Wilkinson, M.T. 2008. Three-dimensional geometry of a pterosaur wing skeleton, and its implications for aerial and terrestrial locomotion. Zoological Journal of the Linnean Society 154(1):27-69. doi: 10.1111/j.1096-3642.2008.00409.x.
[...] An analysis of the
three-dimensional morphology of the wrist lends support to the idea that the
pteroid - a long, slender wrist bone unique to pterosaurs that supported a
membranous forewing - was directed forwards in flight, not towards the body.