نتایج جستجو برای: aptian
تعداد نتایج: 457 فیلتر نتایج به سال:
The fossil record of the turtle clade Baenidae ranges from the Early Cretaceous (Aptian–Albian) to the Eocene. The group is present throughout North America during the Early Cretaceous, but is restricted to the western portions of the continents in the Late Cretaceous and Paleogene. No credible remains of the clade have been reported outside of North America to date. Baenids were warmadapted fr...
The historical view of a uniformly warm Cretaceous is being increasingly challenged by the accumulation of new data hinting at the possibility of glacial events, even during the Cenomanian-Turonian (∼95 Myr ago), the warmest interval of the Cretaceous. Here we show that the palaeogeography typifying the Cenomanian-Turonian renders the Earth System resilient to glaciation with no perennial ice a...
The timing of flood basalt volcanism associated with formation of the Ontong Java Plateau (OJP) is estimated from paleomagnetic and paleontologic data. Much of OJP formed rapidly in less than 3 million years during the early Aptian, at the beginning of the Cretaceous Normal Polarity Superchron. Crustal emplacement rates are inferred to have been several times those of the Deccan Traps. These es...
The new taxon Paraclausastrea vorarlbergensis sp. nov. is described from the upper Barremian-lower Aptian (Schrattenkalk Fm.) of western Austria (Vorarlberg). It belongs to the montlivaltiids and is characterized by thamnasterioid to submeandroid corallite integration, diameters of corallites ranging between 3 and 6.5 mm, and septa that are generally developed in 4 incomplete cycles in 6 genera...
in this study, calcareous nannofossils at the boundary between tirgan and sarcheshmeh formations at taherabad and mozduran sections have been studied. these sections are located in the eastern kopet-dagh basin. 22 nannoplankton species of 14 genera in taherabad section and 20 species of 14 genera in mozduran section were identified. according to the first occurrence of index species and fossil ...
A new species of cassiduloid echinoids, Pygaulus baghinensis is reported for the first time from Aptian sediments of Baghin area, west of Kerman, Iran. The diagnostic features of the species are centrally positioned of the apical disc and approximately low profile of the test. Variation in gonopore size in different individuals allows to conclude that P. baghinensis is sexually dimorphic. Speci...
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