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

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Exceptionally-preserved Mickwitzia from the Indian Springs Lagerstätte.
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology. (Earth Sciences, Palaeobiology)ORCID iD: 0000-0002-1906-0009
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology. (Earth Sciences, Palaeobiology)
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology. (Earth Sciences, Palaeobiology)
Lund. (Palaeobiology)
(English)In: Journal of Paleontology, ISSN 0022-3360, E-ISSN 1937-2337Article in journal (Other academic) Accepted
Abstract [en]

A new assemblage of the early Cambrian stem group brachiopod Mickwitzia is described from the Indian Springs Lagerstätte possessing exceptionally preserved mantle setae. Critical analysis of shell structure and mantle setae from these specimens with those from additional sites with variable diagenetic history reveals the extent of taphonomic alteration and further sheds light on the phylogenetic position of the mickwitziids. A morphometric approach to shell outline and growth landmarks within these specimens reveals a clear species level discriminant signal of Nevada Mickwitzia in comparison to M. monlifera from Sweden. Detailed electron micrographs allow revision of the genus diagnosis for Mickwitzia based on presence of inward pointing phosphatic cones and tangential setae bearing tubes. We also conclude the inward pointing cone structures are not consistent with setal bearing structures as previously thought, but rather represent an endopunctae-like structure. A tommotiid-like shell architecture and presence of acrotretid columns in the dorsal juvenile shell of M. cf. occidens further strengthens the proposed close relationship between stem-group brachiopods and tommotiids.

Keyword [en]
Brachiopoda, Mickwitzia, shell penetrating setae, lower Cambrian, Indian Springs
National Category
Other Earth and Related Environmental Sciences Geology Evolutionary Biology
Research subject
Earth Science with specialization in Historical Geology and Palaeontology
Identifiers
URN: urn:nbn:se:uu:diva-216149OAI: oai:DiVA.org:uu-216149DiVA: diva2:689545
Funder
Swedish Research Council, 2009-4395, 2012-1658
Available from: 2014-01-21 Created: 2014-01-19 Last updated: 2017-12-06
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
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214
Keyword
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
Identifiers
urn:nbn:se:uu:diva-216363 (URN)
Presentation
2014-02-19, Geo/Gm116 Norrland II, Geocentrum, Villavägen 16B, Uppsala, 13:15 (English)
Opponent
Supervisors
Funder
Swedish Research Council
Available from: 2014-02-06 Created: 2014-01-21 Last updated: 2014-02-06Bibliographically approved
2. Decoding the fossil record of early lophophorates: Systematics and phylogeny of problematic Cambrian Lophotrochozoa
Open this publication in new window or tab >>Decoding the fossil record of early lophophorates: Systematics and phylogeny of problematic Cambrian Lophotrochozoa
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
De tidigaste fossila lofoforaterna : Problematiska kambriska lofotrochozoers systematik och fylogeni
Abstract [en]

The evolutionary origins of animal phyla are intimately linked with the Cambrian explosion, a period of radical ecological and evolutionary innovation that begins approximately 540 Mya and continues for some 20 million years, during which most major animal groups appear. Lophotrochozoa, a major group of protostome animals that includes molluscs, annelids and brachiopods, represent a significant component of the oldest known fossil records of biomineralised animals, as disclosed by the enigmatic ‘small shelly fossil’ faunas of the early Cambrian. Determining the affinities of these scleritome taxa is highly informative for examining Cambrian evolutionary patterns, since many are supposed stem-group Lophotrochozoa. The main focus of this thesis pertained to the stem-group of the Brachiopoda, a highly diverse and important clade of suspension feeding animals in the Palaeozoic era, which are still extant but with only with a fraction of past diversity. Major findings include adding support for tommotiid affinity as stem-group lophophorates. Determining morphological character homologies vital to reconstructing the brachiopod stem-group was achieved by comparing Cambrian Lagerstätten with the widespread biomineralised record of Cambrian stem-brachiopods and small shelly fossils. Polarising character changes associated with the putative transition from scleritome organisms to crown-group brachiopods was furthered by the description of an enigmatic agglutinated tubular lophophorate Yuganotheca elegans from the Chengjiang Lagerstätte, China, which possesses an unusual combination of phoronid, brachiopod and tommotiid characters. These efforts were furthered by the use of X-ray tomographic techniques that revealed novel anatomical features, including exceptionally preserved setae in the tommotiid Micrina. The evidence for a common origin of columnar brachiopod shell structures in the tommotiids is suggested and critically examined. Enigmatic and problematic early and middle Cambrian lophotrochozoans are newly described or re-described in light of new evidence, namely: the stem-brachiopod Mickwitzia occidens Walcott from the Indian Springs Lagerstätte, Nevada; a putative stem-group entoproct Cotyledion tylodes Luo and Hu from Chengjiang, China; a new enigmatic family of rhynchonelliform brachiopods exemplified by the newly described Tomteluva perturbata from the Stephen Formation, Canada; and the tommotiid Micrina etheridgei (Tate) from the Flinders Ranges, South Australia. Cladistic analyses of fossil morphological data supports a monophyletic Brachiopoda.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2015. 65 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1284
Keyword
Brachiopoda, Chengjiang, Lagerstätte, Cambrian Explosion, palaeobiology, stem-group, entoproct, phoronid, tommotiid, exceptional preservation
National Category
Other Earth and Related Environmental Sciences Natural Sciences
Research subject
Earth Science with specialization in Historical Geology and Palaeontology
Identifiers
urn:nbn:se:uu:diva-261907 (URN)978-91-554-9327-1 (ISBN)
Public defence
2015-10-23, Hambergsalen, Geocentrum, Villavägen 16, Uppsala, 13:15 (English)
Opponent
Supervisors
Funder
Swedish Research Council, 621-2008-3768, 621-2011-4961Swedish Research Council, 2009-4395, 2012-1658
Available from: 2015-09-29 Created: 2015-09-05 Last updated: 2017-01-20

Open Access in DiVA

No full text

Authority records BETA

Butler, Aodhán D.Streng, MichaelHolmer, Lars

Search in DiVA

By author/editor
Butler, Aodhán D.Streng, MichaelHolmer, Lars
By organisation
Palaeobiology
In the same journal
Journal of Paleontology
Other Earth and Related Environmental SciencesGeologyEvolutionary Biology

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 537 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf