What factor prevents us from finding fossils from the Precambrian era?A.Life was destroyed by a series of mass extinctions.B.This was before life existed on Earth.C.Life-forms in this era had no skeletons.D.There are no rocks left from that era.

Why are there no samples of rocks from the early Precambrian era?A.All rocks were molten in that time period.B.They are buried under sediment.C.They have undergone metamorphosis.D.All of them formed under volcanoes

Which is a reason that many organisms that have existed on Earth have left no fossils?A.Fossils cannot form underwater.B.Many organisms live only in rainforests.C.Fossils can only form near volcanoes.D.Fossils decay according to their half-life.

Select all that applySelect all of the following that explain why the fossil record is incomplete.Multiple select question.Many organisms decomposed before they were buried in sediments.Erosion and movements of the Earth's surface have destroyed many fossils that did form.Fossils were not formed south of the Wallace Line due to proximity to the equator.Many fossils may never be discovered because they are buried deeply or submerged under water.Fossils older than 100 million years old have already decayed past the point of recognition.

Match the era on the left with its characteristic on the right.PrecambrianCenozoicPaleozoicMesozoic?When Earth formed?The age of dinosaurs?When most of our limestone and coal formed?The era of humans

Fossils can be formed when conditions needed for __________ are absent.