Data from: A new method for estimating locomotion type in large ground birds

Estimating the locomotion type of fossil ground birds is necessary for a
better understanding of their ecology. Until now, only one method has
allowed us to estimate the locomotion of fossil ground birds, but its
application is complicated in the majority of fossil cases because it
requires data from the three bones from the same hindlimb of one
individual. Here, we propose a new method using only the maximum length
and minimum width of the tarsometatarsus to estimate the locomotion of
these fossil birds. This method is easy to apply and better distinguishes
the intermediate cases between graviportal (walking) and cursorial
(running) birds. This study shows that the species of large ground birds
of the families Gastornithidae and Brontornithidae were all graviportal,
probably because of their large body mass. More unexpectedly, it also
shows that some Phorusrhacidae (e.g. Paraphysornis), usually described as
cursorial birds, were in fact graviportal, probably because of their
considerable body mass. All these new data about locomotion provide a
better understanding of the ecology of fossil ground birds.