Abstract

The fossil record of phyllocarids in Australia is decidedly limited, with only a few specimens known from Ordovician to Devonian deposits. Therefore, the identification of examples from older deposits would uncover more facets of Gondwanan crustacean evolution. Here, a supposed phyllocarid reported by Chapman (1925 Chapman, F. , 1925. The Wade Collection of Fossils . Government Printer, Melbourne. [Google Scholar]) from the Mount John Shale Member of the Wade Creek Formation is reconsidered. We conclude that the ‘phyllocarid’-like structure is somewhat morphologically comparable to traces ascribed to the activity of bivalved arthropods. However, as the Mount John Shale Member is likely Mesoproterozoic in age, the most parsimonious explanation is that the structure is a cast created by abiotic activity. Re-examination of such specimens represents a useful approach to clarifying previous misidentifications in the literature and is an important application of historically valuable specimens and collections.

R.D.C. Bicknell [rdcbicknell@gmail.com], Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales, 2351, Australia; P.M. Smith [Patrick.Smith@austmus.gov.au], Palaeontology Department, Australian Museum Research Institute, Sydney, New South Wales, 2010, Australia; Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia; N. Schroeder [Natalie.Schroeder@ga.gov.au] Geoscience Australia, Symonston ACT 2609, Australia; J. Kimmig [jkimmig@psu.edu] Earth and Mineral Sciences Museum & Art Gallery, Pennsylvania State University, University Park, PA 16802, USA.

摘要

澳大利亚的叶甲化石记录绝对有限，从奥陶纪到泥盆纪的沉积只有少数标本。因此，从较老矿床中识别出的实例将揭示冈瓦纳甲壳类动物进化的更多方面。在这里，查普曼（1925年 Chapman，F. ，1925年。韦德化石收藏。墨尔本政府印刷厂。 [Google Scholar]），重新考虑了韦德克里克组的约翰·页岩山。我们得出的结论是，“叶甲类”结构在形态上可与双壳节肢动物活动的痕迹相比。但是，由于约翰页岩山成员年龄可能是中元古代的，因此最简约的解释是该结构是由非生物活动产生的。对此类标本进行复检是澄清文献中先前错误识别的有用方法，并且是具有历史价值的标本和馆藏的重要应用。

RDC Bicknell [rdcbicknell@gmail.com]，新英格兰大学环境与农村科学学院，古生物学研究中心，新南威尔士州阿米代尔市，澳大利亚2351；Smith Smith [Patrick.Smith@austmus.gov.au]，澳大利亚博物馆研究所古生物学系，新南威尔士州悉尼，澳大利亚，2010年；麦格理大学生物科学系，澳大利亚新南威尔士州悉尼，2109；N. Schroeder [Natalie.Schroeder@ga.gov.au]澳大利亚地球科学局，澳大利亚Symonston ACT 2609；J. Kimmig [jkimmig@psu.edu]美国宾夕法尼亚州立大学地球与矿物科学博物馆和美术馆，大学公园，宾夕法尼亚州16802。