Distribution and zoogeographical analysis of amphicrossinae (Coleoptera: Nitidulidae)
摘要
Amphicrossinae is represented by a single genus Amphicrossus Erichson, 1843. This subfamily exhibits a wide distribution range and its representatives are found in all the major zoogeographical realms of the world. The current distributional profile, which had happened in past, can be traced from the circumstantial pointers. It showed differential dominance of the species, plasticity or range of the species, sharing of fauna of one realm with others, degree of uniqueness (endemicity) and commonness. The high degree of endemicity indicates the centre of origin of the group; degree of dominance and sharing of species indicates segregation of species and dispersal of lineages in larger geographical areas across time. The most common recent ancestor of the Amphicrossus-lineage might have evolved in the Lower Tertiary period in the African Continent. They migrated to the sub-Himalayan terrain during Miocene, and dispersed and diversified in Southeast Asia and further eastwards in Pliocene and Pleistocene. A small lineage of the primary Amphicrossus assemblage might have entered into Europe and later invaded North America probably during Miocene- Pliocene transition phase. The North American migrants moved southwards and crossed into South America in later phase. Plate tectonic events of Earth, sea level changes and climate fluctuations had obviously influenced their distributional course in geologic past. Historical zoogeography and current distributional pattern of the genus Amphicrossus have been presented here.