Downsizing a giant: re-evalutating Dreadnoughtus body mass

Karl Bates, Sophie Macaulay, Peter Falkingham, Charlotte Brassey, Susannah Maidment

Research output: Contribution to journalArticlepeer-review


Estimates of body mass often represent the founding assumption on which biomechanical and macroevolutionary hypotheses are based. Recently, a scaling equation was applied to a newly discovered titanosaurian sauropod dinosaur (Dreadnoughtus), yielding a 59 300 kg body mass estimate for this animal. Herein, we use a modelling approach to examine the plausibility of this mass estimate forDreadnoughtus. We find that 59 300 kg forDreadnoughtusis highly implausible and demonstrate that masses above 40 000 kg require high body densities and expansions of soft tissue volume outside the skeleton several times greater than found in living quadrupedal mammals. Similar results from a small sample of other archosaurs suggests that lower-end mass estimates derived from scaling equations are most plausible forDreadnoughtus, based on existing volumetric and density data from extant animals. Although volumetric models appear to more tightly constrain dinosaur body mass, there remains a clear need to further support these models with more exhaustive data from living animals. The relative and absolute discrepancies in mass predictions between volumetric models and scaling equations also indicate a need to systematically compare predictions across a wide size and taxonomic range to better inform studies of dinosaur body size
Original languageEnglish
JournalBiology Letters
Issue number201502
Publication statusPublished - 1 Jan 2015

Bibliographical note

Published gold open access. © 2015 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License, which permits unrestricted use, provided the original author and source are credited. Citation :Bates KT, Falkingham PL, Macaulay S, Brassey C, Maidment SCR. 2015 Downsizing a giant: re-evaluating Dreadnoughtus body mass. Biol. Lett. 11:20150215.


Dive into the research topics of 'Downsizing a giant: re-evalutating Dreadnoughtus body mass'. Together they form a unique fingerprint.

Cite this