es lec 1 (part 5 - cambrian)

the cambrian period is the period belonging to the beginning of which era?

paleozoic

the cambrian period is marked by what?

hard parts in the fossil record

what's the hypothesis for why hard parts showed up in the cambrian period?

eroded sediment made of minerals like caco3 go into the ocean changing the chemistry so organisms must adapt or die

what do the cambrian organisms with hard parts do to the minerals in their system?

exude it on their exterior

what does the new earth chemistry do to the marine biota during the cambrian period? this is called?

biological diversity explodes, the cambrian explosion