>  >    Now get to the basic question: IS there handedness at all in
>  >fish, bugs, birds?

Organisms that are active enough to have detectable preferences often show a preference for one side or another in doing things, similar to humans being left or right handed.  Almost all of the carbon-based molecules in organisms show a distinct "handedness".  However, mollusks are relatively unusual in having many kinds that are normally distinctly asymmetric.  Many forminifera have snail-like coiled shells; these can be sinstral or dextral, too.  Bivalves with hinge teeth typically have different teeth in the left and the right, and there are rare individuals with the teeth swapped around, analagous to sinistrality in snails, except that some groups of teeth may swap while the others are normal.

>  >     In shells, it is the shell that is sinistral. How does that
>  >affect the critter in it?
>  >    Q Man

>  Sinistral shells don't affect the critter, as the critter MAKES the
>  shell. A reversed animal will make a reversed shell. So the entire
>  animal and shell are exact mirror-images of a normal specimen.

This includes the coiling direction of the operculum.  Thus, a fossil snail that preserves the operculum can be easily identified as sinistral or dextral.  Without the operculum, known close living relatives, or distinctive shell features (such as a siphonal canal), it is difficult to tell whether a specimen is orthostrophic, hyperstrophic, dextral, or sinistral.  This particularly arises for certain Paleozoic to early Mesozoic extinct snails (or maybe not even true snails!).

    Dr. David Campbell
    Old Seashells
    University of Alabama
    Biodiversity & Systematics
    Dept. Biological Sciences
    Box 870345
    Tuscaloosa, AL  35487-0345 USA
    [log in to unmask]

That is Uncle Joe, taken in the masonic regalia of a Grand Exalted Periwinkle of the Mystic Order of Whelks-P.G. Wodehouse, Romance at Droitgate Spa

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