نتایج جستجو برای: middle eocene

تعداد نتایج: 158502  

Journal: :journal of sciences, islamic republic of iran 2015
y. ghasemi pour afshar m-r. vaziri m. dastanpour a. lotfabad arab

the spatangoid genus schizaster agassiz is recorded, for the first time, from the lutetian (middle eocene) deposits of sargaz area, south of kerman, iran. the lutetian sediments of sargaz region contain a rich and divers echinoid fauna represented by cidaridae, conoclypeidae, echinolampadidae, toxopneustidae, phymosomatidae and schizasteridae. schizasteroid echinoids are an important component ...

2006
Philip F. Sexton Paul A. Wilson Richard D. Norris

[1] Until recently, very few high-quality deep ocean sedimentary sections of Eocene age have been available. Consequently, our understanding of Eocene paleoceanography has become heavily reliant on ‘‘composite’’ records patched together from multiple sites in different ocean basins and generated using multiple taxa (potential sources of ‘‘local’’ noise in the global signal). Here we test the re...

2018
Gabriela J Arreguín-Rodríguez Ellen Thomas Simon D'haenens Robert P Speijer Laia Alegret

The early Eocene greenhouse world was marked by multiple transient hyperthermal events. The most extreme was the Paleocene-Eocene Thermal Maximum (PETM, ~56 Ma), linked to the extinction of the globally recognised deep-sea benthic foraminiferal Velasco fauna, which led to the development of early Eocene assemblages. This turnover has been studied at high resolution, but faunal development into ...

2014
Jaelyn J. Eberle Michael D. Gottfried J. Howard Hutchison Christopher A. Brochu

BACKGROUND Discovery of Eocene non-marine vertebrates, including crocodylians, turtles, bony fishes, and mammals in Canada's High Arctic was a critical paleontological contribution of the last century because it indicated that this region of the Arctic had been mild, temperate, and ice-free during the early - middle Eocene (∼53-50 Ma), despite being well above the Arctic Circle. To date, these ...

Journal: :Science 1983
G Keller S D'Hondt T L Vallier

Microtektites have been recovered from three horizons in eight middle Eocene to middle Oligocene marine sediment sequences. Five of these occurrences are coeval and of latest Eocene age (37.5 to 38.0 million years ago); three are coeval and of early late Eocene age (38.5 to 39.5 million years ago); and three are of middle Oligocene age (31 to 32 million years ago). In addition, rare probable mi...

2003
A. Hope Leonel Silveira Lobo Sternberg

Note: MAT—mean annual temperature; CMM—cold month mean temperature; NLR—nearest living relative analogy; CLAMP—climate–leaf analysis multivariate program. ABSTRACT The exquisite preservation of fossilized Metasequoia trees that grew near 808N latitude during the middle Eocene (ca. 45 Ma) in Nunavut, Canada, allowed for dD and d18O analyses of cellulose, techniques previously restricted to wood ...

2002
Carlos A. Jaramillo

—The late Paleocene-early Eocene transition was characterized by a long period of global warming that culminated with the highest temperatures of the Cenozoic. This interval is associated with a significant increase in plant diversity in temperate latitudes. However, data from tropical regions remain largely unknown. The record of pollen and spore diversity across the late Paleocene to the earl...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2001
P Wilf C C Labandeira K R Johnson P D Coley A D Cutter

Insect damage on fossil leaves from the Central Rocky Mountains, United States, documents the response of herbivores to changing regional climates and vegetation during the late Paleocene (humid, warm temperate to subtropical, predominantly deciduous), early Eocene (humid subtropical, mixed deciduous and evergreen), and middle Eocene (seasonally dry, subtropical, mixed deciduous and thick-leave...

Journal: :Journal of human evolution 2011
E Christopher Kirk Blythe A Williams

Most adapiform primates from North America are members of an endemic radiation of notharctines. North American notharctines flourished during the Early and early Middle Eocene, with only two genera persisting into the late Middle Eocene. Here we describe a new genus of adapiform primate from the Devil's Graveyard Formation of Texas. Mescalerolemur horneri, gen. et sp. nov., is known only from t...

2006
Ellen Thomas

Upper abyssal to lower bathyal benthic foraminifers from ODP Sites 689 (present water depth 2080 m) and 690 (present water depth 2941 m) on Maud Rise (eastern Weddell Sea, Antarctica) are reliable indicators of Maestrichtian through Neogene changes in the deep-water characteristics at high southern latitudes. Benthic foraminiferal faunas were divided into eight assemblages, with periods of faun...

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