Evolutionary patterns in the terebratulid genus Caryona Cooper (Brachiopoda,Jurassic of France) |
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| Authors: | Yves Alméras Annick Boullier |
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| Affiliation: | 1. Centre des Sciences de la Terre , Université Claude‐Bernard, Lyon et Centre de Paléontologie stratigraphique et Paléoécologie associé au C.N.R.S. , (U.RA. 11, Lyon), 27–43 bid du 11 Novembre, Villeurbanne Cedex, 69622, France;2. Laboratoire de Géologie Structurale et Appliquée , Institut des Sciences Naturelles , 1 place Maréchal Leclerc, 25030 Besan?on Cedex et U.R.A. 11, Lyon, France |
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| Abstract: | The study of ontogenetic and morphological changes in different species of the brachiopod genus Caryona COOPER (Terebratulidae) from the Lower Callovian‐Lower Oxfordian of northern France shows a succession (and an interference) of processes which vary according to the characters studied. This is an example of “mosaic evolution”;. The ontogenetic changes result from heterochrony, especially acceleration and hypermorphism. The main phylogenetic tendency is peramorphosis in most characters. This evolutionary pattern agrees with phyletic gradualism. Moreover, analysis of the internal characters demonstrates the limited value of these in discrimination of the various genera. |
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| Keywords: | Brachiopoda Terebratulidae Jurassic France evolutionary pattern |
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