نتایج جستجو برای: lower cretaceous

تعداد نتایج: 699157  

2002
LYNN M. WALTER

-Isotopic measurements (Sr, O, D) on formation waters from the Alberta Basin have been made, covering a stratigraphic range from Devonian to Upper Cretaceous. These measurements, combined with chemical compositional trends, give evidence for two distinct water regimes. One hydrological regime is composed of waters hosted in Devonian-Lower Cretaceous reservoirs, the other waters from Upper Creta...

Journal: :Proceedings. Biological sciences 2013
Nao Kusuhashi Yukiyasu Tsutsumi Haruo Saegusa Kenji Horie Tadahiro Ikeda Kazumi Yokoyama Kazuyuki Shiraishi

We here describe a new Early Cretaceous (early Albian) eutherian mammal, Sasayamamylos kawaii gen. et sp. nov., from the 'Lower Formation' of the Sasayama Group, Hyogo Prefecture, Japan. Sasayamamylos kawaii is characterized by a robust dentary, a distinct angle on the ventral margin of the dentary at the posterior end of the mandibular symphysis, a lower dental formula of 3-4 : 1 : 4 : 3, a ro...

For the lithostratigraphy and microbiostratigraphical studies, a stratigraphical section (named Dareh-Goshayesh) has selected and is located in southeast of Maragheh city, south of eastern Azerbaijan province in the northwest of Iran. The thickness of successions in the selected stratigraphic section is measured about 223.6 m. The mentioned studied stratigraphic section is composed of two clast...

Journal: :Journal of Geological Research 2012

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1993
R L Cifelli

A mammal from the Early Cretaceous of the western United States, represented by a lower jaw exceptional in its completeness, presents unambiguous evidence of postcanine dental formula in an Early Cretaceous marsupial-like mammal, and prompts a reconsideration of the early evolution of marsupial dental characters. A marsupial postcanine dental formula (three premolars and four molars) and severa...

Abstract Lower Cretaceous carbonate units of the Kuhzation, karstification and dolomitization, studies of 40 samples of these carbonate units indicated aragonite as original mineralogy in closed to semi-closed diagenetic system.

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Nicholas R Longrich Tim Tokaryk Daniel J Field

The effect of the Cretaceous-Paleogene (K-Pg) (formerly Cretaceous-Tertiary, K-T) mass extinction on avian evolution is debated, primarily because of the poor fossil record of Late Cretaceous birds. In particular, it remains unclear whether archaic birds became extinct gradually over the course of the Cretaceous or whether they remained diverse up to the end of the Cretaceous and perished in th...

2013
James I. Kirkland Luis Alcalá Mark A. Loewen Eduardo Espílez Luis Mampel Jelle P. Wiersma

Nodosaurids are poorly known from the Lower Cretaceous of Europe. Two associated ankylosaur skeletons excavated from the lower Albian carbonaceous member of the Escucha Formation near Ariño in northeastern Teruel, Spain reveal nearly all the diagnostic recognized character that define nodosaurid ankylosaurs. These new specimens comprise a new genus and species of nodosaurid ankylosaur and repre...

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