Its been a while now but I've been really getting into speculative evolution regarding this book called Cryptozoologicon where it hypothetically imagines cryptids if they were real animals.
Some examples. Gambo being a marine monotreme, kelpie being a northern large aquatic chevrotain, dingonek as an aquatic saber-toothed cat, mbielu-mbielu-mbielu as a species of lungfish that evolved "plates".
I decided to come up with some of my own.
Akhlut: I thought about the idea of making the akhlut a species of predatory pinniped with markings similar to orcas, basically the arctic equivalent to the leopard seal but I wanted to be creative and instead have it be the sole surviving member of a species of wolf-like cetacean that evolved from the same ancestors as whales that branched off into its own lineage while retaining its wolf-like features only taking a more aquatic lifestyle.
Altamaha-ha: A species of freshwater seal. At times at first glance, it might look reptilian but that's because it's sometimes covered in green algae.
Bipedal wolf-like cryptids such as the Beast of Bray Road and Michigan Dogman: Since there were no baboons ever native to North America. I would imagine them being large apes that evolved dog-like snouts as baboons had.
Dobhar-chu and Lemisch: Large species of otters like the giant otter and sea otter.
Mahama: A species of crocodile descended from crocodylus thorbjarnarsoni.
Tatzelwurm: A large species of two-legged lizard that has pretty much adapted to the cold environment in the Alps. It has a facial structure with two pointy horns on its head that would otherwise resemble that of a cat as seen in myths.
Yowie: A species of marsupial that has hominid/primate traits through convergent evolution. Given Australia is dominated by marsupials I think if the Yowie were to be a real animal, it'd be a marsupial.
KingofPhantoms
Mamboo07
Swamp Sensei
you guys might be interested in this book.
