Microcachrys has been called one of the most spectacular cases of
paleoendemism. It is a known relictual plant, being widespread in the past but now having a very restricted distribution. The only extant species today,
Microcachrys tetragona, produces a very distinctive pollen grain compared with other members of its family,
Podocarpaceae, and records of fossil pollen from the genus have been recorded from all over the
Southern Hemisphere throughout the
Cenozoic, being found in Antarctica, Australia, the now sunken islands of the Ninetyeast Ridge of the Indian Ocean, New Zealand, southern Africa and South America. Ocean drillings in the
Kerguelen Plateau near
Heard Island have revealed conifer remains with twigs very similar in appearance to those of
Microcachrys. The genus
Microcachrys clearly had a very broad,
Gondwanic distribution. But now, the sole surviving species,
Microcachrys tetragona, is a shrub restricted to Tasmanian mountain thickets and boulder-fields. The fossil record of
Microcachrys is one of many compelling lines of evidence which points to the highly dynamic and changing Southern Hemisphere vegetation through the Cenozoic since the break up of Gondwana. == References ==