|
|
|
|
| |
|
|
Nahum,Laila Alves; Pereira,Sérgio Luiz; Campos Fernandes,Flora Maria de; Russo Matioli,Sergio; Wajntal,Anita. |
Partial cytochrome b and 12S rDNA mitochondrial DNA sequences of eight representatives of the Ramphastidae family were analyzed. We applied the linearized tree method to identify sequences evolving at similar rates and estimated the divergence times among some of the taxa analyzed. After excluding Ramphastos tucanus and Capito dayi from our data set, the remaining taxa presented a constant rate of DNA substitution, and branch lengths could be re-estimated with a clock constraint using the maximum likelihood method. Branch lengths were calibrated assuming that Galliformes and Piciformes split around 100 million years ago (mya). Our results indicate that Ramphastinae, and probably Capitoninae, diverged from other Piciformes in the Late Cretaceous (~82 mya),... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Divergence times; K/T; Mass extinction; Cytochrome b; 12S rDNA; Paleogeography; Phylogeny. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000400003 |
| |
|
|
Schneider, A.; Panieri, G.; Lepland, A.; Consolaro, C.; Cremiere, A.; Forwick, M.; Johnson, J. E.; Plaza-faverola, A.; Sauer, S.; Knies, J.. |
Multiple proxies in the geological record offshore NW Svalbard track shallow subseafloor diagenesis and seafloor methane seepage during the Last Glacial Maximum (LGM) extent and the disintegration of the Svalbard Barents Sea Ice Sheet (SBIS). Vestnesa Ridge, located at 79°N and in 1200 m water depth, is one of the northernmost known active methane seep sites and is characterised by a subseafloor fluid flow system, numerous seafloor pockmarks and gas flares in the water column. In this study, we develop a Late Pleistocene and Holocene stratigraphic framework, use stable oxygen and carbon isotope signatures (δ18O, δ13C) of benthic and planktic foraminifera, the mineralogical and carbon isotope composition of methane-derived authigenic carbonate (MDAC) and... |
Tipo: Text |
Palavras-chave: Micropaleontology; Foraminifers; Stable isotopes; Methane seepage; Authigenic carbonate; Holocene; Pleistocene; Paleogeography; Deglaciation; Arctic Ocean. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00445/55652/60554.pdf |
| |
|
|
Paumard, Victorien; Zuckmeyer, Eric; Boichard, Robert; Jorry, Stephan; Bourget, Julien; Borgomano, Jean; Maurin, Thomas; Ferry, Jean-noel. |
This study investigates the stratigraphic evolution of the Late Oligocene - Early Miocene carbonate platforms of the Yadana area (offshore Myanmar). Well data, regional 2D and local 3D seismic surveys allow the identification of three shallow-water carbonate platforms (Yadana, 3DF and 3DE) showing various morphologic and stratigraphic patterns influenced by the presence of a paleohigh. The identification of seven seismic sequences in the Yadana area constrains the stratigraphic evolution in three stages: (1) development of aggrading attached and isolated platforms during the Chattian; (2) a period of platform emersion during the Oligocene - Miocene transition; (3) drowning of the smaller buildup (3DE) associated with km-scale backstepping on the large... |
Tipo: Text |
Palavras-chave: Yadana; Carbonate platforms; Oligocene; Miocene; Seismic stratigraphy; Geomorphology; Paleogeography; Control parameters; Burman margin. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00364/47483/47502.pdf |
| |
|
|
Risebrobakken, Bjorg; Andersson, Carin; De Schepper, Stijn; Mcclymont, Erin L.. |
The Pliocene (5.3-2.6Ma) is often described as a relatively stable climatic period, with warm temperatures characterizing high latitudes. New suborbital resolved stable isotope records from Ocean Drilling Program Hole 642B in the eastern Nordic Seas document that the Pliocene was not a stable period characterized by one climate. Rather, seven distinct climate phases, each lasting between 150,000 and 400,000years, are identified and characterized in the time interval 5.1-3.1Ma. Four of the transitions between the defined climate phases occurred close to an eccentricity minimum and a minimum in amplitude of change for Northern Hemisphere summer insolation, while two occurred around an eccentricity maximum and a maximum in amplitude in insolation change.... |
Tipo: Text |
Palavras-chave: Pliocene; Nordic Seas; Stable isotopes; Diagenetic calcite; Paleogeography; External and internal forcing. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00504/61599/65864.pdf |
| |
|
|
Weers, D.J. van. |
Measurements of many hundreds of the high-crowned cheek teeth of Hystrix specimens from the Euro-Asiatic Pleistocene in the collections of European and Asiatic institutions have been compared with extant species for a revision of the genus. A review is given about the extant genera and species of the family. The number of recognisable Euro-Asiatic species in the fossil record is reduced from eight to five. The European H. (A.) vinogradovi Argyropulo, 1941 is here considered to be a synonym of H. (A.) brachyura Linnaeus, 1758, and the three Asiatic species H. (H.) crassidens Lydekker, 1886, H. (H.) gigantea Van Weers, 1985 and H. (H.) magna Pei, 1987 are synonymized with H. (H.) refossa Gervais, 1852. Most of the Chinese fossil specimens are properly... |
Tipo: Article / Letter to the editor |
Palavras-chave: Porcupines; Asia; Evolution; Europe; Paleogeography; Pleistocene; 42.84. |
Ano: 2005 |
URL: http://www.repository.naturalis.nl/record/209654 |
| |
|
| |
|
|
|