He's talking about mammals, not early humans. In ancient times, insects and spiders were of tremendous size due to a higher oxygen concentration in the atmosphere, while early mammals were the size of mice. Those days, spiders sat securely above almost all mammals in the food chain.
Thexin92 t1_iy8ccvw wrote
Reply to comment by kyunirider in Spiders were probably an absolute nightmare to early mammals. by psychoxxsurfer
He's talking about mammals, not early humans. In ancient times, insects and spiders were of tremendous size due to a higher oxygen concentration in the atmosphere, while early mammals were the size of mice. Those days, spiders sat securely above almost all mammals in the food chain.