I'm sure you noticed it from the picture in my thread, but I will post here too for others to find out as well:
So your gyaoppi 2 uses super gyaoppi evolutions, I think. The thin, morose dino is an adult form (2 years old has the happy and edgy teens, 3 and up are considered adults) but I guess it can evolve to better forms with a bit better care. (Uhh, you said yours is 2 yrs old, I thought it was 3...weird. Maybe gyaoppi2 uses this form for the edgy teen?)
Although the standalone duck one (guappi) has unique evolutions not in the super gyaoppi one (I saw frog duck, teapot duck -which was in karugamoland and not in super gyaoppi- and a super awesome squid duck on guappi on instagram!)
My guess is each uniqe gyaoppi pet that uses gyaoppi 2 programming (chuppi, guappi, and your gyaoppi 2) has 15 different adult evolutions for adult forms. While super gyaoppi has 10 different adults each, which is understandable since it is a multi-pet. So it is very possible that there are 5 more unique evolutions for your gyaoppi 2 not shown here in super gyaoppi chart.