You know, I still don't see how it can be found in the Great Marsh. Look at its Dex area in the game, it says Area Unknown. Kangaskhan doesn't, and it's one of the Post-NDex rare Pokémon.
Isn't it possible that the name could have come (directly or indirectly) from the genuine ancient reptile Tanystropheus (Tropius is surely a homophone with the tropheus bit) which apparently means 'Long Necked One'? --NeilTarrant 13:47, 1 February 2008 (UTC)
It seems to me that Tropius share many characteristics with the fictional animal/plant hybrids known as triffids: http://en.wikipedia.org/wiki/Image:JohnWyndham_TheDayOfTheTriffids.jpg
Perhaps this article should be updated to reflect this if enough people are in agreement? Quadropheneom 17:19, 8 November 2008 (UTC)