Saturday, November 20, 2010

Cretaceous Worlds of Queensland, Part IV: Ages of Winton

In the heart of central Queensland is the town of Winton, a place with a long human history, and a even longer geologic history, the latter more so by about three orders of magnitude. So in chronological order and applying those orders of magnitude (base 10), here’s a summary of the history of that area and who was living there.

100 million years ago: Dinosaurs, such as Australovenator, Diamantinasaurus, and Wintonotitan, some crocodiles, insects, and a good number of land plants were thriving in environments on and around rivers, lakes, and the coast of the Cretaceous seaway. Although the climate was fairly warm, the southern part of Australia was only just then waving goodbye to Antarctica, the start of a northward drifting of Australia that brought it ever so closer to the equator.

Depiction of a Cretaceous scene, in which small ornithopod (left) and theropod (right) dinosaurs live together in idyllic harmony on a lakeshore, surrounded by lush semi-tropical vegetation. But note the foreshadowing of impending doom (is there any other kind?), hinted by one ornithopod peeking nervously over its shoulder. What could be warranting its attention? Oh, and if you want to see this artwork in person, just go to Lark Quarry, otherwise known as Dinosaur Stampede National Monument (no, I am not making that up), about 100 km south of Winton, Queensland.

10 million years ago: We know the Cretaceous seaway was long gone. We also know that the last of the non-avian dinosaurs had been gone from Australia (and the rest of the earth, for that matter) for about 55 million years, but these were succeeded by birds, which Australia had in abundance then and now. Marsupial and monotreme mammals were evolving into lineages somewhat familiar to us today, and some of the biotic exchange with the now-nearby New Guinea was starting to take place. The Riversleigh fossil assemblage, several hundred kilometers to the northwest of Winton, provides reasonable precursors of what might have been living in central Queensland about 15 to 25 million years ago.

Reconstruction of the so-called “marsupial lion” Thylacoleo carnifex, stalking some prey (perhaps you, although your species had not yet evolved to be stalked). It or its close relatives lived starting 25 million years ago in this area and persisted until the Pleistocene Epoch, less than a million years ago. As you can see from the diorama, sightings of this extinct animal only happen once in a blue moon. Display is at the Riversleigh Fossil Centre in Mt. Isa, Queensland.

1 million years ago: I know very little about this part of Australian history, other than land plants, invertebrates, and vertebrates were still evolving, diversifying, and occasionally going extinct with changing environments. Australia had continued drifting to the north, and was not too far off where it is today.

100,000 years ago: The landscape would have looked somewhat similar to those today, with grasslands dotted by eucalyptus, lots of marsupials – some rather large, such as the giant kangaroo Procoptodon goliah and the whopping wombat Diprotodon australis – a few reptiles – also large, such as the komodo-dragon-on-steroids Varanus priscus – and flightless birds – yes, these were rather non-small as well, such as Dromornis stirtoni and Genyornis newtoni. No people yet, but they would be there soon enough.

The biggest marsupial that ever lived, Diprotodon australis, and it lived in Australia. Specimen is in the South Australian Museum, Adelaide, South Australia.

The biggest land lizard that ever lived, Varanus priscus, and it lived in Australia. Specimen is in the Museum of Victoria, Melbourne, Victoria.

The biggest land bird that ever lived, Dromornis stirtoni, and it (you guessed it) lived in Australia. See what happens when evolution selects against those pesky placental mammals? Specimen is in the Museum of Central Australia, Alice Springs, Northern Territory.

10,000 years ago: The ancestors of the indigenous people in this region had already been living here for at least 30,000 years (probably longer). All of those big land vertebrates mentioned earlier? Gone. Which fits a pattern in late Pleistocene-Holocene biogeography: whenever people show up, big animals tend to go extinct.

1,000 years ago: Yes, the ancestors of the indigenous people were still living here. Seems they had figured out how to live with the land, despite losing some ecologically important animal resources several tens of thousands of years earlier. The landscape looked very much like that of today, but had been shaped massively by fire. This was partially from pre-human fires, then accelerated by people, who became experts at fire ecology. And however hard it might be to believe for anyone who travels in Australia today, not a single hoofed mammal was anywhere on the continent, let alone in this area.

100 years ago: The descendants of the indigenous people were mostly gone (that’s a long, sad story), and descendants of European people (mostly from the British Isles) had established the town of Winton 35 years earlier, in 1875. Hoofed animals, imported from Europe, were now ubiquitous, as were (unfortunately) rabbits.

And now? Winton does not live in the past, but it certainly lives off the past. Prominent among the points of local pride is a focus on what lived in the area 100 million years ago. The first clue of this, and that something is a little different about Winton and a few other central Queensland towns, is visible as you drive into town and take a look at its rubbish bins:

Winton puts its best foot forward when it comes to taking care of your rubbish. A theropod foot, that is. Gee, I wonder what kind of tracks those would make?

Before arriving, you also see road signs hinting of Winton’s connection to the Cretaceous, including those that tell you you’re on the Dinosaur Trail of Australia.

It’s a sign that people are obsessed with the past here in Winton. And, from this paleontologist's perspective, that’s a good thing.

This is a place that loves dinosaurs and everything about the geologic past. Sure, there’s some attention paid to the fact that Winton is the birthplace of Qantas Airlines (where “QANTAS” = “Queensland And Northern Territory Aerial Service”) and, more importantly, the birthplace of the unofficial “national anthem” of Australia, Waltzing Matilda, penned by famed “bush poet” and songwriter Banjo Patterson and performed there in 1895. Ever since, Winton has attracted numerous bush poets, and has hosted bush poetry festivals and championships.

So before we get to talking about the dinosaurs that used to live in the vicinity of Winton, let’s listen to that beautiful and haunting song, with its lyrics about a billabong and the spirits that still dwell in this land, dinosaurian and otherwise, evoking a history we try to imagine but can never relive.

Three renditions of Waltzing Matilda, which was born in Winton. The first is a classic, performed by the most famous of Australian country singers, Slim Dusty. The second is extraordinarily beautiful, played by Dutch violinist André Rieu in Australia. The third is, well, different from the other two. Nonetheless, this last one was “played” in the North Gregory Hotel, site of the song’s original performance 115 years previously, and the performer was aided considerably through the use of a player piano.

Next week, we will look at some of the fossils that can be viewed in downtown Winton, giving a taste of the paleo-treats that await us in upcoming weeks.

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