The emergence of core eudicots: new floral evidence from the earliest Late Cretaceous
2016 (English)In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 283, p. 1-9, article id 20161325Article in journal (Refereed) Published
Abstract [en]
Eudicots, the most diverse of the three major clades of living angiosperms, are first recognized in the latest Barremian–earliest Aptian. All Early Cretaceous forms appear to be related to species-poor lineages that diverged before the rise of core eudicots, which today comprise more than 70% of angiosperm species. Here, we report the discovery of a well-preserved flower, Caliciflora mauldinensis, from the earliest Late Cretaceous, with unequivocal core eudicot features, including five sepals, five petals and two whorls of stamens borne on the rim of a floral cup containing three free carpels. Pollen is tricolporate. Carpels mature into follicular fruitlets. This character combination suggests a phylogenetic position among rosids, but more specific assignment is precluded by complex patterns of character evolution among the very large number of potentially relevant extant taxa. The whorled floral organization is consistent with ideas that this stable pattern evolved early and was a prerequisite for more integrated patterns of floral architecture that evolved later. However, limited floral synorganization in Caliciflora and all earlier eudicot flowers recognized so far, calls into question hypotheses that substantial diversification of core eudicots had already occurred by the end of the Early Cretaceous.
Place, publisher, year, edition, pages
Royal Society of London , 2016. Vol. 283, p. 1-9, article id 20161325
Keywords [en]
fossil flower, rosids, asterid, SRXTM, synchrotron X-ray microtomography, tricolporate pollen
National Category
Natural Sciences Other Earth and Related Environmental Sciences
Research subject
Diversity of life; The changing Earth
Identifiers
URN: urn:nbn:se:nrm:diva-2247DOI: 10.1098/rspb.2016.1325OAI: oai:DiVA.org:nrm-2247DiVA, id: diva2:1066527
Projects
VR 2014-5228: Blomväxternas tidiga historia och vegetationsutveckling under krittiden
Funder
Swedish Research Council, 2014-52282017-01-182017-01-182017-11-29Bibliographically approved