Australia: The Land Where Time Began

A biography of the Australian continent 

Precambrian-Cambrian Boundary Interval – Occurrence and Form of Shaanxilithes ningqiangensis, an Enigmatic Body Fossil from the Lesser Himalaya, India

Shaanxilithes ningqiangensis, a fossil from the Ediacaran, and putatively related forms, have long been regarded as enigmatic; interpretations have been put forward over the past few decades that range from trace fossils, algae, to metazoans of uncertain phylogenetic placement. In this paper Tarhan et al. have presented combined morphological and geochemical evidence from a new occurrence of S. ningqiangensis in the Krol and Tal Groups of the Lesser Himalaya, India, that indicates that it is not a trace fossil, rather it is a tubular body fossil with an organic wall, but its taxonomic affinity is not known. Tarhan et al. say specimens consist of organic cylindrical structures that have been compressed, that are characterised by extended, overlapping or fragmented iterated units. Rather than branching or intraplanar crossing, overlapping is observed where specimens intersect. An age of Late Ediacaran for the uppermost Krol Group and basal Tal Group have been suggested by lithologic comparisons and sequence stratigraphic data. This new occurrence of S. ningqiangensis has expanded the biostratigraphical utility of this fossil to the inter-regional and intercontinental scale by extending the biogeographical distribution of S. ningqiangensis, that had hitherto been confined to Ediacaran deposits in China, and potentially Siberia, to the Precambrian-Cambrian boundary interval in India. Tarhan et al. suggest that study of these new, exceptionally preserved samples may help to significantly constrain the affinity of Shaanxilithes, that has been debated for a long time, and elucidate its ‘problematic’ status and shed new light on the ecology and taphonomy of an interval of time that is one of the most significant intervals in the history of life on Earth.

Sources & Further reading

1. Tarhan, L. G., N. C. Hughes, P. M. Myrow, O. N. Bhargava, A. D. Ahluwalia and A. B. Kudryavtsev (2014). "Precambrian–Cambrian boundary interval occurrence and form of the enigmatic tubular body fossil Shaanxilithes ningqiangensis from the Lesser Himalaya of India." Palaeontology 57(2): 283-298.