Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Quillévéré, F. Articles by Auffray, J.-C. Search for Related Content GeoRef GeoRef Citation

Ontogenetic and evolutionary patterns of shape differentiation during the initial diversification of Paleocene acarininids (planktonic foraminifera)

¹ Frédéric Quillévéré. Department of Earth Sciences—Marine Geology, Göteborg University, Box 460, Göteborg SE-405 30, Sweden. frederic.quillevere{at}univ\|[lowbar]\|lyon1.fr
² Vincent Debat. Populations, Génétique et Evolution, CNRS, UPR 9034 BP1, 91198 Gif-sur-Yvette, France
³ Jean-Christophe Auffray. Institut des Sciences de l'Evolution (UMR 5554 CNRS), cc064, Université Montpellier II, 34095 Montpellier cedex 05, France
⁴ Present address: Laboratoire Paléoenvironnements et Paléobiosphère, Université Claude Bernard–Lyon 1, 43 Boulevard de 11 Novembre 1918, 69622 Villeurbanne cedex, France

Previous studies have established a close relationship between the evolutionary origin of new clades of planktonic foraminifera and heterochrony. Studies of the Paleogene radiation of the genus Morozovella revealed, for example, a temporal pattern of variation consistent with paedomorphosis. Our study focused on the late Paleocene species of Acarinina, sister group of Morozovella. Shape variations related to evolution and ontogeny are appraised through a morphometric method based on outline analysis using the elliptic Fourier transform. Patterns of developmental and evolutionary changes are studied and compared within each species (Acarinina nitida, A. subsphaerica, and A. mckannai). As no congruence is found, we suggest that the evolutionary change observed within these species is not related to a heterochronic process. We also test for similarity of both evolutionary and ontogenetic changes among species. Although we observe no significant correlation between temporal patterns of shape change among species, the tight congruence of ontogenetic trajectories suggests that the developmental constraints affecting these trajectories have been preserved in spite of the evolutionary diversification of acarininids. Heterochrony is not clearly involved in the early Paleogene diversification of acarininids and therefore may not be as common as previously claimed. The role of developmental constraints in monitoring morphological evolution therefore needs to be reassessed.