ANP 201 Lecture Notes - Lecture 8: Faiyum Oasis, Paleocene, Oligocene
Document Summary
Lecture 8: fossils & their place in time & nature. Favorable media is sedimentary rock and volcanic ash. Fossil: the remains of an organism or of its presence preserved in rock. *taphonomy: the study of the deposition of organisms and the environmental conditions affecting their preservation. *fossilization requires an anoxic environment, where decomposition is limited. Other factors also affect preservation: death of animal/plant, organic decomposition, burial in sediments, organics are replaced by inorganic minerals, further burial, erosion and exposure. Recognition of possible biases is critical in interpreting the fossil record. *produce fossil evidence of primate evolution that ends at 31mya. *environmental change may have violated necessary conditions for fossilization. Species that live outside favorable conditions do not preserve. Larger organisms preserve more often than smaller organisms. Within individual fossils, large and/or hard bones preserve more often than small bones. Many methods are based on stratigraphy and the law of superposition. Many are based on radioactive decay and half-life.
