For your question, I can't really find any other marine reptiles that act like a platypus in the Jurassic or cretaceous, but I am guessing an icthyosaur, plesiosaur or marine crocodile filled that niche. Maybe the eretmorhipis was TOO specialized to survive changes in the later Triassic. It might have stood a chance if other species were less adaptable, or if it became a generalist itself. As for what I would like to see next, the Placodonts or Thalattosaurs would be nice. Even Hupehsuchus itself would be awesome, as it might have been a filter feeder like a balleen whale!
Wow, another Triassic Pokémon creature. 😂 One of my favorite eras with its diversity of lifeforms. It’s crazy that _Eretmorhipis_ were so small, too! If you didn't say they measured a meter long, I'd have assumed they were more like a few meters long! Just judging by the thumbnail & at 0:33 that pic in particular makes me think of it as a bigger animal, maybe comparable to a pinniped or crocodilian in terms of length/body mass.
