User blog comment:Mckrongs/Ecological Tree Plots/@comment-3277384-20140303133613/@comment-4009941-20140303165217

Ancient Fish > Ichthyosauria > Split Some may have stayed more fish like and stayed in water more than others Making the Suborder "Ancient Fish/古魚亜目" (Does not say Wyvern in that). This group known as Ancient Fish Suborder could include the strange fish that look like a plesioth head but ends at neck having a fish body.

While others went to land while keeping their Ichthyosauria appearance developing skin like a Cephalos to remove friction, these would be the 陸魚亜目/Land Fish Suborder including "Delex". And another split where Ichthyosauria species developed more land able and developed limbs to walk upon hard ground, these would be the "有脚魚竜亜目/Having Legs Fish Wyvern Suborder"(Name may sound weird due to being direct translation but its accurate) this includes the "トトス/Totosu" family that includes "Plesioth" and maybe the monster that looks like what may be a plesioths tadpole if they have that sort of development which appears to have majority of its body be head like the fish I mentioned earlier who also just may be a early larval stage.

(Note I did not call plesioth family Plesioth becase it doesn't fully really say plesioths name.)