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 \r\nlife cycle and life form.
Definition: A 1D measurement of a single cell. Typically, this is the distance along a straight line connecting the left-most part of the cell to the right-most part of the cell. It is perpendicular to the length axis and the depth axis.