Dear Harry and others,
I was under the opinion that chomata is restricted to the subfamily
PYCNODONTEINAE, family GRYPHAEIDAE. To me this suggests that Ostrea
denticulata Bone belongs in another genera included in the subfamily
Pycnodonteinae. Dick Squires described an Eocene oyster from Baja
California that is similar to that described in the earlier email, looking
like a Dendostrea but with chomata and I believe he used the genus
Pycnodonte (sorry I can't find the paper at the moment). I also have a
species of oyster from the late Miocene part of the Imperial Formation
(proto-Gulf of California) in Riverside County, southern California that
has chomata and is very similar in form to Dendostrea? vespertina (Conrad)
(subfamily LOPHINAE, family OSTREIDAE). Perhaps a new genus is need in the
subfamily PYCNODONTEINAE, as Pycnodonte doesn't have well formed radial
ribs, and Hyotissa, which does, also has hyote spines which are not found
in the two west coast species.
Best,
Chuck
Charles L Powell, II
Western Earth Surface Processes Team, MS 975
U. S. Geological Survey
345 Middlefield Rd.
Menlo Park, CA 94025
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(650) 329-4985
"Harry G. Lee"
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> cc:
Sent by: Subject: Re: Oyster enigma
Conchologists
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04/30/05 01:38 PM
Please respond to
Conchologists
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Dear Charlie and ostreiphiles,
I consulted the Veliger work cited below and found no mention of (or match
for) Ostrea denticulata Born, 1778. Based on the semilunar adductor scar,
the illustrated specimen (Born, 1780; pl. 6, figs. 9,10) appears to be an
ostreid (vs. gryphaeid) with chomata (internal marginal pustules) extending
to the ventral aspect of the "parasitic" (Born) left valve - the one
cemented to the substrate. This valve appears to be rather convex; the
right valve is flat or concave and much smaller - not reaching the margin
of its mate. In short, Born's species looks like a cross between the
ostreid Dendrostrea and the gryphaeid Pycnodonte cochlear (Poli, 1795).
I don't think we know the identity or provenance of Born's species. It
appears that it may not be the same as the one that Mr. Kerckhof described
to us.
Harry (Lee; not the late Harold)
Born, I. A., 1780. Testacea Musei Caesarei Vindobonensis, quae jussu
Mariae Theresiae Augustae. J. P. Kraus, Vienna. ii + 1-442 + xvii
[unpaginated indices].
At 02:19 PM 4/30/2005, you wrote:
One can also consult the following paper which may help in
determining the
generic assignment:
Harry, Harold W. 1985. Synopsis of the supraspecific classification
of living oysters (Bivalvia: Gryphaeidae and Ostreidae). Veliger 28:
121-158. 30 figures. Oct. 1.
Regards,
Charlie
******************************************************************************
Charlie Sturm, Jr
Research Associate - Section of Mollusks
Carnegie Museum of Natural History
Pittsburgh, PA, USA
Harry G. Lee, M.D.
Suite 500
1801 Barrs Street
Jacksonville, FL 32204 USA
voice (904) 384 6419
fax (904) 388 1827
email: [log in to unmask]
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