Miocene ant-mealybug trophobiosis imaged with X-Ray micro-computed tomography
Amber is a remarkable preserving medium for Mesozoic and Cenozoic terrestrial biotas, but even when transparency is good, available viewing angles can be limited. X-ray micro-computed tomography is used here to study a rare association of a Miocene ant ( Acropyga glaesaria ) trapped in resin while carrying a mealybug Electromyrmococcus inclusus with which to incubate a new colony. The technique allows inspection from any desired viewpoint and detailed anatomical measurements. An addition to an extremely limited corpus, this is a fourth known example of an Acropyga gyne holding a mealybug and the second known specimen of Electromyrmococcus inclusus . Measurements and other features of both ant and mealybug are consistent with the holotypes. Introduction Inclusions in amber not only preserve individual organisms in fine detail, but can record interactions between organisms, including symbiotic relationships of various kinds (e.g. Johnson et al. 2001, LaPolla 2002, Poinar 2011, 2019). In