The Proterozoic Eon and its subdivisions. The earliest evidence for the advent of life includes Precambrian microfossils that resemble algae, cysts of flagellates, tubes interpreted to be the remains of filamentous organisms, and stromatolites (sheetlike mats precipitated by communities of microorganisms).
Q. Why is evidence from the Precambrian rare?
1 Answer. Because only the earliest forms of life (protozoa, algae, etc.) existed at that point in time three billion years ago, and those forms did not survive in the sediments that covered them at the bottom of the seas.
Table of Contents
- Q. Why is evidence from the Precambrian rare?
- Q. What does Precambrian mean?
- Q. Are eras longer than periods?
- Q. Are eras smaller than periods?
- Q. Which method is most likely used to identify what happened before the start of the Paleozoic?
- Q. What happened before the start of the Paleozoic Era?
- Q. Which evidence is most likely used to indicate the beginning of solar system formation?
- Q. Which best explains a primary reason for the inability of life to exist in Earth’s early atmosphere unit test?
Q. What does Precambrian mean?
Precambrian Era. THE PRECAMBRIAN ERA. The Precambrian Era. The name means: “before the Cambrian period.” This old, but still common term was originally used to refer to the whole period of earth’s history before the formation of the oldest rocks with recognizable fossils in them.
Q. Are eras longer than periods?
The period is the basic unit of geological time in which a single type of rock system is formed. Two or more periods comprise a geological Era. Two or more Eras form an Eon, the largest division of geologic time.
Q. Are eras smaller than periods?
Eons and eras are larger subdivisions than periods while periods themselves may be divided into epochs and ages. The rocks formed during a period belong to a stratigraphic unit called a system.
Q. Which method is most likely used to identify what happened before the start of the Paleozoic?
Thus, the method most likely used to identify what happened before the beginning of the Paleozoic era would be to examine fossil evidence during the Precambrian period.
Q. What happened before the start of the Paleozoic Era?
Paleozoic Era, also spelled Palaeozoic, major interval of geologic time that began 541 million years ago with the Cambrian explosion, an extraordinary diversification of marine animals, and ended about 252 million years ago with the end-Permian extinction, the greatest extinction event in Earth history.
Q. Which evidence is most likely used to indicate the beginning of solar system formation?
Which evidence is most likely used to indicate the beginning of solar system formation? Materials were pulled together by gravity.
Q. Which best explains a primary reason for the inability of life to exist in Earth’s early atmosphere unit test?
Which best explains a primary reason for the inability of life to exist in Earth’s early atmosphere? There was insufficient energy from material collisions to change their density. Available oxygen was used to help create an ozone layer within Earth’s atmosphere.
