title: Paleocene Malvaceae from northern South America and their biogeographical implications.
abstract: OBJECTIVE
  The clade Bombacoideae + Malvoideae ('Malvatheca group' sensu Baum et al.) in Malvaceae comprises a mostly tropical lineage with derived taxa that now thrive in higher latitudes. The sparse fossil record, especially for Malvoideae, obscures interpretations of past distributions. We describe fossil leaves of Malvoideae from the middle-late Paleocene Cerrejón Formation in Colombia, which contains evidence for the earliest known neotropical rainforest.
  
  
  METHODS
  Fifty-six leaf compressions belonging to Malvaceae were collected from the Cerrejón Formation in northern Colombia. Leaf architectural characters were scored and optimized for 81 genera of Malvaceae. Synapomorphic characters and unique character combinations support natural affinities for the fossil leaves. Fossil pollen from the same formation was also assessed.
  
  
  RESULTS
  Despite convergence of overall leaf architecture among many Malvaceae, Malvaciphyllum macondicus sp. nov. can be assigned to the clade Eumalvoideae because of distal and proximal bifurcations of the costal secondary and agrophic veins, a synapomorphy for this clade.
  
  
  CONCLUSIONS
  The leaf compressions, the oldest fossils for Eumalvoideae, indicate a minimum divergence time of 58-60 Ma, older than existing estimates from molecular analyses of living species. The abundance of eumalvoid leaves and of bombacoid pollen in the midlate Paleocene of Colombia suggests that the Malvatheca group (Malvoideae + Bombacoideae) was already a common element in neotropical forests and does not support an Australasian origin for Eumalvoideae.
authors.affiliation: Instituto de Biología, Universidad de Antioquia, Medellín, Colombia. moccada@gmail.edu
authors.forename: Mónica R
authors.initials: MR
authors.lastname: Carvalho
authors.forename: Fabiany A
authors.initials: FA
authors.lastname: Herrera
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Jaramillo
authors.forename: Scott L
authors.initials: SL
authors.lastname: Wing
authors.forename: Ricardo
authors.initials: R
authors.lastname: Callejas
mesh_terms: D005580:Fossils; D019660:Malvaceae / Q000145:classification / Q000502:physiology*; D058974:Phylogeography / Q000379:methods; D018515:Plant Leaves / Q000145:classification / Q000502:physiology*; D011058:Pollen / Q000502:physiology; D013020:South America; D013045:Species Specificity; D014197:Trees / Q000502:physiology; D014329:Tropical Climate