نتایج جستجو برای: campanian maastrichtian
تعداد نتایج: 973 فیلتر نتایج به سال:
in present study, diversity and relative abundance of calcareous nannofossils of the boundary between abtalkh and neyzar formations in dobaradar, kalat and chahchaheh sections were studied. taxonomical studies of calcareous nannofossils in the studied areas led to identification of 24 species in dobaradar, 27 species in kalat and 32 species in chahchaheh sections. based on identified nannofossi...
A new crocodyliform from the Upper Cretaceous (Campanian-Maastrichtian) Presidente Prudente Formation of the Bauru Group is described based on two almost complete skulls and mandibles. The material comes from the "Tartaruguito" site, situated at an old railroad between the cities of Pirapozinho and Presidente Prudente, state of São Paulo, Brazil. The new species, Pepesuchus deiseae gen. et sp. ...
The skeletal record of tyrannosaurids is well-documented, whereas their footprint record is surprisingly sparse. There are only a few isolated footprints attributed to tyrannosaurids and, hitherto, no reported trackways. We report the world's first trackways attributable to tyrannosaurids, and describe a new ichnotaxon attributable to tyrannosaurids. These trackways are from the Upper Cretaceou...
Angiosperms evolved rapidly in the late Mesozoic. Data from the genetic-based approach called ’molecular clock’ permit an evaluation of the radiation of flowering plants through geological time and of the possible influences of Mesozoic mass extinctions. A total of 261 divergence ages of angiosperm families are considered. The radiation of flowering plants peaked in the Albian, early Campanian,...
Dinosaur remains from the Arabian subcontinent are exceedingly rare, and those that have been documented manifest indeterminate affinities. Consequently the discovery of a small, but diagnostic, accumulation of elements from Campanian-Maastrichtian (~ 75 Ma) deposits in northwestern Saudi Arabia is significant because it constitutes the first taxonomically identifiable dinosaur material describ...
The cranial anatomy of the flat-skulled hadrosaurine Edmontosaurus regalis (Ornithischia: Hadrosauridae) is extensively described here, based on the holotype and paratype collected from the middle part of the Horseshoe Canyon Formation in southern Alberta. Focus is given to previously undocumented features of ontogenetic and phylogenetic importance. This description facilitates overall osteolog...
Adercotryma glomeratum is one of the most geographically and bathymetrically widespread species of Recent deep-sea benthic foraminifera, but the evolutionary history of this distinct agglutinated species is poorly known. In addition to one or two Recent species probably closely related to A. glomeratum, the Eocene-Oligocene species Adercotryma agterbergi has been described, but we suggest that ...
Chemistry of detrital garnets, chrome spinels and tourmalines of 30 selected samples in combination with the general heavy mineral distribution from 523 sandstone samples of the Upper Cretaceous to Eocene Gosau Group of the eastern part of the Eastern Alps and the western West Carpathians result in an advanced picture of sedimentary provenance and palaeogeographic evolution of that area. Garnet...
Pterosaur fossils from the Campanian-Maastrichtian of North America have been reported from the continental interior, but few have been described from the west coast. The first pterosaur from the Campanian Northumberland Formation (Nanaimo Group) of Hornby Island, British Columbia, is represented here by a humerus, dorsal vertebrae (including three fused notarial vertebrae), and other fragments...
In the present study, Kabir kuh Section, related to the Seymareh or Lopha Limestone member (Gurpi Formation) have been Selected. The member has yielded a rich echinoid fauna and 21 species of Echinoid belonging to 14 genera are recognized and described. The Kabir Kuh section yielded two regular echinoid taxa: Salenia nutrix and Goniopygus superbus, one holectypoid taxa: Coptodiscus noemiae, two...
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