A5061556997- Evolution and Paleontology Studies
- Geology and Paleoclimatology Research
- Paleontology and Evolutionary Biology
- Pleistocene-Era Hominins and Archaeology
- Animal Ecology and Behavior Studies
- Wildlife Ecology and Conservation
- Paleontology and Stratigraphy of Fossils
- Bat Biology and Ecology Studies
- Botany, Ecology, and Taxonomy Studies
- Geomagnetism and Paleomagnetism Studies
- Comparative Animal Anatomy Studies
- Geological and Geochemical Analysis
- Geochemistry and Geologic Mapping
- Morphological variations and asymmetry
- Ecology and biodiversity studies
- Lepidoptera: Biology and Taxonomy
- Species Distribution and Climate Change
- Amphibian and Reptile Biology
- Cephalopods and Marine Biology
- Geological Modeling and Analysis
- Ecology and Vegetation Dynamics Studies
- Avian ecology and behavior
- Analytical Chemistry and Chromatography
- Genetic diversity and population structure
- Mollusks and Parasites Studies
University of California, Riverside
1994-2016
Museum Of Northern Arizona
2005-2015
American Museum of Natural History
1968-2011
Smithsonian Institution
2011
Northern Arizona University
2009
University of North Florida
2008
California Institute of Technology
1989
Southern California Academy of Sciences
1968
Museum of Vertebrate Zoology
1968
University of California, Berkeley
1968
The biotic and geologic dynamics of the Great American Biotic Interchange are reviewed revised. Information on Marine Isotope Stage chronology, sea level changes as well Pliocene Pleistocene vegetation in Central northern South America add to a discussion role climate facilitating trans-isthmian exchanges. Trans-isthmian land mammal exchanges during glacial intervals appear have been promoted by development diverse non-tropical ecologies. ELECTRONIC SUPPLEMENTARY MATERIAL: online version...
The idea that South America was an island continent over most of the Cenozoic, during which its unusual mammalian faunas evolved in isolation, is outstandingly influential biogeography. Although large numbers recent fossil discoveries and related advances require original isolation concept be significantly modified, it still repeated much current literature. persistence inspired us to present here integrated paleobiogeographic account mammals, reptiles, plants from Jurassic Paleogene...
Abstract: The oldest Cenozoic mammalian assemblages in South America have been recovered from levels of the Hansen Member Salamanca Formation, Punta Peligro locality Argentina, and Santa Lucía Formation Tiupampa, Bolivia. These faunas led to recognition Peligran Tiupampan American Land Mammal Ages (SALMAs), each alternatively regarded as Paleocene SALMA. Due lack radioisotopic dates for mammals bearing at these localities, no agreement has reached yet about their relative ages. In this...
ABSTRACT Field work recently completed in the Lake Eyre Basin, South Australia, has resulted development of a land mammal (marsupial) biostratigraphy Etadunna Formation. Whereas traditional interpretations age this sequence suggest it is about 15 m.y. old, new information indicates that likely 24–26 old. In either case, appears possible to document four-fold fossil zonation rock unit at lakes Palankarinna, Kanunka, Pitikanta, and Ngapakaldi, composite section strata spans least 30 m....
The modern effect of climate on plants and animals is well documented. Some have cautioned against assigning a direct role in Cenozoic land mammal faunal changes. We illustrate 3 episodes significant mammalian reorganization the Eocene North America that are considered responses to dramatic climatic events. first episode occurred during Paleocene-Eocene Thermal Maximum (PETM), beginning (55.8 Ma), earliest Wasatchian American Land Mammal Age (NALMA). PETM documents short (<170 k.y.) global...
Monotremes have left a poor fossil record, and paleontology has been virtually mute during two decades of discussion about molecular clock estimates the timing divergence between platypus echidna clades. We describe evidence from high-resolution x-ray computed tomography indicating that Teinolophos , an Early Cretaceous Australia's Flat Rocks locality (121–112.5 Ma), lies within crown clade Monotremata, as basal platypus. Strict echidnas range 17 to 80 Ma, but suggests monotreme clades were...
Two new fossil mammal localities from the Paleogene of central-western Patagonia are preliminarily described as basis for a possible biochronological unit early Eocene Patagonia, correlated being between two conventional SALMAs, Riochican (older) and Vacan subage Casamayoran SALMA. The mammal-bearing strata belong to Middle Chubut River Volcanic-Pyroclastic Complex (northwestern Province, Argentina), Paleocene-Eocene age. This complex includes variety volcaniclastic, intrusive, pyroclastic,...
Alternative hypotheses in higher-level marsupial systematics have different implications for origins, character evolution, and biogeography. Resolving the position of South American monito del monte (Order Microbiotheria) is particular importance that alternate posit sister-group relationships between microbiotheres taxa with disparate temporal geographic distributions: pediomyids; didelphids; dasyuromorphians; diprotodontians; all other australidelphians; marsupials. Among Australasian...
A fossil land mammal, apparently the first found in Antarctica, belongs to extinct marsupial family Polydolopidae. The fossils were recovered from rocks about 40 million years old on Seymour Island, northern Antarctic Peninsula. newly discovered marsupials support theories that predicted their former presence Antarctica and strengthen proposals Australian perhaps originated South American species dispersed across when Australia still was attached it, prior 56 ago.
Seymour Island, Antarctica (64°17'S), offers the first opportunity to examine crisis at end of Cretaceous from high southern latitudes. The K/T boundary sequence on Island consists a nearly continuous siliciclastic sediments deposited in mid-shelf environment. faunal changes across occur through 30-m interval with no single extinction horizon, contrast other well-studied sections. “expanded” nature section makes placement difficult because indicators such as planktic foraminifera, ammonites,...
Although the Arikareean North American land mammal age was first typified in Great Plains, succession there contains significant unconformities, a generally poor magnetic record, relatively sparse radioisotopic calibration, and major faunal hiatus. In John Day Valley of central Oregon, however, is thick, remarkably complete sequence Oligocene through early Miocene strata (the Formation) potentially amenable to addressing these shortcomings long known harbor one richest records mid‐Tertiary...