نتایج جستجو برای: lower cretaceous

تعداد نتایج: 699157  

2013
Darren Naish Martin Simpson Gareth Dyke

BACKGROUND Pterosaurs have been known from the Cretaceous sediments of the Isle of Wight (southern England, United Kingdom) since 1870. We describe the three-dimensional pelvic girdle and associated vertebrae of a small near-adult pterodactyloid from the Atherfield Clay Formation (lower Aptian, Lower Cretaceous). Despite acknowledged variation in the pterosaur pelvis, previous studies have not ...

During the recent field research on the Tirgan Formation in the west of Kopet-Dagh sedimentary basin, ammonite assemblages were obtained from the carbonate strata of this formation. This new finding is important for stratigraphical purpose. In this research, 3 genera belong to Heteroceras, Deshayesites and Cheloniceras? as well as one uncertain genus belongs to Turkmeniceras are determined. The...

Journal: :زمین شناسی اقتصادی 0
محمد حسن کریم پور آزاده ملکزاده شفارودی محراب مرادی نقندر جی لنگ فارمر چارلز استرن

kalateh ahani is located 27 km southeast of gonabad within the khorasan razavi province. the area is part of lut block. sub-volcanic monzonitic rocks intruded regional metamorphosed shemshak formation (jurassic age). magnetic susceptibility of less altered monzonitic rocks is 0.6%., as, pb and zn > 1%, au up to 150 ppb and sn = 133 ppm. the sn content of vein in the northern part of kalateh aha...

2016
Stephen F. Poropat Philip D. Mannion Paul Upchurch Scott A. Hocknull Benjamin P. Kear Martin Kundrát Travis R. Tischler Trish Sloan George H. K. Sinapius Judy A. Elliott David A. Elliott

Australian dinosaurs have played a rare but controversial role in the debate surrounding the effect of Gondwanan break-up on Cretaceous dinosaur distribution. Major spatiotemporal gaps in the Gondwanan Cretaceous fossil record, coupled with taxon incompleteness, have hindered research on this effect, especially in Australia. Here we report on two new sauropod specimens from the early Late Creta...

2017
Sathish A. Nallapa Reddy

The rock strata of Cretaceous sedimentary system represented by Aptian to Maastrichtian age occurs as isolated patches outcropping in the western margin of the Cauvery Basin bordering the Archaean granite and gneiss basement. The Cretaceous system is well known as “Cretaceous of Trichinopoly” containing diverse fauna and flora including dinosaur remains, commercially exploitable limestone, lign...

2014
S. A. Price L. Schmitz C. E. Oufiero R. I. Eytan A. Dornburg W. L. Smith M. Friedman T. J. Near P. C. Wainwright

Living reef fishes are one of the most diverse vertebrate assemblages on Earth. Despite its prominence and ecological importance, the origins and assembly of the reef fish fauna is poorly described. A patchy fossil record suggests that the major colonization of reef habitats must have occurred in the Late Cretaceous and early Palaeogene, with the earliest known modern fossil coral reef fish ass...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2000
D Grimaldi D Agosti

A worker ant preserved with microscopic detail has been discovered in Turonian-aged New Jersey amber [ca. 92 mega-annum (Ma)]. The apex of the gaster has an acidopore and, thus, allows definitive assignment of the fossil to the large extant subfamily Formicinae, members of which use a defensive spray of formic acid. This specimen is the only Cretaceous record of the subfamily, and only two othe...

Journal: :Proceedings. Biological sciences 2004
Paul C Sereno Jeffrey A Wilson Jack L Conrad

Abelisauroid predators have been recorded almost exclusively from South America, India and Madagascar, a distribution thought to document persistent land connections exclusive of Africa. Here, we report fossils from three stratigraphic levels in the Cretaceous of Niger that provide definitive evidence that abelisauroid dinosaurs and their immediate antecedents were also present on Africa. The f...

2016
Wei Wang Li Lin Xiao-Guo Xiang Rosa del C. Ortiz Yang Liu Kun-Li Xiang Sheng-Xiang Yu Yao-Wu Xing Zhi-Duan Chen

The rise of angiosperms has been regarded as a trigger for the Cretaceous revolution of terrestrial ecosystems. However, the timeframe of the rise angiosperm-dominated herbaceous floras (ADHFs) is lacking. Here, we used the buttercup family (Ranunculaceae) as a proxy to provide insights into the rise of ADHFs. An integration of phylogenetic, molecular dating, ancestral state inferring, and dive...

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