Interesting rule ("It is a rule in paleontology that ornamentation and complication
I don't quite agree with the whole rule, though... 'complication', yes; 'ornamentation', no. While ornamentation can become a complication, it seems that, within fairly liberal bounds, it's extremely common and adaptive, even in long lived species (moths, for example).
In human cultures, it seems that ornamentation is a vital and valuable part of our existence. When I picture cultures that have ceased to ornament, those are the ones that strike me as on their way out (lack of time? illness of spirit?). Most indigenous people seem to have worked ornamentation into their every artifact. It's not until urbanization is advanced that there's an attempt to appropriate it for class or state ends.
I'm picturing Bauhaus, corporate art and so many art installations which seem sterile or fetishistic (to me). And I think we're on the way down... other, non-urban cultures were mostly driven to extinction, ours is one of those doing the driving.
Maybe 'industrial revolutionized' needs to qualify in there, somewhere... the turning point strikes me as WWI? No... the twenties roared. WWII? More like it. Third Reich PR/state art. Allied mass git'r'done production. The rise of the Corporation. The suburban nightmare. Now.
Now, I feel like we could use a little more ornamentation in our lives. But I'm probably making it too complicated.