Definition: A taxon is Extinct when there is no reasonable doubt that the last individual has died. A
taxon is presumed Extinct when exhaustive surveys in known and/or expected habitat,
at appropriate times (diurnal, seasonal, annual), throughout its historic range have failed
to record an individual. Surveys should be over a time frame appropriate to the taxon’s
life cycle and life form.
Definition: the transition region between the surf zone and the middle of the shelf, typically spanning water depths from a few meters to a few tens of meters.
Definition: A habitat that is in or on a body of water containing low concentrations of dissolved salts and other total dissolved solids (<0.5 grams dissolved salts per litre).
Definition: A sheet of saline water separated from the open sea by sand or shingle banks. The sheet of water between an offshore reef, especially of coral and mainland. The sheet of water within a ring or horseshoe shaped atoll.
Definition: A habitat that is in or on a sea or ocean containing high concentrations of dissolved salts and other total dissolved solids (typically >35 grams dissolved salts per litre).
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.
