DOI: 10.1016/j.palaeo.2015.07.011
论文题名: A new Late Cretaceous (late Campanian to early Maastrichtian) wood flora from southern Patagonia
作者: Egerton V.M. ; Williams C.J. ; Lacovara K.J.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 441 起始页码: 305
结束页码: 316
语种: 英语
英文关键词: Argentina
; Cerro Fortaleza Formation
; Cretaceous
; Patagonia
; Wood
英文摘要: The Cerro Fortaleza Formation, in southernmost Patagonia (Argentina), contains a unique Late Cretaceous (Campanian) flora and fauna. This formation is characterized by lithified fluvial sands, overbank mud deposits, and paleosols deposited in fluvial, fluvial-palustrine, and coastal plain environments from the northeastern margin of the Austral (Magellanes) Basin. The overlying and underlying formations have been dated as Campanian and Maastrichtian, respectively. Therefore, the Cerro Fortaleza Formation putatively falls within the late Campanian-Maastrichtian. This formation is known for its diverse fauna including dinosaurs, fishes, and turtles. Furthermore, poorly preserved leaf impressions from indeterminate conifers and cycads have also been discovered but not yet described. Fossil wood taxa from the Cerro Fortaleza Formation yields a diverse flora of gymnosperm wood but only two genera of angiosperm wood. Gymnosperm genera identified in this study include Agathoxylon, Planoxylon, Taxodioxylon, Cupressinoxylon, and Podocarpoxylon; and angiosperm genera identified include Hedycaryoxylon and Nothofagoxylon. This is the first record of Planoxylon, Taxodioxylon, Cupressinoxylon, and Hedycaryoxylon from Argentina. Additionally, this is the oldest occurrence of Nothofagoxylon in Argentina. Both the angiosperm and gymnosperm wood samples possess distinct growth rings, providing strong evidence for seasonal growth regimes in the region. All of the wood genera from the Cerro Fortaleza Formation, except Planoxylon, have also been described from Late Cretaceous sediments of the Antarctic Peninsula. Thus, the presence of these taxa in both regions supports Late Cretaceous plant dispersal between them. Despite sharing the same taxa, the floras from the Cerro Fortaleza Formation and the Antarctic Peninsula exhibit strikingly different relative abundances. The ratio of gymnosperm to angiosperm wood in the Cerro Fortaleza Formation is 75:25; whereas coeval floras from the Antarctic Peninsula are ~. 25:75. The floral differences between these locations may be a relict from a widespread older flora that included Antarctica, regional floristic variations or a result of different depositional and/or taphonomic controls in discrete paleoenvironments. © 2015 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68689
Appears in Collections: 过去全球变化的重建
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作者单位: School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Oxford Road, Manchester, United Kingdom; Department of Biodiversity, Earth and Environmental Science, Drexel University, Philadelphia, PA, United States; Department of Earth and Environment, Franklin and Marshall College, 415 Harrisburg Ave., Lancaster, PA, United States
Recommended Citation:
Egerton V.M.,Williams C.J.,Lacovara K.J.. A new Late Cretaceous (late Campanian to early Maastrichtian) wood flora from southern Patagonia[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,441