Hatzegopteryx had a wingspan of about 10 metres - making it one...

Hatzegopteryx had a wingspan of about 10 metres - making it one of the largest known flying animals of all time.
This can be a little hard to visualize, so check this image out. Despite its size, Hatzegopteryx’s hollow skeleton means that the pterosaur only weighs about 1/6 as much as the giraffe.

Image courtesy of Mark Witton, at www.markwitton.com