Robert A. Gastaldo

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The terrestrial crisis that reportedly parallels the P/Tr marine mass extinction is based mainly on Northern Hemisphere microfloral assemblages and Southern Hemisphere Gondwanan macrofloral collections. It is well established that taphonomic filters control the ultimate collectable fossil assemblage in any depositional regime. Recognition and comparison of(More)
Leaves and other non-woody canopy parts are rarely preserved in coals. Although the pH of pore waters within peat swamps is usually relatively low ( 3.5), providing geochemical conditions that would promote preservation after burial, shed canopy parts may remain at the air–soil interface for periods of up to several months prior to burial by additional(More)
The Lower Triassic Katberg Formation (Beaufort Group, Karoo Supergroup) in South Africa is a fine-grained, arenaceous unit deposited under ephemeral bedload-dominated fluvial conditions and previously interpreted as representing a continuous stratigraphic record. Its genesis was linked directly to the end-Paleozoic extinction event and was considered to(More)
a Bernard Price Institute for Palaeontology, University of the Witwatersrand, Johannesburg, 2050, South Africa b Department of Paleobiology, NMNH, Smithsonian Institution, Washington, DC 20013-7012, United States c Department of Entomology, University of Maryland, College Park, MD 20742, United States d Council for Geosciences, Silverton, Pretoria, 0001,(More)
A new ichnogenus and ichnospecies of burrow, Katbergia carltonichnus, are described from Upper Permian and Lower Triassic rocks of the Karoo Basin, South Africa, where they are preserved in pedogenically modified overbank deposits that are interpreted as inceptisols subsequently gleysol overprinted. Sigmoidal burrows consist of a long (‡0.5 m) cylindrical(More)
Isolated logs preserved in the Älterer Flußsande of the Weißelster basin, Germany, are examined relative to their subjacent bedform. Paleocurrent analyses conducted on both the log orientation and its underlying bedform are used to determine whether or not any relationship exists between these two structures. Two patterns emerge from this investigation.(More)
Interregional correlation of the marine zones of major cyclothems between North America and eastern Europe does not support assertions that a major stratigraphic gap exists between the traditional regional Desmoinesian and Missourian stages in North America. Such a gap was previously proposed to explain an abrupt change in megafloral assemblages in the(More)
William A DiMichele2, Hermann W Pfefferkorn3, and Robert A Gastaldo4 2Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560; e-mail: dimichele.bill@nmnh.si.edu 3Department of Earth and Environmental Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104; e-mail: hpfeffer@sas.upenn.edu(More)
The fossil record of wetlands documents unique and long-persistent fl oras and faunas with wetland habitats spawning or at least preserving novel evolutionary characteristics and, at other times, acting as refugia. In addition, there has been an evolution of wetland types since their appearance in the Paleozoic. The fi rst land plants, beginning in the Late(More)