Tasmantis is the huge continental fragment that broke off from Gondwanaland 80 million years ago. Currently most of this landmass has eroded and is submerged, except the islands of New Zealand and New Caledonia which experience the uplift of colliding tectonic plates. During Glacial periods more of this landmass becomes a terrestrial rather than a marine environment.
In New Zealand there is a place called Curio bay in the Catlins- the southern east coast of the South Island. Here can be seen the logs of a fossilized forest that was once growing on terrestrial Tasmantis.
The term Tasmantis for this land mass was coined by the biogeographer Charles Fleming.