Era Period Millions of years ago Quaternary Cenozoic 1.6 Tertiary 66.4 Cretaceous 144 Mesozoic Jurassic 208 Triassic 245 Permian 286 Carboniferous Pennsylvanian Mississippian 320 360 Paleozoic Devonian 408 Silurian 438 Ordovician 508 Cambrian 570 Precambrian
Added by Carol G.
Close
Step 1
The question asks which method is most likely used to identify what happened before the start of the Paleozoic era. This means we are looking for evidence or methods that would provide information about the time period before approximately 541 million years ago, Show more…
Show all steps
Your feedback will help us improve your experience
Suman K and 76 other Biology educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
A geologist studies a layered rock to determine its age. Bacterial fossils from Precambrian time are found in the rock's upper layers, but no bacterial fossils are found in the rock's bottom layers. Which of these conclusions about the fossils within the rock is best supported by the evidence? A. The age of the entire rock is determined by the age of the bacterial fossils within it. B. Most Precambrian organisms were too small to leave fossil remains, so the age of the rock cannot be determined by examining this evidence. C. Because bacterial fossils are found only in the upper layers, scientists can conclude that these bacteria evolved towards the end of Precambrian time. D. The bacterial fossils must have been formed during a different time period because most of the rocks from the Precambrian have been destroyed due to tectonic activity.
Adi S.
The correct chronological order of geological eras, starting with the oldest, is (a) Paleozoic, Cenozoic, and Mesozoic (b) Mesozoic, Cenozoic, and Paleozoic (c) Mesozoic, Paleozoic, and Cenozoic (d) Paleozoic, Mesozoic, and Cenozoic (e) Cenozoic, Paleozoic, and Mesozoic.
Paleontologists have subdivided the Cenozoic era into epochs because a. Homo sapiens evolved at the start of the Cenozoic. $b$. the continents had achieved their present positions. c. the number of species stopped increasing at this time. d. our knowledge of the evolutionary events of the Cenozoic is more extensive than for other eras. e. starting with the Cenozoic, the fossil record is no longer a necessary source of information about evolutionary relationships.
Recommended Textbooks
Biology for AP Courses
Objective Biology for NEET
Introduction to General, Organic and Biochemistry
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD