Pterodactyloidea Pterodactyloidea Pterodactyloidea (derived from the Greek words "πτερόν" ("pterón", for usual "ptéryx") "wing", and "δάκτυλος" ("dáctylos") "finger" meaning "winged finger", "wing-finger" or "finger-wing") is one of the two traditional suborders of pterosaurs ("wing lizards"), and contains the most derived members of this group of flying reptiles. They appeared during the middle Jurassic Period, and differ from the basal (though paraphyletic) rhamphorhynchoids by their short tails and long wing metacarpals (hand bones). The most advanced forms also lack teeth, and by the late Cretaceous, all known pterodactyloids were toothless. Many species had well developed crests on the skull, a form of
Helen (given name) Helen (given name) Helen is a feminine given name derived from the Ancient Greek name , "Helenē" (dialectal variant: , "Helena") whose etymology is unknown; a derivation of the latter from , a variant form of , i.e. "torch", is considered "rather uncertain". Another possible derivation is from Greek "Selene", meaning 'moon'. Helen of Troy is a character in Greek mythology. The name was widely used by early Christians due to Saint Helena, the mother of the emperor Constantine I, who according to legend found a piece of the cross on which Jesus Christ was crucified when she traveled to