Now extinct, earliest group of fish with jaws, ranging from the Silurian to the Permian.

A surface separating layers of sedimentary rocks and deposits. A bedding plane marks termination of one deposit and beginning of another of different character, such as a surface separating a sandston [..]

A group of organisms comprising the kingdom Fungi within Domain Eukarya

Large area of extremely flat ocean floor lying near a continent and generally over 4 km in depth.

Organic-walled microfossils common throughout the Proterozoic and early Paleozoic

Any heritable characteristic of an organism that improves its ability to survive and reproduce in its environment. Also used to describe the process of genetic change within a population, as influence [..]

The diversification, over evolutionary time, of a species or group of species into several different species or subspecies that are typically adapted to different ecological niches (for example, Darwi [..]

A jawless, heavily armored fish that appeared in the Devonian.

Photosynthetic, almost exclusively aquatic, nonvascular plant-like organisms that appeared in the Precambrian and that range in size from simple unicellular forms to giant kelps.

One of the alternative forms of a gene. For example, if a gene determines the color of eyes, one allele of that gene may produce brown eyes and another allele produce blue eyes. In a diploid cell ther [..]