GEOL 105 Lecture Notes - Lecture 3: Trace Fossil, Permineralization, Comparative Anatomy

• School: College of Charleston
• Department: Geology and Environmental Geosciences
• Course: GEOL 105
• Professor: Buetel

Document Summary

Greater differences in dna = older last common ancestor. Fossil record indicates changing morphology and function over time. Fossil : ancient life form whose body and/or impression is preserved in rock. Preservation of the whole or part of the bodily remains of an organism, or their impression in surrounding natural materials. Preservation of evidence of the activity of organisms. Trace fossils, or ichnites , include the preserved traces, burrows, and tracks of once-living organisms. Degraded organic substances from the molecules of living organisms. Occurs when the original material (bone, shell, organic plant matter) is replaced. Minerals carried in groundwater may be deposited in the empty spaces within by minerals. When a plant or animal dies and is buried by sediment, hydrogen and oxygen are eliminated, resulting in a carbon etching. Plant leaves are often fossilized in this manner. Natural molds occur when the original skeletal part dissolves, leaving an impression in the surrounding rock.