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Milam M.J.,Grossflottbeker Strasse 47C | Meyer D.L.,University of Cincinnati | Dattilo B.F.,Indiana University | Hunda B.R.,Cincinnati Museum Center
Palaios | Year: 2017

A Lagerstätte of Glyptocrinus decadactylus collected from the Upper Fairview Formation at Maysville, Kentucky, USA, yields new insights into the paleoautecology of camerate crinoids of the Late Ordovician. The Lagerstätte represents an autochthonous community composed of a single siltstone bed representing an obrution event and containing over 400 individual glyptocrinids that had colonized a slight topographic rise of relatively high energy within the deep subtidal zone. The high density of the crinoid community was accommodated by tiering, in which the crinoids presumably employed macroalgae (not preserved), occasionally bryozoans, and the columns of earlier-settled specimens as attachment sites; differing column lengths positioned the crinoids at various levels within the community. A further strategy for crowded conditions may have been small body size. Storm-induced turbidity flows led to the suspension of silts by a lofting plume that smothered the crinoids in their habitat. The densely packed crinoid-macroalgae assemblage may have baffled the sediment plume and induced deposition, facilitating burial. Some specimens apparently died shortly prior to burial, suggesting more than one earlier killing event, likely related to the storm that ultimately caused the obrution. Other specimens were killed by the obrution event and subjected to little or no subsequent scavenging or decay after burial, leading to excellent preservation. Copyright © 2017, SEPM (Society for Sedimentary Geology).


Van Iten H.,Hanover College | Van Iten H.,Cincinnati Museum Center | Marques A.C.,University of Sao Paulo | Leme J.D.M.,University of Sao Paulo | And 2 more authors.
Palaeontology | Year: 2014

Diploblastic eumetazoans of the phylum Cnidaria originated during the Neoproterozoic Era, possibly during the Cryogenian Period. The oldest known fossil cnidarians occur in strata of Ediacaran age and consist of polypoid forms that were either nonbiomineralizing or weakly so. The oldest possible anthozoans, including the genus Ramitubus, may be related to tabulate corals and occur in the Doushantuo Lagerstätte (upper Doushantuo Formation, South China), the age of which is poorly constrained (approximately 585 Ma?). Conulariid scyphozoans may first appear as early as 635-577 Ma (Lantian Formation, South China). A definite conulariid, most similar to Palaeozoic species assigned to the genus Paraconularia, occurs in association with the possible scyphozoan, Corumbella werneri, in the latest Ediacaran (c. 543 Ma) Tamengo Formation of Brazil. Basal Cambrian (c. 540 Ma) phosphorites in the upper Kuanchuanpu Formation (South China) yield solitary polyps of the oldest probable anthozoan (Eolympia pediculata), which appears to have been a stem hexacorallian. This same formation contains fossils interpreted by some authors as pentaradial cubozoan polyps; however, both the oldest known cubozoans and the oldest hydrozoans, all medusae, may actually occur in the Cambrian (Series 3, c. 505 Ma) Marjum Formation (Utah, USA). Although these recently published palaeontological data tend to corroborate the hypothesis that Cnidaria has a relatively deep Neoproterozoic history, the timing of major internal branching events remains poorly constrained, with, for example, the results of some molecular clock analyses indicating that the two cnidarian subphyla (Anthozoaria and Medusozoa) may have originated as many as one billion years ago. Further progress towards elucidating the evolution and early fossil record of cnidarians may accrue from: (1) an intensive search for phosphatized soft parts in possible anthozoans from the Ediacaran Doushantuo Formation; (2) an expanded search for Ediacaran conulariids; and (3) additional detailed analyses of the taphonomy and preservation of Ediacaran and Cambrian cnidarians, including possible pentaradial cubozoan polyps from the Fortunian upper Kuanchuanpu Formation. © The Palaeontological Association.


McKay B.D.,University of Minnesota | Barker F.K.,University of Minnesota | Mays Jr. H.L.,Cincinnati Museum Center | Doucet S.M.,University of Windsor | Hill G.E.,Auburn University
Molecular Phylogenetics and Evolution | Year: 2010

Phylogenetic relationships among the 14 manakin genera were inferred from DNA sequence data obtained from both mitochondrial and nuclear DNA loci. Phylogenetic analysis resulted in a well-supported hypothesis that corroborates a sister relationship between tyrant-manakins and the "core" manakins (Antilophia, Chiroxiphia, Corapipo, Dixiphia, Heterocercus, Ilicura, Lepidothrix, Manacus, Masius, Machaeropterus, Pipra, and Xenopipo). Our data strongly support these core manakin genera as a monophyletic group. Consistent with previous work, we find two major clades within the core manakins, although the placement of the genus Xenopipo with regards to these two clades is ambiguous. Generic relationships within these clades are generally well resolved. Although we find some concordance between our study and a previous manakin phylogeny based on syringeal characters, we note several fundamental differences between the phylogenies. Thus, we offer a new phylogenetic hypothesis for Pipridae. © 2010 Elsevier Inc. All rights reserved.


Ford R.C.,New Explorers High School | Van Iten H.,Hanover College | Van Iten H.,Cincinnati Museum Center | Clark G.R.,Kansas State University
Journal of Paleontology | Year: 2016

Transmitted light and scanning electron imaging of sectioned specimens of Conularia and Paraconularia, prepared using HCl etching and critical point drying, revealed that their periderm is composed of extremely thin (approximately 0.5-3 μm), variably distinct microlamellae that are alternately organic poor and organic rich. Organic-rich microlamellae are cross-connected by slender strands of organic matter originally embedded in calcium phosphate, which in etched specimens has been dissolved. Microlamellae may be organized in thicker (approximately 5-75 μm) layers, or macrolamellae, that vary in color and organic matter content, possibly owing to changes in the ambient paleoenvironment. Thickening of the periderm to form transverse ribs and internal carinae was achieved through gradual thickening of individual microlamellae. In the core of the transverse ribs and internal carinae the distinction between organic-rich and organic-poor microlamellae may be reduced, owing to organic material becoming dominant over (former) mineral matter or vice versa. Combined with observations of plicated aperture closure in thin-walled conulariids, including Archaeoconularia slateri (Reed, 1933) (Upper Ordovician, Scotland) showing smooth folding of midline carinae through angles greater than 90°, these results suggest a structure and original flexibility in the organic-rich biocomposite forming the conulariid periderm that supports its homology to the chitinous lamellar periderm of coronate scyphozoans. © 2016, The Paleontological Society.


Iten H.V.,Hanover College | Iten H.V.,Cincinnati Museum Center | Leme J.D.M.,University of Sao Paulo | Marques A.C.,University of Sao Paulo | Simoes M.G.,São Paulo State University
Acta Palaeontologica Polonica | Year: 2013

In a letter to Nature (February, 2011), Xunlai Yuan and collaborators recorded carbon compression fossils from black shales of the Lantian Formation (Ediacaran), southern Anhui Province, South China. The new fossils, described under five morphological types (Types A to E), exhibit degrees of morphological differentiation suggesting that they were multicellular eukaryotes. Some of the Lantian macrofossils were interpreted as algae, but others are of unknown affinities. For reasons noted in this discussion, Type A fossils attracted our particular attention, and we suggest an alternative interpretation of their affinities. According to our view, some of them (at least those with three faces and no globose holdfast at their base) may represent conulariid cnidarians or close medusozoan relatives. The undistorted organism probably was a three-sided cone in life. We believe that our suggested alternative interpretations of the anatomy and affinities of the fossils in question can be useful in guiding future research on the oldest currently known fossil assemblage of multicellular organisms. Copyright © 2012.


Mckay B.D.,American Museum of Natural History | Mays H.L.,Cincinnati Museum Center | Yao C.-T.,Endemic Species Research Institute | Wan D.,Liaoning University | And 2 more authors.
Systematic Biology | Year: 2014

Species designations are critically important scientific hypotheses that serve as the foundational units in a wide range of biological subdisciplines. A growing realization that some classes of data fail to delimit species under certain conditions has led to increasingly more integrative taxonomies, whereby species discovery and hypothesis testing are based on multiple kinds of data (e.g., morphological, molecular, behavioral, ecological, etc.). However, although most taxonomic descriptions have been based on morphology, some key morphological features, such as color, are rarely quantified and incorporated into integrative taxonomic studies. In this article, we applied a new method of ultraviolet digital photography to measure plumage variation in a color-variable avian species complex, the varied tit (Sittiparus varius). Plumage measurements corroborated species limits defined by morphometric, mitochondrial DNA, and nuclear DNA disjunctions and provided the only evidence for distinguishing two recently evolved species. Importantly, color quantification also provided a justification for lumping putative taxa with no evidence of evolutionary independence. Our revised taxonomy thus refines conservation units for listing and management and clarifies the primary units for evolutionary studies. Species tree analyses, which applied the newly delimited species as operational taxonomic units, revealed a robust phylogenetic hypothesis for the group that establishes a foundation for future biogeographic analyses. This study demonstrates how digital photography can be used to incorporate color character variation into integrative taxonomies, which should lead to more informed, more rigorous, and more accurate assessments of biodiversity. [Color, digital photography, integrative taxonomy, Sittiparus varius, species delimitation, varied tit.] © 2014 The Author(s) 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.


McKay B.D.,University of Minnesota | Mays Jr. H.L.,Cincinnati Museum Center | Wu Y.,Guangdong Entomological Institute | Li H.,Guangdong Entomological Institute | And 3 more authors.
Molecular Ecology | Year: 2013

The process of discovering species is a fundamental responsibility of systematics. Recently, there has been a growing interest in coalescent-based methods of species delimitation aimed at objectively identifying species early in the divergence process. However, few empirical studies have compared these new methods with character-based approaches for discovering species. In this study, we applied both a character-based and a coalescent-based approaches to delimit species in a closely related avian complex, the light-vented/Taiwan bulbul (Pycnonotus sinensis/Pycnonotus taivanus). Population aggregation analyses of plumage, mitochondrial and 13 nuclear intron character data sets produced conflicting species hypotheses with plumage data suggesting three species, mitochondrial data suggesting two species, and nuclear intron data suggesting one species. Such conflict is expected among recently diverged species, and by integrating all sources of data, we delimited three species verified with independently congruent character evidence as well as a more weakly supported fourth species identified by a single character. Attempts to validate species hypothesis using Bayesian Phylogenetics and Phylogeography (BPP), a coalescent-based method of species delimitation, revealed several issues that can seemingly affect statistical support for species recognition. We found that θ priors had a dramatic impact on speciation probabilities, with lower values consistently favouring splitting and higher values consistently favouring lumping. More resolved guide trees also resulted in overall higher speciation probabilities. Finally, we found suggestive evidence that BPP is sensitive to the divergent effects of nonrandom mating caused by intraspecific processes such as isolation-with-distance, and therefore, BPP may not be a conservative method for delimiting independently evolving population lineages. Based on these concerns, we questioned the reliability of BPP results and based our conclusions about species limits exclusively on character data. © 2013 John Wiley & Sons Ltd.


Brochu C.A.,University of Iowa | Storrs G.W.,Cincinnati Museum Center
Journal of Vertebrate Paleontology | Year: 2012

We describe a new crocodile, Crocodylus thorbjarnarsoni, sp. nov., on the basis of skulls and jaws from Pliocene and Pleistocene deposits in the Lake Turkana Basin of Kenya. The new species has a comparatively broad, deep snout and resembles an extinct horned crocodile from the Quaternary of Olduvai Gorge (C. anthropophagus), but the squamosal horns are not as well developed. The skull table has a strongly trapezoidal outline different from those of the living Nile crocodile (C. niloticus) and crocodiles from late Miocene deposits in the Turkana Basin. The largest specimens are from animals up to 7.5 m in total length. It would have been the largest predator in its environment, and the early humans found in the same deposits were presumably part of its prey base. A phylogenetic analysis, including the new species and an improved sample of extinct crocodyline diversity, suggests a more complex phylogenetic and biogeographic history for the clade in Africa and the eastern Indian Ocean region than previously supposed. The analysis limits the known geographic and stratigraphic range of Rimasuchus lloydi, previously thought to occur throughout Africa from the early Miocene through the Pleistocene of northern Africa. Crocodylus niloticus is not known with certainty from units older than the Quaternary, and most late Miocene fossils from the Turkana Basin previously referred to C. niloticus can instead be referred to C. checchiai. The current first appearance datum for Crocodylus in Africa is approximately 7 Ma. © 2012 Copyright Taylor and Francis Group, LLC.


Brett C.E.,University of Cincinnati | Zambito Iv J.J.,University of Cincinnati | Hunda B.R.,Cincinnati Museum Center | Schindler E.,Senckenberg Forschungsinstitut und Naturmuseum Frankfurt
Palaios | Year: 2012

Spectacular trilobite Lagersttten occur in distinctive offshore calcareous mudstone facies through the Late Ordovician to Devonian, and reflect a combination of mass mortality or molting and burial, coupled with early diagenetic enhancement. Evidence indicates two distinct modes of burial, Type I and II assemblages, which show evidence for burial without or with seafloor disturbance, respectively. Type I assemblages suggest rapid (hours to days), but not instantaneous burial, without bottom disruption, enabling preservation of in situ behavior, including mass aggregations and molt ensembles. Most occurrences contain bedding planes in which trilobites exhibit incipient disarticulation. These assemblages were buried by cascades of flocculated sediment from hypopycnal, detached flows. Type II assemblages show well-articulated, enrolled, semi-enrolled, and outstretched trilobites in varied orientations relative to bedding. In such cases, bottom flows and seafloor disruption by storm or seismic disturbances in shallow waters suspended large amounts of flocculated muds as viscous slurries, which developed into hyperpycnal flows that entrained carcasses of trilobites and other organisms. In many cases, both Type I and II obrution was followed by additional sedimentation, geochemical zones moved upward through the sediment column, and there was little tendency to form diagenetic overprints. Alternatively, if burial was followed by an interval of sediment starvation, the sediments were bioturbated and very early diagenetic mineralization was superimposed, first, in rare cases, as mineralized soft parts in entombed carcasses, and later as pyritization of burrow linings. Development of the concretionary layers required more prolonged periods of stability of the sulfate reduction zone. Cementation of sediment shielded organism bodies from most or all effects of compaction. Thus, ironically, the best preservation of delicate remains required rapid burial, associated with mass mortality, and very low rates of background sedimentation following the event. © 2012 SEPM (Society for Sedimentary Geology).


Borrero F.J.,Cincinnati Museum Center | Breure A.S.H.,Netherlands Center for Biodiversity Naturalis
Zootaxa | Year: 2011

The land snails of the family Amphibulimidae occurring within northwestern South America are critically examined and notes on their distribution are given. The total number of taxa discussed is 61 (7 Dryptus, 54 Plekocheilus); of these, four Colombian Dryptus and 32 Plekocheilus species are included. The following new species are described: Plekocheilus (P.) bigener, P. (P.) incognitus, Plekocheilus (Eurytus) camaritagua, P. (E.) labiosus, and P. (E.) paraguas. The following nominal taxa are now synonymized: Plekocheilus (P.) speciosus (Pfeiffer, 1854) = P. (P.) plectostylus (Pfeiffer, 1848); Plekocheilus (Eurytus) couturesi Ancey, 1900 = P. (P.) glandiformis (Lea, 1838); Plekocheilus (Aeropictus) latilabris (Pfeiffer, 1855) = P. (A.) succineoides (Petit de la Saussaye, 1840); Plekocheilus (Eurytus) virgatus (Pilsbry, 1935) = P. (E.) mabillei (Crosse, 1867) = P. (E.) pulicarius (Reeve, 1848). Also, Simpulopsis fulguratus Miller, 1878 is now consid-ered a junior subjective synonym of Simpulopsis (Eudioptus) citrinovitrea (Moricand, 1836). For the following species, precise localities are given for the first time: Dryptus stuebeli (Martens, 1885), Plekocheilus (Aeropictus) cathcartiae (Reeve, 1848), P. (E.) cardinalis (Pfeiffer, 1853), P. (Eurytus) episcopalis auriformis (Da Costa, 1904), P. (E.) episcopalis corticosus (Sowerby, 1895), and P. (E.) lynciculus (Deville & Huppé, 1850). Newly recorded for the Colombian malaco-fauna are the following taxa: Plekocheilus (P.) couturesi (Ancey, 1900), P. (Eurytus) piperitus (Sowerby I, 1837). The fol-lowing taxa are excluded from the Colombian fauna: Dryptus funckii (Nyst, 1843), Plekocheilus (Aeropictus) veranyi (Pfeiffer, 1848), Plekocheilus (Eurytus) jimenezi (Hidalgo, 1872). Copyright © 2011 · Magnolia Press.

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