Page 458 - The Secret Museum

DID YOU KNOW THAT THE largest dinosaur that ever walked the Earth had a tiny head?

I suppose I did. I’d seen the skeletons and reconstructions of sauropods – the ones
with enormous bodies, long necks and small heads – in museums; I’d watched
Jurassic Park and The Flintstones, but seeing this skull, on a table, in the archive of
the Zoology Museum in Sao Paulo, really surprised me. It was tiny. If I hadn’t known
it was the head of a dinosaur – being quite bad at anatomy – I might have guessed it
was that of a horse.

There are piles of dinosaur bones in museums and many more waiting to be
discovered, but it’s very rare to find a whole skeleton, and rarer still to find a

complete skull of a sauropod. That is what makes this dinosaur skull such a precious
treasure. It is the only complete skull of a sauropod ever described from South
America. In scientific terms, ‘describe’ means it has received a description – its
anatomy has been described and illustrated or photographed in a scientific paper.
There are plenty of things that have been found, but not described, including a skull
found in the late 1990s: so, even though it is in a museum, and people have seen it,

since the discoverers have not written about it, it essentially doesn’t yet exist and
palaeontologists can’t comment on it. This unique skull had been inside the Earth for
120 million years, and it turned up thanks to a social networking site rather like
Facebook.

In 2006, a young geography student was out walking near his mother’s house in
northern Minas Gerais, Brazil. He saw a bone sticking out of the ground. He thought
it was the rib of a giant sloth and posted a note about it on Orkut, a website popular
with Brazilian students.

Students at the University of Sao Paulo showed the boy’s post to their professor,
Hussam Zaher, who realized it was unlikely to be a giant sloth, as their bones are

found inside caves, not in the open. He went to meet the boy and to see the bones. As
he began to dig, his jaw dropped further and further. He found a dinosaur rib, 20 per
cent of its body, and then, a skull: the Holy Grail for a palaeontologist.

He assembled a team to excavate the bones and shipped them back to Sao Paulo.
His team realized they were looking at a new titanosaur species (which includes the
largest creatures ever to roam the Earth). They named it Tapuiasaurus macedoi
(‘macedoi’ after a man in Minais Gerais who helped them to excavate the bones).
The bones and skull were CT-scanned and briefly displayed in the museum, before

being placed in the archive, where palaeontologists can study the bones in peace.

The day I visited, Jeff Wilson, a professor from the University of Michigan, was
bent over the skull.

‘It’s hard to impress on anyone quite how rare this skull is,’ he told me. ‘We know
of 130 sauropod species that existed across 160 million years of time, but we know
them only from pieces of bone. There are only a dozen species of sauropod in the
world known from their complete skulls.’ The skull is really important because ‘it
tells how the animal interacts with the sensory world and provides important