The ecological requirements of inarticulated
brachiopods indicate the need for a lifehistory
approach that emphasizes aspects of
populations rather than individuals because
many such factors as reproduction, survivorship,
dispersion, and evolution depend on
populations. Accordingly there is no single
factor that determines the occupancy of a
niche by a population and that is always directly
related to the biocoenosis in which the
population is living. Those requirements
need to be analyzed carefully at the population
level before using them to interpret species
and genera.
Assemblages with lingulides are routinely
interpreted as indicating intertidal, brackish,
and warm conditions, but the evidence for
such assumptions is mainly anecdotal. In
fact, formation of lingulide fossil beds generally
occurred during drastic to catastrophic
ecological changes.