>
> >By the way, Lynn Scheu, bless her heart, tracked down
> >the cowry for me and sent a scan.  It is, for sure:
> >
> >Sulcocypraea vaughani Johnson, 1889
>
> I believe Sulcocypraea is currently considered an ovulid, despite its
> cowry-like appearance.  It is more common than Cypraeorbis in the Gulf
> Coast Eocene and also occurs in the Eocene silicified fauna near
> Orangeburg, S.C.
>
> Incidentally, the Gulf Coast Eocene faunas are typically a lot smaller than
> those in the limestones in the Carolinas and Florida.  Not sure if this is
> gigantism or dwarfism.
>
> The gigantism in mollusks at the cold end of their ranges has been
> attributed to a lack of suitable breeding conditions.  The energy that
> would be put into reproduction is put into growth instead.  However,
> Florida and mid to outer shelf of the Carolinas was probably warmer rather
> than colder than the Gulf.
>
> David Campbell



David Campbell is, of course, correct. David Dockery does indeed list
Sulcocypraea as an ovulid, though most of them were originally described
as "Cypraea."  What I did for Don Barclay was hunt through the volumes
of David Dockery's work on Mississippi fossils and send him all the
cypraeacean pictures I could find for him to look at, along with the
plate captions. It seems the Eocene of East Texas and Mississippi share
a lot of the same stuff. Also areas of SC, LA, AL.

And I noticed, David, that all the cypraeacean species from Mississippi
were quite small, just as you say, both ovulids and cypraeids.  Isn't it
so that some Indo-Pacific cowrie species get larger as you go south,
into colder water, and much smaller near the equator? The cold to warm
water effect would apply hre, right?

For those who are interested, these were the Mississippi species I found
and the sizes of the pictured specimens:

Cypraeidae:
Bernaya (Protocypraea) mississippiensis (Groves, 1990) 21.5 mm X 13.7
mm. Upper Cretaceous

Cypraeorbis sphaeroides (Conrad, 1848a) and Cypraeorbis aff. C.
sphaeroides holotype 32.5 mm Lower Oligocene

Cypraeorbis aff. C. ventripotens (Cossmann, 1903) 24.6 mm X 17.7mm (syn.
C. pinguis Conrad, 1854) late Eocene to Lower Oligocene.m (Dockery
thinks this is at most a subspecies of C. sphaeroides though he
qualifies his judgment with the fact that he has seen few specimens)

Ovulidae:
Sulcocypraea lintea (Conrad, 1848) 16 mm (A pretty little spirally
sculptured thing! Lower Oligocene

Sulcocypraea lintea menthafons MacNeil, 1984 Lower Oligocene 15.7mm

Sulcocypraea healeyi (Aldrich, 1894) Under 20 mm. Eocene

Sulcocypraea vaughani Johnson, 1889 14.3 mm Eocene

Sulcocypraea kennedyi (Harris, 1895) 13 mm Eocene

The periods I have assigned may extend in either direction, for all I
know.

These books of Dockery's on the Mississippi fossil mollusk fauna are
really exciting...definitely moving the molluscan fauna backward out of
the Pliocene...as far as the Upper Cretaceous...if you want to see
something spectacular, the Aporrhais of the Cretaceous are out of sight!
I can get ordering info and titles if anyone wants.

Lynn Scheu
Louisville KY
[log in to unmask]
Time to Pay Your 2000 COA Dues!
Plan now to go to Houston in June 2000!