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While the land was dominated by dinosaurs, the skies were ruled by flying reptiles: Pterosaurs.
They lived in every continent on earth, and some of them had extraordinary head crests,
like this one,
which belonged to a species called Barbaridactylus.
Now why would a flying reptile have a head crest as large and as cumbersome as that?
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Dr. Darren Naish: These strange, long, thin crests are among the most recently discovered
of a wide diversity of bony crests, seen in pterosaurs as a whole.
Dr. Darren Naish: We now know of around twenty different species, all equipped with differently
Dr. Darren Naish: shaped head crests.
Dr. Darren Naish: They range from short spikes and lumps, to enormous bony sails,
Dr. Darren Naish: and now, to these ridiculous crests that look like antlers,
Dr. Darren Naish: and which are longer than the whole of the rest of the animal.
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David Attenborough: The discovery of so many different pterosaur crests
David Attenborough" triggered a debate among scientists about what they were used for.
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Dr. Liz Martin-Silverstone: Some of the ideas that we've had are, in some way, it's
helping the animal to fly, maybe it's reducing drag.
Dr. Liz Martin-Silverstone: We've done some tests in wind tunnels and all the studies have found
Dr. Liz Marin-Silverstone: that there may be a very small advantage to it, and if there is a very small one,
then what's the point of putting such a huge structure on the back of your skull if it's
not really helping you?
Dr. Liz Martin-Silverstone: So, it's got to be for something else.
An explanation of extraordinary head crests like this one may lie in
the fact that the biggest are restricted to older, male specimens.
David Attenborough: In living animals, where males have antlers or horns, and the females lack them,
you can be pretty sure it's a consequence of sexual selection.
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David Attenborough: Males with the largest crests would be the most
David Attenborough: attractive to females.
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David Attenborough: But the impressively decorated males don't always have
David Attenborough: things their own way.
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David Attenborough: At many modern day mating gatherings, some subordinate
David Attenborough: males still manage to mate by being sneaky.
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David Attenborough: It's a phenomenon recorded in animals as diverse as
David Attenborough: kangaroos,
David Attenborough: cuttlefish,
David Attenborough: lizards,
David Attenborough: and many species of bird.
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David Attenborough: Some males in these species are smaller,
David Attenborough: and their display features are reduced.
David Attenborough: But, they're still looking to mate.
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David Attenborough: A less showy appearance means dominate males don't
David Attenborough: see them as a threat,
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David Attenborough: allowing these smaller males to approach the females.
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David Attenborough: And when the dominate male's back is turned,
David Attenborough: they take their chance to mate.
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Dr. Liz Martin-Silverstone: Having the biggest, fanciest crest doesn't necessarily
Dr. Liz Martin-Silverstone: mean that that's the one you want to go for because maybe
Dr. Liz Martin-Silverstone: that's the one that all of the females are trying to mate with,
so sometimes it's better to go for a smaller, less showy one.
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Well, I think we can seek some inspiration from pterosaurs. (Laughs)
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David Attenborough: The first fossils of pterosaurs were discovered around
David Attenborough: 250 years ago.
But, specimens like this, with this amazing head crest, were found only very recently.
It's a reminder of the fact, that although we know a very great deal about the prehistoric past,
there are still some very exciting and unexpected discoveries to be made.
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