Palaeontology

12 May 2015: Dinosaurs and birds

Archaeornithura meemannae

Archaeornithura meemannae (Credit: Zongda Zhang)

Remarkable new finds announced by China’s Institute of Vertebrate Paleontology and Paleoanthropology includes the earliest date yet established for a true bird and a bird-related dinosaur with leathery wings.

In a summary report on their website, Michael Balter said a team of paleontologists led by Min Wang and Zhonghe Zhou found 130 million year old fossils of two ancient wading birds in northeast China. The two remains of Archaeornithura meemannae show many features that belong to modern birds, including fan-shaped tail feathers and “the U-shaped wishbone familiar to anyone who has carved a roast chicken.” The fossils, dating back 130 million years, pushes “back the lineage that led today’s birds by at least 5 million years.” The report suggests this means the origins of true birds is older still. In an article in Nature, scientists from the Institute described a new species of scansoriopterygidae dinosaur they called Yi qi (pron. ‘yee chee’). Not only is this the shortest binomial ever given to a dinosaur, it’s also the first dinosaur found with striking evidence of ‘bat-like’ wings. Although other species of scansoriopterygidae were first described as early as 2002, this is the first fossil found with convincing evidence of membranous wings. Sometimes defined as ‘avian dinosaurs’, the scansoriopterygidae group belongs to a clade that ultimately lead to true birds. While it is not believed the group are direct ancestors of birds, they are examples of yet another evolutionary experiment in flight. Institute palaeontologist Corwin Sullivan said the while the dinosaur probably did not fly like a bird, “our guess would be that Yi qi was gliding or maybe combining gliding with some relatively inefficient flapping.”

05 December 2014: Graffiti – a primate thing

earliest graffiti

Photo: Wim Lustenhouwer, VU University Amsterdam

What had up to now been the most ancient example of graffiti, at a respectable 100,000 years old, has just been royally trumped.

Published in science journal Nature on 3 December was the announcement by a group of scientists led by José Joordens from Leiden University in the Netherlands that a sea shell had been discovered with etchings that go back around 500,000 years.

Not only does this push the graffiti timeline back by a factor of five, it also means the rough etching wasn’t made by a member of our species.

The artist in this case almost certainly belonged to Homo erectus, which says a great deal about how deeply ingrained is the hominin need to create art.

Go here to get the story from Dr Joordens herself, who point out the contribution made by Dr Stephen Munro, a biological anthropologist from the ANU.

31 October 2014: Homo floresiensis, aka the Hobbit, now 10 years old

It wasn’t as momentous as Copernicus displacing Earth from the centre of the universe, or Darwin displacing humans from the centre of creation, but ten years ago a team of Australian and Indonesian palaeontologsits announced a discovery that changed the way scientists view not just the history of humans, but the history of the entire human clade. If Darwin’s On the Origin of Species started an earthquake, then the discovery of a recently extinct tiny-limbed and tiny-brained human on the Indonesian island of Flores started a serious tremor.

The waves from that tremor are still rippling through palaeontology. Some scientists argue that the new human, dubbed Homo floresiensis but more often referred to as the Hobbit in popular media, is nothing more than a diseased remnant of an isolated population of modern humans. It does seem, however, that proponents of this hypothesis are increasingly desperate to prove their case. The most recent argument is that the remains display classical symptoms of Downs syndrome. I’m still waiting for them to wheel out childhood smoking as the cause for the Hobbit’s miniature status.

It seems to me that the weight of evidence is overwhelmingly on the side of Homo floresiensis being a new member of the human family. It has no chin, its leg bones are unusually thick, and its wrist bones more closely resemble those of an African ape or group of ancient humans called Australopithecines.

Another piece of evidence that H. floresiensis was not a dwarf or diseased version of H. sapiens is the stone implements found with the remains. These tools are the size you’d expect them to be if made by and for humans around a metre tall. More importantly, they and the bones were found in strata laid down as long ago as 95,000 years ago. Modern humans did not arrive in Indonesia until about 45,000 years ago.

The great mystery surrounding H. floresiensis is where exactly it fits in the human clade. Most evidence suggests it is a very primitive member of the genus Homo, but perhaps, just perhaps, it belongs in the group of Australopithecines with A. afarensis and A. africanus.

The one outstanding fact about this tiny cousin of ours is that it may have survived at least until 18,000 years ago, and possibly even as recently as 12,000 years ago. The Neanderthals, our closest relative among all the species of humans that have walked the Earth, died out not later than 35,000 years ago.

Homo floresiensis was a true survivor.

[For more information about the discovery of the Hobbit, go here. For more information about the history of the debate on whether or not the Hobbit is a new species, go here.]