The reconstruction based on Fossil 1 indicates that most of the cladogenetic
events of the suprageneric lineages were concentrated in a narrow interval between 25 and 50 Ma.
Of the 68 cladogenetic
events, 40 speciation events exhibit a biogeographic shift indicating speciation by dispersal (= 37.
In recent years, many cladograms have been published for the species of families and genera of Neotropical animals usually with no discussions of the nature of the vicariance events which caused the numerous cladogenetic
events underlying the speciation patterns depicted.
The fossil record, in combination with the phylogeny, yields minimum divergence times for cladogenetic
events, gives some insights into the temporal and geographic origin of species, and presents us with information about the numbers of extinct species and their characters.
These processes all reduce the adaptative possibilities that support cladogenetic
production (the <<hidden guillotine>>), in stark contrast to what happens in the relatively benign tropics.