New Underwater Biome For Sniffers

I think there should be a new underwater biome for the brand new mob the sniffer and I feel this new biome should kind of show off some maybe why it died off or what it’s habitat was like before they went extinct ( or so we thought ) and maybe some bones of them to show how big they were before now because they probably adapted their size for modern times like real dinosaurs. In all I would like to see maybe a new biome to give some backstory to the sniffer