Their egg cases are sometimes referred to as mermaid's purses ... This is known to occur in sand tiger sharks (Carcharias taurus). Placental viviparity occurs in some species of shark - once the yolk ...

A tiger shark has surprised Australian scientists on ... Echidnas — which are only found in Australia and New Guinea — are ...

SYDNEY — A tiger shark has surprised Australian scientists ... Echidnas — which are only found in Australia and New Guinea — are egg-laying mammals, have spines protruding from their bodies ...