Jurassic Park, Tasmania

 Michael – Thursday

Around 200 million years ago the landmass of this planet was mostly concentrated in one super continent, which was named Gondwana (retrospectively, of course).

Gondwana

About 180 million years ago during the Jurassic period, Gondwana started to break up. The theory behind that involves the movement of the tectonic plates that support the continents and the enormous forces within the Earth’s crust that drive them together and apart, and other complicated stuff. Anyway, over time the super landmass broke up and redistributed its mass around the planet. The practical evidence is the curious way in which the continents fit if you move them back together, as in the pictures. Of course, that might just be chance, but it seems a very unlikely one. There’s also the fact that the continents are still drifting apart – very slowly but measurably.

Pieces of the puzzle

That was also the period when flowering plants started to appear. Forty million years later, Africa and South America took their leave of the rest, and after another 50 million years India was heading north while Australia and Antarctica had just separated. The dinosaurs were around for another 35 million years, and after that the mammals had their turn.

Artist's impression of the Jurassic

So all this implies that there ought to be plant, reptile, and insect ancestors in the fossil record common to several different continents. And, indeed, there are.

Inala Jurassic Garden
...with a hint of the past...

Yes, dragonflies were well established by the Jurassic

That brings us to Inala Jurassic Garden in the south of Bruny Island south of Tasmania. The idea was to create a collection of plant families with examples from different parts of the world that can be traced back to the Jurassic days of Gondwana. It’s a wonderful project comprising nearly fifty plant families and seven hundred different species. Much has changed in the last 150 million years and the plant descendants have evolved and diverged over that time, yet they have very clear features that have survived, indicating their relationship with each other and with those long-ago early flowering plants.

Cypresses
No chance of the Tasmanian Tiger, I'm afraid

Blue cypress

Cypresses with the temperate forest behind

Jurassic barn

I’m very partial to the Proteaceae family of angiosperms that has a multitude of wonderful examples in South Africa – the most luxuriant examples being in the southern Cape. The family has two subfamilies. One, the Proteas themselves, must have evolved after Africa split from South America and Australia since it’s not represented on the latter continents; and the other, the Grevilleas, are widely distributed in Australia and South America. Pollen fossils tend to support their early connection to Gondwana.

King Protea from South Africa
The Australian bee seems happy enough!

Wonderful display of South African pincushion Proteas
I'm pretending to ignore them by watching birds

Silver trees (a type of Protea) and King Proteas

The irritating thing is that Inala Garden has superb examples of the African Proteas, better than mine!

Descriptions of the relationships between species

The point of the garden is that one can see a variety of plants that trace their roots (to coin a phrase) back a hundred million years to a time when all the Earth’s land was connected.

Australian Waratah

One of the Grevilea Sp

Inala has another function. It is a private nature reserve to preserve a piece of Tasmania’s temperate rain forest and especially the Eucalypt trees that are home to the Forty-spotted Pardalote, one of Australia's rarest birds. The birds are restricted to a few sites in south-eastern Tasmania, feeding exclusively around the white gums or manna gums. The sweet gum that collects on the tree trunks represents three quarters of the diet for fledglings, and only occurs on these trees. Perhaps not a great business plan. Inala has been planting these trees and supplying breeding boxes, and now has one of the largest remaining colonies of the birds, thus contributing to the specie's chance of survival. They have also constructed a tower between the trees so that you can get closer to the levels where the birds zoom around between the gums getting on with their lives.

Pardalote viewing platform

Here is a great photograph of one on them. (Remember that you will only find twenty spots on each side if you're tempted to count them.)

Forty-spotted Pardalote
Photo Ian Wilson

Inala means “a peaceful place” in the local Aboriginal language. It certainly is peaceful. But it’s a lot more than that.

View from Bruny Island

Thanks to Pat for the pictures from Inala.