bluuebunny/crossref_metadata_2025 huggingface dataset:
Origin and early radiation of terebratuloid brachiopods: thoughts provoked byProrensselaeriaandNanothyris
Authors: Boucot A. J. , Wilson R. A.
Published: August 2016

The ontogenies ofProrensselaeriaandNanothyris, described here for the first time, suggest that Cloud's Dielasmatidae are closely affiliated phylogenetically with Cloud's Centronellidae. This is based on the fact that the type species ofNanothyrisgoes through an initial mutationellinid (Cloud's Dielasmatidae) growth stage before reaching its adult rensselaerinid (Centronellidae) growth stage. The ontogeny ofProrensselaeriarequires that it be transferred from the Globithyrinae (Rhipidothyrididae) to the Mutationellinae (Meganteridae [=Cloud's Dielasmatidae = Stehli's Mutationellidae]). Further consideration of their ontogenies permits the transfer ofMeganteris, Meganterella, andReeftonellato the Meganterinae of the Meganteridae. It is recommended, because of the placement ofMeganterisin the Meganterinae, that the term Meganteridae replace Mutationellidae, and Mutationellinae be restricted to costate Meganteridae. The subfamily Adreninae of the Meganteridae (=Stehli's Mutationellidae) is proposed to includeAdrenia, Cydimia, Micidus, Sturtella, Barbarothyris, andLingshanella.

The information developed here permits one to conclude that there are two kinds of families: 1) those generated by directional selection, involving major adaptive radiations, the type generated by quantum evolution in Simpson's sense; and 2) those generated by minor developmental changes, that do not involve major adaptive radiations, although they do result in morphological and biogeographical differences great enough to warrant the erection of families.
Extinction of inoceramid bivalves in Maastrichtian strata of the Bay of Biscay region of France and Spain
Authors: MacLeod Kenneth G.
Published: August 2016

Maastrichtian strata of the Zumaya-Algorta Formation of southwestern France and northeastern Spain record a major pulse of extinction among inoceramid bivalves well before the Cretaceous–Tertiary (K–T) boundary. Inoceramids are the most abundant macrofossils preserved in the study sections; at least six species ofInoceramus[I. (Endocostea)aff.I.(En.) balticusGiers,I.(En.) pteroidesGiers,I.(Platyceramus)aff.I.(Pl.) cycloidesWegner,I.(Trochoceramus) nahorianensisKociubynskij,I.(Tr.) morganiSornay, andI.(?)goldfussianusd'Orbigny] are common to abundant in lower Maastrichtian strata. However, all six species disappear over a few tens of meters of section near the base of the upper Maastrichtian, as defined by the first appearance of the planktonic foraminiferAbathomphalus mayaroensis. Tenuipteria argentea(Conrad), which has not been recovered from the lower Maastrichtian portions of the sections, occurs at low abundances through the upper Maastrichtian, disappearing within 10 cm of the K–T boundary.

The mid-Maastrichtian extinction interval among inoceramids occurs within the upperGlobotruncana gansserito lowerAbathomphalus mayaroensisplanktonic foraminiferal zone, in nannofossil zone 24 to 25A, in theAnapachydiscus fresvillensisammonite zone, in magnetochron 31N, and near the base of a change in slope of the seawater strontium curve, all as recognized by previous studies in one or more of the study sections. Whereas the new data presented here are not global in extent, the observed distribution of inoceramids may be the local manifestation of global oceanic changes during the mid-Maastrichtian.
Cuticular structure inCostacopluma mexicanaVega and Perrilliat, from the Difunta Group (Maastrichtian) of northeastern Mexico, and its paleoenvironmental implications
Authors: Vega Francisco J. , Feldmann Rodney M. , Davila-Alcocer Victor M.
Published: August 2016

Examination of extremely well-preserved cuticle samples from the Maastrichtian retroplumid crab,Costacopluma mexicanaVega and Perrilliat, collected in the Difunta Group in Nuevo León State, Mexico, documents the preservation of corpses in an anoxic microenvironment produced by decomposition of soft tissue of the organisms. All four cuticular layers, epicuticle, exocuticle, endocuticle, and membranous layer, as well as pore canals and tegumental glands, can be recognized. There is no evidence of resorption that accompanies molting. X-ray analysis of the cuticle indicates that the organic matrix was replaced by carbonate-hydroxyapatite, that the original calcitic material was replaced by quartz, and that the replacement proceeded from the outer and inner surfaces of the cuticle toward the interior. The specimens were interpreted to have been preserved in an organic-rich, restricted lagoon in which pH was changed by periodic influxes of fresh water.
Lower vertebrates from an Arikareean (earliest Miocene) fauna near the Toledo Bend Dam, Newton County, Texas
Authors: Albright L. Barry
Published: August 2016

A recently discovered vertebrate fossil-bearing locality in the Fleming Formation of easternmost Texas has revealed a highly diverse fauna that contains a minimum of 44 early Miocene vertebrate taxa. At least 17 different species of lower vertebrates were recovered including five fish, two amphibians, one lizard, two snakes, at least five chelonians, and two crocodilians. A tiny boid that compares favorably withAnilioides nebraskensisis the first record in the Gulf Coastal Plain, and remains of a large aquatic turtle referred to the genusDermatemyspossibly represent its first fossil occurrence. Other rare genera represented include the largemouth bassMicropterus, possibly the snookCentropomus, and the crocodilianGavialosuchus.In addition, temporal and spatial range extensions are recorded forMicropterusandAlligator olseni.These taxa, along with the mammalian component to be discussed elsewhere, document the rare preservation of a forested subtropical to tropical coastal lowland paleoenvironment and provide evidence to imply that separation into mid-continent and coastal plain paleobiogeographic provinces had not yet occurred.
The paleoecological implications of the charophyte flora of the Trinity Division, Junction, Texas
Authors: Soulié-Märsche Ingeborg
Published: August 2016

The Trinity Division exposures at Junction, Kimble County, Texas, yield a rich charophyte flora dominated by clavatoraceans. The presence of Atopochara trivolvis ssp. trivolvis (Peck, 1938) Grambast, 1968, and Clypeator corrugatus (Peck, 1941) Grambast, 1962, indicates an Aptian age for these strata and makes them the continental equivalent of the Lower Glen Rose. Atopochara trivolvis, whose type-material was recovered from the Trinity in a deep well in southern Texas, is known from numerous freshwater to oligohaline lakes from the Mesogean area in Europe and North Africa as well as from Cretaceous oil-bearing basins in China. Charophytes are clear indicators of supratidal environments and the abundant remains at Junction suggest a positive structural feature in this part of central Texas that might have been either an island or directly connected to the Llano Uplift.
Atavograptus primitivus (Li) from the earliest Silurian of Arctic Canada: implications for monograptid evolution
Authors: Lukasik Jeff J. , Melchin Michael J.
Published: August 2016

It has long been considered that all monograptids have theca 1 originating from a primary porus in the sicula (i.e., sinus and lacuna stages; Bulman, 1970). The major basis for this assumption has been studies of Late Silurian monograptid species such as Saetograptus chimaera (Barrande), Pristiograptus bohemicus (Barrande), and Pristiograptus dubius (Suess) (e.g., Eisenack, 1942; Walker, 1953; Urbanek, 1958). That all monograptids possessed this type of development was not questioned due to the lack of well-preserved, early monograptid specimens clearly showing the sicula–theca 1 relationship. Hutt et al. (1970) described Monograptus gregarius Lapworth, from the gregarius Zone, as having theca 1 originating through a primary porus (Hutt et al., 1970; Rickards and Hutt, 1970, referred to this as a “primary notch” although, according to Bulman, 1970, p. V11, the notch corresponds only to the sinus stage). Their figures of these specimens, however, do not unequivocally confirm its presence (Hutt et al., 1970, p. 14, Pl. 3, figs. 65, 67). Rickards and Hutt (1970) alluded to the possible presence of a primary porus in Atavograptus ceryx (Rickards and Hutt) from the persculptus Zone, but could not determine its existence with certainty. Mitchell (1987) was the first to question the presence of this mode of development of theca 1 in relation to the origin of the monograptids. He proposed, however, that the development of the fully uniserial rhabdosome was coincident with a change in both the sicular structure (the sinus and lacuna stages) and the early ontogeny of theca 1. He suggested that the sinus and lacuna stages represented a homologue of the hooded foramen seen in the th 11 protheca of some Pattern H species, from which th 12 emerges and that, in the uniserial monograptids, this feature is accelerated in the astogenetic sequence, appearing in the metasicular ontogeny rather than that of the first theca. He pointed out that this hypothesis could only be tested once suitable, isolated specimens of earliest monograptids could be studied to see if the sinus and lacuna stages were, indeed, coincident with the achievement of a fully uniserial rhabdosome. New evidence from isolated, early monograptid material allows us to test Mitchell's theory on monograptid origin.
Generic revision of the cryptostome bryozoanRhabdomesonYoung and Young, 1874, with descriptions of two species from the Lower Carboniferous of the British Isles
Authors: Jackson Patrick N. Wyse , Bancroft Adrian J.
Published: August 2016

Two rhabdomesonid cryptostome bryozoans,Rhabdomeson progracilen. sp. andRhabdomeson rhombiferum(Phillips, 1836), are described from the Lower Carboniferous of the British Isles. A revised familial diagnosis of Rhabdomesidae Vine, 1884, and a revised generic diagnosis ofRhabdomesonYoung and Young, 1874, are presented. Taxonomic complications relating to the type species of the genus, which date from 1844, are discussed, and it is suggested that a new type species is required.
Middle Eocene terebratulide brachiopods from the Bateque Formation, Baja California Sur, Mexico
Authors: Sandy Michael R. , Squires Richard L. , Demetrion Robert
Published: August 2016

Two species of terebratulide brachiopods are described from the upper part of the Bateque Formation (middle Eocene) on the Pacific coast of Baja California Sur, Mexico,Terebratulinacf.Terebratulina louisianaeStenzel, 1940, andTerebratalia batequian. sp.Terebratalia batequian. sp. is the earliest confirmed record of the genusTerebrataliaBeecher, 1893, which has been an important component of Pacific brachiopod faunas through to the present day. The occurrence ofTerebratulinacf.Terebratulina louisianaeStenzel is one of the earliest records of the genus from the west coast of North America. These brachiopods, like other elements of the Bateque invertebrate fauna, may record Eocene migration from the Atlantic to Pacific Ocean via the Central American seaway.
A Turonian clavagellid (Bivalvia) from the Ladd Formation of southern California
Authors: Stallwood Robert B.
Published: August 2016

Stirpulina saulaen. sp. is the first reported clavagellid from the Pacific Province of North America. Specimens of this clavagellid are from the Ladd Formation of the Santa Ana Mountains, Orange County, southern California. The age of these specimens is Late Turonian based upon the presence of the ammoniteSubprionocyclusspp. both above and below the clavagellids in the section. These are, therefore, the oldest reported clavagellids from the western hemisphere, and they give positive support to the European Turonian reports of the genusStirpulina.The deposits indicate an open-shelf habitat of shallow to moderate depth, and the associated fauna suggests a warm temperate to subtropical marine climate. This is consistent with the previously reported Cretaceous distribution for the group.
Origin and spread ofPudoproetus, a survivor of the Late Devonian trilobite crisis
Authors: Feist Raimund , Petersen Morris S.
Published: August 2016

One of the most severe restrictions in taxonomic diversity of trilobites coincides with the Late Devonian “Hangenberg” Event, which is characterized by a pronounced eustatic low-stand. One of the survivors of this event isPudoproetus, which, being adapted to shallow water conditions, experienced an opportunistic worldwide spread during this time. The oldest representatives of this genus are reported from the pre-Hangenberg Late Famennian of the Urals and Kazakhstan. Other known occurrences of this genus, midcontinent U.S.A., Utah, southern China, and southern France, occur at the Devonian-Carboniferous boundary, shortly after the Hangenberg event, and in the earliest Carboniferous. This pattern of distribution suggests that neither climatic nor geographic migration barriers existed around the Old Red landmass at that time. On the other hand, the Hangenberg crisis severely affected outer shelf benthic habitats, whereas nearshore trilobites were largely unaffected by the event.

A proetine origin ofPudoproetus, as originally proposed by Hessler (1963), is emphasized on the basis of paleoecologic, stratigraphic, and morphological arguments. In particular, the presence of ancestral features, such as the possession of 10 thoracic segments and lateral occipital lobes still occurring in earlyPudoproetusspecies, points to a phylogenetic link with proetines rather than with phillipsiids. Within this group two new species are named:P. priscusandP. mediterraneus.
Yarala burchfieldi, a plesiomorphic bandicoot (Marsupialia, Peramelemorphia) from Oligo-Miocene deposits of Riversleigh, northwestern Queensland
Authors: Muirhead Jeanette , Filan Susan L.
Published: August 2016

Yarala burchfieldi n. gen. and sp. is described from Oligo-Miocene deposits of Riversleigh Station, northwestern Queensland. Although the smallest and most plesiomorphic bandicoot known, it shares unique synapomorphies with other peramelemorphs, such as the posteriorly orientated preparacrista on M2, posterolingual location of the hypoconulids, and the buccal position of the centrocrista. However, Y. burchfieldi lacks synapomorphies that would unambiguously allow it to be placed in any of the modern families as currently understood. In its plesiomorphic features, Y. burchfieldi provides a structural link between peramelemorphs and dasyuromorphs and appears to be a descendant of an annectant group that separated long prior to the origin of “typical” bandicoots. This species is present in many sites within the Riversleigh area. It possibly filled an insectivorous-carnivorous niche presently occupied by small dasyurids that are relatively more abundant today than they were when the Riversleigh deposits accumulated.
Chronostratigraphy and “Land-Mammal Ages” in the Cenozoic of southern South America: principles, practices, and the “Uquian” problem
Authors: Cione Alberto L. , Tonni Eduardo P.
Published: August 2016

The concept of “land-mammal age” as developed in South America is examined. The “Uquian Land-mammal age” is used as a study case. “Land-mammal age” parataxonomy is here considered methodologically but not conceptually different from chronostratigraphic taxonomy. “Land-mammal ages” in South America are based on stages. However, we consider that accurate biostratigraphic studies must be done in South America for establishing the biostratigraphy and precise boundary stratotypes of most stages-ages. The Uquia outcrops are here considered inadequate as a stratotype. A new South American continental stage-age is proposed. This stage is based on a biostratigraphic scheme. The stratotypes of the stage and biozones are located in the fossiliferous southeastern Buenos Aires Province marine cliffs. The lower boundary stratotype is proposed. The stage-age is probably correlated with the Gauss Chron and the lower Matuyama Chron. Additionally, some major units of Ameghino are validated and a different timing for the arrival of North American mammals to southern South America is presented.
Rejection of Carboniferous Quasidentalium Shimansky, 1974, from the phylum Mollusca
Authors: Yochelson Ellis L.
Published: August 2016

Upon restudy, Quasidentalium Shimansky, 1974, is transferred to the Coleolidae, a group of “Vermes” that form a calcareous tube.
Trilobite paleobiology: Past, present, and future
Authors: Adrain Jonathan M. , Westrop Stephen R.
Published: August 2016

The first major international trilobite conference (which also dealt with related arthropod groups) was convened by David Bruton in Oslo in 1973. That meeting resulted in a 467 page proceedings volume (Martinsson, 1975) that has become an indispensible reference on arthropod paleobiology. With its abundance of high-quality empirical work and influential ideas, the ongoing utility of “Fossils and Strata 4” is assured, yet it is also a fascinating microcosm of the themes and concerns of paleontology as a whole a quarter of a century ago. Paleoecology blossomed in the late 1960s and early 1970s. Autecology, and particularly functional morphology, dominates the volume, accounting for about one-third of the contributions. Plate tectonics was a relatively recent development in 1973 and, following the lead of Whittington and Hughes (1972), several papers tackled trilobite paleobiogeography. They vary from a bold attempt to determine oceanic circulation through the Ordovician by Ross to more conventional studies of biogeographic distribution that were aimed at providing further support for concepts of continental drift. There was a burgeoning interest in community paleoecology, and Richard Fortey's (1975) now-classic paper on the Early Ordovician faunas of Spitsbergen was the first to define trilobite “communities.” The volume was rounded out by diverse papers on trilobite anatomy based on material from the Burgess Shale and Beecher's Trilobite Bed, the microstructure of the trilobite cuticle, trilobites eyes, high level classification of trilobites, and various evolutionary themes (character displacement in agnostoids; adaptive radiation in Cambrian trilobites).
The rise and fall of late Paleozoic trilobites of the United States
Authors: Brezinski David K.
Published: August 2016

Based on range data and generic composition, four stages of evolution are recognized for late Paleozoic trilobites of the contiguous United States. Stage 1 occurs in the Lower Mississippian (Kinderhookian-Osagean) and is characterized by a generically diverse association of short-ranging, stenotopic species that are strongly provincial. Stage 2 species are present in the Upper Mississippian and consist of a single, eurytopic, pandemic genus,Paladin.Species of Stage 2 are much longer-ranging than those of Stage 1, and some species may have persisted for as long as 12 m.y. Stage 3 is present within Pennsylvanian and Lower Permian strata and consists initially of the eurytopic, endemic generaSevilliaandAmeuraas well as the pandemic genusDitomopyge.During the middle Pennsylvanian the very long-ranging speciesAmeura missouriensisandDitomopyge scitulasurvived for more than 20 m.y. During the late Pennsylvanian and early Permian, a number of pandemic genera appear to have immigrated into what is now North America. Stage 4 is restricted to the Upper Permian (late Leonardian-Guadalupian) strata and is characterized by short-ranging, stenotopic, provincial genera.

The main causal factor controlling the four-stage evolution of late Paleozoic trilobites of the United States is interpreted to be eustacy. Whereas Stage 1 represents an adaptive radiation developed during the Lower Mississippian inundation of North America by the Kaskaskia Sequence, Stage 2 is present in strata deposited during the regression of the Kaskaskia sea. Stage 3 was formed during the transgression and stillstand of the Absaroka Sequence and, although initially endemic, Stage 3 faunas are strongly pandemic in the end when oceanic circulation patterns were at a maximum. A mid-Leonardian sea-level drop caused the extinction of Stage 3 fauna. Sea-level rise near the end of the Leonardian and into the Guadalupian created an adaptive radiation of stentopic species of Stage 4 that quickly became extinct with the latest Permian regression.
Testing the Darwinian legacy of the Cambrian radiation using trilobite phylogeny and biogeography
Authors: Lieberman Bruce S.
Published: August 2016

Since the publication of Darwin (1859), the biological meaning of the Cambrian radiation has been debated. Most commentators agree, however, that the Cambrian radiation is fundamentally a time of major metazoan cladogenesis. In and of itself this does not necessarily mean that unique evolutionary processes operated during the Cambrian radiation. Phylogenetic analysis has been used to study the tempo of speciation during the radiation, and thus far there is no need to invoke special rules relating to the tempo of evolution. Instead, what seems unique about the Cambrian radiation is its place as an important episode in the history of life—that is, as the first major radiation of the Metazoa. Although the tempo of evolution during the Cambrian radiation may not have been uniquely high, there were largely unique tectonic events that transpired during the late Neoproterozoic and Early Cambrian, such as extensive cratonic fragmentation. Biogeographic analysis of Early Cambrian olenelloid trilobites reveals that these tectonic events powerfully influenced evolutionary and distributional patterns in this diverse and abundant trilobite group. This emphasizes the importance of physical earth history in generating evolutionary patterns. In the general study of macroevolutionary patterns and processes, earth history phenomena emerge as powerful forces influencing the history of life and provide insights into evolution that can best be inferred by paleontological data.
The most widely distributed trilobite species: OrdovicianCarolinites genacinaca
Authors: Mccormick Tim , Fortey Richard A.
Published: August 2016

The distributions of trilobite species were controlled by a combination of habitat preferences and paleogeographic constraints, which tend to limit their extent. The Lower Ordovician trilobiteCarolinites genacinacaRoss, 1951, however, had a remarkable range unequaled among polymerid trilobites; it has been recognized on all Ordovician paleocontinents. Its distribution has been explained by an epipelagic mode of life, based on evidence from functional morphology, analogy with modern pelagic crustaceans, and geological occurrence. In such a case, morphological identity throughout its range might be anticipated, if all occurrences can be postulated to be members of a single pandemic population. Rotational superimposition has been used to compare variation within samples drawn from Alberta, Spitsbergen, and Australia with a benchmark population from the western United States. All are morphometrically similar. By any criterion, specimens identical to the benchmark population are found within the Alberta, Spitsbergen and Australia samples, which represent the extremes of the species' geographic range. A lone cranidium from France, previously referred toCarolinites vizcainoi, may be a juvenile ofC. genacinacaorC. tasmaniensis; its differences are consistent with ontogeny. A small number of specimens from Siberia and central China show differences in cranidial proportions from the Utah specimens that may be the result of preservational factors and/or photographic technique, or may represent genuine morphological disparity; this could be clarified if more specimens were to become available. This study suggests thatC. genacinacawas ubiquitous in the epipelagic environment in a belt that encircled the planet between paleolatitudes of approximately 30°N and 30°S.
Cuticular microstructure of some Silurian homalonotid trilobites from Sweden
Authors: Dalingwater John E. , Siveter Derek J. , Mutvei Harry
Published: August 2016

Etched slices of the cuticle of the Silurian trilobiteHomalonotus rhinotropisAngelin, 1854, from two localities in Skåne, southern Sweden, have been examined with the scanning electron microscope. The two major subdivisions of the cuticle are a “prismatic” (originally laminated) outer layer, about 20-30 μm thick, and a principal layer, 200-300 μm thick, which may be foliated or roughly laminated. The original finely-laminated aspect of the outer layer may sometimes be seen as a continuous layer, but is more frequently detected as “shaped inclusions” set in a prismatic background. These “shaped inclusions” are considered to have been produced by accumulation of minerals around the apices of 3-6 μm perpendicular canals early in calcification and preferentially preserved because of subtle differences from the products of later stages of the process. It is possible that calcification started before ecdysis. The difficulties involved in ascertaining the original structure of the principal layer are outlined, and possible reasons for differences in its preservation from the outer layer are proposed.
Relationships of Cambrian Arachnata and the systematic position of Trilobita
Authors: Edgecombe Gregory D. , Ramsköld Lars
Published: August 2016

Cladistic relationships of Trilobita, Naraoiidae (five ingroup taxa), Helmetiida (five ingroup taxa), Xandarellida, and the Cambrian arachnatesRetifacies, Sinoburius, Emeraldella, andSidneyiaare investigated based on 29 characters. Documentation of appendage morphology and other ventral structures inSaperionfrom the Chengjiang fauna permits an appraisal of helmetiid relationships. A monophyletic Trilobita [=“Olenellida” (Emuellida + Eutrilobita)] is defined by numerous synapomorphies, including exoskeletal calcification and dorsal eyes with calcified lenses and circumocular sutures. Helmetiida is a robust clade, resolved as (Helmetiidae (Tegopeltidae (Saperiidae + Skioldiidae))). Naraoiid monophyly is well-supported, but neither a naraoiid-trilobite nor a naraoiid-Retifaciesclade are parsimonious, the latter grouping (“Nectopleura”) being explicitly paraphyletic. A sister group relationship between Xandarellida andSinoburiusis endorsed, although character support is novel compared to previous groupings of these taxa. The fourth postantennal limb pair in trilobites, naraoiids, and apparently helmetiids is based beneath the cephalothoracic articulation. Reweighted characters favor Trilobita and Helmetiida as closest relatives, with Petalopleura and then Naraoiidae as sister groups.
Hexactinellid and calcareous sponges from the Pennsylvanian (Moscovian) Dikanre Formation from Xinjiang-Uygur Autonomous Region, northwestern People's Republic of China
Authors: Rigby J. Keith , Waters Johnny A. , Maples Christopher G. , Lane N. Gary , Zhou-Ting Liao , Lu-Jon Liu
Published: August 2016

A modest assemblage of hexactinellid and calcareous sponges from the Pennsylvanian (Moscovian) Dikanre Formation has been recovered from the Uygur Autonomous Region in eastern Xinjiang Province in northwestern China. Hexactinellids include the reticulosid Stereodictyum proteron Rigby and Washburn, 1972, and the new amphidiscosid species Stioderma sinensis, S. micra, and S. mega. This is the first time the genera Stereodictyum and Stioderma have been reported from Asia. Also included in the assemblage is a silicified porate permosphinctan, Amblysiphonella cf. barroisi Steinmann, 1882, which is the first report of that genus from northwestern China. Species of Stioderma are described from nearly complete specimens for the first time. Previously described species have been based on isolated spicules or relatively small fragments.
Taxonomic discussion of the scolecodont generaNereidavusGrinnell, 1877, andProtarabellitesStauffer, 1933 (Annelida: Polychaeta)
Authors: Eriksson Mats
Published: August 2016

The scolecodont generaNereidavusGrinnell, 1877, andProtarabellitesStauffer, 1933, have been used for several different fossil polychaete taxa over the years.Nereidavusis here considered a nomen dubium, as the holotype of the type species is lost and the original information is insufficient for identification.Protarabellitesis reevaluated and constitutes, besidesRamphoprion, a second genus in the family Ramphoprionidae. The “paratype” ofN. varians(namedRamphoprionsp. in this paper), and the holotype ofP. humilisare redescribed.
A new decapod fauna from the Miocene Tuxpan Formation, eastern Mexico
Authors: Vega Francisco J. , Feldmann Rodney M. , Villalobos-Hiriart José Luis , Gío-Argíez Raúl
Published: August 2016

The first formal report of Tertiary portunid crabs for Mexico is based on two new species,Portunus atecuicitliandNecronectes tajinensis, from the middle Miocene beds of the Tuxpan Formation in Veracruz, east-central Mexico. Associated crustacean remains include fragments of calappid fingers, calappid carapace fragments possibly assignable toMatutaFabricius, and callianassid hands. Low tolerance to osmotic variations of recent species ofPortunusconfirms paleoenvironmental interpretations for shallow, euryhaline, tropical waters during deposition of the Tuxpan Formation.
A new species of Bananogmius (Teleostei: Tselfatiformes) from the Upper Cretaceous Carlile Shale of western Kansas
Authors: Fielitz Christopher , Shimada Kenshu
Published: August 2016

A new species, Bananogmius ellisensis n. sp., known only from the holotype, is described from the Blue Hill Shale Member (Upper Cretaceous, middle Middle Turonian) of the Carlile Shale Formation in western Kansas. The skull and anterior portion of the specimen is well-preserved and was subjected to little post-mortem deformation suggesting rapid burial. The nearly complete skull shows three characters that separate the fish from other species of Bananogmius: a straight, rather than ventrally curved dentary, a narrow band of teeth on the dentary that does not extend onto its lateral side, and a cylindrically-shaped articular condyle of the quadrate. The uncompressed preservation of the skull reveals a pair of long structures ventral to the mandible that are also found, but not described for some other Bananogmius species. Based on the positions of muscles in extant teleosts, these structures are most likely the mineralized protractor hyoidei muscles. Furthermore, these structures may be homologous with ventral structures found in Tselfatia. The presence of Bananogmius adds a new ecological component to the Blue Hill Shale fauna.
Correlation of the Type Bashkirian Stage (Middle Carboniferous, South Urals) with the Morrowan and Atokan series of the midcontinental and western United States
Authors: Groves John R. , Nemyrovska Tamara I. , Alekseev Alexander S.
Published: August 2016

The graphic correlation technique has been used to directly relate the stratigraphic appearances of key species in the Bashkirian Stage stratotype to those in a North American composite section. The type Bashkirian is separated from the underlying Serpukhovian Stage by an erosional unconformity and associated lacuna of undetermined, but probably minor duration. Accordingly, the base of the type Bashkirian (base of Bogdanovkian Horizon) is only slightly younger than the international mid-Carboniferous boundary. A level within the upper part of the Tashastian Horizon (Upper Bashkirian Substage) most likely correlates with the Morrowan-Atokan boundary. This level roughly coincides with a sequence boundary at the Bashkirian stratotype and with a regional unconformity in the North American midcontinent. The top of the Bashkirian Stage (top of Asatauian Horizon) is lower Atokan in North American terms. On the basis of recent 40Ar/39Ar and SHRIMP zircon geochronology studies, the age of the mid-Carboniferous boundary is estimated at 314 Ma and a horizon of early Atokan age is dated at 310.8 Ma. Accepting the present biostratigraphic correlations, these values suggest a duration for the Bashkirian Stage of slightly more than 3.2 m.y. and a duration of the Morrowan Series of slightly less than 3.2 m.y.
Lyriomyophoria Kobayashi, 1954, a junior synonym of Elegantinia Waagen, 1907
Authors: Boyd Donald W. , Newell Norman D.
Published: August 2016

Dr. Thomas Waller has called our attention to a taxonomic problem involving our choice of Lyriomyophoria as the generic assignment for a recently described Triassic bivalve (Boyd and Newell, 1997). We are grateful for his help in finding and analyzing the pertinent literature.
Jujuyaspis borealisand associated trilobites and conodonts from the Lower Ordovician of Texas and Utah
Authors: Stitt James H. , Miller James F.
Published: August 2016

Jujuyaspis borealisis reported from earliest Ordovician (North American usage) limestones in central Texas and western Utah, the first time this species has been recognized in the United States.Jujuyaspisis a widespread olenid trilobite that occurs near the base of the Tremadoc Series in a variety of lithologies in North and South America, Europe, and Asia. When international agreement is reached on the exact horizon at or near the base of the Tremadoc Series that is to be used as the Cambrian–Ordovician boundary,Jujuyaspiswill likely prove to be a very useful taxon for recognition of the boundary interval.
Ugrosaurus olsoni, a new ceratopsian (Reptilia: Ornithischia) from the Hell Creek Formation of eastern Montana
Authors: Cobabe Emily A. , Fastovsky David E.
Published: August 2016

Fragments of a ceratopsian dinosaur from the Maastrichtian Hell Creek Formation, Garfield County, Montana, are unlike any known ceratopsian. Diagnostic features include a low, rounded nasal boss, an especially deep rostral-premaxillary pit, and paired choanae. The snout is elongate. The new taxon, Ugrosaurus olsoni, is referred to the Ceratopsidae.
Sinusoidal trail formed by a Recent biting midge (Family Ceratopogonidae): trace fossil implications
Authors: Metz Robert
Published: August 2016

A Recent sinusoidal trail made by a biting midge (family Ceratopogonidae, genus ?Bezzia) moving on the surface of wet mud along the edge of a freshwater pond has been observed. The trail is similar to the trace fossil Cochlichnus Hitchcock, 1858. The wave length, wave amplitude, and overall form and shape of this modern trail compares favorably to Eocene wave-like trails attributed to nematodes. Consequently, a ceratopogonid larva is believed responsible for at least some of those fossil trails.
Burrow distribution of thalassinidean shrimp on a Fraser Delta tidal flat, British Columbia
Authors: Swinbanks David D. , Luternauer John L.
Published: August 2016

Burrows of the thalassinidean shrimp Callianassa californiensis and Upogebia pugettensis, which resemble the trace fossils Thalassinoides and Ophiomorpha, respectively, occur on the southern tidal flats at the western front of the Fraser Delta. Burrow densities for both shrimp species are highest at lower intertidal levels immediately inshore of an extensive bed of Zostera marina eelgrass, but the high-density shrimp populations are segregated: the highest densities of C. californiensis burrows (350–450 burrow openings/m2) occur in a strip of clean sandy sediments, whereas U. pugettensis burrows are most abundant (30–80 burrow openings/m2) in a patch of muddy sands and sandy muds. On the tidal flats of the Fraser Delta as a whole, however, textural properties of the sediment show no consistent correlation with the burrow density of either shrimp.

In the eelgrass bed, eelgrass root mats appear to markedly restrict the density of C. californiensis burrows. Towards the shore, the well-lined dwelling burrows of U. pugettensis occur no higher than mean sea level where maximum continuous exposure is ≤0.5 days. In contrast, C. californiensis, which has an unlined feeding burrow and a higher tolerance for anoxia, is present up to the margin of the local salt marsh which lies near the mean higher high water level where the flats can be exposed continuously up to 5 days.

In situ experiments indicate that C. californiensis extrudes 18 ± 9 ml of wet sediment/shrimp/ day onto the substrate surface, while U. pugettensis seldom forms a mound around its burrow entrance. Burial of filter-feeding postlarval U. pugettensis under the mounds produced by C. californiensis may increase postlarval mortality and reduce adult populations of U. pugettensis in areas of high C. californiensis burrow density.

The results of this study suggest that in distinguishing Ophiomorpha from Thalassinoides more emphasis should be placed on the presence of an extensive burrow lining in Ophiomorpha than on the presence of a knobby burrow exterior, because the former characteristic has a more profound bearing on burrow function, physiology of the occupant organism, and, consequently, burrow distribution.
Conodonts of the Windsor Group (Lower Carboniferous), Magdalen Islands, Quebec, Canada
Authors: Bitter Peter H. Von , Plint Hilary A.
Published: August 2016

Lower Carboniferous (Viséan-?early Namurian) conodonts, and some of their variably complete reconstructed apparatuses, are described from cyclic marine carbonates, associated with evaporites and mud rocks, of the Windsor Group, Magdalen Islands, Quebec, Canada. The conodont fauna includesClydagnathus windsorensis, Cavusgnathus unicornis, Taphrognathus transatlanticus, Hindeodus cristula, Hindeodus? scitulus, Vogelgnathus campbelli, Ozarkodina laevipostica, Mestognathus bipluti, Mestognathusspp.,Spathognathodus? n. sp. A, andApatognathusspp.
A Bohemian-type Silurian (Wenlockian) pelecypod faunule from Arctic Canada
Authors: Pojeta John , Norford B. S.
Published: August 2016

The pelecypod generaSlavaandRhombopteriaare reported for the first time from Canada, where they occur in a limestone concretion within the Cape Phillips Formation, Cornwallis Island, Arctic Archipelago. These genera are characteristic of Silurian rocks in Bohemia, Czechoslovakia. Graptolites from the same concretion indicate theMonograptus ludensisZone (uppermost Wenlockian); this age is substantiated by associated conodonts, trilobites, vertebrates, and pelecypods but with less precision. It is difficult to explain the occurrence of Slava andRhombopteriain the middle of Laurentia on the basis of some map reconstructions of the Wenlockian world.

The Canadian material ofSlava novaterran. sp. andRhombopteriacf.R. mira(Barrande) is described.Leptodesma(Leptodesma) sp. A and an indeterminate grammysiid pelecypod from the same concretion are illustrated. Information is provided to show thatNewsomellaFoerste, from Wenlockian–Ludlovian rocks of Illinois, Wisconsin, and Tennessee, is not a subgenus ofRhombopteriaJackson.
Upper Paleozoic cephalopod mandibles: frequency of occurrence, modes of preservation, and paleoecological implications
Authors: Mapes Royal H.
Published: August 2016

Thirty localities in the Upper Paleozoic (Mississippian–Permian) of North America have yielded more than 1,000 cephalopod mandibles preserved as carbon films, pyrite/limonite internal molds, and as nuclei in phosphate, carbonate, and ironstone concretions. With occasional exceptions, cephalopod mandibles, as part of either the microfauna or macrofauna, are rare despite the fact that co-occurring cephalopods may be extremely abundant. Without exception, the mandibles recovered co-occur with ammonoids and very frequently with bactritoids. Localities containing only nautiloids, either coiled or orthoconic, have not yet yielded cephalopod mandibles. Also, nekroplanktic accumulations of cephalopods have not yielded mandibles. Except for Lagerstätten deposits (two occurrences), the cephalopod mandibles were always recovered from molluscan-dominated communities; these communities have been interpreted as being in relatively offshore, “deeper” water in normal marine salinities with relatively low to anoxic oxygen conditions.
Lithofacies and biofacies of the Middle and Upper Devonian Sultan Formation at Mountain Springs, Clark County, Nevada: implications for stromatoporoid paleoecology
Authors: Harrington Robert J.
Published: August 2016

The Sultan Formation is a Middle and Upper Devonian inner shelf carbonate sequence in southern Nevada containing four stromatoporoid-dominated biofacies. Reported herein is a study of the Ironside Dolomite and Valentine Limestone Members exposed at Mountain Springs, Nevada. Eight lithofacies are distinguished and interpreted as a transgressive sequence, with deposition ranging from the supratidal zone to just below wave base. Each of the biofacies is unique and confined to a specific depositional environment as interpreted from the lithofacies reconstructions. The purpose of the study was to gain a better understanding of the range of ecologic conditions—physical, chemical, and biological—to which these stromatoporoids were adapted.

Based on the research, it is concluded that stromatoporoids flourished in a variety of nonreef habitats which ranged from highly stressful peritidal environments where only stromatoporoids were accommodated to less stressful offshore habitats where other organisms may have been in direct competition. Although habitat generalists are usually poor competitors, these stromatoporoids appear to have been an exception. Their ability to colonize a variety of substrata, their broad tolerances to chemical conditions and circulation patterns, and their emphasis on high rates of lateral growth have permitted them to simultaneously occupy unstable tidal channel embayments and more benign offshore habitats.
A new Permian waagenophyllid coral from the Klamath Mountains, California
Authors: Stevens Calvin H. , Miller M. Meghan , Nestell Merlynd
Published: August 2016

Specimens of a new species of the Permian waagenophyllid coral genus Waagenophyllum, W. klamathensis, have been recovered from limestone lenses near the top of the Upper Permian Dekkas Formation in the eastern Klamath Mountains, and similar specimens have been collected from an isolated limestone mass in the eastern Hayfork terrane of the southwestern Klamath Mountains, northern California. Another specimen of Waagenophyllum, which may represent another species, has been recovered from another limestone mass in the Hayfork terrane. These specimens of Waagenophyllum, a genus which otherwise is restricted to the Tethyan Province, provide the only tie between the Permian limestone masses of the eastern Hayfork terrane, which also contain typical Tethyan foraminifers, and the eastern Klamath Mountains terrane (McCloud belt), which contains many fossils with non-Tethyan affinities.
Middle OrdovicianLophospira(Archaeogastropoda) from the Upper Mississippi Valley
Authors: Tofel Jane Evans , Bretsky Peter W.
Published: August 2016

A detailed morphological study of over 2,500 Middle Ordovician (Black Riveran) lophospirid archaeogastropods from the lower half of the Platteville Formation (Pecatonica Member and Mifflin Submember of the McGregor Member), principally as it is exposed in southern Wisconsin, has permitted the definition of five species ofLophospira. Lophospira perangulata(Hall),L. milleri(Hall),L. serrulata(Salter),L. helicteres(Salter), andL. delicata(n. sp.) are preserved throughout a three-meter interval of fine-grained, heavily bioturbated carbonates, now dolomitized. Deposition took place on a broad, shallow tropical shelf, which was characterized by low rates of deposition and low physical energy. The sampled interval represents about 500,000 years. The benthic marine invertebrate fauna is well preserved, diverse, and characteristic of an environment of normal marine salinity.

Of the fiveLophospiraspecies, only one,L. perangulata, has been positively identified in older strata (late Whiterockian, eastern North America). The other four species were endemic to the interior seas, and apparently at least two of these,L. serrulataandL. helicteres, did not survive into post-Platteville (post-Black Riveran) environments. Changes in the proportions of lophospirid species from the Pecatonica into the Mifflin strata probably reflect subtle changes in the distribution of carbonate shelf habitats but no major alteration in the kinds of habitats available for colonization.
Late NeogeneNeohipparion(Mammalia, Equidae) from the Gulf Coastal Plain of Florida and Texas
Authors: Hulbert Richard C.
Published: August 2016

Three successive species ofNeohipparionare recognized from the Gulf Coastal Plain:N. affinefrom the early Clarendonian Lapara Creek Fauna of Texas;N. trampasensefrom the very late Clarendonian and early Hemphillian of Florida; andN. eurystylefrom the late early and late Hemphillian of Florida. Numerous specimens from the Love Site, Alachua County, Florida, as well as from other faunas of similar age from Florida, Kansas, and Nebraska (e.g., the Xmas-Kat Quarries), are referred toN. trampasense. This species is ancestral to all later species ofNeohipparion, as it shares with them many advanced dental characters, but often in a rudimentary or intermediate form. Five valid species constitute the monophyletic genusNeohipparion, which ranges from the late Barstovian to the latest Hemphillian (late Miocene through earliest Pliocene) in North America. A close phylogenetic relationship betweenNeohipparionand “Merychippus”republicanusand/orPseudhipparionis proposed based on similarities of cranial and dental features.
Redescription of Early Pennsylvanian trace-fossil holotypes from the nonmarine Hindostan Whetstone beds of Indiana
Authors: Maples Christopher G. , Archer Allen W.
Published: August 2016

The late Namurian Hindostan Whetstone beds are among the oldest Pennsylvanian strata recognized in the Illinois Basin. Trace-fossil holotypes of Haplotichnus indianensis, Plangtichnus erraticus, and Treptichnus bifurcus were first described and illustrated from these nonmarine strata with line drawings without reference to scale in a relatively obscure work by S. A. Miller (1889). These holotypes are refigured and redescribed in this paper. Based on examination of holotype collections, the Ordovician “Feather-stitch Trail” of Wilson (1948) is judged not to be congeneric with Treptichnus. The ichnogenus Ancorichnus, which is present in the Hindostan Whetstone beds, superficially resembles Haplotichnus; however, Haplotichnus lacks the internal meniscae characteristic of Ancorichnus.
The Sweetognathus complex in the Permian of China: implications for evolution and homeomorphy
Authors: Cheng-Yuan Wang , Ritter Scott M. , Clark David L.
Published: August 2016

The well-exposed and fossiliferous Permian carbonates in China have yielded Early and Late Permian species of the Sweetognathus complex that permit worldwide stratigraphic evaluation of members of the group. The sporadic appearance of species of Sweetognathus and related genera throughout the Permian in western North America and Iran, in particular, may represent iterative evolution and homeomorphy. The pectiniform element morphologies of the several species are interpreted as most important for evolutionary studies and document a partial Permian biostratigraphy in China that aids in the interpretation of less complete sequences elsewhere. A new genus, Pseudosweetognathus, and four new species, Pseudosweetognathus costatus, Sweetognathus subsymmetricus, S. paraguizhouensis, and Iranognathus nudus, are described.
New rodents (Mammalia) from the late Barstovian (Miocene) Valentine Formation, Nebraska
Authors: Korth William W.
Published: August 2016

Additional fossil material from the Valentine Formation in Knox and Brown Counties, Nebraska, has allowed for the recognition of three new species of rodents, a heteromyid (Perognathus brevidens), a geomyid (Parapliosaccomys annae), and a zapodid (Schaubeumys cartomylos). The specimens referred here toP. brevidenswere previously identified asP. furlongi, those ofS. cartomyloswere identified asS. grangeri, and those ofP. annaewere previously recognized asLignimuscf.L. hibbardi. It is evident thatLignimusStorer should be restricted to the type speciesL. montis, and the remainder of the species referred to this genus are referred toParapliosaccomysShotwell.Parapliosaccomysis recognized as the earliest member of the subfamily Geomyinae based on its dental morphology, which extends the range of this subfamily into the Barstovian. The fauna from Annie's Geese Cross Quarry (Knox County) is recognized as being late Barstovian based on comparison with the older Norden Bridge Quarry (Brown County).