if they couldent add the mosa i think there were some creatures back then that could go on land and both swim in water wouldent be bad for the shallow water tool they gave us to create like the sarcosuchus the large croc was a land and water creature.
i think there was also this large turtle back then called
Archelon could go on the shores and water though that would need deeper water in the game so may be out the question there is a reptile called Nothosaurus pic below it was around in the Triassic Period just when the first
dinosaurs were beginning to walk on land it was adapt to live on land and water.
also the Psephoderma was around in the Triassic Period aswell looks kinda like a turtle a bit but is not related to them at all pic below there is also the Lariosaurus also was around in the trassic period pic below. The Beelzebufo was around in the
Cretaceous period so that would be a good one was able to live on land and water would be big enough to eat goats pic below.
last one i would sugest is
Dinocephalosaurus was around in the Triassic in china can go on land and in water would be around size of troodon i think a pic below all can go on land and in the water so semi aquatic i think its called all these 6 or 7 if you count that turtle thing could make a simi aquatic dlc pack they could make them so so they need a certain amount of water in there pens and that they spend most of the time in the water in game something like that if they cant do the mosa..
Nothosaurus
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Psephoderma
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:Lariosaurus
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:Beelzlabufo
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Dinocephalosaurus
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