Study Notes Australian Biota
Preliminary Biology: Topic Summary
Australian Biota
Matt Elrick
1. Evidence for the rearrangement of crustal plates and continental drift indicates that
Australia was once part of an ancient super continent
1.1 Identify and describe evidence that supports the assertion that Australia was once part of a landmass called Gondwana, including:
- matching continental margins
- position of mid-ocean ridges
- spreading zones between continental plates
- fossils in common on Gondwanan continents including Glossopteris and Gangamopteris flora , and marsupials
- similarities between present-day organisms on Gondwanan continents
Matching continental margins:
- The continents fit together like a jig-saw puzzle. Rocks on the opposing edges are exactly the same.
Mid-ocean ridges and spreading zones:
- Mid-ocean ridges form the boundaries of Earths crustal plates where plates move apart.
- The plates move because lava is added to these ridges.
- New rock is found in the ridge – the further away from the ridge, the older the rock
Fossils in common on Gondwana continents:
- Fossils of Glossopteris and Gangamopteris plants have been found on all Gondwana continents, nowhere else.
- Also, marsupials provide evidence for plate tectonics and the past existence of
Gondwana. When Australia became isolated from the rest of the world, the marsupials’ evolved and diverse species flourished. Some species of quoll and marsupial mice have several features in common with South American marsupials.
Similarities between organisms on Gondwana continents:
- Flora of southern continents – South America, South Africa, Australia and New Zealand has many features in common.
- Flightless birds have been examined, these include the Rhea (S. America), Emu and
Cassowary (Australia), Ostrich (Africa) and Kiwi (New Zealand). The distribution of these flightless birds on these different continents is due to the super continent, Gondwana.
- Various plant species which are closely related are found in
Australian Biota
Matt Elrick
1. Evidence for the rearrangement of crustal plates and continental drift indicates that
Australia was once part of an ancient super continent
1.1 Identify and describe evidence that supports the assertion that Australia was once part of a landmass called Gondwana, including:
- matching continental margins
- position of mid-ocean ridges
- spreading zones between continental plates
- fossils in common on Gondwanan continents including Glossopteris and Gangamopteris flora , and marsupials
- similarities between present-day organisms on Gondwanan continents
Matching continental margins:
- The continents fit together like a jig-saw puzzle. Rocks on the opposing edges are exactly the same.
Mid-ocean ridges and spreading zones:
- Mid-ocean ridges form the boundaries of Earths crustal plates where plates move apart.
- The plates move because lava is added to these ridges.
- New rock is found in the ridge – the further away from the ridge, the older the rock
Fossils in common on Gondwana continents:
- Fossils of Glossopteris and Gangamopteris plants have been found on all Gondwana continents, nowhere else.
- Also, marsupials provide evidence for plate tectonics and the past existence of
Gondwana. When Australia became isolated from the rest of the world, the marsupials’ evolved and diverse species flourished. Some species of quoll and marsupial mice have several features in common with South American marsupials.
Similarities between organisms on Gondwana continents:
- Flora of southern continents – South America, South Africa, Australia and New Zealand has many features in common.
- Flightless birds have been examined, these include the Rhea (S. America), Emu and
Cassowary (Australia), Ostrich (Africa) and Kiwi (New Zealand). The distribution of these flightless birds on these different continents is due to the super continent, Gondwana.
- Various plant species which are closely related are found in