Animals first appeared during what era
Bony fish first evolved during the. ANSWER: Correct Bony fish first appeared during the Paleozoic. Chapter 25 PreTest Question 7 Part A The atmosphere of early Earth probably contained no O 2 until the emergence of organisms that. Hint 1. Consider the name of the process that releases oxygen into the atmosphere.How can the answer be improved? animals first appeared during what era
When Did the First Animals Appear on Earth? The first occurrence of simple animals was approximately 600 million years ago. These were characterized as multicellular organisms with basic structures, but no true tissues.
Most major animal groups first appeared during the Cambrian Period (544 to 505 million years ago) during the Paleozoic era. During the Cambrian period hard shelled animals appeared in great numbers for the first time, significantly because shallow seas flooded the continents. It is truly an astonishing period in evolution of life on earth. What evidence points to the date of the appearance of the first oxygenproducing organisms? iron oxides in rock The red sedimentary rocks of Western Australia resultedanimals first appeared during what era Start studying Mastering Bio Practice 13. Learn vocabulary, terms, and more with flashcards, games, and other study tools.