Hello Art,

Joe here. I sifted through my collection and literature. All of our
'Hormotoma' specimens are Ordovician or Silurian in age. This is mostly a
North American fossil (although also found 'rarely' in Europe). It was
usually placed (despite its outward appearance) until the 1940's  in the
superfamily Pleurotomariacea by some authors. Its kin, Mourlonia, somewhat
resembles descendents through to the Pleurotmaria.
Subsequesnt authors do not place it in this superfamily but place it  in
agroup archaeogastropods with no further lineage. It is thought to die out
in the Silurian. It is thought by most to have no relationship with the
modern pleurotomaria.
Most authors ( some exceptions) do not accept any known antecedents of the
modern Pleurotomaria until the Mesozoic age.
Your species 'gracilis' was first placed in the genus  Murchisonia (Hall,
1847) and subsequently changed by the author to Hormotoma sometime in the
1850's (I 'think').
    Nora and I just obtained a scanner and it is surprising how well it
scans small fossils. Sometime in the not too distant furue we'll scan some
paleozoic gastropods, mesozoic pleurotomaria, etc. and make them accessible
to Conch-L subscribers to view.



Original Message -----
From: "Art Weil" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, November 14, 2000 7:34 PM
Subject: Hormotoma


> Dear (probably Old Seashells and Andy);-
>         What I have here is a Hormotoma gracilis (maybe Homotoma?). It
> measures 13.48mm long and is about 400 million years old. Since a
> fleeting glance makes it look like an Epitonium (or Cerith or other
> coiled critter) I wondered if there is some descendency from the fossil
> that I have. Inquiring minds want to know.
>             Art