Which of the following was a common life form during the Cambrian Period? A. trilobite B. bryozoan C. land plant D. cephalopod

Sediment layers stop lateral spreading when: they encounter a barrier they encounter an opposing current they run out of additional sedimentary material

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere,b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify,d)anaerobic bacteria kept thriving with more oxygen

What is used to keep track of the gamates and possible offsprings combination