uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
The role of microbes in decay and preservation: a Cambrian Explosion of animals and Lagerstätten.
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology. (Palaeobiology)
University of Bristol. (Earth Sciences, Palaeobiology)
University of Bristol. (Earth Sciences, Palaeobiology)
(English)Manuscript (preprint) (Other academic)
Abstract [en]

The abrupt appearance of animals in the early Cambrian has been interpreted either as an explosive biological diversification or, alternatively, as an artefact resulting from a sudden increase in the probability of animal remains becoming fossilised. We attempt to reconcile these competing interpretations in exceptionally-preserved biota, which provide a vital part of our knowledge of the disparity and diversity of the Cambrian fauna. We assess the factors influencing the potential for exceptional fossil preservation using the brine shrimp Artemia salina as our experimental model. Following gut wall rupture, but prior to cuticle failure, internal, gut-derived microbes spread into the body cavity and formed pseudomorphs of tissues. Gut-derived microbes were shown to be the main factor mediating both decay and biofilm replacement and tissue stabilisation. This pattern of preservation is consistent with results from other experimental studies and with the nature of Burgess Shale type fossil remains. Thus, the evolution of a through-gut may have not only underpinned the ecological revolution that bilaterian diversification represents, but also catalysed the exceptional preservation of early bilaterian fossils.

Keyword [en]
Cambrian Explosion, palaeobiology, taphonomy, bilateria, metazoa
National Category
Other Earth and Related Environmental Sciences Evolutionary Biology Geology
Research subject
Earth Science with specialization in Historical Geology and Palaeontology
URN: urn:nbn:se:uu:diva-216151OAI: oai:DiVA.org:uu-216151DiVA: diva2:689563
Available from: 2014-01-21 Created: 2014-01-19 Last updated: 2014-02-06
In thesis
1. Exceptionally Preserved Cambrian Lophotrochozoa: Taxonomy, Systematics and Taphonomy of Chengjiang and Indian Springs Lophophorates
Open this publication in new window or tab >>Exceptionally Preserved Cambrian Lophotrochozoa: Taxonomy, Systematics and Taphonomy of Chengjiang and Indian Springs Lophophorates
2014 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

The origin and evolution of Lophotrochozoa can be traced to the plethora of lower Cambrian scleritome taxa.  We aim to determine the character suites linking these stem-Lophotrochozoa to their extant crown relatives, in particular the small shelly tommotiids and the stem-group brachiopods. Tracing the origin of morphological characters from these fossils informs the evolution and construction of lophotrochozoan body plans associated with the Cambrian Explosion. This is achieved by comparing records of exceptional preservation, most conspicuously Burgess Shale type Lagerstätten with more widespread Cambrian stem-brachiopods and small shelly fossils with their purported extant relatives, for example. Determining morphological character homologies is crucial to reconstructing the brachiopod stem-group and in polarising character changes associated with the putative transition from scleritome organisms to crown-group brachiopods. In this thesis arguments for a common origin of specific shell structures and exceptionally preserved soft-tissues are investigated. New records of enigmatic stem-group lophotrochozoans are described from two localities, the Indian Springs and Chengjiang Lagerstätte. Comprising the stem-brachiopod Mickwitzia cf. occidens, a putative stem-group entoproct Cotyledion tylodes and an enigmatic agglutinated tubular lophophorate possessing an unusual combination of phoronid, brachiopod and tommotiid characters, Yuganotheca elegans gen. et sp. nov. The interplay of bauplan, microbial activity and environmental factors resulting in such incidences of exceptional soft tissue preservation is also examined critically. Consequently, the evolution of through-gut bearing bilaterians is suggested as the reason for why the Cambrian hosts such a plethora of Lagerstätten. The closure of this taphonomic window is then associated with increased bioturbation following the Cambrian substrate revolution.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2014
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214
Brachiopoda, Chengjiang, Lagerstätte, Cambrian Explosion, palaeobiology, stem-group, entoproct, phoronid, tommotiid, exceptional preservation.
National Category
Evolutionary Biology Geology Other Earth and Related Environmental Sciences
Research subject
Earth Science with specialization in Historical Geology and Palaeontology
urn:nbn:se:uu:diva-216363 (URN)
2014-02-19, Geo/Gm116 Norrland II, Geocentrum, Villavägen 16B, Uppsala, 13:15 (English)
Swedish Research Council
Available from: 2014-02-06 Created: 2014-01-21 Last updated: 2014-02-06Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Butler, Aodhán D.
By organisation
Other Earth and Related Environmental SciencesEvolutionary BiologyGeology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 321 hits
ReferencesLink to record
Permanent link

Direct link