[Taxacom] Lamiaceae clade-Acanthaceae clade divergence time

Kenneth Kinman kennethkinman at webtv.net
Wed Nov 9 16:06:26 CST 2011


Hi Ashley,         
       I particularly enjoyed the recent paper by
Schaeferhoff et al., 2010, although it mainly deals with molecular data
(so it wouldn't help much with the morphology which you are studying). I

would think comparison with the morphology (especially the
micromorphology) of immediate sister groups to the clade in question
would be very useful (especially Stilbaceae and basal genera in
Scrophulariacae).      

        As for dates of origination for the clades
within Lamiales, Schaeferhoff 2010 indicated that it was still somewhat
premature to do so.   However, I've seen mention of a "pending"
Salvia-type pollen from the Coniacian of Africa (Gabon), but that was in

literature in the 1980s. Does anyone know what that pollen turned out to

be?                
      If that pollen was from some member of Lamiaceae, and
being 85.8 to 89.3 million years old, that would perhaps make your
Lamiaceae-Acanthaceae, etc. clade roughly 90 million years old (which
would fit nicely with a roughly 96-million-year age of crown group
Lamiales). However, if there wasn't any Lamiaceae pollen in the
Cretaceous, the earliest Lamiaceae pollen may be that found in the
Eocene of China, and the Lamiaceae may have arisen during the Paleocene
or Early Eocene (far later than 90 million years ago).   
                              -------Ken                  
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