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.
Bibliographical noteFunding Information:
We thank the Synthesis Centre for Biodiversity Sciences of the German Centre for Integrative Biodiversity Research for funding that led to the concept of this paper (grant no. DFG FZT 118). W.G. was supported by the Population Biology Program of Excellence Postdoctoral Fellowship from the University of Nebraska-Lincoln School of Biological Sciences. J.S.L. was supported by the Michael E. Tennenbaum Secretarial Scholar gift to the Smithsonian Institution. We thank J. Csotonyi for his commissioned artwork. We thank B. Wynd and M. Tucker for feedback on earlier versions of this manuscript. This is contribution 98 from the Smithsonian’s MarineGEO and Tennenbaum Marine Observatories Network. This is Paleobiology Database publication 420.
© 2022, The Author(s), under exclusive licence to Springer Nature Limited.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics