Ediacaran Period: Life, Fossils, Climate, and Extinctions
Discover the Ediacaran Period, the age of the Ediacara biota before the Cambrian Explosion, including famous fossils such as Dickinsonia, Arborea, Spriggina, and Kimberella, early animal evolution, major extinction events, and fossil sites that preserve this lost world.
Key Takeaway: The Ediacaran Period lasted from about 635 to 538.8 million years ago and is the final period of the Neoproterozoic Era, immediately before the Cambrian. It is best known for the Ediacara biota: soft-bodied organisms that lived on ancient seafloors before trilobites, hard shells, and active Cambrian-style ecosystems became common.
Fast Facts about the Ediacaran Period
Time Range: About 635 to 538.8 million years ago. The Ediacaran was the final period of the Neoproterozoic Era and directly preceded the Cambrian Period.
Era: Neoproterozoic Era, within the Proterozoic Eon. It is the last major chapter before the Phanerozoic Eon, the eon that contains the Paleozoic, Mesozoic, and Cenozoic eras.
Period Before: Cryogenian Period. The Ediacaran began after major global glaciations often associated with Snowball Earth conditions.
Period After: Cambrian Period. After the Ediacaran, animals became much more diverse and visible in the fossil record during the Cambrian Explosion.
Named For: The Ediacaran is named for the Ediacara Hills in the Flinders Ranges of South Australia, one of the classic regions where Ediacaran fossils were discovered and studied.
Best Known For: Soft-bodied organisms known collectively as the Ediacara biota. These include frond-like forms, quilted oval organisms, segmented forms, possible early animals, and other fossils that do not always fit neatly into living groups.
Major Turnovers: The late Ediacaran records two major faunal turnovers or possible extinction pulses: one near the White Sea-Nama transition around 550 million years ago, and another near the Ediacaran-Cambrian boundary around 540 million years ago. These events mark the decline of many classic Ediacaran organisms before Cambrian-style animal communities became widespread.
Famous Fossils: Dickinsonia, Arborea, Spriggina, Kimberella, Charniodiscus, Rangea, Tribrachidium, Cyclomedusa, Cloudina, and Namacalathus.
Famous Fossil Sites: Ediacara Hills and Nilpena in South Australia, Mistaken Point in Newfoundland, the White Sea region of Russia, Namibia, Charnwood Forest in England, and several important Ediacaran sites in China.
Where the Ediacaran Period Fits in Geologic Time
The Ediacaran Period is the last period of the Neoproterozoic Era and the final period before the Cambrian. It lasted from about 635 to 538.8 million years ago and began in the aftermath of Snowball Earth, one of the most extreme ice ages in Earth's history. This places the Ediacaran between a world shaped by global glaciation and a later world filled with abundant, active, and increasingly complex animals.
The Ediacaran is unique in that it preserves a very different kind of fossil record than the Cambrian. Instead of trilobites, brachiopods, and shelly fossils, many Ediacaran deposits preserve soft-bodied impressions of organisms that lived on or near microbial mats. These fossils are often only preserved as feeding and movement traces or casts and molds on sandstone bedding planes rather than as shells, bones, or mineralized skeletons.
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History of Discovery and Naming
The Ediacaran Period is named after the Ediacara Hills in the Flinders Ranges of South Australia. The name is tied to one of the most important fossil discoveries of the twentieth century, when unusual Precambrian fossils from the region showed that large, complex organisms lived before the Cambrian Period. These fossils helped change the old idea that complex life suddenly appeared only at the beginning of the Cambrian. See the Cambrian Explosion article for more information.
Australian geologist Reginald C. Sprigg recognized important fossils in the Ediacara Hills in the 1940s. At first, the fossils were difficult to interpret because they were far older than the familiar Paleozoic fossil animals known from trilobites, brachiopods, corals, and shells. Some Ediacaran fossils were preserved as soft-bodied impressions in sandstone, while many others are simply trace fossils showing movement, resting, or feeding behavior. They include fronds, discs, quilted forms, segmented organisms, and strange seafloor patterns. Together, they include frond-like organisms, discs, quilted mats, segmented forms, and strange seafloor patterns.
The Ediacaran Period became an official geologic period much later. It was internationally ratified in 2004, making it the first new geologic period added to the time scale in more than a century. Its Global Boundary Stratotype Section and Point, or GSSP, is at Enorama Creek in the Flinders Ranges of South Australia. Unlike many younger period boundaries, which are often defined by fossil appearances or extinctions, the base of the Ediacaran is tied to rocks recording the end of major Cryogenian glaciation and the beginning of a new chapter in ocean chemistry, climate, and life.
What Earth Was Like During the Ediacaran Period
The Ediacaran world was very different from the Cambrian seas that followed. The period began after the severe Cryogenian ice ages, when glaciers may have reached low latitudes and Earth may have experienced near-global glaciation. As the climate recovered, oceans changed, oxygen became more available in some marine settings, and shallow seas spread across continental margins. These conditions helped support larger and more complex organisms, especially during the later Ediacaran, about 575 to 540 million years ago.
Most classic Ediacaran fossils come from marine seafloors, especially surfaces covered by microbial mats. These mats helped stabilize sediment and may have provided food or a living surface for many soft-bodied organisms. With few deep burrowers and few animals with hard skeletons, Ediacaran seafloors were very different from later Paleozoic seafloors. Soft-bodied organisms could rest, feed, or move across the sediment surface, sometimes leaving impressions that were preserved by rapid burial.
The continents were also arranged differently than they are today. Ancient shorelines, shallow seas, and continental margins controlled where Ediacaran organisms lived and where their fossils were later preserved. Fossil sites in Australia, Russia, Newfoundland, Namibia, China, and the United Kingdom each preserve a different piece of this early chapter in complex life.
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Life and Fossils of the Ediacaran Period
The Ediacaran Period is famous for the Ediacara biota, a group of mostly soft-bodied organisms. Many of these organisms lived on or near microbial-mat-covered seafloors. Some were probably animals, some may represent extinct experiments in multicellular life, and others remain difficult to classify. This uncertainty is part of what makes the Ediacaran so fascinating: it captures a world before familiar Cambrian animals became widespread.
Unlike Cambrian fossil sites, where trilobites, shells, and hard parts are often common, Ediacaran fossils are usually impressions of soft bodies. They may appear as leaf-like fronds, quilted ovals, discs, segmented forms, or scratch-like feeding traces. These fossils show that large, complex organisms were already living in marine ecosystems before the Cambrian Explosion, even if many of them were very different from later animals.
Dickinsonia
Dickinsonia is one of the most recognizable Ediacaran fossils. It is usually preserved as an oval, flattened impression with many rib-like segments arranged along a central axis. Some specimens are only a few centimeters long, while others can be much larger. The body appears quilted rather than skeletonized, and it probably lived on microbial mats on the seafloor.
The biology of Dickinsonia has been debated for decades, but it is widely discussed as one of the strongest candidates for an early animal among the classic Ediacaran fossils. Its preservation, growth patterns, and possible feeding traces suggest an organism that interacted directly with the seafloor. It is a perfect fossil for showing how strange and unfamiliar Ediacaran life could be compared with later Paleozoic animals.
Arborea
Arborea is a frond-shaped Ediacaran organism from South Australia. It had a leaf-like body attached to the seafloor by a stem and holdfast. This general body plan is common among many Ediacaran frond-like organisms, which rose above the sediment rather than crawling across it like many later animals.
Frond-like Ediacaran organisms such as Arborea show that some Ediacaran communities included upright, sessile organisms forming low seafloor forests. Their exact biology remains debated. They may have absorbed nutrients directly from seawater or lived in ways unlike most modern animals.
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Left image: Arborea arboreus, a frond-like Ediacaran fossil from the Rawnsley Quartzite of South Australia, on display at the Royal Tyrrell Museum. Image credit: Chris Woodrich, CC BY-SA 4.0. Right image: Reconstruction of Arborea denticulata, a frond-like Ediacaran organism from the Shibantan Member of South China. Figure 5 from Wang et al. (2020), Journal of Paleontology, doi:10.1017/jpa.2020.43, CC BY 4.0.
Spriggina floundersi
Spriggina is one of the most recognizable Ediacaran fossils and is sometimes described as one of the earliest animals with a head-like region. Named in honor of Reg Sprigg, it was a small, segmented organism with a distinct front end and repeated body sections, giving it a more animal-like appearance than many other Ediacaran forms. Because of this, Spriggina has often been compared with early arthropods, annelids, and other bilaterian animals, although its exact relationships remain debated.
Recent research has made Spriggina even more interesting. A 2026 Scientific Reports study of more than 100 specimens found that many Spriggina floundersi fossils are bent leftward. Because these fossils preserve mirror-image impressions, a left bend in the rock represents an animal that bent to the right in life. This is interpreted as evidence that Spriggina preferentially turned right, making it the oldest known example of population-wide behavioral handedness in an animal-like organism (Evans et al., 2026).
Kimberella
Kimberella is one of the most significant Ediacaran fossils because it is often interpreted as a bilaterian animal and possibly a mollusc-like organism. It had an oval body with a raised central region and a flexible outline. Unlike many passive-looking Ediacaran forms, Kimberella appears to have moved across the seafloor.
Some fossils associated with Kimberella include scratch-like feeding marks known as Kimberichnus. These traces indicate that Kimberella may have grazed microbial mats using a feeding structure. This makes it especially important because it provides evidence for active feeding behavior before the Cambrian.
Cloudina
Cloudina and similar Cloudina-type animals, often called cloudinomorphs, represent one of the major changes in late Ediacaran ecosystems. Unlike many classic Ediacaran organisms that are preserved as soft-bodied impressions, these animals formed small, tube-like skeletons. Their tubes were usually only a few millimeters wide, but they are some of the earliest widespread examples of animals building mineralized or semi-mineralized hard parts.
These tube-building organisms help show that Ediacaran ecosystems were becoming more complex before the Cambrian Explosion. Their hard tubes may have helped protect the animal, support its body and raise it above the seafloor. Some cloudinomorph fossils also show possible evidence of predatory damage, indicating that animals may have already been interacting with one another in more active ways. For this reason, Cloudina and Cloudina-like animals help bridge the mostly soft-bodied Ediacaran world with the skeletonized, predator-prey ecosystems that became common during the Cambrian.
Famous Fossil Sites from the Ediacaran Period
Although relatively few Ediacaran rock formations are exposed at Earth's surface today, several world-famous fossil sites preserve remarkable snapshots of this ancient world. The best-known localities include Mistaken Point in Newfoundland, Charnwood Forest in England, the Ediacara Hills and Nilpena fossil beds of South Australia, the White Sea region of Russia, and Nama-aged sites in Namibia. Together, these sites record different slices of Ediacaran time, allowing paleontologists to trace how these early ecosystems changed before the Cambrian began.
Mistaken Point in Newfoundland and Charnwood Forest in England preserve some of the older Ediacaran communities, including frond-like organisms such as Charnia. The Ediacara Hills and Nilpena fossil beds of South Australia are classic White Sea-aged localities, famous for fossils such as Dickinsonia, Spriggina, Arborea, and other soft-bodied organisms. The White Sea region of Russia preserves similarly important fossils, including Kimberella and associated feeding traces.
Namibia preserves younger Nama-aged communities near the end of the Ediacaran, including tube-building and early skeletonizing organisms such as Cloudina and Namacalathus. Viewed together, these sites show that Ediacaran ecosystems were widespread, diverse, and changing through time. That changing fossil record helps explain why paleontologists recognize major faunal turnovers near the end of the period.
Major Evolutionary Events and Faunal Turnovers
One of the biggest questions about the Ediacaran Period is what happened to its strange soft-bodied ecosystems. They did not simply continue unchanged into the Cambrian. Instead, the fossil record shows two major pulses of turnover near the end of the period, both of which may represent early extinction events in the history of complex life (Darroch et al., 2023).
The first turnover happened near the end of the White Sea Assemblage, around 550 million years ago. This was when many classic Ediacaran forms, including dickinsoniomorphs, triradial organisms, and other distinctive soft-bodied groups, declined or disappeared. Darroch et al. (2023) give a simple genus-level extinction estimate of about 74.1% for this White Sea-Nama transition.
After this event, Nama-aged communities looked different. They were generally less diverse and included more surviving frond-like forms, erniettomorphs, rangeomorphs, tube-building animals, and organisms associated with more active seafloor behavior. In other words, the Ediacaran world was already changing before the Cambrian began.
A second turnover occurred at the very end of the Ediacaran, near the Ediacaran-Cambrian boundary around 540 million years ago. This Nama-Fortunian transition removed almost all remaining Ediacara Biota, along with many Nama-aged animals. Darroch et al. (2023) estimate about 91% genus-level extinction for this interval, though the exact number remains difficult to test because of sampling, fossil preservation, and dating challenges.
The causes are still debated. Environmental stress, changing ocean chemistry, carbon-isotope disturbances, competition, burrowing, grazing, and other new animal behaviors may all have played a role. By the start of the Cambrian, many classic Ediacaran organisms were gone, and more active, skeleton-building, Cambrian-style animal communities were beginning to take over.
Click to expand: How to read/understand this figure
Read the diagram from bottom to top. The horizontal divisions represent the three major Ediacaran fossil assemblages: the Avalon assemblage, about 575 to 558 million years ago; the White Sea assemblage, about 558 to 550 million years ago; and the Nama assemblage, about 550 to 538 million years ago. The Cambrian begins at the top of the diagram.
The large blue panel tracks the classic Ediacara Biota. It shows when major groups such as rangeomorphs, arboreomorphs, erniettomorphs, dickinsoniomorphs, and several radially organized forms appeared and disappeared. The changing width of each colored shape represents changes in genus richness through time. Question marks identify groups whose relationships or final appearances remain uncertain.
Rangeomorphs and arboreomorphs were especially important in the older Avalon assemblage. The White Sea assemblage later contained a wider variety of body forms, including Dickinsonia-like organisms and forms that may have moved across or fed on the seafloor. Many of these distinctive groups declined sharply before or during the Nama assemblage. The label "Dead Clade Walking" refers to rare survivors that may have persisted briefly after the main decline of their group.
The middle panel shows groups interpreted more confidently as animals. These include possible sponges, cnidarians, bilaterians, and tubular organisms. Some of these lineages continued toward the Cambrian even as many of the classic soft-bodied Ediacaran groups disappeared.
The yellow ichnogenera column records trace-fossil diversity. Its increase toward the Cambrian reflects animals becoming more active, mobile, and capable of burrowing into the sediment. This growing disturbance of microbial seafloors was an important ecological change near the end of the Ediacaran.
The extinction panel highlights two major biological turnovers. A simple genus-level calculation suggests that about 74 percent of genera disappeared near the White Sea-Nama transition around 550 million years ago, followed by an estimated 91 percent near the Ediacaran-Cambrian boundary. These percentages should be interpreted cautiously because differences in fossil preservation, sampling, and rock availability can affect the apparent extinction rate.
The carbon-isotope curve on the right records changes in the global carbon cycle. It includes the large Shuram excursion during the Ediacaran and another disturbance near the beginning of the Cambrian. Their proximity to major biological changes suggests that the oceans and atmosphere were changing, although the isotope shifts do not by themselves prove what caused the extinctions.
Taken together, the figure shows that the transition into the Cambrian was not a single sudden replacement. It was a prolonged ecological transformation in which many classic Ediacaran organisms declined, trace-making animals became more active, and Cambrian-style marine ecosystems gradually emerged.
Recommended Pre-Cambrian Books and Fossils
Snowball Earth: The Story of the Great Global Catastrophe That Spawned Life as We Know It
Gabrielle Walker: 2003
A gripping science adventure that follows geologist Paul Hoffman's quest to prove that Earth once froze from pole to equator and that this global deep freeze helped reshape the history of life.
The Garden of Ediacara
Mark A. S. McMenamin: 2000
Written as a scientific travelogue, this book follows Mark McMenamin's fossil-hunting journeys through Mexico and Namibia as he investigates the strange Ediacaran organisms that lived before the Cambrian Explosion.
References / Works Cited
Darroch, S. A. F., Smith, E. F., Nelson, L. L., Craffey, M., Schiffbauer, J. D., & Laflamme, M. (2023).
Causes and consequences of end-Ediacaran extinction: An update.
Cambridge Prisms: Extinction, 1, e15.
https://doi.org/10.1017/ext.2023.12
Droser, M. L., & Gehling, J. G. (2015).
The advent of animals: The view from the Ediacaran.
Proceedings of the National Academy of Sciences, 112(16), 4865-4870.
Evans, S. D., Webb, J., Hughes, I. V., et al. (2026).
Earliest evidence of behavioural handedness in the Ediacaran motile bilaterian Spriggina floundersi.
Scientific Reports, 16, 19924.
https://doi.org/10.1038/s41598-026-53857-x
Gradstein, F. M., Ogg, J. G., Schmitz, M. D., & Ogg, G. M. (Eds.). (2020).
Geologic Time Scale 2020.
Elsevier.
International Commission on Stratigraphy. (2024).
International Chronostratigraphic Chart, v2024/12.
stratigraphy.org/chart
Knoll, A. H., Walter, M. R., Narbonne, G. M., & Christie-Blick, N. (2006).
The Ediacaran Period: a new addition to the geologic time scale.
Lethaia, 39(1), 13-30.
Narbonne, G. M. (2005).
The Ediacara biota: Neoproterozoic origin of animals and their ecosystems.
Annual Review of Earth and Planetary Sciences, 33, 421-442.
Schiffbauer, J. D., Selly, T., Jacquet, S. M., et al. (2020).
Discovery of bilaterian-type through-guts in cloudinomorphs from the terminal Ediacaran Period.
Nature Communications, 11, 205.
https://doi.org/10.1038/s41467-019-13882-z
Wang, X., Pang, K., Chen, Z., et al. (2020).
The Ediacaran frondose fossil Arborea from the Shibantan limestone of South China.
Journal of Paleontology, 94(6), 1034-1050.
https://doi.org/10.1017/jpa.2020.43
FAQs: Ediacaran Period Frequently Asked Questions
Quick answers to common questions about the Ediacaran Period, Ediacara biota, famous fossils, fossil sites, and late Ediacaran faunal turnovers.
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When was the Ediacaran Period?
The Ediacaran Period lasted from about 635 to 538.8 million years ago. It was the final period of the Neoproterozoic Era and came immediately before the Cambrian Period.
See: Geologic Time -
What is the Ediacara biota?
The Ediacara biota is the name given to many unusual soft-bodied organisms from the Ediacaran Period, including frond-like forms, quilted oval organisms, segmented forms, possible early animals, and fossils that do not always fit neatly into modern animal groups.
See: Life and Fossils
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What was life like during the Ediacaran Period?
Life during the Ediacaran Period was mostly marine. Many organisms lived on or near microbial-mat-covered seafloors. Famous fossils include Dickinsonia, Arborea, Spriggina, Kimberella, Cloudina, Rangea, Charniodiscus, and other soft-bodied forms.
See: Life and Fossils -
Why is the Ediacaran Period important?
The Ediacaran Period is important because it preserves some of the earliest large, complex multicellular organisms and some of the earliest evidence of animal-like ecosystems before the Cambrian Explosion.
See: Major Evolutionary Events -
Were there animals before the Cambrian Explosion?
Yes. The Ediacaran fossil record shows that large, complex organisms and possible early animals existed before the Cambrian Explosion. Some Ediacaran fossils may represent stem-group animals or early relatives of later animal groups, although the relationships of many forms are still debated.
See: Life and Fossils -
What are the most famous Ediacaran fossils?
Famous Ediacaran fossils include Dickinsonia, Arborea, Spriggina, Kimberella, Charniodiscus, Rangea, Tribrachidium, Cyclomedusa, Cloudina, Namacalathus, and Charnia.
See: Life and Fossils -
Where are famous Ediacaran fossils found?
Famous Ediacaran fossil sites include the Ediacara Hills and Nilpena in South Australia, Mistaken Point in Newfoundland, the White Sea region of Russia, Namibia, Charnwood Forest in England, and several important Ediacaran sites in China.
See: Famous Fossil Sites -
How was the Ediacaran Period named?
The Ediacaran Period is named after the Ediacara Hills in the Flinders Ranges of South Australia, where important Ediacaran fossils were discovered and studied.
See: Discovery and Naming -
What happened at the end of the Ediacaran Period?
Near the end of the Ediacaran Period, many classic Ediacaran organisms declined or disappeared. Researchers recognize two major faunal turnovers or possible extinction pulses: one near the White Sea-Nama transition around 550 million years ago, and another near the Ediacaran-Cambrian boundary around 540 million years ago.
See: Major Evolutionary Events -
What was the White Sea-Nama turnover?
The White Sea-Nama turnover was a major change in Ediacaran ecosystems around 550 million years ago. Many classic White Sea-aged Ediacaran organisms declined or disappeared, and later Nama-aged communities included a different mix of organisms, including tube-building animals and more evidence of active seafloor behavior.
See: Major Evolutionary Events -
What was the Nama extinction near the end of the Ediacaran?
The Nama extinction, or Nama-Fortunian turnover, occurred near the Ediacaran-Cambrian boundary around 540 million years ago. It marks the disappearance of most remaining Ediacara biota and many Nama-aged organisms before Cambrian-style animal communities became widespread.
See: Major Evolutionary Events -
How was the Ediacaran different from the Cambrian?
The Ediacaran was dominated by soft-bodied organisms, microbial-mat-covered seafloors, and ecosystems with few hard skeletons. The Cambrian that followed had more abundant shells, skeletons, burrowing animals, predators, and more recognizable animal groups.
See: What Earth Was Like
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