Repository logo
 

Three-dimensional reconstruction, taphonomic and petrological data suggest the oldest record of bioturbation is a body fossil coquina

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Psarras, Christos 
Donoghue, Philip 
Garwood, Russell 
Grazhdankin, Dmitriy V 
Parry, Luke A 

Abstract

Fossil material assigned to Nenoxites from the late Ediacaran Khatyspyt Formation of Arctic Siberia (550–544 Ma) has been presented as evidence for bioturbation prior to the basal Cambrian boundary. However, that ichnological interpretation has been challenged, and descriptions of similar material from other global localities support a body fossil origin. Here we combine X-ray computed tomography (μCT), scanning electron microscopy (SEM), and petrographic methods to evaluate the body- or tracefossil nature of Nenoxites from the Khatyspyt Formation. The fossilised structures comprise densely-packed chains of three-dimensionally preserved silicic, bowl-shaped elements surrounded by distinct sedimentary halos, within a dolomitized matrix. Individual bowl-shaped elements can exhibit diffuse mineralogical boundaries and bridging connections between elements, both considered here to result from silicification and dolomitization during diagenesis. This new morphological and petrological evidence, in conjunction with recent studies of the late Ediacaran tubular taxa Ordinilunulatus and Shaanxilithes from China, leads us to conclude that the Khatyspyt specimens most likely reflect a coquina deposit of Shaanxilithes-like body fossils. Our data support the possibility of Shaanxilithes-like organisms representing total group eumetazoans.

Description

Keywords

Ediacaran, sedimentology, taphonomy, Nenoxites, bioturbation, petrology

Journal Title

Papers in Palaeontology

Conference Name

Journal ISSN

2056-2802

Volume Title

Publisher

Wiley
Sponsorship
Natural Environment Research Council (NE/L011409/2)
NERC (NE/L011409/1 and NE/P013678/1 Leverhulme Trust Research Fellowship (RF-2022-167). Early career fellowship from St. Edmund Hall, Oxford. Government Contract FWZZ-2022-0002 (Fundamental Scientific Research Programme of the Russian Federation). Russian Science Foundation (grant 20-67-46028)
Relationships
Is previous version of: