Body mass estimation from the talus in primates and its application to the Pondaung fossil amphipithecid primates

Abstract

The relationship between talar size and body mass in extant primates is examined to provide the regression equations for estimating the body mass of extinct primate species based on the talar size. The results indicate that, among the linear talar dimensions, the whole talar size and the tibial trochlear size are good body mass estimators for primates. As an example, the regression equations presented here were applied to the body mass estimates of the fossil tali (NMMP-39 and NMMP-82) of the amphipithecid primates from the middle Eocene Pondaung Formation of Myanmar. Based on the estimated body masses determined by this study, NMMP-39 (estimated body mass: ca. 2.7 kg) should likely be assigned to Ganlea megacanina or Myanmarpithecus yarshensis, while NMMP-82 (estimated body mass: ca. 4.9 kg) should likely be assigned to ‘Amphipithecus’ mogaungensis or Pondaungia cotteri.

Keywords::

• talus
• regression equation
• extant primates
• Eocene
• Myanmar

Acknowledgements

The authors thank Shin-ichiro Kawada (National Museum of Nature and Science, Tsukuba, Japan) for graciously providing access to the specimens examined. Thanks are also due to Masahito Natori (Okayama University of Science, Okayama, Japan) for his help in statistical analysis. This manuscript was improved by useful comments from the two reviewers, Laurent Marivaux (Université Montpellier 2, Montpellier, France) and Tai Kubo (Fukui Prefectural Dinosaur Museum, Katsuyama, Japan).

Additional information

Funding

This work was supported by the Cooperation Program [grant number 2011-A-3], [grant number 2012-B-2], [grant number 2013-B-15] of Primate Research Institute (Kyoto University, Inuyama, Japan) and by JSPS KAKENHI [grant number 21770265], [grant number 25840172] (to T. Tsubamoto).