Diet and body mass are inextricably linked in vertebrates: while herbivores and carnivores have converged on much larger sizes, invertivores and omnivores are, on average, much smaller, leading to a roughly U-shaped relationship between body size and trophic guild. Although this U-shaped trophic-size structure is well documented in extant terrestrial mammals, whether this pattern manifests across diverse vertebrate clades and biomes is unknown. Moreover, emergence of the U-shape over geological time and future persistence are unknown. Here we compiled a comprehensive dataset of diet and body size spanning several vertebrate classes and show that the U-shaped pattern is taxonomically and biogeographically universal in modern vertebrate groups, except for marine mammals and seabirds. We further found that, for terrestrial mammals, this U-shape emerged by the Palaeocene and has thus persisted for at least 66 million years. Yet disruption of this fundamental trophic-size structure in mammals appears likely in the next century, based on projected extinctions. Actions to prevent declines in the largest animals will sustain the functioning of Earth's wild ecosystems and biomass energy distributions that have persisted through deep time.

Item Type:	Refereed Article
Keywords:	vertebrates, body size, trophic guild
Research Division:	Biological Sciences
Research Group:	Evolutionary biology
Research Field:	Biogeography and phylogeography
Objective Division:	Environmental Policy, Climate Change and Natural Hazards
Objective Group:	Understanding climate change
Objective Field:	Understanding climate change not elsewhere classified
UTAS Author:	Edgar, GJ (Professor Graham Edgar)
UTAS Author:	Stuart-Smith, RD (Dr Rick Stuart-Smith)
ID Code:	150857
Year Published:	2022
Web of Science® Times Cited:	2
Deposited By:	Ecology and Biodiversity
Deposited On:	2022-07-04
Last Modified:	2022-11-09
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