This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
In a number of recent studies we used computer modeling to investigate the evolution of muscle leverage (moment arms) and function in extant and extinct archosaur lineages (crocodilians, dinosaurs including birds and pterosaurs). These studies sought to quantify the level of disparity and convergence in muscle moment arms during the evolution of bipedal and quadrupedal posture in various independent archosaur lineages, and in doing so further our understanding of changes in anatomy, locomotion and ecology during the group’s >250 million year evolutionary history. Subsequent work by others has led us to re-evaluate our models, which revealed a methodological error that impacted on the results obtained from the abduction-adduction and long-axis rotation moment arms in our published studies. In this paper we present corrected abduction-adduction and long axis rotation moment arms for all our models, and evaluate the impact of this new data on the conclusions of our previous studies. We find that, in general, our newly corrected data differed only slightly from that previously published, with very few qualitative changes in muscle moments (e.g. muscles originally identified as abductors remained abductors). As a result the majority of our previous conclusions regarding the functional evolution of key muscles in these archosaur groups are upheld.
Herein we presented corrected data on hind limb muscle moments from a range of living and extinct archosaurs that we have studied previously. Reanalysis of this corrected data from four previously published studies shows few substantive differences from our previously published results, although several reinterpretations of specific muscle functions have resulted. Nevertheless, these minor amendments do not undermine our earlier conclusions regarding the function and evolution of these locomotor systems and in some cases provide additional support for our previous interpretations. Our corrected data is available in the supplementary material for use in future studies on these interesting taxa.
Corrected abduction-adduction and long axis rotation moment arm data