Charnia Masoni is an extinct rangeomorph and famously one of the first described forms of complex life in the Ediacaran. It is the holotype for the world-renowned Charnia genus that lived millions of years in the Precambrian.
This leaf-like creature baffled scientists with its unique frond-like appearance, characterised by a series of branching ridges in a self-similar fractal branching pattern.
Unlike many modern organisms, Charnia lacked obvious organs such as a mouth, gut, or even a clear front and back.
Its importance to science cannot be overstated. Yet its enigmatic nature has led to numerous debates about its classification and lifestyle. What was Charnia Masoni? How did it live?
About Charnia Masoni
Scientific Classification
- Kingdom: Animalia
- Phylum: Petalonamae
- Class: Not applicable
- Order: Rangeomorpha
- Family: Charniidae
- Genus: Charnia
- Species: C. masoni
New research by Dunn et al. 2021 suggests that Charnia is likely a stem-eumetazoan (a proposed basal clade for all animal types except sponges) and it likely diverged before the last common ancestor of Eumetazoa (which would go on to become Coelenterata [ancestors of jellyfish, corals etc.] and Bilateria [almost all other animals, from snails and insects to fish, reptiles, mammals and us humans]) before it developed features such as a gut etc. Which means Charnia’s ancestry could possibly go back as early as the Cryogenian.
Temporal Range
The species lived approximately 575 to 550 million years ago, during the Ediacaran Period (635 to 541 million years ago). We know this because Charnia Masoni fossils have been found in the:
- Avalon Assemblage: Fossil sites that formed in deep water, found in Charnwood Forest, UK, and Newfoundland, Canada – dated to 575 – 560 million years ago.
- White Sea Assemblage: Fossil sites from mid- to shallow depth, found in Russia – dated to 560 – 550 million years ago.
There is a slightly contentious fossil (listed as a sister species of Charnia Grandis, which some contend is actually just a mature form of Charnia Masoni) which is found in the shallow marine Ediacaran Assemblage of Australia. This is interesting because it’s slightly younger – 555-541 million years ago. Showing that Charnia Masoni, or at least a sister species, might have survived right up to the end of the Ediacaran period.
Description
Charnia Masoni has been interpreted as a mainly soft-bodied, aquatic, sessile (not mobile) osmotroph (a creature that absorbs nutrients through osmosis) of the animal kingdom that grew from 1cm to 68cm in length.
Based on research of other rangeomorphs, specifically Fractofusus misrai, showing fine filaments running from mature rangeomorphs to nearby clusters of younger ones, it’s believed that rangeomorphs might have used something similar to stoloniferous reproduction of some plants today – where a mature organism extends a stolon or “runner” (propagule) from which new organisms grow.
It’s also notable that Charnia Masoni was originally described as having no stalk from which its branching “fronds” grew. In 2007, though, Laflamma et al. claimed it did have a stalk. Yet this was disputed again by Dunn et al. in 2018 who reinterpreted Charnia Masoni as having no stalk but “holdfasts” instead.
Sister Species
Charnia Masoni originally had a whole host of sister species, although most of them have been reclassified. The only remaining official ones are:
- Rangea Grandis – grew up to 1.8m to 2m in length* (now including Charnia Grandis)
- Charnia Siberica – famous 3-dimensionally preserved specimen(s) from Russia**
* Although it has been suggested that Charnia Grandis might not be a sister species at all but instead a more mature individual of Charnia Masoni itself.
** Similarly, Fedonkin et al. in 2007 subjectively stated that they think Charnia Siberica is actually just Charnia Masoni and not a separate species.
Previous Sister Species Now Reclassified
The following were all thought to have been sister species, but have since been reclassified:
- Charnia Antecedens – is now Vinlandia Antecedens.
- Charnia Wardi – is now Trepassia Wardae.
- Charnia Grandis and Ranges Grandis are now considered the same thing.
What was Charnia Masoni exactly?
Although falling in the kingdom of Animalia, people originally thought Charnia Masoni, like all rangeomorphs, looked like plants, because of their frond-like appearance. They don’t seem to have a gut, digestive tract or mouth, after all.
However, when you look at how Ediacaran rangeomorph fossils are distributed in assemblages across the ocean floor, their distribution is unlike plants. In forests, the taller trees are the densest and the lower-growing shrubs and plants are the least dense. Rangeomorphs like Charnia are the exact opposite. The smaller, lower-growing organisms are the most dense and the taller ones are the least dense.
What’s more, Charnia lived in absolute pitch-black darkness.
Research on the Avalon Assemblage, which includes the original Charnia from Charnwood Forest and places like Mistaken Point in Canada, shows that the rocks were turbidite sediments, deposited in the deep ocean. Charnia may have lived up to 1km below water.
That’s extremely deep. Light only penetrates up to 200m into the water. So most photosynthesising organisms (plants) live well above the 200m subsurface mark.
This probably means Charnia didn’t photosynthesise and was therefore not a plant.
But it couldn’t move and had no gut, so it’s not very animal-like either. In fact, many scientists now believe Charnia could have been an Osmotroph – a non-moving organism that absorbs organic compounds through osmosis. (Fungi are osmotrophs, for example.) And was potentially a stem-eumetazoan.
It’s believed Charnia just sat there in the dark, depths of oceans or lakes and absorbed dissolved carbon and nutrients in the ancient water.
What was its body like?
Firstly, Charnia seemed to come in a huge variety of sizes. Some were just 1cm tall, while others were up to 68cm long, and every size in between. Some may have been much taller – although there are no complete fossils, the fragments of Charnia Grandis from Charnwood suggest a creature up to 1 metre in length. (There are unconfirmed reports of a potentially 2m long specimen from Newfoundland, but we cannot find any actual proof of that.)
And they all looked like fronds.
One of the most incredible features of Charnia is that it has self-similar fractal branching, which works like so… If you look at the whole creature, it looks like a fern frond. But, if you look at each little branching cluster on the frond, each one looks like a mini replica of the entire animal.
It seems to have grown fractally, where the smallest parts of itself looked like replicas of its whole body, to increase its surface area for feeding.
And then, it must have anchored itself to the ocean floor somehow, but scientists can’t really agree on that one… There are a range of trace fossil imprints that might have been Charnia’s holdfast to the ocean floor, but it’s unclear which belongs to this species in particular.
When did Charnia Masoni live?
Charnia Masoni thrived during the Ediacaran Period, a time frame that spanned from approximately 635 to 541 million years ago.
This period is crucial in Earth’s history as it marks the emergence of multicellular organisms, preceding the famous Cambrian Explosion.
The Ediacaran Period saw the rise of a variety of unique and enigmatic life forms. Charnia Masoni being one of its most iconic representatives.
Xiao and Laflamme (2009) provide an in-depth look into the Ediacaran biota, offering valuable insights into the world Charnia inhabited
How did Charnia Masoni live?
The lifestyle of Charnia Masoni has been a subject of much speculation. Most scientists agree that it was a sessile organism. This means it was anchored to the sea floor and likely absorbed nutrients directly from the water.
Its frond-like structure suggests that it might have been involved in filter-feeding or absorbing nutrients through its surface.
This mode of life is quite different from most modern marine animals. But it was likely common in the soft-bodied communities of the Ediacaran seas.
At first glance, people thought that Charnia might have been a type of plant. Studies have now shown that Charnia doesn’t seem to have had any chlorophyll. And is instead on the animal branch of life.
There’s also evidence that it lived in very deep waters of the ocean or perhaps even lakes. Very far below the depths where light couldn’t reach.
Narbonne (2005) provides a comprehensive analysis of the ecology of Ediacaran biota, shedding light on how organisms like Charnia could have survived in the prehistoric oceans.
When and where was Charnia Masoni first discovered?
Charnia Masoni was first discovered in April 1957 in Charnwood Forest, located in Leicestershire, England.
The area is today renowned for its well-preserved fossils from the Ediacaran period. But at the time no one believed that rocks of that age could have preserved any form of life.
The discovery site, a quarry in Charnwood Forest, exposed ancient rock surfaces that contained the fossil. These rocks were part of a group known as the Charnian Supergroup. They date back to the Ediacaran period, approximately 575 to 560 million years ago.
Who discovered Charnia Masoni?
The discovery of Charnia Masoni is a fascinating tale of serendipity and scientific curiosity.
The all-important first fossil was found by Roger Mason, a then 17-year-old schoolboy who was passionate about geology.
Mason, along with members of a local geological society and his schoolmaster, found the fossil during a field trip.
This discovery by a young amateur geologist sparked a significant scientific inquiry. It also highlighted the potential for important scientific contributions by enthusiasts and amateurs.
Incidentally, Sir David Attenborough, who grew up in Leicester near Charnia Forest, notes in his biographies and documentaries that Roger Mason was a boy from his school, Wyggeston Grammar School for Boys.
Roger was a few years behind Attenborough, also an avid fossil hunter. Yet Attenborough never even thought to go looking for fossils in Charnia Forest. Because scientists back then believed that rocks of that great age would not contain any.
Who first described Charnia and when?
The first scientific description of Charnia Masoni was made by Trevor D. Ford, a geologist, in 1958 (referenced here).
Ford’s description marked a significant milestone in palaeontology, as it shed light on the mysterious life forms of the Ediacaran period.
His initial work paved the way for further research into these ancient organisms, which were unlike anything previously known in the fossil record. Most notably because they occurred prior to the Cambrian, the previously (and wrongfully) assumed “starting point” of complex life.
The formal publication of Ford’s findings in a scientific journal brought Charnia Masoni to the attention of the broader scientific community.
Why was Charnia significant?
Charnia Masoni is super important to palaeontology because, before Charnia, people used the “Cambrian Explosion” to try and disprove evolution.
See, because we only had Cambrian fossils before Charnia, it looked as if complex life suddenly just appeared at once on Earth – out of the blue, hence the name the “Cambrian Explosion”. And that made it seem like someone or “something” just waved a magic wand and poof, life was created in a day.
When Charnia was found, it was one of the first Ediacaran fossils to be scientifically described. This was the earliest evidence of complex life on Earth BEFORE the Cambrian.
Charnia Masoni challenged existing views on the evolution of life. It showed that complex organisms had evolved much earlier than previously thought.
This discovery was pivotal in establishing the Ediacaran period as a distinct era in Earth’s history. Today we recognise the Ediacaran as when most multicellular life forms emerged.
Furthermore, Charnia Masoni’s unique morphology contributed to new insights into the diversity of pre-Cambrian life. It sparked a renewed interest in the study of early life on Earth.
When and why did Charnia Masoni go extinct?
Charnia Masoni, like many Ediacaran organisms, went extinct around the end of the Ediacaran Period, approximately 540 million years ago.
The extinction of Charnia and other Ediacaran biota is thought to be linked to a variety of environmental and ecological changes. These include increased competition and predation from newly evolving organisms during the Cambrian Explosion. There might also have been significant shifts in ocean chemistry. And possibly changes in the global climate.
Most notably, Ediacaran biota tended to be sessile (unable to move themselves around). And the forms of life directly after them were all mobile. So it might just be that life learned the important trick of locomotion. Soon after that, vision and predation would follow.
Perhaps lifeforms like Chanria Masoni were simply too slow to adapt to the new competitive nature of life in the late Ediacaran and early Cambrian.
A study by Laflamme et al. (2009) discusses the ecological changes during this period that could have led to the extinction of the Ediacaran biota, including Charnia Masoni.
Are sea pens related to Charnia?
No, sea pens are not related to Charnia at all.
They look somewhat similar, so people once assumed they were. But sea pens are from a different class and order of animal altogether.
Sea pens are a colonial animal, meaning it’s made up of many different animals living in a colony. And it’s a cnidarian, related to jellyfish and corals.
Charnia, on the other hand, is not a cnidarian at all, but from the separate order of rangeomorpha. This is according to research by Dunn et al. 2021.
What’s more, Charnia is NOT a colony creature, it’s one organism.
What is interesting, though, is that Dunn et al. in 2022 actually showed that the ancestor to sea pens and all cnidarians lived alongside Charnia. It was found right next to Charnia Masoni, in fact. In the same assemblage, and it is called Auroralumina attenboroughii, named after David Attenborough.
Charnia’s assumed preserved anchor points in the Ediacaran rocks were also once thought to have been jellyfish. However, that’s also been disproven.
Also discover the exciting next chapter on animals called eumetazoa, as well as the world-defining arrival of bilateria, including all of us deuterostomes and our often-scary cousins, the protostomes.
Fossil locations: Where can you go to see Charnia fossils?
If you live nearby or can make the trip, there are a few great places to go and see Charnia for yourself…
1. The Leicester Museum & Art Gallery
The Leicester Museum & Art Gallery at 53 New Walk, Leicester, UK, is where you can see the original holotype fossil of Charnia Masoni. It’s the actual Charnwood Forest one that Roger Mason first discovered back in 1957.
Phone: +44 116 225 4900 (UK)
Or visit their website for more info
2. Mistaken Point, Newfoundland Canada
Although it’s on the other side of the world, the Mistaken Point Ecological Reserve in Newfoundland’s Avalon Peninsula in Canada is of the same Avalon Assemblage as the original Charnia specimen. And it has loads more examples of Charnia and other Ediacaran biota.
It’s a UNESCO World Heritage site. And there’s an area of 5.7km of rocks with various Ediacran fossils all over the place. Not to mention it’s a beautiful place just on its own.
Email MistakenPointTour@gov.nl.ca to book a tour
Or visit their website for more info
3. Ediacaran Hills, Australia
Although not part of the same assemblage, the Ediacaran Hills in the Flinders Ranges of mountains in Southern Australia (about 650km from Adelaide) are extremely important. This is where the first Ediacaran trace fossils were discovered. It’s where the Ediacaran gets its name.
The White Sea Assemblage here is both younger and from shallower water than where the original Charnia Masoni was first found. But some forms Charnia were also found here, as were the first trace and body fossils of the proposed first bilaterian animal.
Email hello@ediacarafoundation.org to book a tour
Or visit their website for more info
Documentaries featuring Charnia
They’re not always 100% accurate because we make new scientific discoveries all the time. But documentaries at least deliver the gist of the information in a fun and engaging way. Just click play, hit full screen and enjoy hours’ worth of awesome documentaries on Charnia, right here…
First Life
David Attenborough, BBC, 2010
Episode 1 of David Attenborough’s First Life features the discovery of Charnia and the evolution of the first complex life. It was produced by the BBC in 2010. You can also buy it on DVD or Blu-ray via Amazon. And it is available to watch in some regions via Prime Video.
Charles Darwin and the Tree of Life
David Attenborough, BBC, 2013
Though it features only briefly, Charnia does appear in David Attenborough’s Charles Darwin and the Tree of Life. It’s available for purchase via Amazon.
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