scholarly journals Postcranial anatomy ofPissarrachampsa sera(Crocodyliformes, Baurusuchidae) from the Late Cretaceous of Brazil: insights on lifestyle and phylogenetic significance

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2075 ◽  
Author(s):  
Pedro L. Godoy ◽  
Mario Bronzati ◽  
Estevan Eltink ◽  
Júlio C. de A. Marsola ◽  
Giovanne M. Cidade ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Evolutionary History ◽  
Minor Role ◽  
Phylogenetic Significance ◽  
Top Predator ◽  
Data Set ◽  
History Of ◽  
A Minor ◽  
Bauru Group ◽  
Postcranial Anatomy

The postcranial anatomy of Crocodyliformes has historically been neglected, as most descriptions are based solely on skulls. Yet, the significance of the postcranium in crocodyliforms evolution is reflected in the great lifestyle diversity exhibited by the group, with members ranging from terrestrial animals to semi-aquatic and fully marine forms. Recently, studies have emphasized the importance of the postcranium. Following this trend, here we present a detailed description of the postcranial elements ofPissarrachampsa sera(Mesoeucrocodylia, Baurusuchidae), from the Adamantina Formation (Bauru Group, Late Cretaceous of Brazil). The preserved elements include dorsal vertebrae, partial forelimb, pelvic girdle, and hindlimbs. Comparisons with the postcranial anatomy of baurusuchids and other crocodyliforms, together with body-size and mass estimates, lead to a better understanding of the paleobiology ofPissarrachampsa sera, including its terrestrial lifestyle and its role as a top predator. Furthermore, the complete absence of osteoderms inP. sera, a condition previously known only in marine crocodyliforms, suggests osteoderms very likely played a minor role in locomotion of baurusuchids, unlike other groups of terrestrial crocodyliforms. Finally, a phylogenetic analysis including the newly recognized postcranial features was carried out, and exploratory analyses were performed to investigate the influence of both cranial and postcranial characters in the phylogeny of Crocodyliformes. Our results suggest that crocodyliform relationships are mainly determined by cranial characters. However, this seems to be a consequence of the great number of missing entries in the data set with only postcranial characters and not of the lack of potential (or synapomorphies) for this kind of data to reflect the evolutionary history of Crocodyliformes.

scholarly journals Diversification events and the effects of mass extinctions on Crocodyliformes evolutionary history

2015 ◽  
Vol 2 (5) ◽  
pp. 140385 ◽  
Author(s):  
Mario Bronzati ◽  
Felipe C. Montefeltro ◽  
Max C. Langer
Keyword(s):  
Mass Extinction ◽  
Fossil Record ◽  
Evolutionary History ◽  
Continuous Process ◽  
Mass Extinctions ◽  
Terrestrial Habitats ◽  
History Of ◽  
The Rich ◽  
A Minor ◽  
Diversification Event

The rich fossil record of Crocodyliformes shows a much greater diversity in the past than today in terms of morphological disparity and occupation of niches. We conducted topology-based analyses seeking diversification shifts along the evolutionary history of the group. Our results support previous studies, indicating an initial radiation of the group following the Triassic/Jurassic mass extinction, here assumed to be related to the diversification of terrestrial protosuchians, marine thalattosuchians and semi-aquatic lineages within Neosuchia. During the Cretaceous, notosuchians embodied a second diversification event in terrestrial habitats and eusuchian lineages started diversifying before the end of the Mesozoic. Our results also support previous arguments for a minor impact of the Cretaceous/Palaeogene mass extinction on the evolutionary history of the group. This argument is not only based on the information from the fossil record, which shows basal groups surviving the mass extinction and the decline of other Mesozoic lineages before the event, but also by the diversification event encompassing only the alligatoroids in the earliest period after the extinction. Our results also indicate that, instead of a continuous process through time, Crocodyliformes diversification was patchy, with events restricted to specific subgroups in particular environments and time intervals.

Climatic, Solar, Oceanic, and Geomagnetic Influences on Late-Glacial and Holocene Atmospheric 14C/12C Change

1991 ◽  
Vol 35 (1) ◽  
pp. 1-24 ◽  
Author(s):  
Minze Stuiver ◽  
Thomas F. Braziunas ◽  
Bernd Becker ◽  
Bernd Kromer
Keyword(s):  
Ocean Circulation ◽  
Time Scale ◽  
Late Glacial ◽  
Minor Role ◽  
Activity Levels ◽  
Data Set ◽  
The Holocene ◽  
Spectral Interpretation ◽  
Late Glacial And Holocene ◽  
A Minor

AbstractLate-glacial and Holocene 14C/12C ratios of atmospheric CO2 vary in magnitude from a few per mil for annual/decadal pertubations to more than 10% for events lasting millennia. A data set illuminating 10- to 104-yr variability refines our understanding of oceanic (climatic) versus geomagnetic or solar forcing of atmospheric 14C/12C ratios. Most of the variance in the Holocene atmospheric 14C/12C record can be attributed to the geomagnetic (millennia time scale) and solar (century time scale) influence on the flux of primary cosmic rays entering the atmosphere. Attributing the observed atmospheric 14C/12C changes to climate alone leads to ocean circulation and/or global wind speed changes incompatible with proxy records. Climate-(ocean-)related 14C redistribution between carbon reservoirs, while evidently playing a minor role during the Holocene, may have perturbed atmospheric 14C/12C ratios measurably during the late-glacial Younger Dryas event. First-order corrections to the radiocarbon time scale (12,000–30,000 14C yr B.P.) are calculated from adjusted lake-sediment and tree-ring records and from geomagnetically defined model 14C histories. Paleosunspot numbers (100–9700 cal yr B.P.) are derived from the relationship of model 14C production rates to sunspot observations. The spectral interpretation of the 14C/12C atmospheric record favors higher than average solar activity levels for the next century. Minimal evidence was found for a sun-weather relationship.

scholarly journals New Findings on Evolution of Metal Homeostasis Genes: Evidence from Comparative Genome Analysis of Bacteria and Archaea

2005 ◽  
Vol 71 (11) ◽  
pp. 7083-7091 ◽  
Author(s):  
J. M. Coombs ◽  
T. Barkay
Keyword(s):  
Metal Binding ◽  
Metal Homeostasis ◽  
Open Reading Frames ◽  
Minor Role ◽  
Gene Trees ◽  
New Findings ◽  
Atpase Gene ◽  
History Of ◽  
A Minor ◽  
Multiple Loss

ABSTRACT In order to examine the natural history of metal homeostasis genes in prokaryotes, open reading frames with homology to characterized PIB-type ATPases from the genomes of 188 bacteria and 22 archaea were investigated. Major findings were as follows. First, a high diversity in N-terminal metal binding motifs was observed. These motifs were distributed throughout bacterial and archaeal lineages, suggesting multiple loss and acquisition events. Second, the CopA locus separated into two distinct phylogenetic clusters, CopA1, which contained ATPases with documented Cu(I) influx activity, and CopA2, which contained both efflux and influx transporters and spanned the entire diversity of the bacterial domain, suggesting that CopA2 is the ancestral locus. Finally, phylogentic incongruences between 16S rRNA and PIB-type ATPase gene trees identified at least 14 instances of lateral gene transfer (LGT) that had occurred among diverse microbes. Results from bootstrapped supported nodes indicated that (i) a majority of the transfers occurred among proteobacteria, most likely due to the phylogenetic relatedness of these organisms, and (ii) gram-positive bacteria with low moles percent G+C were often involved in instances of LGT. These results, together with our earlier work on the occurrence of LGT in subsurface bacteria (J. M. Coombs and T. Barkay, Appl. Environ. Microbiol. 70:1698-1707, 2004), indicate that LGT has had a minor role in the evolution of PIB-type ATPases, unlike other genes that specify survival in metal-stressed environments. This study demonstrates how examination of a specific locus across microbial genomes can contribute to the understanding of phenotypes that are critical to the interactions of microbes with their environment.

scholarly journals Transcriptomics provides a robust framework for the relationships of the major clades of cladobranch sea slugs (Mollusca, Gastropoda, Heterobranchia), but fails to resolve the position of the enigmatic genus Embletonia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dario Karmeinski ◽  
Karen Meusemann ◽  
Jessica A. Goodheart ◽  
Michael Schroedl ◽  
Alexander Martynov ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Evolutionary History ◽  
Phylogenetic Signal ◽  
Set Covering ◽  
Phylogenetic Position ◽  
Data Sets ◽  
Transcriptome Data ◽  
Data Set ◽  
Sea Slugs ◽  
History Of

Abstract Background The soft-bodied cladobranch sea slugs represent roughly half of the biodiversity of marine nudibranch molluscs on the planet. Despite their global distribution from shallow waters to the deep sea, from tropical into polar seas, and their important role in marine ecosystems and for humans (as targets for drug discovery), the evolutionary history of cladobranch sea slugs is not yet fully understood. Results To enlarge the current knowledge on the phylogenetic relationships, we generated new transcriptome data for 19 species of cladobranch sea slugs and two additional outgroup taxa (Berthella plumula and Polycera quadrilineata). We complemented our taxon sampling with previously published transcriptome data, resulting in a final data set covering 56 species from all but one accepted cladobranch superfamilies. We assembled all transcriptomes using six different assemblers, selecting those assemblies that provided the largest amount of potentially phylogenetically informative sites. Quality-driven compilation of data sets resulted in four different supermatrices: two with full coverage of genes per species (446 and 335 single-copy protein-coding genes, respectively) and two with a less stringent coverage (667 genes with 98.9% partition coverage and 1767 genes with 86% partition coverage, respectively). We used these supermatrices to infer statistically robust maximum-likelihood trees. All analyses, irrespective of the data set, indicate maximal statistical support for all major splits and phylogenetic relationships at the family level. Besides the questionable position of Noumeaella rubrofasciata, rendering the Facelinidae as polyphyletic, the only notable discordance between the inferred trees is the position of Embletonia pulchra. Extensive testing using Four-cluster Likelihood Mapping, Approximately Unbiased tests, and Quartet Scores revealed that its position is not due to any informative phylogenetic signal, but caused by confounding signal. Conclusions Our data matrices and the inferred trees can serve as a solid foundation for future work on the taxonomy and evolutionary history of Cladobranchia. The placement of E. pulchra, however, proves challenging, even with large data sets and various optimization strategies. Moreover, quartet mapping results show that confounding signal present in the data is sufficient to explain the inferred position of E. pulchra, again leaving its phylogenetic position as an enigma.

The Politics of Territorial Claims: A Geospatial Approach Applied to Africa

2016 ◽  
Vol 71 (1) ◽  
pp. 31-64 ◽  
Author(s):  
Hein E. Goemans ◽  
Kenneth A. Schultz
Keyword(s):  
Ethnic Groups ◽  
Colonial Period ◽  
Geospatial Data ◽  
Minor Role ◽  
Data Set ◽  
Secondary Role ◽  
Border Areas ◽  
Territorial Claims ◽  
A Minor ◽  
Analysis Of Variation

AbstractWhy do states make claims to some border areas and not others? We articulate three models of territorial claims and test them using a novel geospatial data set that precisely maps disputed and undisputed border segments in post-independence Africa. The geospatial approach helps eliminate problems of aggregation by permitting an analysis of variation both within and between dyadic borders. We find that ethnic political considerations are the most important driver of territorial claims in Africa, while institutional features of the border play a secondary role. Border segments that partition ethnic groups are at greatest risk of being challenged when the partitioned groups are politically powerful in ethnically homogeneous societies. Border segments that follow well-established and clear focal principles such as rivers and watersheds are significantly less likely to be disputed, while changes to the border in the colonial period created opportunities for later disputes to arise. Power considerations or resources play only a minor role in explaining the location of territorial claims.

scholarly journals The Power of Shop Culture

1992 ◽  
Vol 37 (3) ◽  
pp. 350-375 ◽  
Author(s):  
Erik Olssen ◽  
Jeremy Brecher
Keyword(s):  
Social Relations ◽  
Large Scale ◽  
Scientific Management ◽  
The Political ◽  
Minor Role ◽  
Skilled Workers ◽  
Labour Process ◽  
History Of ◽  
Hiring And Firing ◽  
A Minor

SummaryThis paper investigates the history of the labour process in New Zealand's state-owned railway workshops and questions the idea that large-scale industry inevitably destroyed whatever agency skilled workers had enjoyed. It also shows that relations of production vary with the political and cultural contexts. Craft control of the labour process survived in New Zealand's state-owned railway workshops and the union played only a minor role. Jop control was more important in achieving bureaucratic instead of autocratic control over such matters as hiring and firing; the retention of apprentice-based crafts; the institutionalization of seniority; and in resisting both de-skilling and the “premium bonus”. The strength and vitality of shop culture, based on craft control of the labour process, also survived and modified the Government's vigorous attempt to introduce “scientific management”. In brief the article concludes that productive processes do not inevitably determine social relations of production, that capitalism has been neither homogeneous nor uniform, and that mechanization never inevitably results in de-skilling.

scholarly journals LIMINAL CRAFT, EXCEPTIONAL LAW: PRELIMINARY NOTES ON MIDWIVES IN MEDIEVAL ISLAMIC WRITINGS

2010 ◽  
Vol 42 (2) ◽  
pp. 202a-202a ◽  
Author(s):  
Avner Giladi
Keyword(s):  
Islamic Law ◽  
Formative Period ◽  
Minor Role ◽  
Ongoing Research ◽  
Legal Rules ◽  
Legal Texts ◽  
History Of ◽  
Ambivalent Attitude ◽  
The Moment ◽  
A Minor

In this article, the first fruit of an ongoing research on the sociocultural history of midwifery in medieval Muslim societies, I trace the attitudes toward midwives as revealed in Arabic biographical, medical, and legal texts. These texts, the product of male scholars, mirror an ambivalent attitude toward midwives: a mixture of repressed admiration, open repulsion, and fear. Thus, midwives are almost totally absent from Islamic scriptures, and Muslim writers make them play only a minor role in biographical and hagiographic literature, where the midwives of the Prophet's family are consciously or unconsciously “blocked” from becoming mythological figures. Women, sometimes hesitatingly identified as midwives, nevertheless played a role through their very presence at the moment of the Prophet's birth. In a storylike manner, they set an example for the implication of the legal rules concerning the midwife's exceptional status as a witness in court, rules that were formulated and consolidated in the formative period of Islamic law side by side with the traditions on the Prophet Muhammad's birth.

The skeletal morphology of the solemydid turtleNaomichelys speciosafrom the Early Cretaceous of Texas

2014 ◽  
Vol 88 (6) ◽  
pp. 1257-1287 ◽  
Author(s):  
Walter G. Joyce ◽  
Juliana Sterli ◽  
Sandra D. Chapman
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Lower Cretaceous ◽  
Fossil Record ◽  
Posterior Margin ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Ventral View ◽  
Skeletal Morphology ◽  
History Of

The fossil record of solemydid turtles is primarily based on isolated fragments collected from Late Jurassic to Late Cretaceous sediments throughout North America and Europe and little is therefore known about the morphology and evolutionary history of the group. We here provide a detailed description of the only known near-complete solemydid skeleton, which was collected from the Lower Cretaceous (Aptian–Albian) Antlers Formation of Texas during the mid-twentieth century, but essentially remains undescribed to date. Though comparison is limited, the skeleton is referred toNaomichelys speciosa, which is based on an isolated entoplastron from the Lower Cretaceous (Aptian–Albian) Kootenai (Cloverly) Formation of Montana. The absence of temporal emarginations, contribution of the jugals to the orbits, and a clear subdivision of the middle and inner cavities, and the presence of elongate postorbitals, posteriorly expanded squamosals, a triangular fossa at the posterior margin of the squamosals, an additional pair of tubercula basioccipitale that is formed by the pterygoids, foramina pro ramo nervi vidiani (VII) that are visible in ventral view, shell sculpturing consisting of high tubercles, a large entoplastron with entoplastral scute, V-shaped anterior peripherals, and limb osteoderms with tubercular sculpture diagnoseNaomichelys speciosaas a representative of Solemydidae. The full visibility of the parabasisphenoid complex in ventral view, the presence of an expanded symphyseal shelf, and the unusual ventromedial folding of the coronoid process are the primary characteristics that distinguishNaomichelys speciosafrom the near-coeval European taxonHelochelydra nopcsai.

scholarly journals Expanded Multilocus Sequence Typing and Comparative Genomic Hybridization of Campylobacter coli Isolates from Multiple Hosts

2010 ◽  
Vol 76 (6) ◽  
pp. 1913-1925 ◽  
Author(s):  
Ping Lang ◽  
Tristan Lefebure ◽  
Wei Wang ◽  
Paulina Pavinski Bitar ◽  
Richard J. Meinersmann ◽  
...  
Keyword(s):  
Comparative Genomic Hybridization ◽  
Host Species ◽  
Multilocus Sequence Typing ◽  
Evolutionary History ◽  
Comparative Genomic ◽  
Campylobacter Coli ◽  
Genomic Hybridization ◽  
Data Set ◽  
History Of ◽  
Microarray Comparative Genomic Hybridization

ABSTRACT The purpose of this work was to evaluate the evolutionary history of Campylobacter coli isolates derived from multiple host sources and to use microarray comparative genomic hybridization to assess whether there are particular genes comprising the dispensable portion of the genome that are more commonly associated with certain host species. Genotyping and ClonalFrame analyses of an expanded 16-gene multilocus sequence typing (MLST) data set involving 85 isolates from 4 different hosts species tentatively supported the development of C. coli host-preferred groups and suggested that recombination has played various roles in their diversification; however, geography could not be excluded as a contributing factor underlying the history of some of the groups. Population genetic analyses of the C. coli pubMLST database by use of STRUCTURE suggested that isolates from swine form a relatively homogeneous genetic group, that chicken and human isolates show considerable genetic overlap, that isolates from ducks and wild birds have similarity with environmental water samples and that turkey isolates have a connection with human infection similar to that observed for chickens. Analysis of molecular variance (AMOVA) was performed on these same data and suggested that host species was a significant factor in explaining genetic variation and that macrogeography (North America, Europe, and the United Kingdom) was not. The microarray comparative genomic hybridization data suggested that there were combinations of genes more commonly associated with isolates derived from particular hosts and, combined with the results on evolutionary history, suggest that this is due to a combination of common ancestry in some cases and lateral gene transfer in others.

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