Red Devonian trilobites with green eyes from Morocco and the silicification of the trilobite exoskeleton

Christian Klug, Hartmut Schulz, Kenneth De Baets

Research output: Contribution to journalArticle (Academic Journal)peer-review

41 Citations (Scopus)


Latest Emsian (Early Devonian) sediments at the famous mud-mound- and trilobite-locality Hamar Laghdad (Tafilalt, Morocco) yielded some red-coloured remains of phacopid trilobites. Closer examination revealed that the eyes of these phacopids are often greenish in colour. EDX-analyses showed that the lenses retained their original calcitic composition, possibly greenish due to Fe- and Mn-impurities, while most of the exoskeleton was silicified. The silicified parts contain elevated concentrations of iron which causes the red colour. This phenomenon is explained by the porosity of the exoskeleton in contrast to the homogeneous and massive construction of the lenses and their Mg-content. These incompletely silicified trilobites enabled a reconstruction of the silicification process in trilobites. Their diagenetic alteration probably occurred as a result of events associated with the Cretaceous transgression.

Original languageEnglish
Pages (from-to)117-123
Number of pages7
JournalActa Palaeontologica Polonica
Issue number1
Publication statusPublished - Mar 2009

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