نتایج جستجو برای: oligocene
تعداد نتایج: 2183 فیلتر نتایج به سال:
T of woodpeckers and allies (Pici) is very poor, but the members of this group—barbets and toucans (Ramphastidae including “Capitonidae”; see Prum 1988); honeyguides (Indicatoridae); and woodpeckers, wrynecks, and piculets (Picidae)—today have an almost worldwide distribution and occur in most forested habitats (del Hoyo et al. 2002). Paleogene (pre-Miocene; i.e. older than 23 Ma) remains of th...
The marine dO record indicates precipitous cooling or significant expansion of Antarctic ice volume across the Eocene-Oligocene epoch boundary at 33.7 Ma. This climatic step is also found in estimates of decreased paleoprecipitation from paleosols in Oregon, Montana, and Nebraska but is only a part of a long-term decline across the Eocene-Oligocene transition rather than a sudden shift. This su...
The Oligocene Epoch was a time of major radiation of the Odontoceti (echolocating toothed whales, dolphins). Fossils reveal many odontocete lineages and considerable structural diversity, but whether the clades include some crown taxa or only archaic groups is contentious. The New Zealand fossil dolphin "Prosqualodon" marplesi (latest Oligocene, ≥23.9 Ma) is here identified as a crown odontocet...
An apparent mismatch between published oxygen isotopic data and other paleoclimate proxies for the span from 26–16 Ma is resolved by calibration against global sea-level estimates obtained from backstripping continental margin stratigraphy. Ice-volume estimates from calibrated oxygen isotope data compare favorably with stratigraphic and palynological data from Antarctica, and with estimates of ...
Three new species of bibionid flies are described from the late Oligocene deposit of Bes-Konak, Anatolia, Turkey: Bibio anatolicus sp.n., Bibio nigricosta sp.n. and Penthetria beskonakensis sp.n. These genera are associated with temperate climate, contrasting with the bibionid Oligocene fossils from some other European localities with warmer climates, where the intertropical genus Plecia often ...
Paliurus favonii Unger is recognized and described based on fruits from the Oligocene Ningming flora of Guangxi, South China. Characteristics of the present specimens include circular winged fruits that are 10.0-11.5 mm in diameter with a central endocarp at 3.0 to 4.0 mm in diameter. The specimens fall into the morphological range of the fossil species P. favonii, which has been observed in ot...
Six Oligocene sequences and one earliest Miocene sequence were identified at Island Beach, Atlantic City, and Cape May, New Jersey, and correlated to the dO proxy of glacioeustasy and the eustatic record of Haq et al. by integrating lithostratigraphy, biostratigraphy, Sr isotopic stratigraphy, and magnetostratigraphy. Seven global dO increases are recognized by correlating dO records among deep...
A 1500-m-thick Cenozoic sequence was recovered in a series of 3 drill holes from the Victoria Land Basin, Antarctica, in association with the Cape Roberts Project. The CRP-3 drill hole penetrated the oldest Palaeogene strata in the Granite Harbour region and terminated in strata from the Devonian Beacon Supergroup. The upper 823-m of the CRP-3 drill-core is an expanded sequence that may span th...
The Jebel Qatrani Formation of northern Egypt has produced Afro-Arabia's primary record of Paleogene mammalian evolution, including the world's most complete remains of early anthropoid primates. Recent studies of Fayum mammals have assumed that the Jebel Qatrani Formation contains a significant Eocene component ( approximately 150 of 340 m), and that most taxa from that succession are between ...
Rasmussen, D. Tab, Storrs L. Olson, and Elwyn L. Simons. Fossil Birds from the Oligocene Jebel Qatrani Formation, Fayum Province, Egypt. Smithsonian Contributions to Paleobiology, number 62, 20 pages, 15 figures, 1986.—^Fossils from fluvial deposits of early Oligocene age in Egypt document the earliest known diverse avifauna from Africa, comprising at least 13 families and 18 species. Included ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید