| Both faunal endemicity and provincialism in the mid- and Late Cretaceous of the Pacific realm complicate the recognition of stage boundaries in that area. Correlations with other areas (e.g., Europe, United States Western Interior, Pacific coast of North and South America) therefore have to rely solely on event stratigraphy; not only extinctions, but all biotic events must be considered. During the Cretaceous, Pacific faunas were characterised not so much by the presence of typical ‘Boreal’ assemblages, but rather by the absence or extreme paucity of other widely distributed biota. Clearly, faunal similarities depended more on regional facies development than on their spatial distribution. The regional diversity curve reflects all global mass extinctions,... |
