Middle Ordovician conodonts from the Atlantic Faunal Region
and the evolution of key conodont genera.
Yet on the local scale of a single water mass or faunal region
in the midwater, the species richness may be high; hundreds of kinds of fishes, crustaceans, and gelatinous animals can be caught in a single trawl.
The tribe Cryptotympanini Handlirsch, 1925 currently includes 20 genera that are distributed in all faunal regions
except continental Africa (Sanborn 2013).
1963 A preliminary study of the demarcation of marine molluscan faunal regions
of China and its adjacent waters, Oceanologia et Limnologia Sinica 5: 124-38.
1990) used cluster analysis and detrended reciprocal averaging (DRA) to examine the distributional data for terrestrial reptiles and found discrete faunal regions
with complex zones of transition between the regions (Fig.