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

Direct link
Tissue diversity and evolutionary trends of the dermal skeleton of Silurian thelodonts
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology. (Ahlberg Lab)
Natural History Museum.
Vilnius University.
King's College London, Dental Institute. (Department of Craniofacial Development and Stem Cell Biology)
2013 (English)In: Historical Biology, ISSN 0891-2963, Vol. 25, no 2, 143-154 p.Article in journal (Refereed) Published
Abstract [en]

Previously described scale morphotypes of Silurian thelodonts, constrained by their representation as isolated dermaldenticles are reassessed to provide a more robust character basis for their inclusion in future phylogenetic studies. Asrelatively common microfossils, thelodonts are important biostratigraphical markers, but their interrelationships withgeologically younger species known by complete skeletons are still unresolved. We examined scales of 21 knownmorphotypes from north-eastern Europe, Siberia and central Asia and described their distinct tissue arrangementsconsidering (1) thickness and direction of dentine tubules, (2) presence or absence of a pulp canal, (3) number and positionof pulp canals, (4) the presence or absence of a distinct outer crown layer and (5) the extent of Sharpey’s fibres penetratingthe scale base. We correlated the traditional thelodont scale type morphologies with these distinct scale histologies, as foundin Silurian thelodonts. In addition, a new histological type for thelodont scales, the Talimaalepis type, is described torepresent a new taxon, from the Early-Mid Silurian. Our study suggests that, through time, there is a general trend ofincreasing complexity in thelodont dermal tissue structures. Three types of dentine and internal scale organisations weredistinguished in Silurian species studied, namely (1) irregular, thin tubular dentine; (2) irregular, thick tubular dentine, withtwo subtypes as a function of pulp canal development and (3) regular, tubular dentine (orthodentine).

Place, publisher, year, edition, pages
2013. Vol. 25, no 2, 143-154 p.
National Category
Natural Sciences Evolutionary Biology Earth and Related Environmental Sciences
URN: urn:nbn:se:uu:diva-209296DOI: 10.1080/08912963.2013.766184OAI: oai:DiVA.org:uu-209296DiVA: diva2:656654
Available from: 2013-10-16 Created: 2013-10-16 Last updated: 2013-10-16Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Zigaite, Zivile
By organisation
Evolution and Developmental Biology
In the same journal
Historical Biology
Natural SciencesEvolutionary BiologyEarth and Related Environmental Sciences

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

Altmetric score

Total: 228 hits
ReferencesLink to record
Permanent link

Direct link