LAUSR

PREMISE The Lower Cretaceous Crato Konservat-Lagerstätte (CKL) preserves a rich flora including early angiosperms from northern Gondwana. From this area, the recently described fossil genus Santaniella was interpreted as a ranunculid (presumably Ranunculaceae). However, based on our examination of an additional specimen and a new phylogenetic analysis, we offer an alternative interpretation. METHODS The new fossil was collected from an active quarry for paving stones in the state of Ceará, north-eastern Brazil. We assessed support for alternative phylogenetic hypotheses using a combined analysis of morphological data and DNA sequence data using Bayesian inference. We used a consensus network to visualize the posterior distribution of trees and we used RoguePlot to illustrate the support for alternative positions on a scaffold tree. RESULTS The new material includes a flower-like structure not present in the original material and also includes follicles preserved at early stages of development. The flower-like structure is a compact terminal cluster of elliptical sterile laminar organs surrounding internal filamentous structures that occur on flexuous axes. Phylogenetic analyses did not support its placement among eudicots. Instead Santaniella appears to fall in the magnoliid clade. CONCLUSIONS The presence of seeds in a marginal-linear placentation and enclosed in a follicle supports the fossil as an angiosperm. However, even though most characters are clearly recognizable, its combination of characters does not provide strong support for a close relationship to any extant order of flowering plants. Its position under the magnoliid clade is intriguing, and based on plicate carpels it is definitely a mesangiosperm. This article is protected by copyright. All rights reserved.