P is for….Proteaceae

This is a group of plants very close to my heart. You could even say that I am addicted to them.

They have a huge Southern hemisphere distribution including South America, Africa, Madagascar, Australia, Indonesia and New Zealand. They are also very highly speciated with around 1700 different species among over 80 genera.

It comes as no surprise then that they have a fossil record that dates back all the way to the middle Cretaceous.

The earliest putative fossil record is dispersed pollen from (Late Cenomanian) Gabon in West Africa and has been assigned the name Trioris africaensis. It isn’t then until the Late Cretaceous (Santonian) that we find the first unequivocal proteaceous fossils in Australia. There are many species identified from fossil pollen found in the Otway basin, south eastern Australia. Some of these fossils are comparable to extant species. Macrofossils of the Proteaceae are less common, but are found. Of particular interest are leaves assigned to the extinct Banksieaephyllum and Banksieaeformis but also of the extant genera Banksia, and others, from Cenozoic Australia.

Many believe that the extinct and extant distribution of Proteaceae tell the story of how the ancient continent of Gondwana drifted apart. They do make a perfect example of Antarctic flora and their distribution has helped form the theory of continental drift. Not everyone is agreed on this though. Recent genetic evidence shows a close link between the Western Australian and Southern African species. Some believe this makes long distance seed dispersal an alternative force in their distribution and partially brings into question the mechanism by which they spread across the Southern Hemisphere.

They are represented in the fossil garden by species from South America, Africa, Australia and New Zealand and a walk around the garden to look at the species we have forms an interesting story of planet Earth’s prehistory.

Lomatia myricoides

 

Banksia ericifolia