Once considered the simplest form of animal life, they are now known to consist of several distinct and unrelated groups of protists.

Amphibian A class of vertebrates that have to return to water to lay their eggs.

radioactive fossil dating definition-8

Paleontologist Björn Kurtén wrote a popular intelligent layperson book with the same title.

The Age of Mammals is also the name of a mural by Rudolph Zallinger for the Yale Peabody Museum (link), which follows his earlier and better known The Age of Reptiles.

Elsberry's talk.origins jargon FAQ (mirror as convenient single document text file and William Hudson's more readable glossary of terms, and also more relevant as a general evolution and science glossary (Talk Origins emphasises good and bad arguments, geek culture, etc.); the US Geological Survey Glossary of Terms, the Understanding Evolution Glossary, the PBS evolution Glossary, as well as Wikipedia: evolutionary biology topics, and other Wikipedia pages on evolution and Creation–evolution controversy; the Evo Wiki Encyclopedia (including Geology, Paleontology, Paleontologists, Evo Wiki: History of science, although more topics need to be added or listed, and some of my (MAK) own interests and definitions.

Where an entry is taken from a single reference, the source is given; sometimes where there it integrates a number of references none is.

To this day, this mural, along with a spindle diagram of vertebrate evolution in G. Well's Science of Life, have been the two central influences that determined the way I think about deep time and the evolution of life on Earth.

I think of Palaeos as in many ways simply an extension, update (in keeping with more recent discoveries) and commentary on this magnificent work.

Perfectly intermediate between reptile (or more correctly, theropod dinosaur) and modern bird, its discovery was powerful evidence for Darwinian evolution.

Archosaur derived from the Greek terms ἀρχός‚ (arkhos, "ruling") and σαῦρος‚ (sauros, "lizard"); it names any member of a major clade of tetrapods that includes birds, dinosaurs, pterosaurs, crocodiles, and their paraphyletic thecodont ancestors.

The Age of Reptiles is also the title of a 110-foot (30 meter) mural painted by Rudolph Zallinger depicting the time from the Devonian to the Cretaceous and featuring dinosaurs and other prehistoric animals (His The Age of Mammals mural is similar and covers the Cenozoic).