Saurus Pen/1.03.25

Ssrathi
The Saururs Pen is the biggest of all the Ssrathi buildings and also one of the more expensive ones. Fortunately, it doesn't produce units, meaning only a single one is ever needed. The building offers only researches and isn't actually needed for the production of any Ssrathi units - the Tyrannosaurus Rex is documented incorrectly in game as requiring one for production, when in fact it actually checks for a Sun Temple level 5. Not many races at all have a tier 5 building other than their Eyrie / Nest / Brood level 3 upgrade, and especially not one that is dedicated towards researches. But it's the sheer power that those researches that make the building so great, so sort after and thus its place in tier 5.