Abstract:
:The trace fossil record is important in determining the timing of the appearance of bilaterian animals. A conservative estimate puts this time at approximately equal 555 million years ago. The preservational potential of traces made close to the sediment-water interface is crucial to detecting early benthic activity. Our studies on earliest Cambrian sediments suggest that shallow tiers were preserved to a greater extent than typical for most of the Phanerozoic, which can be attributed both directly and indirectly to the low levels of sediment mixing. The low levels of sediment mixing meant that thin event beds were preserved. The shallow depth of sediment mixing also meant that muddy sediments were firm close to the sediment-water interface, increasing the likelihood of recording shallow-tier trace fossils in muddy sediments. Overall, trace fossils can provide a sound record of the onset of bilaterian benthic activity.
journal_name
Proc Natl Acad Sci U S Aauthors
Droser ML,Jensen S,Gehling JGdoi
10.1073/pnas.202322499keywords:
subject
Has Abstractpub_date
2002-10-01 00:00:00pages
12572-6issue
20eissn
0027-8424issn
1091-6490pii
202322499journal_volume
99pub_type
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