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Article: Oldest fossil ciliates from the Cryogenian glacial interlude reinterpreted as possible red algal spores

Palaeontology - Vol. 63 Part 6 - Cover Image
Publication: Palaeontology
Volume: 63
Part: 6
Publication Date: November 2020
Page(s): 941 950
Author(s): Phoebe A. Cohen, Maoli Vizcaíno, and Ross P. Anderson
Addition Information

How to Cite

COHEN, P.A., VIZCAíNO, M., ANDERSON, R.P. 2020. . Palaeontology, 63, 6, 941-950. DOI: /doi/10.1111/pala.12497

Author Information

  • Phoebe A. Cohen - Department of Geosciences Williams College Williamstown MA USA
  • Maoli Vizcaíno - Department of Geosciences Williams College Williamstown MA USA
  • Ross P. Anderson - All Souls College University of Oxford Oxford OX1 4AL UK

Publication History

  • Issue published online: 25 November 2020
  • Manuscript Accepted: 12 May 2020
  • Manuscript Received: 12 December 2019

Funded By

NASA Astrobiology Institute. Grant Number: NNA13AA90A
Williams College
Geological Society of America ExxonMobil Student Geoscience Grant
NASA. Grant Numbers: NNA13AA90A, NNX14AP10H
Yale Institute for Biospheric Studies
Peabody Museum of Natural History

Online Version Hosted By

Wiley Online Library
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The Cryogenian Period experienced two long lived global glaciations known as Snowball Earths. While these events were dramatic, eukaryotic life persisted through them, and fossil evidence shows that eukaryotes thrived during the c. 30‐million‐year interlude between the glaciations. Carbonate successions have become an important taphonomic window for this interval. One of the most notable examples is the c. 662–635 Ma Taishir Formation (Tsagaan Olom Group, Zavkhan Terrane, Mongolia) which has yielded a number of eukaryotic fossil taxa. Here, we examine more closely the morphology and taxonomic affinity of some of these Taishir fossils previously interpreted as remains of ciliate tintinnid loricae (purportedly the oldest fossil ciliates). New morphological and ultrastructural analyses indicate that these fossils are not ciliate tintinnids. Instead, we propose a new interpretation: that they are algal reproductive structures related to coeval macroscopic organic warty sheets described as putative red algae. We report the first occurrence of these fossils in the earliest Ediacaran Ol Formation, indicating that this taxon persisted through the Marinoan Snowball Earth. A new interpretation of these fossils as putative red algal spores has broad implications for our understanding of biodiversity in the Neoproterozoic Era, specifically during the Cryogenian Period, and for the antiquity of ciliates.

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