Vertebrate Paleontology - Geological Time Scale
Introduction
- Lecturer: Benjamin Burger
- Course: Vertebrate Paleontology, Utah State University
- Focus: Geological time scale development based on fossils
Geological Time Scale Overview
- Phanerozoic Eon:
- Time span: 541 million years ago to present
- Divided into three eras:
- Paleozoic Era:
- Periods:
- Cambrian
- Ordovician
- Silurian
- Devonian
- Carboniferous (Mississippian and Pennsylvanian in the US)
- Permian
- Mesozoic Era:
- Periods:
- Triassic
- Jurassic
- Cretaceous (Time of the dinosaurs)
- Cenozoic Era:
- Traditional periods:
- Recent division:
- Paleogene
- Neogene
- Quaternary
- Epochs within the Cenozoic:
- Paleocene
- Eocene
- Oligocene
- Miocene
- Pliocene
- Pleistocene
- Holocene
Development of the Geological Time Scale
- Reason for Period Names:
- Based on fossil records rather than specific dates
- Allows easier geological dating and correlation
- Comparison to Photo Album:
- Geological records akin to organizing a photo album by life stages
- Absolute dates (like birthdays) are known but not always specific for each 'photo' (fossil)
- Dating Techniques:
- Absolute dating requires igneous rocks and laboratory settings
- Fossils provide a quicker and cheaper method of dating rocks
Role of Index Fossils in Geological Dating
- Definition:
- Fossils used to identify and date rock layers
- Characteristics of Good Index Fossils:
- Distinctive
- Widespread
- Abundant
- Limited time span
- Marine and Terrestrial Index Fossils:
- Most are marine due to common fossil formation in oceans
- Terrestrial examples include common mammals like rodents
Conclusion
- Memorization:
- Importance of memorizing the geological time scale
- Further Learning:
- Visit the Utah State University geology website or Benjamin Burger’s personal site for more information
Links to additional resources are provided in the lecture description.