Wikipedia
Pseudotriakidae
The Pseudotriakidae are a small family of ground sharks, belonging to the order Carcharhiniformes, containing the false catsharks (genera Pseudotriakis and Planonasus) and gollumsharks (genus Gollum). It contains the only ground shark species that exhibit intrauterine oophagy, in which developing fetuses are nourished by eggs produced by their mother.