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RE: Henocitta brodkorbi
--- firstname.lastname@example.org schrieb:
> HI ALL:
> I was wondering if anyone has any literature
> citations on: Henocitta brodkorbi? I was wondering
> if any reconstructions have been done on it? Was it
> from the early or late Pleistocene? What are it's
> closest living relatives?
It was described from the Arredondo Clay at Williston,
Florida. The original description has Illinoian (=
Wolstonian, late Middle Pleistocene). I don't know if
it was found anywhere else; in 1972 at least it was
not; only the type material (distal left humerous,
Pierce Brodkorb collection UF/PB 2323 probably - not
(yet?) in FLMNH databases though) was known then. It
has not been quantitatively analyzed to date I think.
The original description is online here:
A bit of further data is in the description of
The dimensions allow for a rather good size estimate:
_Henocitta_ presumably was a bird as much larger than
a Clark's Nutcracker as that is larger than a Pinon
Thus it was quite exactly the size of a Eurasian Jay
_Garrulus glandarius_ (c.30-35 cm) if short-tailed, or
of a small White-throated Magpie-jay _Calocitta
formosa_ (about 45 cm) if long-tailed (or in between -
That is of course with all the caveat emptors that
need to be applied when inferring from a single piece
The genus description says:
"Closest to _Psilorhinus_ [...] in distal length of
entepicondyle, extent and depth of brachial
depression, shape of internal condyle." and that it
seems less close to _Calocitta_.
The brachial depression character is likely a
plesiomorphy however. As per the Condor paper, it is
also similar in _Gymnorhinus_ _Aphelocoma_,
_Nucifraga_, _Cissa_ and _Dendrocitta_ but very
shallow in the crows and "true" (Hoarctic
black-and-white) magpies and the Old World jays
(_Garrulus_ clade). As you can see here:
the character state of _Henocitta_ is found in two
branches of Corvidae that are separated by one where
the alternate state (lesser depression) exists.
But given the late age and its range, there are
basically just 3 possibilities remaining:
* late survivor of an (unknown) extinct lineage
* American (blue/green) jay (that includes
_Psilorhinus_ is now in _Cyanocorax_ (but this may not
necessarily be correct). In any case, they together
with _Calocitta_ are a robustly-supported clade. And
therefore the most consistent scenario is that
_Henocitta_ was a member of that clade also.
As regards reconstructions, this is very difficult. We
can assume that it was a tree-dwelling bird with a
fairly but not excessively long tail, making for a
total length of about a little over 35 cm or so. Among
birds living today, the Purplish-backed Jay
or the Black-chested Jay _Cyanocorax affinis_
would seem a very close match in general shape, size
Assuming the above relationships are correct:
_Henocitta_ may or may not have had a forehead or top
crest. It is reasonable to assume (but not certain)
that the upperside was largely blue or dark bluish.
The underside was more likely than not lighter,
possibly white. It is also likely that there was some
amount of black on the head, perhaps a complex
pattern, perhaps the entire head was black.
But phylogeography of the blue jay subclade to which
it seems to belong does not map well on color pattern
evolution; there seems to have been strong character
displacement initially and partial reversal in
allopatry later (apparently the more ancient lineages
of _Cyanocorax_ are the most distinct from their
relatives as regards coloration).
It is quite likely that the young of _Henocitta_ had a
yellow bill and the adults a black one. The feet and
legs were probably dark at least in adults. The iris
was either dark or yellow.
All this is of course complete inference that cannot
support a dedicated quantitative analysis, and
therefore is to be taken with a generous dose of salt.
PS: if you find out anything else, let me know OK?
Heute schon einen Blick in die Zukunft von E-Mails wagen?