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When we talk of dinosaur fossils, we tend to think of their bones.
But they also left behind other evidence of their existence.
Their footprints.
Like this one.
Sometimes these prints occur not singly but in groups,
David Attenborough: suggesting that they lived in groups.
And if they lived in groups, maybe they hunted in groups.
(Growling)
David Attenborough: The idea that dinosaurs had the intelligence
David Attenborough: to cooperate and to hunt together may seem surprising.
David Attenborough: But like all the behavior in Prehistoric Planet,
David Attenborough: there is scientific evidence for deadly dinosaurs joining forces.
(Wind blowing)
Dr. Susannah Maidment: In the fossil record, we sometimes find accumulations
Dr. Susannah Maidment: called monospecific bone beds.
And these are accumulations of a single species of dinosaur.
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Dr. Susannah Maidment: These can lead us to conclude that these animals
Dr. Susannah Maidment: were actually living alongside each other.
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David Attenborough: And at one site, multiple footprints were discovered.
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In 2014, scientists in British Columbia discovered trackways
Dr. Darren Naish: made by 3 Tyrannosaurs that had all been walking side by side.
Dr. Darren Naish: These animals had all been moving together in the same direction
Dr. Darren Naish: all within just a few meters of each other.
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As well as fossil evidence of group hunting,
further evidence comes from the behavior of living hunters,
who often have to form teams in order to take on large herbivores.
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David Attenborough: Today this behavior is seen in large intelligent mammals.
David Attenborough: Lions, wolves...and orca.
David Attenborough: All working together.
David Attenborough: But there are examples of group hunting
David Attenborough: in dinosaurs closest living relatives too.
In birds, the modern cousins of Tyrannosaurs, group hunting behavior is fairly common.
It's seen in various sea birds, in some crows and also in various falcons, hawks and eagles.
Dr. Darren Naish: In some species, like the American Harris Hawk,
Dr. Darren Naish: groups of related individuals work together to capture prey.
David Attenborough: Once more, studies have shown that when times are hard
David Attenborough: and very large prey becomes available
David Attenborough: predators are much more likely to cooperate
David Attenborough: and they then form packs.
(Wind blowing)
(Growling)
David Attenborough: These are just the conditions in the harsh arctic winter
David Attenborough: of the late Cretaceous, that you might expect to see group hunting Tyrannosaurs
David Attenborough: tackling the ice world's largest, most formidable prey.
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