Leg Similarities (1)

http://books.google.ca/books?id=idta6AVV-tIC&printsec=frontcover&source=gbs_v2_summary_r&cad=0#v=onepage&q&f=false
"In pterosaurs, the tibia is much longer and more slender than the femur, and the fibula is considerably reduced as in birds."

Pterosaur tibia (T) and fibula (F).
Femur not shown.


































Modern Bird Leg (diagram on the right)
Notice the tibia (T.T) and fibula (Fi)
http://etc.usf.edu/clipart/48100/48103/48103_bird_limbs.htm

Description: "Fore-limb and hind-limb compared. H., Humerus; R., radius; U., ulna; r., radiale; u., ulnare; C., distal carpals united to carpo-metacarpus; CC., the whole carpal region; MC.I., metacarpal of the thumb; I., phalanx of the thumb; MC.II., second metacarpus; II., second digit; MC.III., third metacarpus; III., third digit. F., femur; T.T., tibio-tarsus; Fi., fibula; Pt., proximal tarsals united to lower end of tibia; dt., distal tarsals nited to upper end of tarso-metatarsus (T.MT.); T., entire tarsal region; MT.I., first metatarsal, free; I.-IV., toes." -Thomson, 1916
Source: Thomson, J. Arthur Outlines of Zoology (New York: D. Appleton & Company, 1916) 650

http://onlinelibrary.wiley.com/doi/10.1111/evo.12882/full

In fact, besides birds, distal fibular reduction also occurred independently within at least three other lineages of Ornithodira: Alvarezsauridae (Chiappe et al. 2002), Oviraptorosauria (Vickers-Rich et al. 2002), and Pterosauria (Dalla Vecchia 2003; Bonaparte et al. 2010; Fig. 7).