Materpiscis ( from the Latin meaning `` mother fish '' ) is a genus of pyctodontid placoderm from the Late Devonian period about 380 million years ago . Materpiscis ( Latin for mother fish ) is a genus of ptyctodontid placoderm ( a class of extinct , superficially shark-like armored fishes ) from the Late Devonian ( about 380 million years ago ) located at the Gogo Formation of Western Australia .