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Stefan Schlager, Antonio Profico, Fabio Di Vincenzo, Giorgio Manzi
Many fossil specimens exhibit deformations caused by taphonomic processes. Due to these deformations, even important specimens have to be excluded from morphometric analyses, impoverishing an already poor paleontological record. Techniques to retrodeform and virtually restore damaged (i.e. deformed) specimens are available, but these methods genenerally imply the use of a sparse set of bilateral landmarks, ignoring the fact that the distribution and amount of control points directly affects the result of the retrodeformation...
2018: PloS One
Svetlana A Semerikova, Yuliya Y Khrunyk, Martin Lascoux, Vladimir L Semerikov
The origin of conifer genera, the main components of mountain temperate and boreal forests, was deemed to arise in the Mesozoic, although paleontological records and molecular data point to a recent diversification, presumably related to Neogene cooling. The geographical area(s) where the modern lines of conifers emerged remains uncertain, as is the sequence of events leading to their present distribution. To gain further insights into the biogeography of firs (Abies), we conducted phylogenetic analyses of chloroplast, mitochondrial and nuclear markers...
March 15, 2018: Molecular Phylogenetics and Evolution
Tanja Stadler, Alexandra Gavryushkina, Rachel C M Warnock, Alexei J Drummond, Tracy A Heath
A birth-death-sampling model gives rise to phylogenetic trees with samples from the past and the present. Interpreting "birth" as branching speciation, "death" as extinction, and "sampling" as fossil preservation and recovery, this model - also referred to as the fossilized birth-death (FBD) model - gives rise to phylogenetic trees on extant and fossil samples. The model has been mathematically analyzed and successfully applied to a range of datasets on different taxonomic levels, such as penguins, plants, and insects...
March 14, 2018: Journal of Theoretical Biology
Isaac V Pratt, James D Johnston, Ernie Walker, David M L Cooper
Cortical bone porosity and specifically the orientation of vascular canals is an area of growing interest in biomedical research and comparative/paleontological anatomy. The potential to explain microstructural adaptation is of great interest. However, the determinants of the development of canal orientation remain unclear. Previous studies of birds have shown higher proportions of circumferential canals (called laminarity) in flight bones than in hindlimb bones, and interpreted this as a sign that circumferential canals are a feature for resistance to the torsional loading created by flight...
March 8, 2018: Journal of Anatomy
Diana A Monteiro, Edwin W Taylor, Marina R Sartori, André L Cruz, Francisco T Rantin, Cleo A C Leite
The present study has revealed that the lungfish has both structural and functional features of its system for physiological control of heart rate, previously considered solely mammalian, that together generate variability (HRV). Ultrastructural and electrophysiological investigation revealed that the nerves connecting the brain to the heart are myelinated, conferring rapid conduction velocities, comparable to mammalian fibers that generate instantaneous changes in heart rate at the onset of each air breath...
February 2018: Science Advances
Ewa Wagner-Wysiecka
Natural Baltic amber (succinite) is the most appreciated fossil resin of the rich cultural traditions dating back to prehistoric times. Its unequivocal identification is extremely important in many branches of science and trades including archeology, paleontology, chemistry and finally mineralogical and gemological societies. Current methods of modification of natural succinite are more and more sophisticated making the identification of natural Baltic amber often challenging. In article the systematic analytical approach for identification of natural and modified under different conditions succinite, using mid-infrared spectroscopy (transmission, Drifts and ATR techniques) is presented...
February 21, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Christopher J Dunmore, Gert Wollny, Matthew M Skinner
Paleontological research increasingly uses high-resolution micro-computed tomography (μCT) to study the inner architecture of modern and fossil bone material to answer important questions regarding vertebrate evolution. This non-destructive method allows for the measurement of otherwise inaccessible morphology. Digital measurement is predicated on the accurate segmentation of modern or fossilized bone from other structures imaged in μCT scans, as errors in segmentation can result in inaccurate calculations of structural parameters...
2018: PeerJ
Clément Zanolli, Lei Pan, Jean Dumoncel, Ottmar Kullmer, Martin Kundrát, Wu Liu, Roberto Macchiarelli, Lucia Mancini, Friedemann Schrenk, Claudio Tuniz
Locality 1, in the Lower Cave of the Zhoukoudian cave complex, China, is one of the most important Middle Pleistocene paleoanthropological and archaeological sites worldwide, with the remains of c. 45 Homo erectus individuals, 98 mammalian taxa, and thousands of lithic tools recovered. Most of the material collected before World War II was lost. However, besides two postcranial elements rediscovered in China in 1951, four human permanent teeth from the 'Dragon Bone Hill,' collected by O. Zdansky between 1921 and 1923, were at the time brought to the Paleontological Institute of Uppsala University, Sweden, where they are still stored...
March 2018: Journal of Human Evolution
Russell D C Bicknell, Ada J Klinkhamer, Richard J Flavel, Stephen Wroe, John R Paterson
Limulus polyphemus, an archetypal chelicerate taxon, has interested both biological and paleontological researchers due to its unique suite of anatomical features and as a useful modern analogue for fossil arthropod groups. To assist the study and documentation of this iconic taxon, we present a 3D atlas on the appendage musculature, with specific focus on the muscles of the cephalothoracic appendages. As L. polyphemus appendage musculature has been the focus of extensive study, depicting the muscles in 3D will facilitate a more complete understanding thereof for future researchers...
2018: PloS One
William G Parker
Calyptosuchus wellesi is a medium-sized desmatosuchian aetosaur common in Adamanian (early to middle Norian) age rocks from the Chinle Formation and Dockum Group of the Western United States. Known chiefly from osteoderms, this taxon has never been fully described and non-osteoderm material assigned to Calyptosuchus has been done so based on questionable criteria. Mapping of aetosaurian elements from the Placerias Quarry allows for the recognition of associated material providing support for referrals of non-osteoderm material...
2018: PeerJ
Alexandra Houssaye, Maxime Taverne, Raphaël Cornette
Long bone inner structure and cross-sectional geometry display a strong functional signal, leading to convergences, and are widely analyzed in comparative anatomy at small and large taxonomic scales. Long bone microanatomical studies have essentially been conducted on transverse sections but also on a few longitudinal ones. Recent studies highlighted the interest in analyzing variations of the inner structure along the diaphysis using a qualitative as well as a quantitative approach. With the development of microtomography, it has become possible to study three-dimensional (3D) bone microanatomy and, in more detail, the form-function relationships of these features...
February 6, 2018: Journal of Anatomy
Timothy P Cleland, Elena R Schroeter
The last two decades have seen a broad diversity of methods used to identify and/or characterize proteins in the archeological and paleontological record. Of these, mass spectrometry has opened an unprecedented window into the proteomes of the past, providing protein sequence data from long extinct animals as well as historical and prehistorical artifacts. Thus, application of mass spectrometry to fossil remains has become an attractive source for ancient molecular sequences with which to conduct evolutionary studies, particularly in specimens older than the proposed limit of amplifiable DNA detection...
January 31, 2018: Journal of Proteome Research
Filipe O Da Silva, Anne-Claire Fabre, Yoland Savriama, Joni Ollonen, Kristin Mahlow, Anthony Herrel, Johannes Müller, Nicolas Di-Poï
The ecological origin of snakes remains amongst the most controversial topics in evolution, with three competing hypotheses: fossorial; marine; or terrestrial. Here we use a geometric morphometric approach integrating ecological, phylogenetic, paleontological, and developmental data for building models of skull shape and size evolution and developmental rate changes in squamates. Our large-scale data reveal that whereas the most recent common ancestor of crown snakes had a small skull with a shape undeniably adapted for fossoriality, all snakes plus their sister group derive from a surface-terrestrial form with non-fossorial behavior, thus redirecting the debate toward an underexplored evolutionary scenario...
January 25, 2018: Nature Communications
Gabriel S Yapuncich, Steven E Churchill, Noël Cameron, Christopher S Walker
OBJECTIVES: Predicting body mass is a frequent objective of several anthropological subdisciplines, but there are few published methods for predicting body mass in immature humans. Because most reference samples are composed of adults, predicting body mass outside the range of adults requires extrapolation, which may reduce the accuracy of predictions. Prediction equations developed from a sample of immature humans would reduce extrapolation for application to small-bodied target individuals, and should have utility in multiple predictive contexts...
January 25, 2018: American Journal of Physical Anthropology
C T Griffin
Understanding ontogenetic patterns is important in vertebrate paleontology because the assessed skeletal maturity of an individual often has implications for paleobiogeography, species synonymy, paleobiology, and body size evolution of major clades. Further, for many groups the only means of confidently determining ontogenetic status of an organism is through the destructive process of histological sampling. Although the ontogenetic patterns of Late Jurassic and Cretaceous dinosaurs are better understood, knowledge of the ontogeny of the earliest dinosaurs is relatively poor because most species-level growth series known from these groups are small (usually, maximum of n ~ 5) and incomplete...
January 23, 2018: Journal of Anatomy
André Parent
Exactly 200 years ago, the London surgeon-apothecary James Parkinson (1755-1824) published a 66-page-long booklet entitled An Essay on the Shaking Palsy, which contains the first clear clinical description of the shaking palsy or paralysis agitans, which we now refer to as Parkinson's disease. However, the value of this essay was not fully recognized during Parkinson's lifetime, which spanned the American Revolution, the French Revolution, and the Napoleonic Wars. James Parkinson was one of the most singular figures of his time and place...
January 2018: Canadian Journal of Neurological Sciences. le Journal Canadien des Sciences Neurologiques
Sebastián Poljak, Alejandro M Ferreiro, Marina B Chiappero, Julieta Sánchez, Magalí Gabrielli, Marta S Lizarralde
Little is known about phylogeography of armadillo species native to southern South America. In this study we describe the phylogeography of the screaming hairy armadillo Chaetophractus vellerosus, discuss previous hypothesis about the origin of its disjunct distribution and propose an alternative one, based on novel information on genetic variability. Variation of partial sequences of mitochondrial DNA Control Region (CR) from 73 individuals from 23 localities were analyzed to carry out a phylogeographic analysis using neutrality tests, mismatch distribution, median-joining (MJ) network and paleontological records...
2018: PloS One
Sara S Kahanamoku, Pincelli M Hull, David R Lindberg, Allison Y Hsiang, Erica C Clites, Seth Finnegan
Body size distributions can vary widely among communities, with important implications for ecological dynamics, energetics, and evolutionary history. Here we present a dataset of body size and shape for 12,035 extant Patellogastropoda (true limpet) specimens from the collections of the University of California Museum of Paleontology, compiled using a novel high-throughput morphometric imaging method. These specimens were collected over the past 150 years at 355 localities along a latitudinal gradient ranging from Alaska to Baja California, Mexico and are presented here with individual images, 2D outline coordinates, and 2D measurements of body size and shape...
January 9, 2018: Scientific Data
Yuri G Arzanov, Vasily V Grebennikov
We summarize knowledge of the weevil tribe Cleonini worldwide, including its monophyly, relationships, distribution, biology, immature stages, economic significance and paleontology. We score adult morphological characters for 79 of a total of 96 extant genus-group Cleonini taxa considered valid to date. The resulting matrix contains 121 parsimoniously informative characters scored for 145 ingroup (Cleonini) and 29 outgroup terminals. Maximum Parsimony (MP) and Bayesian Inference (BI) analyses consistently recover monophyletic Lixinae and Cleonini...
October 3, 2017: Zootaxa
Christopher J Bae, Katerina Douka, Michael D Petraglia
The traditional "out of Africa" model, which posits a dispersal of modern Homo sapiens across Eurasia as a single wave at ~60,000 years ago and the subsequent replacement of all indigenous populations, is in need of revision. Recent discoveries from archaeology, hominin paleontology, geochronology, genetics, and paleoenvironmental studies have contributed to a better understanding of the Late Pleistocene record in Asia. Important findings highlighted here include growing evidence for multiple dispersals predating 60,000 years ago in regions such as southern and eastern Asia...
December 8, 2017: Science
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