Underused Premises in Anime

[Lone Lancer]

Since I first started following anime as a regular, I was surprised by all the different themes they came in. There are anime about casual outdoor camping ( "Laid Back Camp" ), anime where much of the dialogue is about trade ( "Spice & Wolf" ), others that are dedicated to common snack food items of the Orient ( like "Dagashi Kashi" ), and even shows about cooking specific types of dishes or baking. There is even anime erotica ( called "hentai" ); unfortunately this category seems to be heavily stigmatized as something depraved and awful...I guess a lot of people must assume that it only caters to the freaks wearing BDSM gear or something? Ranging from the fantastic to the very most mundane aspects of life, you can usually bank that there is probably an anime about it...or is there always?

Though I have seen anime with nearly every type of plot imaginable, there are yet still a few themes I am surprised and disappointed that we don't see more of. For example, I know from reading that Japan has entire theme parks dedicated to Dinosaurs and assorted Mesozoica, yet I can't name a single manga or anime that is specifically about Dinosaurs or the ABCs of fossil digs and preparation...titles like "Fancy Lala", "You Are Umasou" and "Fossil Fighters/Digimon" don't really count. I am talking about mature content where this is the primary motif of the story. It's pretty clear that dinosaurs are popular over there. Japan even has its own collection of dinosaur fossils which were excavated on the island - Fukuiraptor  immediately comes to mind as an example that is obscure to the rest of the world but is likely well known locally. No animes about botany or conservation either ( that I am aware of ).