Recent studies have shown that over a third of shark and ray species are threatened with extinction. But which species are the most at risk? What are some of the rarest, but least well known, sharks in the world? And, when a species has seemingly fallen off the face of the earth, how on earth do you find it again? This week, we’re joined on the pod by rare shark expert Dr Dave Ebert (@lostsharkguy)! Dave has travelled all over the world in search of sharks who are thought to have gone extinct, and has contributed to many an IUCN red list assessment for sharks and rays. At Sharks International in Valencia, host Isla sat down with Dave to talk  pondicherry sharks, lost sharks, sawfishes and guitarfishes; how to find sharks that haven’t been seen for 50 years and what it’s like to name a shark that’s brand new to science. Shownotes: https://saveourseas.com/worldofsharks/thewholetooth Get in touch: [email protected] (email), @saveourseasfoundation (instagram) and @SaveOurSeas (twitter)