30-1 Form, Function, or Fossilization? Decoding Internal Features in Pteridinium from Stanly County, North Carolina

Session: Laws of the Grave: Advances in Taphonomy Across the Paleontologic Record (Posters)

Presenting Author:

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Abstract:

Pteridinium is known from several Ediacaran-aged localities globally, yet specimens from Stanly County, North Carolina—originally described in the late 20th century—remain understudied. This is likely due to both the rarity of specimens and the poor preservation typically seen in creek-cut exposures, where there is high erosion and weathering. This project focuses on a newly collected, extremely well-preserved, three-dimensional specimen of Pteridinium carolinensis, recovered as float along the Rocky River by avocational fossil-hunter Brandon Moore. As one of the best-preserved examples of this taxon from the eastern US, this specimen presents a rare opportunity to assess internal features using X-ray tomographic microscopy (µCT), with the goal of characterizing potential biological and/or taphonomic structures.

To examine internal morphology, we used non-invasive µCT imaging at the University of Missouri X-Ray Microanalysis Laboratory. Segmentation and visualization were conducted using Dragonfly 3D World by Comet Tech. These methods allow for high-resolution, three-dimensional renderings of internal features, which can provide unique insight into both organismal biology and the taphonomic conditions responsible for their preservation. Our results reveal a network of internal, tube-like structures distributed throughout the specimen. If biological, these features may reflect internal organization, fluid transport, or some type of hydraulic skeleton, any of which may offer insight into constructional complexity in early multicellular life. If taphonomic, these structures could instead represent later diagenetic structures, scavenging traces, or microbial features imparted during preservation.

In November 2024, we revisited previously reported fossil sites in Stanly County, in addition to Moore’s locality on the Rocky River, where we confirmed the presence of limited Pteridinium, but abundant pyritized Aspidella, in addition to a large, enigmatic, pyritized microbial structure. This project contributes to broader efforts in reconstructing the ecological, biological, and taphonomic framework of enigmatic Ediacaran metazoans. By comparing multiple Pteridinium specimens, as well as expanding the study to co-occurring taxa such as Aspidella, we aim to build a more comprehensive picture of early multicellular life in the understudied eastern US.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-6785

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