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Re: hadrosaurs outgrew tyrannosaurs
I've just read the paper, and I think there's a simple logical error.
The authors write two critical sentences
1. Life-history theory suggests that prey species should experience
rapid growth if juvenile mortality (caused mainly by predation) is
high and resources are plentiful (or readily available) (Arendt &
2. ..we predict that Hypacrosaurus grew faster and matured sooner
than coeval theropods.
Sentence 1 is, I presume, a fair summary of a *theoretical* model.
Sentence 2 is an unwarranted prediction from that model. The model
suggests only that prey should grow fast if they can. It does NOT say
that they should grow faster than their predators.
The authors make a great flag-waving display of the result that they
find: that the hadrosaur grew faster than *one* of its potential
predators. I am surely not so cynical as to think that this apparent
fulfilment of their (faulty) prediction was a contrived ploy to get
publicity. It wasn't in the title of their paper, for example. But
it's clearly been given great play by the reporters at National
Geographic and elsewhere.
So where are we? The authors show unambiguously that this hadrosaur
species grew fast, considerably faster than a contemporary predator.
The fast growth is impressive in itself. But it's not the smash hit
that the commentators suggest!