Any of a group of microorganisms that resemble bacteria but are different from them in certain aspects of their chemical structure, such as the composition of their cell walls. Archaea usually live in extreme, often very hot or salty environments, such as hot mineral springs or deep-sea hydrothermal vents, but some are also found in animal digestive systems. The archaea are considered a separate kingdom in some classifications, but a division of the prokaryotes (Monera) in others. Some scientists believe that archaea were the earliest forms of cellular life. Also called archaebacterium.
a reptilelike fossil bird of the genus Archaeopteryx, from the late Jurassic Period, having teeth and a long, feathered, vertebrate tail. Historical Examples It is in this matter that the famous archaeopteryx plays an important part. At the Deathbed of Darwinism Eberhard Dennert The birds we described (after the archaeopteryx) also belong to the Cretaceous, […]
noun an extinct primitive Jurassic bird, formerly placed in the genus Archaeornis but now thought to be a species of archaeopteryx
. noting or pertaining to the earlier half of the Precambrian Era, from about 5 billion to 2.5 billion years ago, during which the earliest datable rocks were formed and from which the oldest known fossil forms, blue-green algae and bacteria, have been recovered. the Archeozoic division of geologic time or the rock systems formed […]
noun the analysis and interpretation of animal remains found at archaeological sites