What kind of organism makes up the base of any ecological pyramid?

Plants

Explanation: Plants are all ways at the start of the food chain becuase they are the only thig that can make their own food. Herbivores eat the plants to gain energy and carnivores eat the herbivores to gain their energy.

the base of the pyramid is composed of species called autotrophs, the primary producers of the ecosystem

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .

there's the proffessional site that will you.