[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Stegosaurus body mass (free pdf)

Ben Creisler

A new online paper (free pdf):

Charlotte A. Brassey , Susannah C. R. Maidment & Paul M. Barrett (2015)
Body mass estimates of an exceptionally complete Stegosaurus
(Ornithischia: Thyreophora): comparing volumetric and linear bivariate
mass estimation methods.
Biology Letters (advance online publication)
DOI: 10.1098/rsbl.2014.0984

Body mass is a key biological variable, but difficult to assess from
fossils. Various techniques exist for estimating body mass from
skeletal parameters, but few studies have compared outputs from
different methods. Here, we apply several mass estimation methods to
an exceptionally complete skeleton of the dinosaur Stegosaurus.
Applying a volumetric convex-hulling technique to a digital model of
Stegosaurus, we estimate a mass of 1560 kg (95% prediction interval
1082–2256 kg) for this individual. By contrast, bivariate equations
based on limb dimensions predict values between 2355 and 3751 kg and
require implausible amounts of soft tissue and/or high body densities.
When corrected for ontogenetic scaling, however, volumetric and linear
equations are brought into close agreement. Our results raise concerns
regarding the application of predictive equations to extinct taxa with
no living analogues in terms of overall morphology and highlight the
sensitivity of bivariate predictive equations to the ontogenetic
status of the specimen. We emphasize the significance of rare,
complete fossil skeletons in validating widely applied mass estimation
equations based on incomplete skeletal material and stress the
importance of accurately determining specimen age prior to further