Data from: Three-dimensional reconstructions come to life – interactive 3D PDF animations in functional morphology

Digital surface mesh models based on segmented datasets have become an
integral part of studies on animal anatomy and functional morphology;
usually, they are published as static images, movies or as interactive PDF
files. We demonstrate the use of animated 3D models embedded in PDF
documents, which combine the advantages of both movie and interactivity,
based on the example of preserved Trigonopterus weevils. The method is
particularly suitable to simulate joints with largely deterministic
movements due to precise form closure. We illustrate the function of an
individual screw-and-nut type hip joint and proceed to the complex
movements of the entire insect attaining a defence position. This posture
is achieved by a specific cascade of movements: Head and legs interlock
mutually and with specific features of thorax and the first abdominal
ventrite, presumably to increase the mechanical stability of the beetle
and to maintain the defence position with minimal muscle activity. The
deterministic interaction of accurately fitting body parts follows a
defined sequence, which resembles a piece of engineering.