bluuebunny/crossref_metadata_2025 huggingface dataset:
A gradual morphologic transition during a rapid speciation event in marginellid gastropods (Neogene: Dominican Republic)
Authors: Nehm Ross H. , Geary Dana H.
Published: August 2016

We document a speciation event between two species of Prunum (Marginellidae: Gastropoda) in Pliocene strata of the northern Dominican Republic. The ancestral species, P. coniforme, is widely distributed in the Mio-Pliocene of the Dominican Republic and Jamaica, and has a range of at least 11 m.y. The descendant species, P. christineladdae, is endemic to the northern Dominican Republic. The ancestral species persists after its descendant arises. The transition between species is marked by stratigraphic and morphologic intermediates, and occurs during an interval estimated to be between 73,000 and 275,000 years (representing 0.6-2.5 percent of the duration of the ancestral species). Although the transition takes more than a geologic instant, the overall pattern of morphologic change is best described by the model of punctuated equilibrium. The change between species apparently involved a habitat shift into deeper water, and occurred during accelerated deepening. All of the Neogene Dominican species of Prunum appear to have had depth-defined ranges.
A new species of the oligopygoid echinoidHaimeafrom the lower Eocene of Baja California Sur, Mexico
Authors: Squires Richard L. , Demetrion Robert A.
Published: August 2016

The oligopygoid echinoidHaimea bajasurensisn. sp. is described from middle lower Eocene (”Capay Stage”) shallow-marine sandstones in the middle part of the Bateque Formation and shallow-marine limestones in the upper part of the Tepetate Formation, Baja California Sur, Mexico. The new species is both the earliest and the westernmost oligopygoid, and the first occurrence ofHaimeain North America.
Eutherian tarsal bones from the Late Cretaceous of India
Authors: Prasad G. V. R. , Godinot M.
Published: August 2016

Eutherian tarsal bones of Late Cretaceous age are reported for the first time from sedimentary beds intercalated with the Deccan Traps of peninsular India. The tarsal bones, represented mainly by calcanea and astragali, occur in association with dental elements of palaeoryctid mammals:Deccanolestes hislopiPrasad and Sahni andD. robustusPrasad, Jaeger, Sahni, Gheerbrant, and Khajuria. Two size variants in the tarsals correlate well with the teeth ofD. hislopiandD. robustus.Morphologically, the tarsal complex ofDeccanolestesis quite different from that of other Cretaceous eutherians for which the relevant anatomy is known (ProtungulatumandProcerberus). Rather, the tarsals ofDeccanolestesexhibit a close affinity to the tarsal morphology of Archonta. A large number of tarsal characters indicate a highly arboreal mode of life for these animals. Presence of such specialized animals as early as the Cretaceous suggests that mammals had already diversified their locomotor adaptations by this time.
Petaloconchus sculpturatus alaminatus, a new Pliocene subspecies of vermetid gastropods lacking its defining generic character, with comments on vermetid systematics in general
Authors: Gould Stephen Jay
Published: August 2016

The systematics of vermetid gastropods is in a shambles, with few genera defined by valid autapomorphic characters. Heretofore, the genusPetaloconchushas been included among the few adequately characterized groups, thanks to possession of a double internal lamina on the middle whorls. Yet abundant anecdotal information has been available for 100 years on the absence of laminae in high percentages of individuals within samples, and in entire populations that must be placed within the genealogical nexus ofPetaloconchus.I demonstrate that such a nonlaminate population exists within the very material used to define the type species of the genus, PliocenePetaloconchus sculpturatusLea, 1843, from the Gulf and Atlantic Coastal Plain of the United States. I use X-radiography and multivariate biometry to show that this population from the Pliocene Jackson Bluff Formation at Jackson Bluff, Florida, is fully alaminate, but otherwise indistinguishable fromP. sculpturatus.After considering a range of solutions, I name this population as a new subspecies,Petaloconchus sculpturatus alaminatus.I discuss theoretical and practical issues arising from populations that lack the defining feature of their genus.
Unusual accessory muscle scar patterns in two species of Palaeoneilo, a paleotaxodont bivalve from the Devonian of Bolivia
Authors: Babin Claude , Farjat Alejandra Dalenz
Published: August 2016

New Devonian fossil material from Bolivia includes internal molds of two species of paleotaxodont bivalve, Palaeoneilo musculosa (Knod) and P. pondeana (Hartt and Rathbun), with numerous accessory muscle scars. The unusual pattern of these scars appears to have been derived from excessive splitting. These muscle scars are described and a tentative interpretation is made. An adaptative role cannot be determined with certainty and it appears that these patterns were short-lived novelties without later success.
Quantitative analysis of ontogenetic changes of cell-reflecting sculptures in Ostracoda (Crustacea)
Authors: Irizuki Toshiaki
Published: August 2016

The distributional patterns of reticulate sculptures, corresponding to those of the underlying epidermal cells, of two Baffinicythere species (Ostracoda, Crustacea) are discussed from a geometrical point of view to understand whether they are under some rule or not. Reticulation geometry has been quantified by applying the method of Dirichlet domains defined as convex polygons, each being demarcated by bisectors normal to the lines connecting neighboring pairs of points. Studies of the distributional patterns of reticulation during growth reveal that these polygons become closer to Dirichlet domains and are dominated by hexagonal or subcircular fossa outlines toward the adult stage, and ultimately reach an equilibrium and stable pattern at maturity.
The lichid trilobiteBorealargesn. gen., with species from the Silurian of Arctic Canada
Authors: Adrain Jonathan M.
Published: August 2016

Borealargesn. gen. (type speciesB. reedin. gen. and sp.) is a group of trochurine trilobites of mainly northern Laurentian distribution, closely related to bothRichterargesPhleger andTerranoviaMaximova.Richterargesis restricted to a Laurentian Ludlow-Přídolí clade of unambiguous monophyly. Taken together, the genera form a monophyletic subdivision of Trochurinae. Phylogenetic relationships within this clade are poorly resolved. The precise relationships of some members of the group are difficult to determine at present, and these species are referred toBorealargessensu lato. Members ofBorealargesare ubiquitous elements of silicified Wenlock–Ludlow trilobite faunas contained in debris flows of the Cape Phillips Formation of the central Canadian Arctic. At present, known post-Wenlock diversity ofBorealargesis exclusively northern Laurentian, although this may be a function of lack of study in other areas. New species includeB. reedi, B. morrisoni, andB. tuckerae, andB.s.l.B. calei. Borealarges mikulicorum(Perry and Chatterton) is revised.
Some molluscan problematica from the Upper Cambrian–Lower Ordovician of the Ozark uplift
Authors: Stinchcomb Bruce L. , Darrough Guy
Published: August 2016

The mollusk Hemithecella, which occurs abundantly both above and below the Cambrian-Ordovician boundary in the Ozark region of Missouri, is discussed and compared with Matthevia and with the polyplacophoran order Paleoloricata and found to be distinctly different. Based upon the presence of monoplacophoran-like multiple muscle scars and asymmetrical valves, Hemithecella and related forms described here are considered to be molluscan problematica. Hemithecellids are mollusks; however, their affinity to other classes is unclear although structural similarities to the Monoplacophora are noted. The new order Hemithecellitina is proposed. It contains two new families, the Hemithecellidae and the Robustidae. Three new genera, Conodia, Robustum, and Elongata, and nine new species are proposed: Conodia levicosta, C. acuminata, Robustum nodum, R. phallarium, Elongata perplexa, Hemithecella elongata, H. abrupta, H. quinquelites, and H. eminensis.
New occurrences ofLeukadiellaandParoniceras(Ammonoidea) from the Toarcian (Lower Jurassic) of the Canadian Cordillera
Authors: Jakobs G. K.
Published: August 2016

Previous studies of the Toarcian of the North American Cordillera have mentioned the rare occurrence ofParonicerasin the Queen Charlotte Islands. Recent work has identified the presence ofLeukadiellain the Middle Toarcian of the Queen Charlotte Islands, the Spatsizi area, and the Hazelton area. They occur withRarenodia planulata, Peronoceras pacificum, Peronoceras verticosum, andPhymatocerascf.P. pseudoerbaense.TheLeukadiellaspecimens are well preserved and generally larger than those found in the Mediterranean region. Taxa present in North America includeParoniceras sternale, Leukadiella ionica, Leukadiella amuratica, Leukadiellaaff.L. helenae, andLeukadiellaaff.L. ionica.MorphologicallyLeukadiellais closely related to such genera asHildaitesandHildocerasand is more suitably placed within the subfamily Hildoceratinae rather than the Bouleiceratinae. The distribution ofLeukadiellaandParonicerasindicates the influence of the Hispanic Corridor linking western Tethys and the eastern Pacific during the Middle Toarcian.
First record of the early Mesozoic sphenodontianClevosaurus(Lepidosauria: Rhynchocephalia) from the Southern Hemisphere
Authors: Sues Hans-Dieter , Reisz Robert R.
Published: August 2016

An incomplete skull of a small sphenodontian lepidosaur from the upper part of the Stormberg Group of southern Africa is referable toClevosaurusSwinton, 1939. It is most closely related toC. bairdifrom the McCoy Brook Formation (Lower Jurassic) of Nova Scotia (Canada) andC. mcgillifrom the Dark Red Beds of the Lower Lufeng Formation (Lower Jurassic) of Yunnan (China). The new specimen is important because it represents the first record ofClevosaurusfrom the Southern Hemisphere. Like many other taxa of Early Jurassic continental tetrapods (crocodylomorph archosaurs, dinosaurs, synapsids),Clevosaurushad an apparently Pangaean distribution.
Biogeography of Ordovician sponges
Authors: Carrera Marcelo G. , Rigby J. Keith
Published: August 2016

Sponges have an unrealized potential importance in biogeographic analysis. Biogeographic patterns determined from our analysis of all published data on distribution of Ordovician genera indicate Early Ordovician sponge faunas have relatively low diversity and are completely dominated by demosponges. Early Ordovician (Ibexian) faunas are characterized by the widespread co-occurrence ofArchaeoscyphiaand the problematicCalathium.This association is commonly found in biohermal structures. Middle Ordovician faunas show an increase in diversity, and two broad associations are differentiated: Appalachian faunas (including Southern China and the Argentine Precordillera) and Great Basin faunas.

Late Ordovician faunas show important changes in diversity and provincialism. Hexactinellid and calcareous sponges became important and new demosponge families appeared. Four Mohawkian-Cincinnatian associations are recognized here, including: 1) Midcontinent faunas; 2) Baltic faunas; 3) New South Wales faunas; and 4) Western North American (California and Alaska) faunas. However, two separate biogeographic associations are differentiated based on faunal differences. These are a Pacific association (western North American and New South Wales) and an Atlantic association (Midcontinent Laurentia and Baltica).

Distribution of sponge genera and migration patterns are utilized to consider paleogeographic dispositions of the different continental plates, climatic features, and oceanic currents. Such an analysis points to close paleogeographic affinities between the Argentine Precordillera and Laurentian Appalachian faunas. However, significant endemicity and the occurrence of extra-Laurentian genera suggest a relative isolation of the Precordillera terrane during the Late Ibexian-Whiterockian. The study also shows a faunal migration from the Appalachian region to South China during the Middle Ordovician and the migration of faunas from Baltica to Laurentia in the Late Ordovician. The occurrence of Laurentian migrants in New South Wales during the Late Ordovician could be related to inferred oceanic current circulation between these two areas, although other paleogeographic features may be involved.
A new pleurocystitid rhombiferan echinoderm from the Middle Ordovician Galena Group of northern Iowa and southern Minnesota
Authors: Brower James C.
Published: August 2016

Pleurocystites strimpleinew species, from the Galena Group of Iowa and Minnesota, is closely related toP. squamosusBillings from the Appalachians and Michigan. Numerous specimens provide information about growth, living habits, functional morphology, and respiration. The development ofP. strimplein. sp. is largely isometric with several exceptions. New dichopores form throughout ontogeny. Length of the dichopores and the area available for respiration are characterized by strong positive allometry relative to the volume of the animal. The length of the distal stem increases with respect to the size of the theca. During life the aboral side faced up. Some animals were largely covered by a thin layer of sediment whereas others lay directly on the seafloor. The orientation of the brachioles is most consistent with deposit feeding. Quantitative models of respiration suggest that the pectinirhombs accounted for over half of the needs of youngsters but this contribution falls to about 38 percent in adults. Respiration by the surface area of the theca and the water vascular system provide small amounts of oxygen, especially for animals living on the surface of the seafloor. Cloacal pumping or a similar type of respiratory device probably furnished the remainder of the oxygen required byP. strimplein. sp. The morphometric data in conjunction with parameters taken from Recent oceans and echinoderms produce a plausible respiration budget, which is affected by size, age, allometry, and living orientation.
On the superfamily Darwinuloidacea, the type species of Darwinuloidea Mandelstam, 1956, and on the status of Cheikella Sohn and Morris, 1963 (Ostracoda)
Authors: Sohn I. G. , Swain F. M.
Published: August 2016

Molostovskaja (1979, p. 54) described without illustrations the family Darwinuloididae Molostovskaja, 1979. The following year, Molostovskaja (1980, p. 33) described the family again as new [Darwinuloididae fam. nov.]. She included the genus Whipplella Holland, 1934, in the family and illustrated Darwinuloides svijazhicus (Sharapova 1948) (Molostovskaja, 1980, p. 28, figs. 5a, b, 8). Schneider (1948, p. 29, pl. 2, figs, 1a, b) originally described and illustrated this species as “Darwinula svijazhicus Sharapova n. mns.” Two years later, Molostovskaja (1982, p. 158) illustrated cross-sections of the adductor muscle attachment scar patterns in the families of the Darwinulacea Brady and Norman, 1889. Later Molostovskaja (1990, p. 166) erected the superfamily Darwinuloidacea Molostovskaja, 1979 to include Whipplella Holland, 1934, Vymella Kalis and Mischina in Mischina and Kalis, 1975, and questionably Pruvostina Scott and Summerson, 1943. In the same paper, she illustrated Whipplella sp. (pl. 72, figs. 6a, b) [from Sohn, 1977], Vymella dobrinini (Kashevarova, 1961) (pl. 72, figs. 7a-c), Darwinuloides sentjakensis (Sharapova in Schneider, 1948) (pl. 73, figs. 5, 6), and D. svijazhicus (Sharapova in Schneider, 1948) (pl. 74, figs. 14a, b).
Trilobite faunas from Upper Cambrian microbial reefs in the Central Appalachians
Authors: Taylor John F. , Loch James D. , Perfetta Patrick J.
Published: August 2016

Trilobites from thrombolitic reefs in the Ore Hill Member of the Upper Cambrian Gatesburg Formation are assigned to (in ascending order) the Pseudosaratogia magna, Cliffia lataegenae, and Irvingella major Subzones of the Elvinia Zone. These reef faunas contrast markedly with those from coeval off-reef grainstones (tempestites), representing separate biofacies rather than biostratinomic variants. Associated lithologies suggest that the fauna of the P. magna Subzone at the base of the member comprises a biofacies associated with shallower microbial reef environments than those occupied by faunas in the overlying C. lataegenae Subzone. Reefs in the C. lataegenae Subzone yield a fauna dominated by Buttsia drabensis, extending the documented range of catillicephalid abundance in microbial reef biofacies downward into the highest strata of the Steptoean Stage. This reef fauna also includes several new taxa, including Cheilocephalus quadratus new species (described herein), an atypical species of Cheilocephalus with catillicephalid-like cranidial features. The fauna in off-reef tempestites low in the C. lataegenae Subzone contains the genera that characterize the Xenocheilus–Kindbladia Biofacies, expanding the known environmental and geographic range of that biofacies. Sulcocephalus, typically a minor component of faunas in the I. major Subzone, dominates the fauna in reefs within this subzone such that a distinct Sulcocephalus Biofacies can be recognized immediately above the extinction horizon that defines the base of the Sunwaptan Stage.
Comparative paleoecology of Cambrian trilobite extinctions
Authors: Westrop Stephen R. , Cuggy Michael B.
Published: August 2016

Analysis of 164 collections from shelf facies of Laurentian North America indicates that three successive trilobite mass extinctions at Late Cambrian stage boundary intervals (“biomere” boundaries) are characterized by a common pattern of change in distributional paleoecology and species diversity. In all cases, the extinction intervals are marked by a shift to biofacies that have broader environmental distributions than those prior to the onset of extinctions, implying a reduction in between-habitat (beta) diversity. Significant declines in within-habitat (alpha) diversity also characterize each extinction and the compositions of shelf biofacies record extensive immigration of taxa from off-shelf and shelf-margin sites. The nature and extent of ecologic disruption of the shelf appears to be comparable to changes associated with major mass extinctions, such as those at the end of the Ordovician and Permian. Unlike major mass extinctions, the Cambrian events are followed by a complete recovery of diversity and biofacies structure within a few million years.
A North American freshwater sponge (Eospongilla morrisonensis new genus and species) from the Morrison Formation (Upper Jurassic), Colorado
Authors: Dunagan Stan P.
Published: August 2016

Eospongilla morrisonensis n. gen. and sp., the oldest-described freshwater sponge (Demospongea: Spongillidae), is found in the Upper Jurassic (?Oxfordian/Kimmeridgian to Tithonian) Morrison Formation, east-central Colorado, U.S.A. Eospongilla morrisonensis occurs within the well-developed lacustrine carbonate succession of the Morrison Formation, and is represented by two micritic body fossils with calcite-replaced megascleres that range in length from 180 to 300 μm and in diameter from 20 to 35 μm. Megascleres are simple oxeas and strongyles and lack apparent ornamentation, possibly due to the diagenetic replacement. The oxeas are straight but the strongyles display a slight curvature. Microscleres are absent; gemmoscleres were not observed.
Crinoids and stelleroids (Echinodermata) from the Broken Rib Member, Dyer Formation (Late Devonian, Famennian) of the White River Plateau, Colorado
Authors: Webster Gary D. , Hafley Daniel J. , Blake Daniel B. , Glass Alexander
Published: August 2016

A crinoid and stelleroid fauna is described from the Famennian (Late Devonian) Broken Rib Member of the Dyer Formation of the White River Plateau, Colorado. The fauna postdates the Late Devonian extinction event. Six new crinoid species described, including the new genusTarassocrinus, are:Strimplecrinus dyerensis, Catactocrinus?torus, Hypselocrinus?bisonensis, Gilmocrinus?albus, Eireocrinus?coloradoensis, andTarassocrinus synchlydus.The cladid-dominated crinoid fauna is transitional between earlier Devonian and later Carboniferous faunas. It contains the first report ofCupressocrinites(a Famennian Lazarus taxon) andEireocrinus? in North America and extends ranges of several Carboniferous genera into the Late Devonian. A preliminary revision of the Rhenocrinidae is recommended. The family Glossocrinidae is recognized, and the Cupressocrinitidae are transferred to the Gasterocomacea.

A new stelleroid genus and species,Pleiadeaster inceptus(Asteroidea; family unknown), and an ophiuroid,Ophiopolytretus aethus(Ophiuroidea; Lapworthuridae?) are named. In addition,Hudsonaster(Hudsonasteridae; Asteroidea) and two unassigned asteroids are present, and three further stelleroids cannot be assigned to the class level.PleiadeasterandHudsonasterare important because they suggest that the Late Devonian might have been a time of transition for asteroids.Ophiopolytretus aethusis an oegophiurid ophiuroid with distinctive respiratory? pores penetrating the disk plates.
Review of the Ordovician conodont zonal indexEoplacognathus suecicusBergström, 1971
Authors: Jian-Hua Zhang
Published: August 2016

Over 600 elements of the Ordovician conodont indexEoplacognathus suecicusBergström, 1971, were obtained from the Segerstad and Skärlöv Limestones at the Lunne section, which is the type locality ofE. suecicus, and at the Kullstaberg section both in Jämtland, Sweden. Specimens ofE. suecicusfrom different stratigraphic levels and representing different growth stages show obvious morphological differences. The stratigraphically early elements ofE. suecicusare very similar to the stratigraphically late elements ofEoplacognathus pseudoplanus(Viira), being distinguished mainly by the appearance of the secondary postero-lateral denticle row in the stelliplanate element.Eoplacognathus suecicusapparently was derived fromE. pseudoplanus, and probably evolved intoEoplacognathus lindstroemi(Hamar).
Quadriloba, new name for the genus Tetraloba Alvarez, Rong, and Boucot, 1998 (Brachiopoda, Athyridida); preoccupied by Tetraloba Lee, 1983 (Insecta, Collembola)
Authors: Alvarez Fernando , Jia-Yu Rong , Boucot A. J.
Published: August 2016

John K. Page, Chief of the Production Section of the Zoological Record has kindly informed us (personal commun., 16 November 1998) that the generic name Tetraloba Alvarez, Rong, and Boucot, 1998 (Brachiopoda: Athyridida) (Alvarez et al., 1998, p. 843) is preoccupied by an insect (Collembola) genus published by Lee, 1983. According to Article 60 of the ICZN rules, we here propose Quadriloba (from the Latin, quattuor, four and lobus, a rounded projection or protuberance) as replacement name for Tetraloba Alvarez, Rong, and Boucot, 1998, not Tetraloba Lee, 1983.
Tabulaconus Handfield: microstructure and its implication in the taxonomy of primitive corals
Authors: Debrenne Francoise M. , Gangloff Roland A. , Lafuste Jean G.
Published: August 2016

Numerous specimens of Tabulaconus Handfield, 1969, have been collected in carbonate buildups within the Adams Argillite (Early Cambrian, Tatonduk area, Alaska). The wall structure of this form has been investigated, along with contemporaneous archaeocyaths and algae, through the use of polished ultra-thin sections (2–3 μm thick) and scanning electron microscopy. The results of this microstructural comparison indicate that despite diagenetic alteration Tabulaconus has a skeleton that is unlike any presently known and is quite distinct from associated algae or archaeocyaths. It is more elaborate than that found in the archaeocyaths but has not reached the stage of complexity seen in the primitive coral Cothonion Jell and Jell, 1976. The presence of some elongated units may represent an initial step towards the fibrous skeleton typical of Paleozoic corals.

This study shows that even though diagenesis alters the original microstructure of calcareous skeletons, the resultant fabrics and detailed structures can be useful in systematic descriptions.

Tabulaconus is removed from the Gastroconidae Kordae due to the presence of rudimentary septa and constitution of the tabularium. A number of species assigned to the genus Bačatocyathus Vologdin and included within the Archaeocyatha appear to be examples of Tabulaconus or very close relatives. An emended description of Tabulaconus kordae, the type species, is proposed.
The rugose coralTabulophyllum traversensisfrom the Oñate Formation (Middle Devonian) of the Mud Springs Mountains, New Mexico
Authors: Sorauf James E.
Published: August 2016

The Oñate Formation of Middle Devonian (Givetian) age is exposed in the Mud Springs Mountains of New Mexico, where it is represented by an unusually shaly and extremely fossiliferous facies.Tabulophyllum traversensis(Winchell) found here is the only rugose coral species known thus far from Middle Devonian rocks of New Mexico and is of special interest as evidence of migration between the area of the Oñate occurrence and those in the Cedar Valley Limestone in Iowa and the Traverse Group of Michigan. The occurrence is also of interest because of the association of the Oñate coral with the receptaculitidSphaerospongiasp. cf.S. tessellata(also known from Canada, Australia, and New York). The corals apparently utilized receptaculitids as a solid substrate for post-larval growth and developed an extremely broad flat base, fixed to the upper surface ofSphaerospongia.
Recognition of Macluritella (Gastropoda) from the Upper Cambrian of Missouri and Nevada
Authors: Yochelson Ellis L. , Stinchcomb B. L.
Published: August 2016

Open-coiled euomphalacean gastropods have been identified for the first time in the Upper Cambrian Eminence Dolomite of Missouri. These gastropods have a triangular whorl profile and are conspecific with Hyolithes walcotti described from the Upper Cambrian of Nevada. That species is questionably reassigned to the gastropod genus Macluritella, hitherto known only from the Lower Ordovician of Colorado.
Gyrodiform gastropods from the Pacific Coast Cretaceous and Paleocene
Authors: Popenoe W. P. , Saul L. R. , Susuki Takeo
Published: August 2016

Seven previously described and seven new taxa of gyrodiform naticoids from West Coast Late Cretaceous–Paleocene age strata are discussed. Gyrodes (Gyrodes) dowelli White of Turonian age is a typical Gyrodes; G. robustus Waring from the Paleocene has the shape of Gyrodes s.s. but lacks the crenulations. G. greeni Murphy and Rodda, G. yolensis n. sp., G. quercus n. sp., G. banites n. sp., G. canadensis Whiteaves, G. pacificus n. sp., and G. expansus Gabb comprise the new subgenus Sohlella, which thus ranges from Cenomanian through Maastrichtian. Gyrodes robsauli n. sp. resembles “Polinices” (Hypterita) helicoides (Gray), and Hypterita is reassigned to the Gyrodinae as a subgenus of Gyrodes. Gyrodes onensis n. sp. of Albian age is similar to the G. americanus group of Sohl (1960). Three texa—Natica allisoni (Murphy and Rodda) of Cenomanian age and N. conradiana Gabb and N. conradiana vacculae n. subsp. of Turonian age—which have all been previously considered to be Gyrodes are placed in Natica. Well marked relict color patterns on N. conradiana and N. conradiana vacculae suggest that these naticids from northern California and southern British Columbia were tropical forms.

Diversity of taxa and size of specimens are reduced at the end of the Turonian, suggesting a change in West Coast marine conditions at that time.
Brachylepas Woodward and Virgiscalpellum Withers (Cirripedia) from the Upper Cretaceous of Arkansas
Authors: Zullo Victor A. , Russell Ernest E. , Mellen Frederic F.
Published: August 2016

Brachylepas americana n. sp. is described from abundant and well-preserved capitular and basal whorl plates from a littoral facies in the basal part of an Upper Cretaceous (upper Campanian) conglomerate questionably assigned to the Brownstown Formation in Hot Spring County, Arkansas. The new species resembles the European littoral Campanian–Maastrichtian species B. guascoi (Bosquet), and differs markedly from the only other known American species, B. angulosa Collins, from the Upper Cretaceous middle Ripley Formation of Mississippi. A few juvenile carinae of Virgiscalpellum may represent V. gabbi apertus Collins, previously known from the Ripley and basal Prairie Bluff Formations in Mississippi.
Perryella, a new temnospondylous amphibian from the Lower Permian of Oklahoma
Authors: Carlson Keith J.
Published: August 2016

Perryella olsoni, a new temnospondylous amphibian from the lower Permian Wellington Formation of northern Oklahoma, is described. Features of the palatine, quadratojugal, and stapes are distinctive among described temnospondyls. The specimens share derived character states with the Dissorophoidea and Trimerorhachoidea, but cannot be assigned to either of these superfamilies as presently defined. The difficulties of temnospondyl classification in light of the confusion of primitive, juvenile, and paedomorphic features are discussed.
Trace fossils and regional significance of a Middle Devonian (Givetian) disconformity in southwestern Ontario
Authors: Landing Ed , Brett Carlton E.
Published: August 2016

The Hungry Hollow Formation on the southeastern margin of the Michigan Basin is interpreted as a composite stratigraphic unit representing the lateral equivalents of two depositional cycles in the northern Appalachian Basin. The basal beds (? = Pompey and upper Levanna transgressive hemicycle of the upper Skaneateles Formation in New York) are separated by disconformity surfaces both from the underlying Arkona Shale and from the upper part of the Hungry Hollow (= upper part of Centerfield Limestone Member). These basal beds were deposited on eroded, overcompacted claystones of the Arkona Shale, contain a diverse suite of remanie sediments, and fill deep, delicately sculpted furrows of Cruziana transversa n. ichnosp., C. reticulata n. ichnosp., and Rusophycus bilobatum (Vanuxem, 1842). This lower disconformity may be recognizable regionally over the Northern Midcontinent. Overlying beds feature the lowest local occurrence of an offshore-aspect conodont fauna of the lower Polygnathus varcus Subzone. The underlying Arkona Shale yields Icriodus-dominated (nearer-shore aspect) faunas apparently representing Polygnathus xylus ensensis Zone assemblages. The upper part of the Hungry Hollow Formation and overlying lower part of the Widder Formation represent an offlap-onlap cycle within the lower Polygnathus varcus Subzone that is comparable to that of the upper part of the Centerfield Limestone.

Cruziana and Rusophycus from the Hungry Hollow were not originally produced as “under-tracks” but were formed at the sediment–water interface on erosion-resistant, overconsolidated muds. The producer of Cruziana reticulata n. ichnosp. appeared in the benthic community of the field area before the excavator of C. transversa n. ichnosp. and of Rusophycus bilobatum (possibly the trilobite Dipleura). The degree of limb swing required to produce the reticulate scratch patterns in C. reticulata n. ichnosp. suggests the evolution of specialized coxa-sternite and inter-podomere hinges that were not previously considered to be present in trilobites. Comparable reticulate scratch patterns occur as early as the earliest Cambrian and are apparently related to excavation on disconformity-related mud firmgrounds.
An Upper Mississippian trace-fossil assemblage from the Tar Springs Sandstone, southern Illinois
Authors: Wescott William A. , Utgaard John E.
Published: August 2016

A trace-fossil assemblage is exposed in the uppermost portion of an interpreted tidal sand-flat deposit in the Upper Mississippian Tar Springs Sandstone in southwestern Illinois. Sedimentary structures, indicative of a tidal origin for this unit, include herringbone crossbeds, flaser and lenticular beds, reactivation surfaces, small channel scours, and shrinkage cracks. The trace fossils include trackways, trails, feeding structures, dwelling burrows, and escape structures. Vertical dwelling and escape structures dominate the assemblage with lesser numbers of horizontal and inclined traces. The ichnological and sedimentological characteristics are diagnostic of the Skolithos ichnofacies. Preservation of the assemblage at the top of the Tar Springs Sandstone was the result of substrate stabilization as the tidal flat subsided and was transgressed. The present trace-fossil assemblage probably was formed by a combination of a pre-omission tidal-flat suite and an omission suite formed during and after the transgression. Preservation of the assemblage suggests a passive transgression with minimal scouring and reworking of the tidal-flat deposit.
Rousseauspira: new gastropod operculum from the Ordovician of Alaska and California
Authors: Rohr David M. , Potter A. W.
Published: August 2016

Rousseauspira teicherti, a new genus and species of an unusual, untwisted, horn-shaped gastropod operculum from shallow-subtidal limestones of the Upper Ordovician of Alaska and the Middle Ordovician of California, is described and compared to two other Ordovician opercula,CeratopeaUlrich, 1911, andTeiichispiraYochelson and Jones, 1968. The shell to which the operculum belonged is not yet known.
Scalpelloid and brachylepadomorph barnacles (Cirripedia, Thoracica) from the Upper Cretaceous Mt. Laurel Sand, Delaware
Authors: Zullo Victor A.
Published: August 2016

A diverse cirriped fauna, including the scalpelloids Cretiscalpellum homseyi n. sp., Arcoscalpellum withersi Collins, Arcoscalpellum bakeri Collins, Virgiscalpellum gabbi heintzi n. subsp., Virgiscalpellum sp., V. cf. V. gabbi apertus Collins, and the brachylepadomorph Brachylepas solida n. sp., occurs in the Upper Cretaceous Mt. Laurel Sand at the Biggs Farm locality on the Chesapeake and Delaware Canal, New Castle County, Delaware. This fauna represents the Maastrichtian Virgiscalpellum Zone originally identified in the Ripley and Prairie Bluff formations of the eastern Gulf Coast.
First occurrence of a phyllodont tooth plate (Osteichthyes, Platysomidae) from the Permian San Andres Formation, subsurface, Texas Panhandle
Authors: Fracasso Michael A. , Hovorka Susan D.
Published: August 2016

A single phyllodont tooth plate was identified in core from the Permian San Andres Formation of the Palo Duro Basin, Texas Panhandle. This is the first vertebrate fossil recorded from the San Andres Formation, and extends the Permian range of phyllodont dentitions into the lower Guadalupian Stage. The life environment is inferred to have been normal marine to marginally hypersaline, based on the occurrence of the specimen near the top of a carbonate unit in a carbonate-evaporite cycle.
Osteology and Systematics of the fossil catfishes (genus Ictalurus) of central Mexico
Authors: Smith Michael Leonard
Published: August 2016

An extinct ictalurid catfish, Ictalurus spodius n. sp., is described from the Pleistocene of Central Mexico. It shares derived osteological characters with the subgenus Ictalurus and the I. punctatus species group. The new species is known from middle Pleistocene fluvial and lacustrine sediments and was abundant until near the end of the Pleistocene when it was replaced by a closely related species, I. dugesi. The latter is known from late and post-Pleistocene lake-bottom deposits and is widespread in Central Mexico today.
The coral fauna of the Pitkin Formation (Chesterian), northeastern Oklahoma and northwestern Arkansas
Authors: Webb Gregory E.
Published: August 2016

The Upper Chesterian Pitkin Formation of the Ozark Dome region contains a large and diverse, yet highly endemic, coral fauna consisting of 10 genera of rugose corals and three of tabulate corals. Coral distribution within the formation is affected by stratigraphic, paleoecologic, and possibly paleogeographic controls. Although it is impossible at this time to fully evaluate the importance of stratigraphic controls on the coral distribution, the occurrence of two types of carbonate bioherms within the formation provides substantial paleoecologic control on the distribution of certain corals. Despite the high endemism and facies restriction, the coral fauna has proven to be biostratigraphically sensitive, correlating with middle and upper Chesterian coral zones in the Western Interior Province of North America. Among the Pitkin corals herein described are the new genera: Lesliella n. gen. (L. amplexa n. sp., type species) and Parvaxon n. gen. (P. minutum n. sp., type species). Other newly described species are: Amplexizaphrentis browni n. sp., Barytichisma clubinei n. sp., B. ozarkana n. sp., and Leonardophyllum arkansanum n. sp., which represents the first reported occurrence of the genus in strata below the Pennsylvanian boundary.
Brassfield Compsocrinina (Lower Silurian crinoids) from Ohio
Authors: Ausich William I.
Published: August 2016

Four compsocrinine camerate crinoids are described from the Lower Silurian Brassfield Formation of southwestern Ohio. These late early or early middle Llandoverian crinoids are assigned to the Periechocrinidae and include Tirocrinus trochos n. gen. and sp., Ibanocrinus petalos n. gen. and sp., Acacocrinus anebos n. sp., and the taxon Dimerocrinites? vagans Foerste, herein referred to periechocrinid incertae sedis.

These Brassfield forms are the oldest known members of the Periechocrinacea and Periechocrinidae. Diagnoses of these supergeneric concepts are broadened to include the morphologic variability embodied within the Brassfield forms but not otherwise present in later periechocrinaceans.
Presentation of the Harrell L. Strimple Award of The Paleontological Society to Ted White
Authors: Mapes Royal H. , Pabian Roger K.
Published: August 2016

For over 30 years, Ted White has scoured the quarries and road cuts of the lower Platte River Valley in southeastern Nebraska for late Pennsylvanian invertebrate and vertebrate fossils. His years of collecting have provided information that significantly amplifies the history of the late Pennsylvanian in the entire North American Midcontinent. Some highlights of Ted's influence in paleontology show that he is an excellent and well-deserving recipient of the Harrell L. Strimple Award for 1986. Ted's work has not only led several young people into paleontological careers but has altered the course of research of many established professionals.
A new trace fossil from the Cambrian Bright Angel Shale, Grand Canyon, Arizona
Authors: Elliott David K. , Martin Daryl L.
Published: August 2016

Angulichnus alternipesn. ichnogen. and n. ichnosp. is a distinctive epichnial trail from the heterolithic facies of the Middle Cambrian Bright Angel Shale at Horn Creek, Grand Canyon, Arizona. It consists of a central zig-zag furrow bordered by biserially opposed alternating tracks. Though clearly formed by a benthonic arthropod, the trail cannot be attributed to a trilobite and is therefore important as an indicator of the presence of nontrilobite arthropods in the Bright Angel Shale. It is suggested that an arthropod similar toHabelia optatafrom the Burgess Shale would be a convincing trail-former. Sedimentologic analysis indicates that the heterolithic facies represents storm-induced deposition of sand, followed by a low-energy period during which traces were formed as mud settled to the bottom.
Impact of two sequential Pacific hurricanes on sub-rubble cryptic corals: the possible role of cryptic organisms in maintenance of coral reef communities
Authors: Kobluk David R. , Lysenko Mary A.
Published: August 2016

The hermatypic scleractinian cryptic coral biota living under mobile rubble in the reef flat and back reef zones of a Fijian fringing reef was surveyed in detail in August of 1984; only 138 days later the reef was struck by the first of two sequential hurricanes (57 days apart). The same sample areas were re-studied in August 1985, thereby providing the first detailed census of pre- and post-hurricane cryptic reef coral populations, and allowing an assessment of hurricane impact on these populations.

The 61 cryptic species (60 corals andMillepora) show 88 percent commonality with the intertidal and shallow subtidal reef surface coral population (68 species), and therefore are a good representation of the surface biota.

A major effect of the hurricanes was a reduction of almost 50 percent in the number of boulders sheltering cryptic coral. However, among boulders that retained coral through the storms, there was only a 5 percent reduction in the mean number of corals per boulder, signifying that damage to the surviving population was minor. The composition of the surviving cryptic coral population is essentially unchanged from its pre-hurricane state (there are differences in absolute abundances), and the relative importance of the species does not show marked change in most cases. Coral morphologies show little change in their absolute and relative percent abundances after the hurricanes. In contrast to what is normally seen in reef surface habitats, therefore, coral colony form did not appear to be an important determinant in survivability for those living under boulders; primary selection by the storms seems to have been on boulder form rather than cryptic coral form.

Cryptic sub-rubble coral populations may function as a preserve for elements of the pre-hurricane reef surface community. For example, delicately-branching forms that are commonly devastated in reef surface habitats during hurricanes may, in some cases, be preserved in great numbers under boulders or in other cryptic habitats. This provides a “recruitment pool” that can greatly accelerate their recovery and re-establishment on the post-hurricane reef surface, and dampen the potentially severe community dislocations arising from intense competition for space in “instantaneous” new reef substrate.
Review of the Devonian camerate crinoid Bogotacrinus scheibei Schmidt from Colombia
Authors: Mcintosh George C.
Published: August 2016

Two recently collected specimens of Bogotacrinus scheibei Schmidt, 1937, from the Devonian (Emsian–Eifelian) Floresta Formation of Colombia reveal that Bogotacrinus is a dicyclic camerate crinoid genus closely related to Pterinocrinus Goldring, 1923 (Lower–Upper Devonian of eastern North America and western Europe), and Ampurocrinus McIntosh, 1981 (Lower Devonian of Bolivia). The new diplobathrid camerate crinoid family Pterinocrinidae, characterized by species with low conical dicyclic cups and rami composed of compound, bipinnulate brachials, is herein proposed to accommodate these three genera. This family originated in western Europe and migrated into the Malvinokaffric and southern Eastern Americas Realms during the Early Devonian and into the northeastern Appalachian Basin by the Late Devonian.
Micropaleontology across the Precambrian—Cambrian boundary in Spitsbergen
Authors: Knoll Andrew H. , Swett Keene
Published: August 2016

Paleobiological studies of early metazoan evolution are critically dependent on the accurate stratigraphic subdivision and correlation of uppermost Proterozoic and Lower Cambrian sequences. Planktonic microfossils evolved rapidly during this period and are widely distributed and abundant in Vendian and Lower Cambrian rocks; therefore, they provide what is potentially one of the best means of correlating successions of this age. In Ny Friesland, Spitsbergen, tillite-bearing detrital rocks of the uppermost Proterozoic Polarisbreen Group are overlain without apparent unconformity by the Tokammane Formation, a tripartite lithologic sequence consisting of quartzarenites (Blårevbreen Member) overlain by dark shales with subordinate sandstone (Topiggane Member) and dolomites (Ditlovtoppen Member).Salterella, hyoliths, and other invertebrate remains occur in the upper part of the Tokammane succession; trace fossils are found in the Tokammane quartzarenites and shales, as well as in the uppermost few meters of the Polarisbreen sequence. Planktonic microfossils occur throughout the succession. They indicate that the Polarisbreen Group is Vendian in age and that a hiatus corresponding in time to the latest Vendian and (perhaps) earliest Cambrian coincides with the Polarisbreen/Tokammane boundary. Lower Topiggane shale samples contain acritarchs comparable to those found in the sub-HolmiaLontova Beds of Eastern Europe. Upper Topiggane samples contain diverse acritarch assemblages that indicate a lateHolmiaorProtolenusage, suggesting the presence of a second hiatus within the Tokammane Formation. Planktonic microfossils allow biostratigraphic correlation with other sequences both within (East Greenland) and between (East European Platform) paleocontinents. Like those from other areas, diversity trends exhibited by late Proterozoic and Early Cambrian acritarchs from Spitsbergen indicate a major Vendian episode of extinction followed by Early Cambrian rediversification of planktonic microfossils.
Brissus bridgeboroensis, a new spatangoid echinoid from the lower Oligocene of southwestern Georgia
Authors: Carter Burchard D.
Published: August 2016

A new species of Brissus is described from the lower Oligocene (Rupelian–Vicksburgian) Bridgeboro limestone of southwestern Georgia. Brissus bridgeboroensis n. sp. most closely resembles the Recent Brissus unicolor (Leske) of the West Indies and the Gulf of Mexico, but it differs primarily in features of the posterior paired petals. Brissus bridgeboroensis is the oldest known member of the genus from continental North America.
Late Miocene plants from northeastern Nebraska
Authors: Thomasson Joseph R.
Published: August 2016

Systematically diverse assemblages of fossil plants have been collected in late Miocene strata at seven sites in northern Antelope County, Nebraska. Fossils were found in several members of the Valentine and Ash Hollow Formations of late Barstovian to medial Clarendonian (13–10 MYBP) age and unnamed members of the Ash Hollow Formation of late Clarendonian to early Hemphillian (9.5–8.0 MYBP) age. Seeds, fruits, and leaf-sheath fragments of 18 species from the families Equisetaceae, Cyperaceae, Gramineae, Boraginaceae, Juglandaceae, and Ulmaceae are described. These occurrences represent a 200 mile (322 km) eastward extension of the known geographic range of all of the taxa during the Miocene. The occurrence of Juglandaceae is the first reported from widespread Miocene strata of the Ogallala Group in central North America.
The identity of Chonetes falklandicus (Brachiopoda, Devonian)
Authors: Hiller Norton
Published: August 2016

Examination of collections from the Falkland Islands and South Africa shows that Chonetes falklandicus Morris and Sharpe, 1846, is a true Chonetes and is probably conspecific with Chonetes (Pleurochonetes) lauriata Isaacson, 1977, from Bolivia. Notiochonetes skottsbergi (Clarke, 1913) is quite different from C. falklandicus but is often associated with it in Malvinokaffric Realm Lower Devonian deposits.
A new species of the Jurassic (Callovian) brachiopod Septirhynchia from northern Sinai
Authors: Feldman Howard R.
Published: August 2016

Septirhynchia hirschi n. sp. is described from the Callovian (Jurassic) strata of Gebel El-Maghara, northern Sinai, Egypt. Significant ontogenetic changes from juvenile to adult include: 1) increase in height of the ventral median septum; 2) change from hypothyridid to mesothyridid pedicle foramen; 3) change from a pyriform to a gibbous outline; 4) change from a weakly defined to a strongly defined pedicle sulcus; and 5) change from a relatively straight to a strongly arched lateral commissure. All ontogenetic stages, except for neanic, possessed a pedicle tube. Muscle scars (diductor) were observed for the first time in the genus on several pedicle valve interiors; none were noted on any brachial valve interiors. Juveniles lived epifaunally, attached to the substrate by a small but functional pedicle, while adults lived semi-infaunally with the umbos buried in the mud.
Review of the camerate crinoid Closterocrinus elongatus Hall from the Silurian of New York
Authors: McIntosh George C.
Published: August 2016

Closterocrinus elongatus Hall, 1852, long assigned to the cladid inadunate crinoid family Ampheristocrinidae (=Euspirocrinidae), has been found to possess pinnulate biserial arms and a cup composed of four exsert basals, five radials, a primanal above the radial circlet, and fixed primibrachials and secundibrachials. Accordingly, this species is herein reassigned to the monobathrid camerate crinoid family Paramelocrinidae.