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| Format: | Artículo científico |
| Language: | en |
| Published: |
Universitat de Barcelona
2005
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| Online Access: | https://www.redalyc.org/articulo.oa?id=50530210 |
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Table of Contents:
- Heterochrony in Middle Jurassic species of Gryphaea (Ostreoidea, Gryphaeidae) from southern South America A. Rubilar Ciencias de la Tierra Oysters Systematics Heterochrony South America Middle Jurassic Morphological changes along ontogeny, based on size, are analysed in five species of Gryphaea from the MiddleJurassic of southern South America. Three of these taxa are new: G. apiculata n. sp., G. varillasensis n. sp.and G. euteicha n. sp. All five species have thin radial striae on the left valve. They are regarded as closelyrelated on the basis of the similar configuration of the main part of the left valve (especially during the firstontogenetic stages), the associated development of the posterior flange (and sulcus), the comparable variabilityand/or recurrent morphology of these and other structures, and their relative stratigraphic position or age. Theyshow differences in the relative appearance time and development of several characters, and similar changesprobably have also occurred stratigraphically, at least, in G. oxytropis PHILIPPI and G. euteicha n. sp. All thesefeatures allow the recognition of size (morphology)-based heterochronic processes (peramorphic and paedomorphic),either in the origin of most of these taxa or in morphologic changes which developed along time insome of them. This work provides preliminary evidence of the most remarkable iterative occurrence of heterochronyknown to date in oysters. 2005 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50530210 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.2 Vol.3