>Where was it found?   There are silicified deposits
>throughout the geologic record, so it could be just about
>anywhere from the Ordovician to the Pleistocene.  Although
>the Cardioidea first appear in the Triassic, there are
>unrelated Paleozoic species with enough superficial
>resemblance to cardiids to have been called Cardium back
>in the 1800's.

Cardiidae goes back to at least the late Triassic (Norian), with Septocardia.

>I feared this answer... The problem is simple:
>Here in Bremen, Germany the harbor was not deep enough
>and they removed alot of sand & stones from it. In a
>area near the harbor they deposite that sediments.
>There i find the fossil...
>
>Flintstone in this ice age sediments (when i remember
>right this city stands on a big sand dune build up in the
>ice age) is not really uncommon - but it should not really
>help to determinate the age when i understand it right.

Then you'll have to identify it from the specimen itself from scratch.
--
Andrew Grebneff
Dunedin, New Zealand
64 (3) 473-8863
<[log in to unmask]>
Fossil preparator
Seashell, Macintosh & VW/Toyota van nut
I want your sinistral gastropods!
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Q: Because it reverses the logical flow of conversation.
A: Why is top posting frowned upon?