A Late Cretaceous Piper (Piperaceae) from Colombia and diversification patterns for the genus.

Abstract

Documented fossil floras in the neotropics are sparse, yet their records provide evidence on the spatial and temporal occurrence of taxa, allowing for testing of biogeographical and diversification scenarios on individual lineages. A new fossil Piper from the Late Cretaceous of Colombia is described here, and its importance for assessing diversification patterns in the genus is addressed. Leaf architecture of 32 fossil leaf compressions from the Guaduas Formation was compared with that of 294 extant angiosperm species. The phylogenetic position of the fossil named Piper margaritae sp. nov. was established based on leaf traits and a molecular scaffold of Piper. The age of the fossil was independently used as a calibration point for divergence time estimations. Natural affinities of P. margaritae to the Schilleria clade of Piper indicate that the genus occurred in tropical America by the Late Cretaceous. Estimates of age divergence and lineage accumulation reveal that most of the extant diversity of the genus accrued during the last ∼30 Myr. The recent radiation of Piper is coeval with both the Andean uplift and the emergence of Central America, which have been proposed as important drivers of diversity. This pattern could exemplify a recurrent theme among many neotropical plant lineages.