Bivalves In Burrowing Organisms

VI.2 Paleoecology and paleoenvironment: The investigated Middle Miocene rocks of Siwa Oasis contain a rich macroinvertebrate fauna. A total of 1,618 sample were collected, dominated by oysters (58.03%), pectinids (12.54%), echinoids (5.68%), bivalves (14.77%), and gastropods (8.96%) (Fig. 39). Instead of their great abundance they surprisingly show a low diversity, and they are randomly distributed all over the successions (Figs.12, 13, 15, 17). But it is noticeable that the Oasis and Escarpment

mass extinction is high levels of toxic compounds released from volcanic activity. Directly around volcanic activity in the rift zone, there perhaps would have been high levels of Fluorine and Chlorine, both of which could have directly poisoned organisms. These large ejections of Chlorine and Fluorine could have led to ozone depletion and acid rain (McHone 2003). However, due to the fact that high levels of either of these compounds would have caused extinction without prejudice, the actual role

Introduction: The sandy shores of beaches can be considered as a very harsh environment to live in (Ted Klenk, 1999). Survival in such a habitat requires an organism to withstand strong wave and current action, tidal rise and fall, unstable substrate, heavy predation and wide variations in salinity and temperature (The Otter Island Project). Any organism found in this type of harsh environment is specialized and highly adapted (The Otter Island Project). Fine, sandy beaches often occur in areas with