Dataset for: On the estimation of body mass in temnospondyls: A case study using the large-bodied Eryops and Paracyclotosaurus

Temnospondyli are a morphologically varied and ecologically diverse clade of tetrapods that survived for over 200 million years. The body mass of temnospondyls is a key variable in inferring their ecological, physiological, and biomechanical attributes. However, estimating the body mass of these extinct creatures has proven difficult because the group has no extant descendants. Here we apply a wide range of body mass estimation techniques developed for tetrapods to the iconic temnospondyls Paracyclotosaurus davidi and Eryops megacephalus. These same methods are also applied to a collection of extant organisms that serve as ecological and morphological analogues. These include the giant salamanders Andrias japonicus and Andrias davidianus, the tiger salamander Ambystoma tigrinum, the California newt Taricha torosa, and the saltwater crocodile, Crocodylus porosus. We find that several methods can provide accurate mass estimations across this range of living taxa, suggesting their suitabil..., Graphic Double Integration. Silhouettes of all seven taxa were created based on lateral and dorsal views of the 3-dimensional skeletal meshes. The extent of soft tissue surrounding the skeletons was reconstructed based on comparisons with living examples (following Witzmann and Brainerd 2017). Pixel measurement of these silhouettes was carried out in GIMP v2.10.8 (The Gimp Development Team, 2019). Here, lines were drawn across the lateral and dorsal silhouettes (effectively creating dorsal and lateral cross-sections), and the number of pixels for each was recorded.
Three estimates were generated to accommodate variable body density assumptions. For the extant taxa, this included the raw estimate above (calculated assuming a neutral specific gravity of 1.0) and a second estimate based on the specific gravity of amphibians (1.05 for the salamanders) or crocodiles (1.06 for C. porosus) as outlined by Larramendi et al. (2020). The median of the two estimates above was calculated to generate...,