The key difference between Ediacaran extinction and Cambrian explosion is that Ediacaran extinction is the first know mass extinction of macroscopic eukaryotic life while Cambrian explosion is the sudden appearance in the fossil record of complex animals with mineralized skeletal remains.
Ediacaran extinction and Cambrian explosion are two events that are most important in the history of life on Earth. Ediacaran extinction immediately precedes the Cambrian explosion. Ediacaran extinction refers to the mass extinction of macroscopic animals. It is followed by Cambrian explosion or the rapid appearance of mineralized skeletons and complex trace fossils of complex animals. Ediacaran extinction occurred 542 million years ago while Cambrian explosion occurred 541 million years ago.
CONTENTS
1. Overview and Key Difference
2. What is Ediacaran Extinction
3. What is Cambrian Explosion
4. Similarities Between Ediacaran Extinction and Cambrian Explosion
5. Side by Side Comparison – Ediacaran Extinction vs Cambrian Explosion in Tabular Form
6. Summary
What is Ediacaran Extinction?
Ediacaran extinction is the mass extinction that occurred at the end of the Ediacaran period. It occurred 542 million years ago. The first appearance of the macroscopic animal occurred twenty million years before the Ediacaran extinction. This is the Earth’s first know mass extinction event. During this extinction, Ediacaran biota and calcifying organisms suddenly disappeared. Ediacaran biota includes soft-bodied organisms which are macroscopic, multicellular and complex organisms. Calcifying organisms possessed a carbonate skeleton. Two types of calcifying organisms that disappeared in Ediacaran extinction are Cloudina and Namacalathus.
Figure 01: Life in the Ediacaran Sea
Over time, the extinct animals were progressively replaced by newly evolved animals. The exact cause for the Ediacaran extinction is still unknown. However, some evidence suggests that the loss of dissolved oxygen level in Earth’s oceans caused a greater effect on marine anoxia. It is believed that marine anoxia contributed to the decline and eventual extinction of the early animals.
What is Cambrian Explosion?
Cambrian explosion is the sudden appearance in the fossil record of complex animals with mineralized skeletal remains. In other words, Cambrian explosion is the rapid appearance of mineralized skeletons and complex trace fossils. It occurred after one million years of Ediacaran extinction, so it took place 541 million years ago.
Similar to Ediacaran extinction, Cambrian explosion is one of the most important evolutionary events that occurred in the history of life on Earth. It was a rapid event that occurred during a short time and also a remarkable process due to the revealing of the most major animal body plans in the fossil records. However, the majority of the fossils discovered in Cambrian explosion are poorly understood and difficult to classify.
Figure 02: Timeline of Life on Earth
During this time period, the rapid appearance of a wide variety of animals took place. Therefore, the new ecological interactions developed between organisms. Moreover, ecosystems became more complex as the number and variety of organisms increased.
What are the Similarities Between Ediacaran Extinction and Cambrian Explosion?
- Ediacaran extinction and Cambrian explosion are two-phased biotic turnover events that occurred in Ediacaran–Cambrian transition.
- Both processes describe the Earth’s first major biotic crisis of macroscopic eukaryotic life.
- Ediacaran Period took place just prior to Cambrian Explosion.
What is the Difference Between Ediacaran Extinction and Cambrian Explosion?
Ediacaran extinction is the mass extinction that occurred at the end of the Ediacaran period while Cambrian explosion is the sudden appearance in the fossil record of complex animals with mineralized skeletal remains. So, this is the key difference between Ediacaran extinction and Cambrian explosion. Moreover, Ediacaran extinction occurred 542 million years ago while Cambrian explosion occurred 541 million years ago.
Besides, another difference between Ediacaran extinction and Cambrian explosion is that the major event of the Ediacaran extinction is the mass extinction of macroscopic eukaryotic life, but the major event of the Cambrian explosion is the sudden appearance of mineralized skeletons and complex trace fossils.
Summary – Ediacaran Extinction vs Cambrian Explosion
Ediacaran extinction is the mass extinction that occurred in Ediacaran biota and calcifying organisms at the end of the Ediacaran period. They were macroscopic eukaryotic organisms. After a million years of Ediacaran extinction, Cambrian explosion occurred. It is the sudden appearance of mineralized skeletons and complex trace fossils. So, this is the main difference between Ediacaran extinction and Cambrian explosion.
Reference:
1. “The Burgess Shale.” The Cambrian Explosion – Origin of Animals and the Cambrian Explosion – Science, 10 June 2011, Available here.
2. G, Lidya, et al. “Ecological Expansion and Extinction in the Late Ediacaran: Weighing the Evidence for Environmental and Biotic Drivers.” OUP Academic, Oxford University Press, 27 Apr. 2018, Available here.
Image Courtesy:
1. “Life in the Ediacaran sea” By Ryan Somma – Life in the Ediacaran SeaUploaded by FunkMonk (CC BY-SA 2.0) via Commons Wikimedia
2. “LifeTimeline-TemplateImage-20200101” By Drbogdan – Own work (CC BY-SA 4.0) via Commons Wikimedia
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