Fossils can shed new light on plant biogeography and phylogeny. Pinnately lobed leaves from the Oligo-Miocene Newvale lignite mine, South Island, New Zealand are the first extra-Australian leaf fossils of the charismatic genus Banksia (Proteaceae), and they are assigned to a new species, B. novae-zelandiae. Comparison with extant taxa shows that the fossils are best regarded as an extinct stem relative of Banksia because their available features are either plesiomorphic for the genus (notably, the stomata are superficially placed, not sunken in balloon-like pits as in many extant species) or lack evidence of synapomorphies that would enable them to be placed in the crown group. Banksia novae-zelandiae does, however, exhibit two cuticular features that are unique or highly derived for Banksia. These are rugulate subsidiary cell ornamentation and the presence of complex papillae that extensively cover the abaxial leaf surface. The fossils add to the widespread records of the pinnately lobed leaf form in Banksia in Australia beginning in the late Paleocene. This form is now limited to species confined to sclerophyllous heathlands of Mediterranean climate in southwestern Australia. Banksia novae-zelandiae could be part of a lineage that had a long history in New Zealand, perhaps dating to the early Paleogene.

Item Type:	Refereed Article
Keywords:	Banksia, crown group, cuticle, leaf fossils, long-distance dispersal, Proteaceae, stem group, vicariance
Research Division:	Biological Sciences
Research Group:	Evolutionary Biology
Research Field:	Biogeography and Phylogeography
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Biological Sciences
Author:	Carpenter, RJ (Dr Raymond Carpenter)
Author:	Jordan, GJ (Associate Professor Greg Jordan)
ID Code:	66824
Year Published:	2010
Web of Science® Times Cited:	21
Deposited By:	Plant Science
Deposited On:	2011-02-15
Last Modified:	2014-11-04
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