Peter:
 >>How about a little reality check on this alleged, past paleo-vegetarian
 >>glory of ours?... Here is what the Natural Hub
 >>website has to say on the issue:
 >>http://www.naturalhub.com/natural_food_guide_grains_beans_seeds.htm

Amadeus:
 >100% d'accord with what naturalhub said.
 >One first lesson to hear from this is variation over the year.

Yet, the diet that you are proposing is quite far off from such a diet.

 >The mainstream anthropology thinks that the main fallback food for
 >erectines was hunted game meat.

I am not sure what a "fallback" food is but as far as I know they do
not dispute that animal foods played a pivital role in the evolving
hominid diet.

 >I follow the tuber path, it seems more probable to me.

Well, lucky you that coincides with you happening to be a vegetarian. ;-)

 >However the bipedal hominids now walking upright into the heat of the day
 > with little fear of predators - have one more option to the gathering
 >tubers. Predator leftovers - carrion.  Particularly brain and marrow may
 >have been available.

Yes, all of the above.

Peter