Superposition is a relative age dating principle which states
Paleontologist Edwin Colbert wrote a popular intelligent layperson book with the same title.The Age of Reptiles was followed by the Age of Mammals.The traditional term "amphibian" is disliked by cladists because it does not constitute a natural clade and so is considered phylogenetically meaningless.Hence instead terms like basal tetrapod or the names of individual clades and taxa (temnospondyls, lepidospondyls, Lissamphibia, etc), are used. Archaea one of the three domains of life in the molecular phylogeny described by Carl Woese (originally Archaeobacteria, renamed Archaea by Woese et al 1990), prokaryotes that are metabolically and morphologically distinct from Eubacteria; includes many types of extremophiles, remnants from the earlier history of the earth. 2010 and other refs) rejects ancient origin on morphological and paleontological grounds.The Age of Reptiles was at one time the largest painting in the world, and depicts a span of nearly 350 million years in Earth's history.
Amoeba A microscopic, single celled protozoan consisting of a naked mass of protoplasm.Due to constraints of time, I have not hyperlinked the entries, nor is this listing complete.In addition, because of limitations of time and energy, or perhaps just sheer laziness and apathy, I have for the most part only included on-line references, which are easier to copy and paste ;-) Age of Mammals term found in popular books on evolutionary systematics for the Cenozoic era, beginning with the Paleocene Epoch when following the K–T (end Cretaceous) mass extinction, mammals underwent a huge evolutionary radiation and thus replaced reptiles as the dominant life on Earth.Dodson was nearly moved to tears upon first seeing it as a college senior.Editor's note: In my own case (MAK), a photo of this mural in a book (I no longer remember which one) when I was still a young child (maybe 10 or so) exerted a huge influence on me, like a revelation, and for the first time gave me a visual appreciation of deep time in terms of succession and transformation of various forms of plant and animal life.