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Sauropod diet and gigantism, omnivorous juveniles (free pdf)
From: Ben Creisler
A new online paper--the pdf is free.
David M. Wilkinson & Graeme D. Ruxton (2012)
High C/N ratio (not low-energy content) of vegetation may have driven
gigantism in sauropod dinosaurs and perhaps omnivory and/or endothermy
in their juveniles.
Functional Ecology (advance online publication)
1.Sauropod dinosaurs were the largest terrestrial animals ever, and
the combination of selective pressures that might have lead to such
extraordinary sizes has long been discussed.
2.Here, we argue that a previous suggestion that large size may be a
response to unusually high C/N ratios in available plant foods has
been prematurely discarded. C/N ratios were likely to be high during
much of the Mesozoic, and C/N ratio is entirely different from gross
energy density as a measure of the value of a plant as food. In
addition, we use recently published allometric equations for herbivore
nitrogen and carbon use to make tentative calculations which suggest
that if Mesozoic C/N ratios were greater than extant ones, this would
have selected for one of two strategies: gigantism in ectothermic
herbivores or endothermy (and selective foraging on high N material)
in very small herbivores.
3.We speculate that smaller-bodied juvenile sauropods might have had a
broader omnivorous diet and/or had higher mass-specific metabolic
rates than adults. The former is potentially testable by changes in
dentition; the latter matches evidence of high growth rates of