Sawfly Media Package

BRoll CSIRO Sawfly Media Package

[Image appears of a large red rock with a sawfly fossil and pans in]

[Image changes as camera angle changes while still focused on the sawfly fossil]

[Image changes as camera continues to focus on sawfly fossil but the red rock is now a more orange colour]

[Image changes to a woman seated in a desk chair. She has a light top and dark trousers with pink hair below her shoulders. Her desk is in a set of four with low walls, there are two monitors behind her showing the sawfly on the left and a picture of the fossil on the right. Text on screen: Dr Juanita Rodriguez, Research Scientist, CSIRO]

Dr Juanita Rodriguez: Yes. So what we found with this fossil, we were able to put in this fossil in a molecular phylogeny of all pergidae, so all sawflies. And what we found is that they had an ancestor that was widespread and that is puzzling because the continents are separated right now. But because we dated the origin of this family to about 100 million years ago, we were able to infer that the spread ancestor was found in a supercontinent that existed at the time called Gondwana. And that later this supercontinent was separated through continental drift and there were separate groups in South America and Australia. But then the most interesting part is that later in the evolution of the group, there were separate migrations, probably through Antarctica, that led to different lineages being present in South America and in Australia, um, kind of mixed up throughout the phylogeny.

[Image changes to close up of a drawing of the sawfly on a leaf with flowers to the left and a clump of maggots behind it]

[Image changes to a drawing of the sawfly on a leaf, some other leaves and plants visible as well as other flies and insects]

[Image changes to a man seated in a desk chair. He has short dark hair that is greying, a grey beard and moustache and black rimmed glasses. He is wearing a blue and white checked shirt that is open at the neck with a white t-shirt visible underneath, light coloured pants and a watch is visible on his right wrist. His desk has two monitors on it, on the left monitor is an illustration of a sawfly, on the right monitor is a close up of the fossil. Text on screen: Dr Michael Frese, University of Canberra palaeontologist and CSIRO visiting scientist]

Dr Michael Frese: Okay. So we know now that, uh, McGraths flat was deposited in Oxbow Lake and that the Oxbow Lake was close to a flowing river and still had some connection to this river because we found insects, aquatic insects, in that lake that would normally not exist in still water, so that like fast flowing oxygen rich waters. So and we also know that the lake was surrounded by, um, lush vegetation and we think that we had a pocket of rainforest around that Oxbow Lake and along the river, but that there was drier vegetation and drier ecosystems around. So this was basically a remnant of a once larger rainforest.