Cretaceous Period Dinosaur Fossils Excavation Paleobiology Jurassic Period Footprint Analysis Triassic Period Cyanobacteria Fossils Footprints Dental Analysis Microfossils Oldest Fossils Thylakoid Membranes Ancient Organisms Fossil Preservation Discovery Opal Fossils Marine Fossils Opalization Fossil Record Late Cretaceous Pterosaur Fossils Carboniferous Period Rock Identification Paleoecology