IMPROVING WITH AGE - THE FOSSIL RECORD OF LINGULIDE BRACHIOPODS AND THE NATURE OF TAPHONOMIC MEGABIASES

Variation in the actual preservation of fossils can be used to detect taphonomic megabiases-large-scale distortions caused by changes in the quality of the fossil record. For example, temporal changes in the ta phonomy of lingulide brachiopods suggest that Paleozoic lingulides had a higher fossilization potential than the post-Paleozoic ones. The fr equency of stratigraphic occurrences of lingulides covaries with their fossilization potential. Thus, the apparent decline in the importance of lingulides in Phanerozoic communities may be due to changes in the ir fossilization potential. Taphonomic megabiases may be very common. We distinguish four major types of megabiases: within taxon, static am ong taxon, dynamic among taxon, and global.