DOI: 10.1016/j.palaeo.2016.12.024
论文题名: First Lower Jurassic vertebrate burrow from southern Africa (upper Elliot Formation, Karoo Basin, South Africa)
作者: Bordy E.M. ; Sciscio L. ; Abdala F. ; McPhee B.W. ; Choiniere J.N.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
卷: 468 起始页码: 362
结束页码: 372
语种: 英语
英文关键词: Advanced tritheledontid cynodont
; Early Jurassic
; Southwestern Gondwana
; Vertebrate trace fossil
英文摘要: Vertebrate burrows are common ichnofossils in the Permo-Triassic of the main Karoo Basin in South Africa. They are generally attributable to one of several lineages of therapsid, including the derived clade known as cynodonts. Despite the presence of cynodont species in the Upper Triassic and Lower Jurassic of the Karoo Supergroup, vertebrate burrows have never been reported from this part of the succession. Recent fieldwork recovered a semi-elliptical burrow cast in the Lower Jurassic upper Elliot Formation (Stormberg Group) on the farm Edelweiss 698 (Free State). The horizontal and vertical diameters of the burrow cast are ~ 18 and ~ 7 cm, respectively. This semi-horizontal, straight to slightly sinuous tunnel is ~ 50 cm long with a ramp angle of < 5°. The tunnel lacks branching, terminal chambers, and associated fossil bones. The burrow cast consists of medium, massive sandstone and very rare, faint, horizontal to slightly inclined lamination. The burrow cast is hosted in fine-grained, palaeo-pedogenically altered, crevasse splay sandstone that is 10–20 cm thick and is under- and overlain by a massive, red, bioturbated floodplain mudstone unit with large-scale (> 20 cm deep) desiccation cracks, invertebrate trace fossils, calcareous rhizoconcretions, and spherical-to-elongated carbonate nodules. These and other associated sedimentary features provide evidence for a semi-arid, fluvio-lacustrine palaeoenvironment during the burrowing activity. Based on comparisons to fossil and modern burrows, this burrow cast is interpreted as a vertebrate burrow, and is the first record of vertebrate fossorial activity within the Lower Jurassic of southern Africa. The ancient burrow architect has yet to be positively identified. However, given the size and morphology of the burrow and the occurrence of similar sized fossil cynodont therapsids that inhabited the main Karoo Basin in the earliest Jurassic, the potential burrow-maker may be tentatively linked to the Cynodontia (e.g., Pachygenelus - an advanced tritheledontid). © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/67971
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geological Sciences, University of Cape Town, South Africa; Evolutionary Studies Institute, University of the Witwatersrand, South Africa; School of Geosciences, University of the Witwatersrand, South Africa
Recommended Citation:
Bordy E.M.,Sciscio L.,Abdala F.,et al. First Lower Jurassic vertebrate burrow from southern Africa (upper Elliot Formation, Karoo Basin, South Africa)[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01,468