ORIGINS AND BIOMECHANICAL EVOLUTION OF TEETH IN ECHINOIDS AND THEIR RELATIVES
2009 | journal article. A publication with affiliation to the University of Göttingen.
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- Authors
- Reich, Mike; Smith, Andrew B.
- Abstract
- Echinoid teeth are without doubt the most complex and highly specialized skeletal component to have evolved in echinoderms. They are biomechanically constructed to be resilient and tough while maintaining a self-sharpening point. Based on SEM analysis of isolated tooth elements collected primarily from the Ordovician and Silurian of Gotland, we provide a detailed structural analysis of the earliest echinoderm teeth. Eight distinct constructional designs are recognized encompassing various degrees of sophistication, from a simple vertical battery of tooth spines to advanced teeth with multiple tooth plate series and a reinforced core of fibres. These provide key data from which we reconstruct the early stages of tooth evolution. The simplest teeth are composed of stacked rod-like elements with solid replacement of tooth elements, as a simple self-sharpening mechanism. Within echinoids tooth design was refined by evolving thinner, flatter primary plates with buttressing, allowing maintenance of a sharper and stronger biting edge. Despite the obvious homology between the lanterns of ophiocistioids and echinoids, their teeth are very different in microstructural organization, and they have evolved different self-sharpening mechanisms. Whereas echinoid teeth evolved from a biseries of mouth spines, ophiocistioid goniodonts evolved from a single series of mouth spines. Rogeriserra represents the most primitive known battery of tooth elements but its taxonomic affinities remain unknown.
- Issue Date
- 2009
- Status
- published
- Publisher
- Wiley-blackwell Publishing, Inc
- Journal
- Palaeontology
- ISSN
- 0031-0239
- Sponsor
- SYNTHESYS [GB-TAF-2446, SE-TAF-2969]