally used since then and has been a problem for evaluation of coenopterid fern diversity. The monotypic genus Notoschizaea is placed in synonymy with Corynepteris Baily, and N. robusta Graham is redescribed as C. robusta (Graham) Mickle comb. nov. The original specimens are reillustrated and reinterpreted in light of more recent discoveries of permineralized Corynepteris species. Spores within sporangia are identified as being of the Apiculatisporis Potonie and Kremp type.
By-the-wind-sailors from a Late Devonian foreshore environment in western Montana
Authors: Gutschick Raymond C. , Rodriguez Joaquin
Published: August 2016

Three remarkable fossil medusoid hydrozoans (Plectodiscus latinautilus n. sp.) with disc, topsail, and pendant tentacular appendages were recovered from the latest Late Devonian beds of the Sappington Member of the Three Forks Formation in the Gallatin Range, southwest Montana. This is the first velellid reported from a Paleozoic beach paleoenvironment. Top and underside patterns of these chondrophorine velellids display well-preserved casts and mold imprints in fine siltstone. Outlines of the circular disc and the profile of the wide sail and tentacular structures embedded in soft tissue can be recognized.

These floating colonial animals were moved along the southeast shores of the Sappington Basin during a time of eustatic sea level lowering and regression in a tropical setting. Colonies were washed up on the upper beach where they were stranded in the bubbling swash left behind by the surf. The foreshore was constructed of tabular, planar cross-bedded, seaward-dipping, foreset accretionary beds which contain parallel laminations and lime-coated grains. Bedding is inclined 17° to 24° seaward.
Late Paleozoic (Gondwanan) ostracodes in the Corumbataí Formation, Paraná Basin, Brazil
Authors: Sohn I. G. , Rocha-Campos A. C.
Published: August 2016

An abundant, low diversity, poorly preserved Late Permian ostracode faunule was recovered from residues of dissolved limestone. Collections are from the Corumbataí Formation exposed near Conchas, about 194 km northwest of São Paulo and from a borehole into the upper part of the Corumbataí Formation. Although the Corumbataí Formation has been interpreted mainly as a restricted marine-transitional offshore/shoreface and tidal-flat deposit, the ostracodes represent nonmarine taxa. Steinkerns ofCandona, Cypridopsis?, Darwinula?, Gutschickia?, and genus unknown are illustrated in open nomenclature; they indicate freshwater influences. Several Permian marine genera from lower Gondwana (=Carboniferous-Permian), illustrated in open nomenclature, show that their steinkerns would differ from those illustrated here from Brazil. Although the Late Permian drainage from the north into the Paraná Basin has been considered to have been meager, rivers from the north must have supplied sufficient water to freshen the margins of the basin so that immigration of nonmarine ostracodes occurred.

Based on the similarity of the distinctive lateral outline of the Brazilian specimens to the nonmarine living genusCandona, the stratigraphic range of the genus is tentatively extended into the Permian.
Taphonomy of owl pellet deposition
Authors: Kusmer Karla D.
Published: August 2016

Remains derived from owl pellets are a major source of small-animal remains in paleontological and archaeological sites. Pellet remains are examined here to further develop workable strategies for extracting taphonomic information from microvertebrate assemblages. Study of the remains of three wild owl species yielded characteristic patterns of bone fragmentation and skeletal element representation. At the assemblage level, owl-derived assemblages are shown to differ quantitatively from other assemblages. The possible variability to be expected in owl-derived assemblages is examined and the patterns are contrasted with those produced by other depositional agents. The patterns can be useful in the identification of owl-deposited remains in some assemblages; however, overlap with patterns produced by other mechanisms may complicate analysis.
Type locality designation for the Middle Eocene echinoid Fibularia texana (Twitchell)
Authors: Zachos Louis G.
Published: August 2016

The Clypeastroid echinoid Fibularia texana (Twitchell) has been reported in the literature from only two localities. Twitchell (Clark and Twitchell, 1915) reported that the holotype was collected by T. H. Aldrich from an unspecified locality in Lee County, Texas, from the “Lower Claiborne,” Middle Eocene. Cooke (1942, 1959) reported F. texana from the Weches Formation, lower Claiborne, in San Augustine County, Texas (see Eargle, 1968, for stratigraphic nomenclature). He intimated that the type occurrence in Lee County was also from the Weches Formation. I have recently collected F. texana from the fossiliferous Cook Mountain (upper Claiborne) deposits exposed along Elm Creek in Lee County. Evidence is presented to show that Aldrich's original collection was from Cook Mountain exposures along Elm Creek, and this is designated as the type locality.
Revision of Lower Devonian (Emsian) brachiopod biostratigraphy and biogeography, central Nevada
Authors: Johnson J. G.
Published: August 2016

A diverse, previously unknown fauna with Skenidioides and other small brachiopods, ostracodes, trilobites, and corals has been dated as gronbergi Zone on coexisting conodonts. Conodonts date the Leptocoelina globosa fauna as serotinus Zone. Cymostrophia seca, Strophodonta luxor, and Atrypa kobar are new species. These assignments and new occurrences allow retabulation of most Emsian brachiopod ranges in Nevada.

Plotting of provincial, endemic, and cosmopolitan brachiopod genera on a time vs. percent graph shows that the shift through time of Nevada faunas from Eastern Americas Realm to Old World Realm took place gradually during Emsian transgression. Endemic genera were prominent during early phases of Devonian transgression.
Statistical study of Ozarkodina excavata (Branson and Mehl) and O. tuma Murphy and Matti (Lower Devonian, delta Zone, conodonts, Nevada)
Authors: Murphy Michael A. , Cebecioglu M. Kemal
Published: August 2016

Denticle number per unit of length in the (P) element of contemporaneously occurring Ozarkodina excavata (Branson and Mehl) and O. tuma Murphy and Matti is a characteristic that shows that these taxa belong to two discrete species. Their morphological ranges with respect to this character do not overlap.

Ozarkodina tuma has a short range within the delta Zone (Lower Devonian) of the central Great Basin and is useful in intrabasin correlation.
Preliminary report on the age and palynology of the Bear Gulch Limestone (Mississippian, Montana)
Authors: Cox Robt S.
Published: August 2016

Palynostratigraphic study of the Bear Gulch Member of the Heath Formation, central Montana, indicates an Upper Mississippian age for the deposit corresponding to Carboniferous palynofloral zone TK (ammonoid zone E2b, Namurian A). The palynoflora contains a diverse spore assemblage, including the Mississippian index Tripartites vetustus. In addition, the Bear Gulch Member contains an abundant and diverse acritarch assemblage. The age assignment is consistent with age determinations from studies of the ammonoid, conodont, and bryozoan faunas.
Delthyris sculptilis Hall, 1843 (Brachiopoda) from the Middle Devonian Hamilton Group is a Megakozlowskiella
Authors: Koch William F.
Published: August 2016

Delthyris sculptilis Hall, 1843, from the Middle Devonian Hamilton Group of New York and equivalent rocks elsewhere in eastern North America, has long been assigned to the genus Delthyris or, in certain older studies, to the genus Spirifer. Recent restudy of this brachiopod shows that it belongs to the genus Megakozlowskiella Boucot, 1962. This extends the upper limit of Megakozlowskiella from the Eifelian (Southwood Stage, Onondaga Limestone in New York) to the Givetian (Tioughnioga Stage, Moscow Formation of the Hamilton Group in New York).
Vetupraeca n. gen. and Mucopraeca n. gen. (Cryptodonta, Bivalvia): A reappraisal of Late Devonian bivalves from the Hercynian Facies
Authors: Nagel-Myers Judith , Amler Michael R. W. , Becker R. Thomas
Published: August 2016

Bivalves from the Late Devonian pelagic or Hercynian Facies of classical regions such as eastern North America and Europe have not been investigated for almost a century.

A group of small, radially ribbed bivalves frequently occurs in association with ammonoids and conodonts in pelagic cephalopod limestones and shales of the latest Frasnian and early Famennian. These bivalves have traditionally been assigned to the Late Silurian genus Praecardium Barrande, 1881. Re-studying the types of the Late Devonian taxa, Cardium? vetustum Hall, 1843, Cardiola duplicata Münster, 1840, Praecardium clymeniae Beushausen, 1895, Praecardium melletes Clarke, 1904, and Praecardium multicostatum Clarke, 1904 shows that they differ significantly from Praecardium.

As a result, two new genera, Vetupraeca n. gen. and Mucopraeca n. gen, are established. Furthermore, neotypes are designated for Cardiola nehdensis, Kayser, 1873 and Vetupraeca clymeniae (Beushausen, 1895), and lectotypes are chosen for Mucopraeca multicostata (Clarke, 1904) and Vetupraeca duplicata (Münster, 1840). These bivalve taxa were widely distributed in the subtropical to tropical, latest Frasnian/early Famennian outer shelf habitats of Laurussia and Gondwana.