Pterosaur size comparison. Computer illustration comparing the size and appearance of three different pterosaurs (prehistoric flying reptiles). From top to bottom: an azhdarchid, Moganopterus sp., Darwinopterus sp. Darwinopterus lived around 161 to 160 million years ago during the middle Jurassic Period, in what is now China. Moganopterus lived during the Early Cretaceous period (around 146 to 100 million years ago) in what is now China. Azhdarchids (family Azhdarchidae) lived during the late Cretaceous (around 100 to 66 million years ago) and included some of the largest known flying animals that ever existed.