نتایج جستجو برای: gondwanaland
تعداد نتایج: 101 فیلتر نتایج به سال:
The biogeographical history of major groups of bees with worldwide distributions have often been explained through hypotheses based on Gondwanan vicariance or long distance dispersal events, but until recently these hypotheses have been very difficult, if not impossible, to distinguish. New fossil data, comprehensive information on Mesozoic and Cenozoic coastline positions and the availability ...
Cladistic analyses of plastid DNA sequences rbcL and trnL-F are presented separately and combined for 48 genera of Amaryllidaceae and 29 genera of related asparagalean families. The combined analysis is the most highly resolved of the three and provides good support for the monophyly of Amaryllidaceae and indicates Agapanthaceae as its sister family. Alliaceae are in turn sister to the Amarylli...
Ticks are monophyletic and composed of the hard (Ixodidae) and soft (Argasidae) tick families, as well as the Nuttalliellidae, a family with a single species, Nuttalliella namaqua. Significant biological differences in lifestyle strategies for hard and soft ticks suggest that various blood-feeding adaptations occurred after their divergence. The phylogenetic relationships between the tick famil...
The basal Cambrian sandstone unit in the North China craton (NCC) is an example of globally widespread siliciclastic succession that resides on Great Unconformity and deposited a hypothesized low-lying peneplain during global eustatic sea-level rise. Detrital zircon age signatures from this distinct sequence enable recognition ancient drainage system NCC deep time track its potential linkage wi...
The Pacific margin of East Antarctica records a long tectonic history of crustal growth and breakup, culminating in the early Paleozoic Ross Orogeny associated with Gondwanaland amalgamation. Periods of older tectonism have been proposed (e.g. Precambrian Nimrod and Beardmore Orogenies), but the veracity of these events is difficult to document because of poor petrologic preservation, geochrono...
One of the traditional enigmas in freshwater zoogeography has been the evolutionary origin of Scleropages formosus inhabiting Southeast Asia (the Asian arowana), which is a species threatened with extinction among the highly freshwater-adapted fishes from the order Osteoglossiformes. Dispersalists have hypothesized that it originated from the recent (the Miocene or later) transmarine dispersal ...
The landforms and landscapes discussed in this book developed in a variety of terrains, which together express the diversity of the geological background of the Brazilian territory. Located essentially in the old and relatively stable nucleus of the South American plate (known as the South American platform), Brazil comprises seven major categories of tectonic units, which are as follows: crato...
SINCE THE l6TH CENTURY, CARTOGRAPHERS HAVE NOTICED THE jigsaw-puzzle fit of the continental edges. Since the 19th century, geologists have known that some fossil plants and animals are extraordinarily similar across the globe, and some sequences of rock formations in distant continents are also strikingly alike. At the turn of the 20th century, Austrian geologist Eduard Suess proposed the theor...
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