Potassium argon is a radiometric dating method that involves
Almost all the present phyla plants (Asterids - Verbena) appeared during this period, with the exception of Bryozoa, which are a phylum of aquatic invertebrate animals who made its earliest known appearance later, in the Lower Ordovician. First land plants occurs in the Ordovician, in the form of fossil spores.Land plants began to diversify in the Late Silurian, from around 430 million years ago, and the results of their diversification are displayed in remarkable detail in an early Devonian fossil assemblage from the Rhynie chert.Cretaceous–Paleogene Extinction Event is also known as the Cretaceous–Tertiary (K–T) extinction, was a mass extinction of some three-quarters of the plant and animal species on Earth that occurred over a geologically short period of time approximately 66 million years ago.With the exception of some ectothermic species like the leatherback sea turtle and crocodiles, no tetrapods weighing more than 25 kilograms (55 lb) survived.Gondwana is the name given to an ancient supercontinent.
Paleozoic Timeline of Plant Evolution (wiki) - Photosynthesis Horseshoe Crab Living Fossil is an extant taxon that closely resembles organisms otherwise known only from the fossil record. Carboniferous is a geologic period and system that spans 60 million years from the end of the Devonian Period 358.9 million years ago (Mya), to the beginning of the Permian Period, 298.9 Mya. Hangenberg Event is a bioevent that occurred at the end of the Famennian epoch (late Devonian) associated with the Late Devonian extinction (roughly 358.9 ± 0.4 million years ago); Bioevent is an event recognised in a sequence of sedimentary rocks, where there is a significant change in the biota as recorded by assemblages of fossils over a relatively short period of time.The photo above is not to make you feel insignificant, it is only for reference and scale. Depending on your field of view, you would have to be around 100,000 light years away to see this Galaxy using the naked human eye.And as you got closer, it would almost disappear because of the tremendous amount of space there is between everything, like with atoms.Gondwana formed prior to Pangaea, and later became part of it.Continental Drift - Earths Surface Dinosaurs go extinct.