sentences:  Some of the vertebrae were fused into a notarium, to which the shoulder blades connected.It had very large forelimbs, with a wing-membrane distended by a long wing-finger, but the hindlimbs were very short.Until the 21st century, "Istiodactylus" was the only known pterosaur of its kind, and was placed in its own family, Istiodactylidae, within the group Ornithocheiroidea.