Curator Interview: Brian Gill
Brian Gill is Auckland Museum’s Curator of Land Vertebrates, looking after a collection of 14,000 bird specimens, 3,000 amphibians and reptiles and 1,500 land mammals.Brian has been the curator for 26 years and his most recent research has been to look at the remains of extinct birds, including moa eggs and eggshells and the bones of New Zealand’s extinct ravens.
The three main kinds of marine reptiles, Plesiosaur, Ichthyosaur and Mosasaur are all represented in this case and many of these are the real fossils, from the Mangahouanga Valley in Hawke’s Bay, along with casts of some of the spectacular finds made by Joan Wiffen and her team .
Do we now know that New Zealand had dinosaurs?
Yes, but only since1975, when the first bone was found by Joan Wiffen and her team, but of course she wouldn’t have known it was a dinosaur bone at first and I think it took several more years before she worked out what it was. The result was published in 1981.
Was Joan was looking for dinosaur bones in particular?
She probably wasn’t looking for dinosaur bones but the area was known for its vertebrate fossils. It had been marked on old petroleum survey maps as having Cretaceous fossils. She was an amateur palaeontologist working with a group of friends, and it was close to where they lived, so they went searching there.
What did Joan find, just a tiny fossil fragment that was later identified as belonging to a dinosaur?
Well a lot of the remains they found were quite big, they were the remains of marine reptiles and so that is mostly what they were looking for and then they would have found this one and they probably saw that it was a bit different in size and shape from the ones they were used to and thought it was pretty interesting and paid a lot of attention to it. And when it went to a dinosaur expert in Queensland it was recognised as a dinosaur, as the tailbone of a theropod.
So that was the beginning of the New Zealand dinosaur story?
We didn’t know we had dinosaurs until then and it was just this fragment but now we know we’ve got them and her team kept working and eventually they found in amongst the marine reptile bones various other fragments that turned out to be dinosaurs and so now it adds up to four different kinds of dinosaurs. And now we‘ve also got bones found on the Chatham Islands and there was also a tiny little dinosaur bone found in Port Waikato, so now there are three sites but still just the four broad groups of dinosaurs. But all the bones are either just small bones or fragments of bones so there is no way they can tell us what the whole animal was, so we don’t know any of the genera or any of the species, we just know the broad groups they belonged to.
This is a cast of fossilised paddle bones that once propelled the Haast Elasmosaur, of one of New Zealand’s plesiosaurs, through the coastal waters of prehistoric New Zealand in search of prey.
What were these broad groups of dinosaurs?
Theropod, sauropod, ornithopod of the hypsilophodont group and an ankylosaur, an armoured dinosaur.
So the dinosaur skeletons on display in the ‘Origins’ gallery are the best guesses of what our dinosaurs might have looked like?
We chose from skeletons that were available for sale around the world - these are relevant kinds from the same groups our ones belonged to and for two of them we were able to get a southern hemisphere example rather than a northern hemisphere example. So the Cryolophosaurus, the theropod, comes from the New Zealand sector of Antarctica, from the Ross Dependency so at least that is geographically close to New Zealand. The other one, the sauropod is Malawisaurus from Africa which is at least a Gondwana dinosaur rather than a northern hemisphere one. For the hypsilophodont we had to buy a northern hemisphere dinosaur, which is a thing called Thescelosaurus and then we do not have an ankylosaur represented by a skeleton we just have the picture in the mural and a small model.
The Chatham Island bones are all from theropods, are these the most common groups of dinosaurs in New Zealand?
I don’t think there are enough samples to imagine it could reflect abundance, there is just so much chance involved in the whole thing. And with the theropods there is a problem in that a lot of them are toe bones and the toes bones of a theropod and the toe bones of a large flightless bird like a moa are very hard to tell apart, because the birds had arisen from the theropods.
Why are there so few fossils in New Zealand?
The places where all the great fossil finds have been discovered are big flat continents like North America and China, and they are old continents with the right strata with the right age rocks present. New Zealand does not have so many rocks of the right age exposed and it’s a relatively small place and it’s covered in forest, unlike the deserts of China and central North America where you just walk around in those lovely open, dusty areas looking for bones sticking up. It’s not so easy in the New Zealand bush, plus New Zealand is so active geologically, anything exposed can be eroded away very quickly. We have earthquakes and volcanoes and everything else, so that is why so little has been found. In New Zealand the odds are so much against it.
What was New Zealand like during the Cretaceous?
Well, climate-wise New Zealand was closer to the pole than it is now but the temperatures were warmer then than they are now, so even though it was closer to the south pole it was warmer than now. A lot of work has been done on a site in Victoria in Australia where a whole lot of different dinosaurs have been found and they call them polar dinosaurs, because it was much closer to the pole then. As far as the look of the place was concerned with the plants and so forth it would have been a bit different from now because you would have not had many flowering plants, however, various other things such as tree ferns and the ancestors of the podocarps, and trees like the kauri, would have been there, so in a way New Zealand now is in a vague sort of way a bit like it would have been then. That is why the BBC came to New Zealand to film for its series on dinosaurs.
What about other animals at that time?
There would have been ancestors of many, many other things that we have here now, many, many kind of insects, fish and frogs and lizards.
What about birds?
The birds at that time would not have been very familiar to us now, they would have been groups that have largely gone and been succeeded, except perhaps the ratites, the moas and the kiwi. There would have been the ancestors of the moas and they might have been fairly similar, you know, big and flightless, but unfortunately there are no fossils so we don’t know for sure.
A lot of the other birds we are familiar with now have developed since the absence of the dinosaurs, including all the song birds, the parrots, the ducks, all the main groups. There must have been water birds, shore birds and forest birds but they would have been very different kinds to what we know now.
What about a big meat eating theropod dinosaur like T. rex?
Among the few bones that have been found in New Zealand a lot are theropod bones and some of them are quite large theropod bones indicating they came from quite large animals and they were predatory, so there presumably was something a bit like T. rex, perhaps not quite as big, but a close relative of T. rex.
Flying reptiles like this pterosaur shared the Cretaceous skies with the birds but died out along with the dinosaurs 65 million years ago. Now the birds have unbridled access to the air, only sharing it with mammals at night when the bats come out to feed.
From tiny fossils like this one from an Ankylosaur, the story of New Zealand’s dinosaur past in constructed.
This is a cast of a plesiosaur skull that was found in the Hawke’s Bay. It sharp, crooked teeth once devoured fish as it used a long slender neck to hunt down prey.