Definition: A taxon is Extinct when there is no reasonable doubt that the last individual has died. A \r\ntaxon is presumed Extinct when exhaustive surveys in known and/or expected habitat, \r\nat appropriate times (diurnal, seasonal, annual), throughout its historic range have failed \r\nto record an individual. Surveys should be over a time frame appropriate to the taxon’s life cycle and life form.
Definition: overall repetitive or reflective pattern in the body of one individual of this taxon. eg: bilateral symmetry, rotational symmetry, radial symmetry
Definition: Living in the fluid medium (water or air) but unable to maintain their position or distribution independently of the movement of the water/air mass (adapted from Lincoln et al., 1998).
Definition: The marine benthic biome (benthic meaning 'bottom') encompasses the seafloor and includes such areas as shores, littoral or intertidal areas, marine coral reefs, and the deep seabed.
Definition: The number of fossil occurrences in the Paleobiology Database (https://paleobiodb.org) that are identified as belonging to a particular taxon or any of its subtaxa.
Definition: Hard framework, internal or external, which supports and protects softer parts of plant, animal or unicellular organism, and to which muscles usually attach in animals, includes skeletons (derived from Lawrence, 2005).
Definition: A compound eye with no separation between the crystalline-cone layer and the retinula, each rhabdom receiving light only from its own corneal lens.
