| [Thread Prev] | [Thread Next] | [Thread Index] | [Date Prev] | [Date Next] | [Date Index] |
>And also, can anyone tell me how to distinguish, using only shells, monoplacophorans >from limpet-type gastropods? Some types of limpets have distinctive shell mineralogies or microstructure. If there's preservation of muscle scars, that's the best indication. Serial repetition of muscle scars is prvery probably a monoplacophoran (though it's conceivable); a single asymmetric scar is rather suggestive of a torted gastropod. A single symmetric scar is ambiguous. Some limpet-shaped snails have distinctive muscle scars such as a horseshoe shape. If there's a protoconch, that might help. However, there are a lot of forms, especially in the Paleozoic, where no specimens are known to preserve adequate detail to definitively assign the taxon to a class. Limpets usually don't give much help from shell shape, but in some taxa it's possible to compare what the water flow would be for a torted or untorted animal and see which one works better. I think it was Paul Morris who did this for macluritids. Dr. David Campbell 425 Scientific Collections Box 870345, University of Alabama Tuscaloosa AL 35487-0345 "James gave the huffle of a snail in danger/ But no one heard him at all."-A. A. Milne
Partial index: