spiral fossilized shells

ages ammonites ancient animal antediluvian aragonite archaeologist archeology arthropods background calcite calcium chalk chemical circles deposit diagenesis dinosaur excavation exhibit fauna find fossil fossilized fossils geology gray huge insect limestone mineral molluscs mollusks museum organism paleontologist paleontology persisted physical plane precambrian print relic remnants rock sediment shell shells silica sink skeleton snails spiral stone texture trace tracks transformations transition