There is no particle system class packaged with G3D, though I know many of our users have implemented their own. ArticulatedModel has support for animated meshes loading from .dae and .fbx files (in the latest revision of g3d in svn, I think 9.00 beta 4 only supports .dae for animated meshes), with the caveat that all bone transformations must be rotation/translation only, scaling and skewing is not yet supported. See the MaterialTest scene in the starter project for an example, the "Seymour" entity uses an animated mesh.