bluuebunny/crossref_metadata_2025 huggingface dataset:
Early Paleozoic Hyolitha from North America: reexamination of Walcott's and Resser's type specimens
Authors: Malinky John Mark
Published: August 2016

Concepts of the family Hyolithidae Nicholson fide Fisher and the generaHyolithesEichwald andOrthothecaNovak have been expanded through time to encompass a variety of morphologically dissimilar shells. The Hyolithidae is here considered to include only those hyolithid species which have a rounded (convex) dorsum; slopes on the dorsum are inflated, and the venter may be flat or slightly inflated.Hyolithesencompasses species which possess a low dorsum and a prominent longitudinal sulcus along each edge of the dorsum; the ligula is short and the apertural rim is flared. The emended concept ofOrthothecaincludes only those species of orthothecid hyoliths which have a subtriangular transverse outline and longitudinal lirae covering the shell on both dorsum and venter.

Eighteen species ofHyolithesand one species ofOrthothecafrom the Appalachian region and Western Interior were reexamined in light of more modern taxonomic concepts and standards of quality for type material. Reexamination of type specimens ofH. similisWalcott from the Lower Cambrian of Newfoundland,H. whiteiResser from the Lower Cambrian of Nevada,H. billingsiWalcott from the Lower Cambrian of Nevada,H. gallatinensisResser from the Upper Cambrian of Wyoming, andH. partitusResser from the Middle Cambrian of Alabama indicates that none of these species representsHyolithes. Hyolithes similisis here included under the new genusSimilotheca,in the new family Similothecidae.Hyolithes whiteiis designated as the type species of the new genusNevadotheca,to whichH. billingsimay also belong.Hyolithes gallatinensisis referred toBurithesMissarzhevsky with question, andH. partitusmay representJoachimilitesMarek. The type or types ofH. attenuatusWalcott,H. cecropsWalcott,H. comptusHowell,H. cowanensisResser,H. curticeiResser,H. idahoensisResser,H. prolixusResser,H. resseriHowell,H. shaleriWalcott,H. terranovicusWalcott, andH. wanneriResser and Howell lack shells and/or other taxonomically important features such as a complete aperture, rendering the diagnoses of these species incomplete. Their names should only be used for the type specimens until better preserved topotypes become available for study. Morphology of the types ofH.?corrugatusWalcott and “Orthotheca”solaResser does not support placement in the Hyolitha; the affinities of these species are uncertain.
Mesozoic history and neontology of Lepidoptera in relation to Trichoptera, Mecoptera, and angiosperms
Authors: Shields Oakley
Published: August 2016

The Mesozoic history of Lepidoptera and Trichoptera is reviewed and their phylogeny traced back to early Mesozoic specialized Permochoristidae Mecoptera. Queensland emerges as the center of origin for the earliest Lepidoptera and Trichoptera and is also the region where the first lepidopteran hostplants, primitive dicot angiosperms, arose from Glossopteridae, probably at the Triassic–Jurassic boundary. Protomecoptera evolved from extinct Protoblattodea (not Neuroptera) during Late Carboniferous or Early Permian time. The first Lepidoptera, terrestrial Agathiphagidae, evolved from aquatic Necrotauliidae Trichoptera probably at the close of the Triassic when an extreme drought dried up many streams. The very small size of Amphiesmenopteran Mecoptera and the first Trichoptera and Lepidoptera fossils obeys Cope's Rule.
The first report of a macroloxoceratine cephalopod from the North American Mississippian
Authors: Edgecombe Gregory D.
Published: August 2016

The pseudorthoceratid subfamily Macroloxoceratinae Flower, 1957, comprises a rare group of nautiloid cephalopods homeomorphic with the Actinoceratida in the development of a siphonal canal system. With the exception of Macroloxoceras Flower, 1957, from the Upper Devonian of Colorado and New Mexico, this subfamily has previously been reported only from the Mississippian of Europe. A specimen described herein from the late Viséan–?early Namurian Kennetcook Limestone of the Windsor Group of Nova Scotia, assigned to Campyloceras cf. C. unguis (Phillips, 1836), extends the range of the Macroloxoceratinae into the North American Mississippian. This discovery further provides new data on the complex siphonal morphology of this poorly known group of nautiloids, and supplements the recent documentation of the pseudorthoceratids in the Windsor Group cephalopod fauna (Edgecombe, 1987).
An inexpensive source of dolomite powder for use with airbrasive units
Authors: Hannibal Joseph T. , Williams Michael E. , Jackson Gary L.
Published: August 2016

In the past few years the Cleveland Museum of Natural History has received several inquiries as to our source of dolomite for use with S.S. White® industrial airbrasive units. We have been using inexpensive, “agricultural” dolomite with these units for several years. This source was “discovered” by testing of a wide variety of dolomite sources by Peter Kotulak, a former preparator at the Museum, under the direction of M.E.W. We are currently using OHSO® Pulverized Limestone, a kiln-dried dolomitic limestone recommended for agricultural, and lawn and garden, use. It is produced by the Ohio® Lime Co., of Woodville, Ohio. A 22.7 kg (50 pound) bag costs $2.25, and is available at building supply companies. The dolomite must be sieved and dried to prevent clogging of the unit's line and nozzle. We use a Ro-Tap® Testing Sieve Shaker to sieve the material, with #30 (595 micron), #60 (250 micron), and #100 (150 micron) U.S.A. standard testing sieves. An incandescent desk lamp can be placed over an open container of the sieved dolomite to keep it dry. Used powder may be re-sieved for reuse if desired.
Approaches to systematic and evolutionary studies of perplexing groups: an example using fenestrate Bryozoa
Authors: Hageman Steven J.
Published: August 2016

Recognition of discrete taxa is an enduring problem in the biological sciences, especially for taxonomists who work with groups that display a great degree of homeomorphy at low taxonomic levels. Selection of the type and number of characters used to make taxonomic distinctions is important because it reflects taxonomic concepts for a group as a whole. Often the validity of characters used to develop classifications is not documented and resulting classifications are therefore suspect. However, classifications can be tested for their objectivity with numerical analysis and characters can be evaluated for their relative value for making taxonomic splits by a variety of statistical techniques. In addition, evaluation of the distribution of character states can lead to insights into evolutionary histories of any group. This study provides such an analysis.

Fenestrate cryptostome Bryozoa are abundant and diverse in many upper Paleozoic rocks, and are therefore potentially highly useful for a variety of paleontologic studies. However, study of fenestrates is hampered by necessary complex preparation techniques and problems encountered with homeomorphy. In addition, inconsistent applications of inadequate methodologies have contributed to an unsatisfactory taxonomy. Results from cluster and discriminant analyses demonstrate that fenestrate species can be objectively recognized. Species distinctions are most clear when all available characters are used, although some characters are more diagnostic than others.

Results from cluster and discriminant analyses suggest that fenestrate genera represent major evolutionary shifts associated with the development of key character(s) that allowed entry into new adaptive zones. Key characters allow for an oligothetic classification of genera, which is not merely an artifact created to simplify taxonomic analysis. Diversification of species within adaptive zones resulted in a natural hierarchy of genus-level and species-level characters. Iterative evolution at the species level within separate adaptive zones resulted in a great deal of homeomorphy.

Morphometric analysis provides insights into several aspects of the paleobiology of this traditionally problematic group. Similar comprehensive studies may prove equally productive for other groups.
Comments on the genus Amyzon (family Catostomidae)
Authors: Bruner John Clay
Published: August 2016

At least four of the seven described species of Amyzon are valid species with doubtful status given to Amyzon pandatum Cope, 1874, and Amyzon fusiforme Cope, 1875. Amyzon gosiutensis Grande, Eastman, and Cavender, 1982, is a junior synonym of Amyzon aggregatum Wilson, 1977b. The Klondike Mountain Formation specimens examined from Republic, Washington, are identified as Amyzon aggregatum Wilson, 1977b. The known range of A. aggregatum is extended south to Republic, Washington, and southeast to the Laney Shale Member of the Green River Formation, Wyoming.
Borings in the shell of an Ordovician (Whiterockian) gastropod
Authors: Rohr David M.
Published: August 2016

A single specimen of the platyceratacean gastropod Raphispira showing one complete and one incomplete, slightly elliptical borehole was recovered from the Antelope Valley Formation in central Nevada. Circular boreholes may be formed by a variety of causes, but they are most commonly attributed to the predators. In the Paleozoic the holes are most common in brachiopods, both calcareous and phosphatic. This is the oldest reported occurrence in a calcareous shell. In most instances, if a hard-bodied form is consumed by a carnivore, little recognizable evidence remains; therefore, predator boreholes are helpful in determining trophic relationships.
The first find of Eurycephalitinae (Jurassic Ammonitina) in New Zealand and its biogeographic implications
Authors: Westermann Gerd E. G. , Hudson Neville
Published: August 2016

Uppermost temaikan strata from southwest Auckland Province, North Island, New Zealand, have recently yielded a small fauna of Middle Jurassic ammonites previously believed to be endemic to the eastern Pacific borderlands, although a single fragment of the new species described below was previously reported in a large Tethyan assemblage from Papua, New Guinea, by Westermann and Callomon (1988). The New Zealand assemblage consists of the dimorphic pair Xenocephalites (♂) and Lilloettia (♀) with close morphologic ties to species from the latest Bathonian Steinmanni Standard Zone of the Andean Province (Riccardi et al., 1989). This new find permits direct time-correlation of the uppermost part of the Temaikan Stage (Marwick, 1951, 1953) with the East-Pacific latest Bathonian Steinmanni Zone and with the East-Tethyan Late Bathonian Macrocephalites apertus Association. The upper Temaikan Stage of south Otago Province, southeastern South Island, New Zealand, has also yielded rare representatives of the Tethyan Macrocephalitinae, so that the New Zealand area in the late Middle Jurassic was in the overlap area of Tethyan and East-Pacific Subrealms.
Dimorpharaeade Fromentel, 1861 (Scleractinia, Anthozoa) from the Middle Jurassic of Kachchh, India
Authors: Pandey Dhirendra K. , McRoberts Christopher A. , Pandit Manoj K.
Published: August 2016

The current classification of scleractinian corals based upon gross morphological features has been found unsatisfactory due to additional information from skeletal microarchitecture and microstructure. It is necessary to investigate microstructural details and limits in morphologic variation within and between different coral clades before a revised classification is constructed. Variations in morphologic characters and microstructural details from a population ofDimorpharaeade Fromentel, 1861 (Family Microsolenidae) from Upper Bathonian (Jumara Dome) strata in Kachchh are described. The data used include the diameter (D) and height (H) of the corallum, number of corallites in the colony (NC), number of septa in the mother corallite at the center of the colony (NS), minimum distance between centers of central corallite and corallite of the inner ring (C1), minimum distance between corallite centers of the outer ring (C2), septal density (DS) and trabecular density (DT). The principal components analysis reveals that most of the variation is explained by “size” related characters (D and H) while corallite density (NC and C1) and septal structures (DS and DT) contribute to the second and third principal component axes, respectively. The microarchitecture and distribution of characters observed in the KachchhDimorpharaearequire a re-evaluation of familial-specific concepts and suggest that the population belongs to a single species,Dimorpharaea stellansGregory, 1900, rather than four nominal species (D. stellans, D. distincta, D. continuaandD. orbica) as has been assumed.
Life association of shell and operculum of Middle Ordovician gastropod Maclurites
Authors: Rohr David M. , Yochelson Ellis L.
Published: August 2016

The only two known life associations of the shell and operculum of Maclurites Le Sueur, 1818, are described for the first time. Maclurites cf. magnus Le Sueur, 1818, from the Middle Ordovician of Alaska demonstrates that the operculum fits slightly inside the aperture, and when closed, the operculum extends down below the base of the shell and may have acted as an anchor. The operculum of Maclurites bigsbyi (Hall, 1861), from the Middle Ordovician of Wisconsin, is illustrated for the first time and is confirmed to be distinct from Maclurina logani (Salter, 1859).
Development, taxonomy, and phylogenetic relationships of species ofParaclimacograptus(Graptoloidea) from the Canadian Arctic and the Southern Urals of Russia
Authors: Russel Jennifer C. , Melchin Michael J. , Koren' Tatjana N.
Published: August 2016

An investigation of the morphology and astogenetic pattern of isolated specimens of two species ofParaclimacograptuspermits an assessment of the phylogenetic relationships of this genus. Forty-two specimens previously assigned toParaclimacograptus innotatusssp. isolated from turbiditic limestone from the Southern Urals of Russia (Cystograptus vesiculousZone) and limestone concretions from the Canadian Arctic (Coronograptus cyphusZone) were examined using the method of infrared video microscopy.Paraclimacograptushas a Pattern H astogeny and is therefore a member of the family Normalograptidae. At least three species can be distinguished using biometric criteria,P. innotatus, P. exquisitus, andP. obesus.Rhabdosomal characteristics ofParaclimacograptusindicate that it is phylogenetically related to early species of the genusNeodiplograptus.The point of divergence of the proximal thecae is defined by the interfingering of fuselli of markedly different widths. This suggests that fuselli were not necessarily secreted at a constant rate. In addition, this pattern of fusellar interfingering is here regarded as more consistent with a pterobranch mode of secretion than with a model of growth under an enveloping extrathecal mantle.
Conodonts from the Upper Olentangy Shale (Upper Devonian, central Ohio) and stratigraphy across the Frasnian-Famennian Boundary
Authors: Over D. Jeffrey , Rhodes Meredith K.
Published: August 2016

The Upper Olentangy Shale of Ohio, a green pyritic shale interbedded with thin dark gray shale beds, disconformably overlies the lithologically similar Middle Devonian Lower Olentangy Shale. The muds were deposited in a quiet offshore environment on the distal margin of the Appalachian Basin during the Late Frasnian through Early Famennian. The Upper Olentangy Shale contains abundant and diverse conodonts of MN Zone 13 and the Middle triangularis Zone. The Frasnian-Famennian boundary is 4-8 cm below the base of the Huron Shale at the Olentangy Shale type section in Delaware, Ohio. The boundary interval is a green shale containing a mixed highest Frasnian (e.g., Palmatolepis bogartensis, P. linguiformis) and lowest Famennian (e.g., P. delicatula, P. subperlobata, P. triangularis) conodont fauna. An ash horizon, pyritic bed, finely laminated dark shale, and a thin green-blue shale comprise the upper 3 cm of the Olentangy, and contain a conodont fauna indicative of the Middle triangularis Zone.
Morphological and paleoecological analysis of the Ordovician ankyroid Lagynocystis (Stylophora: Echinodermata)
Authors: Parsley Ronald L.
Published: August 2016

Despite its atypical thecal plate pattern, Lagynocystis pyramidalis (Jaekel, 1918) (Middle Ordovician, Northern Gondwanaland) is composed of normally positioned marginal plates on the left side of the theca, whereas those on the right side are shortened or missing in comparison with marginal plates of other ankyroids. The only somatic on the lower thecal surface is the CS plate. The abnormally long distal aulacophore, reduced theca, and internal ctenoid organ are interpreted as adaptations to deep water, dysaerobic environmental conditions. Ctenoid organ morphology is re-evaluated and is interpreted to have both feeding and respiratory functions. Loss of plates relative to a presumed ancestor similar to Barrandeocarpus has resulted in torsion that places somatic platelets, originally on the superior face, onto the inferior face and in contact with both CS and M′3 plates.
Presence of Helicoprion (Chondrichthyes, Elasmobranchii) in the Permian Patlanoaya Formation, Puebla, Mexico
Authors: Sour-Tovar Francisco , Quiroz-Barroso Sara A. , Applegate Shelton P.
Published: August 2016

A newly discovered Helicoprion specimen from the Patlanoaya Formation, State of Puebla, represents the southernmost finding of this genus of edestoid-shark in the Western Hemisphere. It was found in sediments assigned to the upper part of the Early Permian, based on its association with Perrinites hilli, an index ammonoid for the Leonardian age.
Paleoecologic and taxonomic implications of Sphenothallus and Sphenothallus-like specimens from Ohio and areas adjacent to Ohio
Authors: Neal Maxwell Lewis , Hannibal Joseph T.
Published: August 2016

Sphenothallus and fossils similar to Sphenothallus are found in Ordovician, Devonian, and Mississippian rock units in Ohio and adjacent states and provinces. Although the Ordovician of Québec, Ontario, and Indiana has yielded parts of tubes, Ordovician specimens from southwest Ohio and nearby areas consist almost entirely of holdfasts on hardgrounds and shelly fossils. Sphenothallus is abundant in the Chagrin Shale (Famennian) of northeast Ohio where it is found in about four percent of concretions that contain identifiable fossils. The Chagrin specimens, usually parts of tubes, are occasionally preserved three-dimensionally. The rate of distal expansion of Chagrin Sphenothallus tubes varies intraspecifically; thus, this rate cannot be used to distinguish species. Some Chagrin specimens are attached to larger, conspecific specimens and to articulate brachiopods. Brachiopods have also been found attached to Chagrin Sphenothallus. Bedford-Berea sequence (Famennian) specimens from northern Kentucky and Meadville Member (Kinderhookian or Osagian) specimens from the Cuyahoga Formation of northeast Ohio are usually preserved as flattened tubes. In both occurrences tubes are similar in width, indicating that individuals in each assemblage are probably the same age. Meadville tubes possess characteristics diagnostic of Sphenothallus, but Bedford-Berea specimens, which lack longitudinal thickenings and exhibit little tube tapering, cannot be assigned to Sphenothallus sensu strictu.

Sphenothallus was a gregarious, opportunistic species, tolerant of dysaerobic conditions and able to colonize environments ranging from hardgrounds to soft, muddy sea bottoms. No distinct branching was observed among the Chagrin, Bedford-Berea, or Meadville specimens, suggesting that larval dispersal was the primary mode of reproduction for the genus.
Suture modification by pectinirhomb growth in Lepadocystis decorus, a new species of callocystitid glyptocystitid rhombiferan (Echinodermata) from Illinois
Authors: Sumrall Colin D. , Carlson David T.
Published: August 2016

A new species of Late Ordovician callocystitid rhombiferan (Glyptocystitidae), Lepadocystis decorus, is described from the Brainard Shale of north-central Illinois. This species is characterized by five pectinirhombs, open infralateral and lateral plate circlets, and well-developed ridges on the thecal plates. Lepadocystis decorus well illustrates that open vs. closed plate circlets in glyptocystitids can largely be a function of pectinirhomb length and is therefore in part an ontogenetically linked characteristic. Consequently, great care must be taken to assure maturity when using this feature in taxonomy.
Subspeciation within a punctuated equilibrium evolutionary event: Phylogenetic history of the Lower-Middle OrdovicianParoistodus originalis—P. horriduscomplex (Conodonta)
Authors: Albanesi Guillermo L. , Barnes Christopher R.
Published: August 2016

A microevolutionary event involving the conodontParoistoduslineage is documented in the Gualcamayo Formation (Middle Ordovician), Argentine Precordillera. A detailed sampling of limestones throughout the upper part of the San Juan Formation and the lower member of the Gualcamayo Formation yielded over 14,000 well-preserved conodont elements.Paroistodus originalis(Sergeeva, 1963) was recorded through the upper 230 m of the San Juan Formation and the lower member (10 m thick) of the Gualcamayo Formation. The derived speciesParoistodus horridus(Barnes and Poplawski, 1973) was recorded throughout the middle member of the Gualcamayo Formation (65 m thick). The intermediate linking forms between both species are identified as two new taxa:Paroistodus horridus primusAlbanesi, 1998b, andP. h. secundusAlbanesi, 1998b. They were recorded in the uppermost 70 cm of the lower member. Apparently, the speciation event occurred under stressed environmental conditions with the drowning of the carbonate platform, i.e., the San Juan Formation, and the beginning of a deeper and restricted environment represented by the Gualcamayo black shales. The demise of the carbonate production was caused by a sea level rise and a significant influx of volcanic ashes. The punctuated speciation event occurred within an allopatric setting while the Precordillera occupied an isolated (Iapetus) oceanic position in its overall drift from Laurentia to Gondwana.
Szecladia new genus, a late Permian conifer with multiveined leaves from South China
Authors: Yao Zhao-Qi , Liu Lu-Jun , Rothwell Gar W. , Mapes Gene
Published: August 2016

A conifer from the uppermost Permian with small, helically arranged leaves is described from the Guangxi Autonomous Region and Guizhou Province of South China as Szecladia multinervia, new genus and species. The material includes both impression specimens and the first anatomically preserved Paleozoic conifer fossils from China. Shoots are irregularly branched, with small, helically arranged, multiveined leaves. Stems display an endarch eustele with abundant, dense wood. Leaf traces diverge from the stele as a single bundle that divides several times in the cortex and at the base of the leaves, forming about seven or eight parallel veins in each leaf. Szecladia is the earliest known conifer with multiveined leaves and it represents a distinctive coniferous element of the uppermost Permian Cathaysian flora in South China. Szecladia further demonstrates that conifers with wood and leaf venation suggestive of the Podocarpaceae may have evolved by the end of the Paleozoic.
External morphology and paleobiology of Heliophyllum halli (Zoantharia, Rugosa), from the Middle Devonian Hamilton Group of New York State
Authors: Sorauf James E.
Published: August 2016

Heliophyllum halli contains highly variable, mostly solitary rugose corals. Specimens reported here come from shaly beds of the Middle Devonian Hamilton Group in New York State. Early recognition of morphotype variation led James Hall to establish numerous species in the H. halli group that were later interpreted by John Wells in terms of varying life history. Life on unstable and/or soft substrates was facilitated for these corals by talons, root-like structures that allowed larval settling and post-larval development on hard particles such as echinoderm or shell debris. Variation in subsequent growth history is reflected in corallum shape and change in diameter. Straight growth axes reflect partial burial accompanied by vertical growth, while growth axis curvature resulted from unequal settling into substrate or alternatively, life at the surface of substrate, with sharp bends (geniculations) reflecting major changes in growth orientation. Decrease in diameter resulted from environmental stress, with greatest effects on the peripheral portion of the calice. Other major reactions to increased burial rate (through sinking or increased sedimentation) are epithecal secretion to form an outer wall for isolation of itself from surrounding sediment or decrease in polyp size as shown by terminal shrinking of the corallum diameter, at times nearly to zero. Yonge's (1940) summary of observations on living coral polyps suggests that the living H. halli was nonzooxanthellate, with an efficient system of feeding that utilized its multitude of tentacles without the help of cilia, which thus were able to generate currents to promote efficient sediment cleansing. Sediment shedding would also have been aided by polypal distension (swelling) above a reflexed calical margin.
Arthropod trace fossils from the Permian De Chelly Sandstone, northeastern Arizona
Authors: Sadler Christa J.
Published: August 2016

Four previously undescribed arthropod trackways from the Lower Permian De Chelly Sandstone of northeastern Arizona are assigned toPaleohelcuraandOctopodichnus, originally described from the Coconino Sandstone (Lower Permian) of northeastern Arizona. In addition toP. dunbariandO. minor, a new ichnospecies,O. raymondi, is described. Analysis of the De Chelly specimens, and comparison with similar tracks from the Coconino Sandstone and with experimental traces produced by modern arthropods, clarifies some problems in arthropod trace fossil analysis. The experiments support earlier hypotheses that spiders and scorpions were possible trail makers for the Coconino and De Chelly trackways, and show that features of these tracks can be used to determine direction of movement. These experiments also reaffirm that an animal can produce more than one morphology in a single trackway, patterns that would be classified as two distinct ichnogenera. In addition, the results of this research suggest that the tracks were made on slightly damp sand, and were preserved by being rapidly covered with dry sand.
New thalattosaurs (Reptilia: Diapsida) from the Triassic Sulphur Mountain Formation of Wapiti Lake, British Columbia
Authors: Nicholls Elizabeth L. , Brinkman Donald
Published: August 2016

A new assemblage of thalattosaurs is described from the Lower to Middle Triassic Sulphur Mountain Formation of eastern British Columbia. The following new species are described:Thalattosaurus borealisn. sp.;Paralonectes merriamin. gen. and sp.; andAgkistrognathus campbellin. gen. and sp. In addition, specifically indeterminate material is described. This assemblage extends the geographic range of the Thalattosauria to Canada and demonstrates that thalattosaurs were more taxonomically diverse and widely distributed than previously thought.
Late Cretaceous dinosaurs from the Blufftown Formation in western Georgia and eastern Alabama
Authors: Schwimmer David R. , Williams G. Dent , Dobie James L. , Siesser William G.
Published: August 2016

Fragmentary bones and teeth of three Late Cretaceous dinosaur taxa occur along both sides of the Georgia-Alabama border, in the extreme southeastern Coastal Plain Province. The localities lie in the middle and upper Blufftown Formation, in nearshore marine deposits.Exogyrassp. and calcareous nannofossils give a late Santonian through mid-Campanian age range. Taxa determined are: Hadrosauridae, genus and species indeterminate; Ornithomimidae, genus and species indeterminate; andAlbertosaurus? sp.
Biostratigraphic implications of the first North American occurrence of the Upper Mississippian ammonoid Platygoniatites
Authors: Titus Alan L.
Published: August 2016

The late Mississippian ammonoid family Delepinoceratidae is comprised of the genera Platygoniatites and Delepinoceras, and is considered one of the more biostratigraphically significant families for lower Namurian correlation (Manger et al., 1985). Platygoniatites, the earliest member, is known from eastern and southern Europe (Ruzhencev and Bogoslovskaya, 1971; Wagner-Gentis, 1963, 1980) and North Africa (Lemosquet et al., 1985). Despite its wide distribution, Platygoniatites is generally a rare member (with the exception of the southern Ural Mountains) of latest Visean and earliest Namurian faunas. It has never been reported previously from North America, though thousands of ammonoids have been collected here from age equivalent beds. The discovery of a new species of the genus in the late Mississippian faunas of east-central Nevada provides new data for precise correlation of the ammonoid zonations of Gordon (1970) to the type Namurian and indicates a need for revision of the current correlations between the southern Urals and northwestern Europe.
A revision of Palaeacmaea (Upper Cambrian) (?Cnidaria)
Authors: Webers Gerald F. , Yochelson Ellis L.
Published: August 2016

Palaeacmaea typica, the type species of the genus, and P. irvingi, the only other Late Cambrian taxon considered congeneric are redescribed herein. Their morphology suggests that they are neither Monoplacophora, where they are currently assigned, nor are they Mollusca. Specimens of P. irvingi demonstrate considerable variation in shape, interpreted as distortion of a flexible integument, of essentially no thickness. A neotype is designated for P. irvingi; it is interpreted as a medusiform fossil, possibly a cnidarian. Only the holotype of P. typica is known, but it shows comparable features. The genus and the family Palaeacmaeide are placed in Phylum Incertae Sedis. Four Ordovician species previously assigned to Palaeacmaea, show none of the characteristics noted, and they are tentatively reassigned to other genera.
Phalangeal fusion in schizotheriine Chalicotheres (Mammalia, Perissodactyla)
Authors: Coombs Margery C. , Rothschild Bruce M.
Published: August 2016

In four genera of schizotheriine Chalicotheriidae—Moropus, Tylocephalonyx, Phyllotillon,andAncylotherium–proximal and middle phalanges of digit II of the manus fuse to form a duplex bone. Fusion of proximal and middle phalanges of digit II of the pes also occurs in many species of these genera. Radiographic and sagittal-sectional study of the fused duplex phalanges ofMoropus elatusandTylocephalonyx skinnerishows that the joint between the two bones formed fully prior to fusion but had little movement. Fusion proceeded by external enthesial interactions at the insertion of the ligament capsule and by disruption of cortical bone with trabecular bridging along the internal part of the original articular surface. Cortical disruption is more rapid on the middle than on the proximal phalangeal component of the duplex. InM. elatus,the degrees of external and internal fusion roughly correspond, and a ventral surficial groove sometimes traces the former facet, whereas inT. skinneriexternal fusion is much more developed than internal fusion. Phalangeal fusion seems to have strengthened the digit against strong forces applied along the medial (radial or tibial) side of the foot.
Vertebrate faunal changes through Lancian and Puercan time in southern Wyoming
Authors: Lillegraven Jason A. , Eberle Jaelyn J.
Published: August 2016

We summarize faunal changes through the thickest and one of the most complete records of terrestrial vertebrates spanning Lancian (∼latest Cretaceous) and Puercan (∼earliest Paleocene) ages, the type Ferris Formation in the Hanna Basin, southern Wyoming. Observed faunal changes predate tectonic definition of local Laramide basins. Nonmammalian vertebrates exhibit no major changes in taxonomic composition below the Lancian-Puercan boundary; diversity of non-avian dinosaurs remains high within uppermost levels of the Lancian section. Nevertheless, dinosaurian extinction was not necessarily “catastrophic” within a biologically relevant interval. Primitive condylarths appear locally above the highest known dinosaurs, probably as immigrants. At least in this part of the North American western interior, the first evolutionary radiation of condylarths was subsequent to the last appearance of dinosaurs, not synchronous with or prior to it. Niche-partitioning among condylarths is first recorded near the boundary between Puercan Interval-zones Pu1 and Pu2 (early and middle Puercan time, respectively), by which time the first great mammalian diversification of the Cenozoic had begun. Major experimentations in dental morphology and increasing ranges of body sizes had developed within 400,000 years of the Lancian-Puercan boundary. We recognize no evidence suggesting that placental mammals were “recovering” from events that led to demise of the dinosaurs. The true diversity of marsupials and condylarths precisely at the Cretaceous-Tertiary boundary, throughout the western interior, remains unknown. We cannot, therefore, evaluate extensiveness of competition, if any, at that time among members of the two groups.
First report of the genusLophomastixBenedict, 1904 (Crustacea: Decapoda: Albuneidae) in the fossil record and a reappraisal of the status ofBlepharipoda bruceiRathbun, 1926
Authors: Schweitzer Carrie E. , Boyko Christopher B.
Published: August 2016

Newly discovered fossils from Eocene rocks of the Quimper Sandstone, Washington, USA, constitute the first reported occurrence of the albuneid genusLophomastixBenedict, 1904, in the fossil record.Lophomastixand the closely related genusBlepharipodaRandall, 1839, are thought to be basal taxa within the decapod family Albuneidae Stimpson, 1858, based upon possession of primitive trichobranch gill structures. The occurrence ofLophomastix antiquanew species in Eocene deposits indicates that the genus is at least as old as the more derived genus,AlbuneaWeber, 1795, as would be expected for the basal taxon within the family. Based upon examination of type material,Blepharipoda bruceiRathbun, 1926, is herein removed from that genus and placed within the Paguroidea asPagurus brucei(Rathbun, 1926) new combination.
Adriosaurus and the affinities of mosasaurs, dolichosaurs, and snakes
Authors: Lee Michael S. Y. , Caldwell Michael W.
Published: August 2016

The poorly-known, long bodied, limb-reduced marine lizard Adriosaurus suessi Seeley, 1881, is reassessed. Adriosaurus and a number of other marine lizards are known from Upper Cretaceous (Upper Cenomanian-Lower Turonian) marine carbonate rocks exposed along the Dalmatian coast of the Adriatic Sea, from Komen, Slovenia, to Hvar Island, Croatia. A revised vertebral count reveals 10 cervical, 29 dorsal, and at least 65 caudal vertebrae. The projections previously interpreted as hypapophyses are instead transverse processes. Openings on the anterior part of the skull, previously described as external nares, are probably internal nares. Important features not noted previously include accessory articulations on all presacral vertebrae, pachyostosis of dorsal vertebrae and ribs, and the presence of two pygal vertebrae. Phylogenetic analysis of 258 osteological characters and all the major squamate lineages suggests that Adriosaurus and dolichosaurs are successive sister-taxa to snakes. This is consistent with their long-bodied, limb-reduced morphology being intermediate between typical marine squamates (e.g., mosasaurs) and primitive marine snakes (pachyophiids). The analysis further reveals that up to five successive outgroups to living snakes (pachyophiids, Adriosaurus, dolichosaurs, Aphanizocnemus, and mosasauroids) are all marine, suggesting a marine (or at least, semi-aquatic) phase in snake origins. These phylogenetic results are robust whether multistate characters are ordered or unordered, thus refuting recent suggestions that snakes cluster with amphisbaenians and dibamids (rather than aquatic lizards) if multistate characters are left unordered. Also, the recent suggestion that Pachyrhachis shares synapomorphies with advanced snakes (macrostomatans) is shown to be poorly supported, because the reinterpretations of the relevant skull elements are unlikely and, even if accepted, the character states proposed to unite Pachyrhachis and advanced snakes are also present in more basal snakes and/or the nearest lizard outgroups, and are consequently primitive for snakes.
Scanning electron microscope inverse imaging technique for positive image photomicrographs of microfossil molds
Authors: Over D. Jeffrey , Grimson Mark , Barrick James E.
Published: August 2016

Macro- and microfossils are commonly preserved as external molds as a result of decay or dissolution of soft and mineralized body parts after compaction and cementation of the surrounding matrix. The molds, which often preserve external features of the organism in great detail, are difficult to compare to other specimens. To enhance study, positive casts are typically made. Numerous compounds can serve as a casting medium (Rigby and Clark, 1965; Rixon, 1976). In microfossil studies latex rubber (Klapper in Winder, 1966; Ellison, 1987; Tull et al., 1988) and silicone rubber (G. Miller, personal commun.) are the most commonly used materials. An alternative technique is to photograph the mold directly using a scanning electron microscope (SEM).
Devonian hyoliths from Bolivia
Authors: Marek L. , Isaacson P. E.
Published: August 2016

Two orthothecid genera, Bolitheca n. gen. (type species Orthotheca steinmanni Knod, 1908) and Neobactrotheca n. gen. (type species Neobactrotheca pharetra n. sp.) are described from Bolivian rocks of Emsian and Eifelian age. Two incomplete and poorly preserved hyolithids are also described, one tentatively assigned to the family Pauxillitidae. Because so few specimens are known, it is not possible to compare Bolivian Devonian hyoliths with faunas from other regions, which are also poorly known.
Cupulocrinid crinoids from the Middle Ordovician (Galena Group, Dunleith Formation) of northern Iowa and southern Minnesota
Authors: Brower James C.
Published: August 2016

Two cupulocrinids,Cupulocrinus crossmanin. sp. andPraecupulocrinus conjugans(Billings) n. gen., are known from the Middle Ordovician (Galena Group, Dunleith Formation) of northern Iowa and southern Minnesota. Various morphologic and ontogenetic features demonstrate thatPraecupulocrinusis more primitive thanCupulocrinus. The two species commonly occur together. In addition, both taxa coexisted at similar levels with stem lengths ranging from about 1.5 cm in juveniles to 15 cm in adults. Relatively complete growth sequences illustrate growth and variation and show how two related crinoids subdivided feeding niches. The crown volume provides a satisfactory surrogate variable for the size of the animal. The food-gathering system of the cupulocrinids is mainly augmented by the addition of new plates at the ends of the arms. The number of plates in the arms and the arm length exhibit positive allometry relative to crown volume, largely due to development of new branches at the arm tips. The food-gathering capacity equals the number of food-catching tube-feet multiplied by the average width of the food grooves. Food-gathering capacity is also positively allometric with respect to crown volume and the amount of tissue that must be supplied with food. Consequently, the ratio of food-gathering capacity:crown volume is either constant or declines slightly with increasing size and age. The food groove width increases throughout ontogeny so adult crinoids ate larger food particles than juveniles.Praecupulocrinus conjugans(Billings) n. gen. has more narrow food grooves thanCupulocrinus crossmanin. sp. of comparable size and age, which suggests niche differentiation based on food-particle size. The arm and tube-foot geometry indicates that both cupulocrinids utilized the same type of suspension feeding.

The morphology of the anal sac and the lack of “patelloid” processes in the arms indicate thatCupulocrinus sepulchrumRamsbottom from the Upper Ordovician of Scotland belongs toDendrocrinus.
Mode of life of a new onychochilid mollusc from the Lower Devonian of Bohemia
Authors: Frýda Jiří
Published: August 2016

A new molluscan genus,Voskopiella, from the Lower Devonian of Bohemia is described and assigned to the Onychochiloidea. The type and only known species isVoskopiella barboraen. sp. from theNowakia elegansZone (uppermost Zlichovian, =Emsian) of the Suchomasty Limestone. Also discussed are its ontogeny, variability, and pathological development of ornamentation, as well as the mode of life, in order to resolve the problem as to whether onychochiloideans are torted gastropods or untorted paragastropods. A foliage supported mode of life or life in close association on or within algal mats is suggested forVoskopiella barboraen. gen. and sp.
Significance of ultrastructural features in etched conodonts
Authors: Burnett Richard D. , Hall Jack C.
Published: August 2016

Acid etching combined with scanning electron microscopy (S.E.M.) accentuates a variety of conodont microstructural patterns as compared to unetched specimens. External and internal organic layers surrounding apatitic lamellae are found with internal organic layers apparently thinner than their external counterparts. This may imply partial removal of the outermost organic layer prior to secretion of the next lamella. Etching also provides evidence of internally preserved striate ornament. Polygonal etch artifacts and zones of crystallites aligned in small areas are interpreted as possible sites for apatite biomineralization.
Scenella and “a chondrophorine (medusoid hydrozoan) from the basal Cambrian (Placentian) of Newfoundland”
Authors: Landing Ed , Narbonne Guy M.
Published: August 2016

In a recent article, Narbonne et al. (1991) documented that the stratigraphic range of the chondrophorine Kullingia delicata continues above the the uppermost Precambrian (Vendian) into the lowermost Cambrian (Placentian Series) of the Avalonian faunal province. The revised text published in the Journal of Paleontology includes several references to Scenella Billings, 1872, as a Cambrian chondrophorine. This classification is in error and unfortunately serves to reinforce several recent reports that conclude that Scenella is a chondrophorine rather than a helcionacean mollusk.
First Oligocene occurrence of the irregular echinoid Macropneustes mortoni (Conrad)
Authors: Heller James A. , Bryan Jonathan R.
Published: August 2016

A nearly complete test and several test fragments of the irregular echinoid species Macropneustes mortoni (Conrad) were recently discovered in Lower Oligocene (Vicksburgian) strata of southern Alabama. To date, M. mortoni has only been reported from Upper Eocene (Jacksonian) sediments of Alabama, Georgia, and Florida (Cooke, 1959; Toulmin, 1977; Carter, 1987). This is one of the very few species of the diverse Eocene echinoid fauna of this region to survive the terminal Eocene extinctions.
Upper Cretaceous gastropods (Fissurellidae, Haliotidae, Scissurellidae) from Puerto Rico and Jamaica
Authors: Sohl Norman F.
Published: August 2016

The fissurellid, haliotid, and scissurellid gastropods described herein are representatives of a diverse, but poorly documented, molluscan assemblage from the Upper Cretaceous carbonate-platform deposits of the Caribbean Faunal Province. Among the Fissurellidae, the Emarginulinae are represented byEmarginula pojetain. sp.,E. marchmontensisn. sp.,E.sp.,Puncturella(Alatrix)leesin. sp., andP.(A.) sp.; the Diodorinae byDiodora decussatan. sp.,Diodora hazelin. sp.,Diodora? pedinostoman. sp., andD.sp.; the Fissurellinae byFissurella kollmannin. sp.Haliotis antillesensisn. sp. is only the second verifiable member of the family Haliotidae to be described from the Cretaceous andScissurella marchmontensisn. sp. represents the first record of the Scissurellidae in that period.
Occurrence of the Upper Cretaceous ammonite Rhaeboceras in the Baculites eliasi Zone of the Pierre Shale
Authors: Grier Joyce C. , Grier James W. , Petersen Jack G.
Published: August 2016

The discovery of a specimen of Rhaeboceras coloradoense Cobban, 1987, in the Baculites eliasi zone in east-central Montana is significant for three reasons: 1) it is the most geologically recent occurrence of Rhaeboceras; 2) it connects more closely than previous specimens the lineage between the genus Rhaeboceras Meek and Ponteixites Warren, its apparent smaller descendant; and 3) it significantly extends the geographical range of the species.
Sedge (Cyperaceae) achenes from the late Barstovian of Nebraska
Authors: Gabel Mark L. , Backlund Douglas C. , Haffner Jacob
Published: August 2016

Plant fossils from the Tertiary strata of the Great Plains are relatively common and have been reported for over 100 years (Stansbury, 1852; Elias, 1942; Thomasson, 1979, 1985, 1991; Gabel, 1987). However, fossils of the family Cyperaceae are uncommon at most sites in Tertiary strata of central North America.
Eoplicoplasia, a new genus of Silurian–Lower Devonian ambocoeliid brachiopods
Authors: Johnson J. G. , Lenz A. C.
Published: August 2016

The genus Plicoplasia Boucot, 1959 (type species P. cooperi Boucot, 1959), embraces certain Lower Devonian brachiopods of the subfamily Ambocoeliinae, family Ambocoeliidae. The geographic range of Plicoplasia includes North America (Eastern Americas Realm) and South America and South Africa (Malvinokaffric Realm).
First recognition of the genus Verneuilia Hall and Clarke (Brachiopoda, Spiriferida) from North America (west-central Alaska)
Authors: Blodgett Robert B. , Johnson J. G.
Published: August 2016

The brachiopod genus Verneuilia Hall and Clarke, 1893, is recognized for the first time in North America, where it is represented by a new species described here, V. langenstrasseni. This occurrence not only extends the geographic range of the genus, but also the lower age and stratigraphic limit into the Eifelian (early Middle Devonian). Previously, the oldest known species was the type, V. cheiropteryx d'Archiac and de Verneuil, 1842, from the Givetian (late Middle Devonian) of Germany. Internal structures of V. langenstrasseni n. sp. are similar to those of genera in the ambocoeliid subfamily Rhynchospiriferinae, providing the first good evidence of a systematic relationship.
New occurrence of Periastron reticulatum Unger emend. Beck, an enigmatic Mississippian fossil plant
Authors: Gastaldo Robert A.
Published: August 2016

Two new specimens of Periastron reticulatum Unger emend. Beck have been collected from the Erin Slate, Talladega Slate Belt, southern Appalachians. Preserved anatomical features provide a basis for an expanded understanding of the genus and provide a biostratigraphic basis for dating the uppermost unit of the Talladega Slate Belt.
Microstructure and diagenesis of calcified demosponges from the Upper Triassic of the northeastern Dolomites (Italy)
Authors: Mastandrea A. , Russo F.
Published: August 2016

The calcareous skeletons of 17 species of Triassic demosponges from the northeastern Dolomites have been analyzed for microstructure and diagenesis. The four microstructures recognized (irregular, spherulitic, penicillate aragonitic, and homogeneous granular Mg calcite) are described in terms of mineralogy; shape, dimension, and arrangement of microstructural elements; mode of growth; and possible biomineralization. The diagenesis in these sponge carbonate skeletons is of an aggrading type that occurred in diagenetic units, semi-closed systems, delineated by organic phragmas, which controlled the flux of diagenetic fluids. We tentatively interpret these phragmas as the remains of water-insoluble macromolecules for space delineation during the biomineralization process. In the aragonitic skeletons the preservation grade is correlated with Sr content, and the replacement of aragonite by calcite is marked by a Sr value around 4,000 p.p.m. Calcitized aragonite still retains a detectable amount of Sr. In Mg calcite skeletons the continuous and regular increase of grain size is inversely correlated with Mg content and directly with the distance from the organic phragmas.