نتایج جستجو برای: early aptian

تعداد نتایج: 686306  

Journal: :Fossil Record 2023

Ornithischian dinosaurs have been discovered in Thailand, Laos, and Malaysia. These bird-hipped herbivores remain relatively rare by comparison with saurischian dinosaurs. In the Late Jurassic, stegosaurs basal neornithischians from Thailand showed similarities to Middle-Late Jurassic taxa China. Ornithischians appeared fossil record again during late Early Cretaceous (Aptian-Albian) of Laos. T...

A.L. Arab M.R. Vaziri

The echinoid fauna of Basab area (Aptian), northwest of Kerman, is fairly rich and diverse, represented by Pygaulidae, Acropeltidae, Emiratiidae, Toxasteridae, Holectypidae, Stomechinidae and Saleniidae. Four regular echinoid species, among which three are new, assigned to genus Tetragramma Agassiz, are described and illustrated in the present paper. The new species are Tetragramma basabensis, ...

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 ...

Journal: :Molecular phylogenetics and evolution 2016
Brent A Berger Ricardo Kriebel Daniel Spalink Kenneth J Sytsma

We examine the eudicot order Myrtales, a clade with strong Gondwanan representation for most of its families. Although previous phylogenetic studies greatly improved our understanding of intergeneric and interspecific relationships within the order, our understanding of inter-familial relationships still remains unresolved; hence, we also lack a robust time-calibrated chronogram to address hypo...

2015
Lida Xing Lisa G. Buckley Richard T. McCrea Martin G. Lockley Jianping Zhang Laura Piñuela Hendrik Klein Fengping Wang Peter Dodson

Trace fossils provide the only records of Early Cretaceous birds from many parts of the world. The identification of traces from large avian track-makers is made difficult given their overall similarity in size and tridactyly in comparison with traces of small non-avian theropods. Reanalysis of Wupus agilis from the Early Cretaceous (Aptian-Albian) Jiaguan Formation, one of a small but growing ...

Journal: :Science 1998
Sereno Beck Dutheil Gado Larsson Lyon Marcot Rauhut Sadleir Sidor Varricchio Wilson

Fossils discovered in Lower Cretaceous (Aptian) rocks in the Tenere Desert of central Niger provide new information about spinosaurids, a peculiar group of piscivorous theropod dinosaurs. The remains, which represent a new genus and species, reveal the extreme elongation and transverse compression of the spinosaurid snout. The postcranial bones include blade-shaped vertebral spines that form a ...

Journal: :Basin Research 2022

Atolls are faithful recorders helping us understand eustatic variations, the evolution of carbonate production through time, and changes in magmatic hotspots activity. Several early Cretaceous Mid-Pacific atolls were previously investigated ocean drilling, but due to low quality vintage seismic data available, few spatial constraints exist on their stratigraphic large-scale diagenesis. Here, we...

Journal: :Science 1991
J A Tarduno W V Sliter L Kroenke M Leckie H Mayer J J Mahoney R Musgrave M Storey E L Winterer

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...

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