Precambrian–Cambrian boundary interval occurrence and form of the enigmatic tubular body fossil Shaanxilithes ningqiangensis from the Lesser Himalaya of India |
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Authors: | Lidya G. Tarhan Nigel C. Hughes Paul M. Myrow Om N. Bhargava Arun D. Ahluwalia Anatoliy B. Kudryavtsev |
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Affiliation: | 1. Department of Earth Sciences, University of California, , Riverside, CA, 92521 USA;2. Department of Geology, Colorado College, , Colorado Springs, CO, 80903 USA;3. , Panchkula, Harayana, 134109 India;4. Department of Geology, Panjab University, , Chandigarh, 160014 India;5. Department of Earth and Space Sciences, and Molecular Biology Institute, University of California, , Los Angeles, CA90095, USA |
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Abstract: | The affinity of the Ediacaran fossil Shaanxilithes ningqiangensis and putatively related forms has long been enigmatic; over the past few decades, interpretations ranging from trace fossils to algae to metazoans of uncertain phylogenetic placement have been proposed. Combined morphological and geochemical evidence from a new occurrence of S. ningqiangensis in the Krol and Tal groups of the Lesser Himalaya of India indicates that S. ningqiangensis is not a trace fossil, but rather an organic‐walled tubular body fossil of unknown taxonomic affinity. Specimens consist of compressed organic cylindrical structures, characterized by extended, overlapping or fragmented iterated units. Where specimens intersect, overlapping rather than branching or intraplanar crossing is observed. Lithologic comparisons and sequence stratigraphic data all suggest a late Ediacaran age for the uppermost Krol Group and basalmost Tal Group. By extending the biogeographical distribution of S. ningqiangensis, hitherto confined to the Ediacaran of China and potentially Siberia, to the Precambrian–Cambrian boundary interval of India, this new occurrence of S. ningqiangensis expands the biostratigraphic utility of this enigmatic fossil to the inter‐regional and intercontinental scale. Moreover, study of these new and exceptionally preserved samples may help to significantly constrain the long‐debated problem of Shaanxilithes' affinity, elucidating its ‘problematic’ status and shedding new light upon the ecology and taphonomy of one of the most significant intervals in early life history. |
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Keywords: | Precambrian– Cambrian boundary Lesser Himalaya
Shaanxilithes
tubular fossil Krol Group Tal Group |
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