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GNETOPHYTES & LEAF WARBLERS
Further to the recent discussion on this list about gnetophytes, I have a
One of Heilmann's most famous drawings is of a group of
ornithomimids walking around/feeding from a large plant that looks
something like a _Welwitschia_. Is it a _Welwitschia_ and, if not,
what is it?
RE: recent discussions on OW warbler systematics, I always thought
that _Phylloscopus_ was paraphyletic because Pallas' warbler (_P.
reguloides_) looks an awful lot like an intermediate between leaf
warblers and kinglets. However, phylogenetic analyses of plumage
patterns indicate that _Regulus_ is basal and outside of the clade that
includes _Acrocephalus_, _Phylloscopus_, _Locustella_ and _Cettia_.
These genera can all be distinguished osteologically - characters
include tarsal length, size and shape of naris, rostrum and forehead
shape and shape of pygostyle - but the boundaries are fuzzy.
It's not the genera but the species that are the big problem
osteologically: now they really are indistinguishable (WRT leaf
warblers and other passerine species flocks). And don't forget - DNA
indicates the presence of not one taxon within _Phylloscopus
sibilatrix_ but 15... cue arguments re: 'frog's eye view'.
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