scholarly journals A Review of the Fossil record of Gymnophiona (Tetrapoda; Lissamphibia) with Comments on Its Use to Calibrate Molecular Timetrees

2020 ◽  
Author(s):  
Rodolfo Otávio Santos ◽  
Michel Laurin ◽  
Hussam Zaher
Keyword(s):  
South America ◽  
Geographic Distribution ◽  
Fossil Record ◽  
Future Research ◽  
Time Range ◽  
Geological Time ◽  
Origin And Evolution ◽  
North And South America ◽  
North And South

Gymnophiona, the most poorly known group of extant amphibians, includes elongated limbless tetrapods, with compact ossified skulls and reduced eyes, mainly adapted to fossorial life (only the Typhlonectidae exhibits adaptations for an aquatic or semiaquatic behavior). Caecilians are poorly represented in the fossil record, and despite the low number of fossil specimens described until now (only four taxa, in addition to indeterminate fragmentary material), their fossils play a key role in the knowledge of Lissamphibia origin and evolution, as well as contribute directly to a better understanding of phylogeny, taxonomy and biogeography of extant gymnophionan taxa. These records are scattered throughout geological time (from the Jurassic to the Neogene) and space (they are represented only on North and South America and Africa). Here, we revisit the caecilian fossil record, providing a brief description of all known extinct taxa described so far, along with general remarks about their impact on systematics, time range and geographic distribution of the clade, as well as prospects for future research. Possible calibration constraints based on the caecilian fossil record are provided.

scholarly journals A review of the fossil record of caecilians (Lissamphibia: Gymnophionomorpha) with comments on its use to calibrate molecular timetrees

2020 ◽  
Vol 131 (4) ◽  
pp. 737-755
Author(s):  
Rodolfo Otávio Santos ◽  
Michel Laurin ◽  
Hussam Zaher
Keyword(s):  
South America ◽  
Geographical Distribution ◽  
Fossil Record ◽  
Future Research ◽  
Time Range ◽  
Geological Time ◽  
Origin And Evolution ◽  
Major Taxon ◽  
North And South America ◽  
North And South

Abstract Gymnophiona, popularly known as caecilians, the most poorly known major taxon of extant amphibians, are elongate and limbless tetrapods, with compact ossified skulls and reduced eyes, mainly adapted to fossorial life as adults. Caecilians are poorly represented in the fossil record, but despite the scarcity of fossil specimens described (only four named taxa, in addition to indeterminate fragmentary material), their fossils play a key role in our knowledge of the origin and evolution of Lissamphibia, as well as contribute directly to a better understanding of the phylogeny, taxonomy and biogeography of extant gymnophionan taxa. These records are scattered throughout geological time (from the Jurassic to the sub-Recent) and space (North and South America and Africa). Here, we revisit the caecilian fossil record, providing a brief description of all known extinct taxa described so far, along with general remarks about their impact on systematics, time range, and geographical distribution of the clade, as well as prospects for future research. Possible calibration constraints based on the caecilian fossil record are provided.

scholarly journals Biogeography of Neotropical Meliaceae: geological connections, fossil and molecular evidence revisited

2021 ◽  
Author(s):  
Alexandra N. Muellner-Riehl ◽  
Blanca M. Rojas-Andrés
Keyword(s):  
North America ◽  
South America ◽  
Fossil Record ◽  
Central American ◽  
Molecular Evidence ◽  
Geological Evidence ◽  
North Central ◽  
Modern Distribution ◽  
North And South America ◽  
North And South

AbstractWe here provide, first, a general introduction into the woody angiosperm family Meliaceae, including updated numbers of the genera and species found in different parts of the globe, paying attention to geographic centres of diversity and patterns of endemism. Second, and more specifically, we review the latest literature concerning land connections (i) between Eurasia and North America, (ii) between North America and South America, as well as (iii) dispersal paths between Africa and South America that have existed since the proposed evolutionary origin of modern Meliaceae, i.e. from the Upper Cretaceous onwards (ca. 100 Million years ago). Comparing geological evidence with the fossil record as well as biogeographic studies, there is indication that the nowadays pantropically distributed family has made use of all these three routes. Five out of the eight modern Neotropical genera have a fossil record, namely Carapa Aubl., Cedrela P. Browne, Guarea F. Allam., Swietenia Jacq., and Trichilia P. Browne. Carapa and Trichilia have a modern transatlantic disjunction (distribution in Africa, Central and South America), and a fossil record in Africa and North/Central America (Trichilia), or Africa and Eurasia (Carapoxylon). Cedrela has a rich fossil record in Eurasia and the Americas. The global decrease in temperatures and a lack of Cedrela fossils in North America from the Late Miocene onwards suggest the genus had gone extinct there by that time, leading to its modern distribution in Central and South America. Oligocene to Pliocene fossils of Guarea, Swietenia and Trichilia in Central American key regions support biotic interchange between North and South America at various times.

scholarly journals Coleções osteológicas identificadas: importância para a antropologia

2019 ◽  
Author(s):  
Ana Luisa Santos
Keyword(s):  
Nineteenth Century ◽  
South America ◽  
History Of Medicine ◽  
Human Evolution ◽  
Geographic Distribution ◽  
Continuous Development ◽  
History Of ◽  
North And South America ◽  
Number Of Individuals ◽  
North And South

One of the main pillars of bioanthropological studies are the identified osteological collections. The goal of this document is to describe this heritage and show its importance. Since the nineteenth century, several countries have collected sets of skulls and skeletons from people about whom we know some biographical data; among other details, their age when they died and their sex. There are currently around fifty collections in different countries of North and South America, Africa, Europe, and Asia. Researching into them has applications for the study of human evolution, past populations, palaeopathology, and the history of medicine, among others. The need to increase the number of individuals and extend the geographic distribution of samples leads to the continuous development of these collections.

IV.—The Geological Development, Descent and Distribution of the Mammalia

1893 ◽  
Vol 10 (9) ◽  
pp. 401-412 ◽  
Author(s):  
Karl A. von Zittel
Keyword(s):  
South America ◽  
The Past ◽  
Limited Experience ◽  
The World ◽  
Relationship Of ◽  
North And South America ◽  
The Relationship ◽  
North And South ◽  
Animal World

In a spirited treatise on the ‘Origin of our Animal World’ Prof. L. Rütimeyer, in the year 1867, described the geological development and distribution of the mammalia, and the relationship of the different faunas of the past with each other and with that now existing. Although, since the appearance of that masterly sketch the palæontological material has been, at least, doubled through new discoveries in Europe and more especially in North and South America, this unexpected increase has in most instances only served as a confirmation of the views which Rutimeyer advanced on more limited experience. At present, Africa forms the only great gap in our knowledge of the fossil mammalia; all the remaining parts of the world can show materials more or less abundantly, from which the course followed by the mammalia in their geological development can be traced with approximate certainty.

Transatlantic Radicalism

2021 ◽  
Keyword(s):  
South America ◽  
Atlantic Ocean ◽  
Case Studies ◽  
Individual Case ◽  
History Of ◽  
Late Nineteenth ◽  
Organizational Ties ◽  
North And South America ◽  
North And South ◽  
Political Radicalism

The Atlantic Ocean not only connected North and South America with Europe through trade but also provided the means for an exchange of knowledge and ideas, including political radicalism. Socialists and anarchists would use this “radical ocean” to escape state prosecution in their home countries and establish radical milieus abroad. However, this was often a rather unorganized development and therefore the connections that existed were quite diverse. The movement of individuals led to the establishment of organizational ties and the import and exchange of political publications between Europe and the Americas. The main aim of this book is to show how the transatlantic networks of political radicalism evolved with regard to socialist and anarchist milieus and in particular to look at the actors within the relevant processes—topics that have so far been neglected in the major histories of transnational political radicalism of the late nineteenth and early twentieth centuries. Individual case studies are examined within a wider context to show how networks were actually created, how they functioned and their impact on the broader history of the radical Atlantic.

scholarly journals Modelling tree ring cellulose <i>δ</i><sup>18</sup>O variations in two temperature-sensitive tree species from North and South America

2017 ◽  
Vol 13 (11) ◽  
pp. 1515-1526 ◽  
Author(s):  
Aliénor Lavergne ◽  
Fabio Gennaretti ◽  
Camille Risi ◽  
Valérie Daux ◽  
Etienne Boucher ◽  
...  
Keyword(s):  
South America ◽  
Isotopic Fractionation ◽  
Circulation Model ◽  
Effect Of Temperature ◽  
Temperature Sensitive ◽  
Nothofagus Pumilio ◽  
Climate Signal ◽  
North And South America ◽  
North And South ◽  
Two Temperature

Abstract. Oxygen isotopes in tree rings (δ18OTR) are widely used to reconstruct past climates. However, the complexity of climatic and biological processes controlling isotopic fractionation is not yet fully understood. Here, we use the MAIDENiso model to decipher the variability in δ18OTR of two temperature-sensitive species of relevant palaeoclimatological interest (Picea mariana and Nothofagus pumilio) and growing at cold high latitudes in North and South America. In this first modelling study on δ18OTR values in both northeastern Canada (53.86° N) and western Argentina (41.10° S), we specifically aim at (1) evaluating the predictive skill of MAIDENiso to simulate δ18OTR values, (2) identifying the physical processes controlling δ18OTR by mechanistic modelling and (3) defining the origin of the temperature signal recorded in the two species. Although the linear regression models used here to predict daily δ18O of precipitation (δ18OP) may need to be improved in the future, the resulting daily δ18OP values adequately reproduce observed (from weather stations) and simulated (by global circulation model) δ18OP series. The δ18OTR values of the two species are correctly simulated using the δ18OP estimation as MAIDENiso input, although some offset in mean δ18OTR levels is observed for the South American site. For both species, the variability in δ18OTR series is primarily linked to the effect of temperature on isotopic enrichment of the leaf water. We show that MAIDENiso is a powerful tool for investigating isotopic fractionation processes but that the lack of a denser isotope-enabled monitoring network recording oxygen fractionation in the soil–vegetation–atmosphere compartments limits our capacity to decipher the processes at play. This study proves that the eco-physiological modelling of δ18OTR values is necessary to interpret the recorded climate signal more reliably.

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