The family Threskiornithidae, which belongs to the bird order Pelecaniformes, includes 36 species of large wading birds. 

Pelecanus: Greek pelekan, pelekanos pelican.

Threskiornis Greek threskeia religious worship (threskeuo to worship); ornis bird. 
The Sacred Ibis Threskiornis aethiopicus was venerated by the ancient Egyptians for its crescent-shaped bill and bright white plumage. They considered it to represent Thoth the moon god.