68 D21. Laying the Foundation for the Modern Earth System at the Neoproterozoic-Paleozoic Transition

Monday, 10 October 2022
8:00 AM - 12:00 PM
Mile High Ballroom 4C

MORPHOLOGICAL INVESTIGATION OF TRIBRACHIDIUM FROM NILPENA, SOUTH AUSTRALIA

Paper number: 68-7
Program: Technical Sessions
Time: 9:20 AM – 9:35 AM

Authors

Abstract

The Ediacara Biota is a suite of globally distributed, exceptionally-preserved, soft-bodied fossils spanning from 575 million years ago to the onset of the Cambrian. Nilpena Ediacara National Park in the Flinders Ranges of South Australia preserves one of the most morphologically and taxonomically diverse assemblages of this period. Tribrachidium heraldicum is one of the more abundant taxa at this site (over 200 specimens) and is described as a circular organism, ~3–40 mm in diameter, showing triradial symmetry. Our study utilises the application of rotational geometric morphometrics to determine whether any morphological change occurred between the specimens found in the Ediacara Member and in the recently-identified, overlying Nilpena member by observing their positioning in the morphospace. Additionally, approximately 30 specimens of a possible new species of Tribrachidium are compared to the type species T. heraldicum to quantify the morphological differences. Multivariate regressions were also used to determine how Tribrachidium grew by analysing the allometric relationship between size and shape.

Geological Society of America Abstracts with Programs. Vol. 54, No. 6

doi: 10.1130/abs/2022AM-379941

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