The discovery of Uncus dzaugisi, a 555-million-year-old fossil in South Australia, confirms Precambrian origins for Ecdysozoans, bridging a key evolutionary gap.
A remarkable fossil discovery in remote South Australia has provided crucial insights into one of evolution’s long-standing mysteries: the origins of Ecdysozoa, a superphylum of molting animals that includes insects, crustaceans, and nematodes.
Ecdysozoans are the most diverse and species-rich animal group on Earth, comprising over half of all known animal species. Despite their dominance, the fossil record has long been puzzlingly sparse when it comes to evidence of their ancient ancestors. This absence is particularly striking given molecular studies, which indicate that ecdysozoans should have existed as far back as the Precambrian.
Now, in a new study published in Current Biology, researchers describe Uncus dzaugisi, a 555-million-year-old worm-like organism preserved in the Precambrian rocks of Nilpena Ediacara National Park (NENP). This tiny fossil, barely over a few centimeters long, represents the oldest confirmed member of the Ecdysozoa and the only one known from the Precambrian period.
“It’s an incredibly exciting discovery,” said lead author Ian Hughes, a Ph.D. candidate in the Department of Organismic and Evolutionary Biology at Harvard. “Ecdysozoans were prevalent in the Cambrian fossil record and we know they didn’t just appear out of nowhere. But, until now, we had no concrete fossil evidence to confirm it.”
The Significance of Nilpena Ediacara National Park
Hughes discovered Uncus in the Precambrian sandstone rocks at NENP, a site renowned for its exceptionally well-preserved Ediacaran lifeforms. Once an ancient seafloor, the park is dedicated to the research and preservation of Ediacaran fossils found in the sandstone sediments in the area. The site’s fine-grained sediments actually allowed for the extraordinary preservation and detail of Uncus.
“A lot of the beds that we have are relatively coarse-grained,” said Hughes, “but the sandstone in several new beds at Nilpena is so fine-grained that it allows for finer details and preservation of smaller animals.” The researchers worked carefully, using hand tools to dig into the rocky hillside. The Ediacaran seafloor reveals a time before animals began burrowing up and down between sediment. The top few ancient millimeters were covered in thick microbial mat materials where these first animals lived. Eventually, sediment covered and compressed these communities, creating a mold of their ancient ecosystem.
“Imagine pouring concrete over the ocean, waiting a half-billion years, and then flipping it over to find an entire ecosystem,” Hughes said. “That’s what’s really unique about this locality. Because they were all smothered at the same time, we can actually also conduct ecological work on the first animal ecosystems on Earth.”
There are over one hundred genera of Ediacaran fossils, yet none had ever been confidently assigned to the Ecdysozoa. The discovery of Uncus helps address the dilemma of the origins and rapid diversification of the Ecdysozoa lineages in the Cambrian. For the first time, Uncus offers direct evidence of early ecdysozoan life forms from the Precambrian.
The fossil’s unique features—including its cylindrical body, a consistent length-to-width ratio, remarkably rigid cuticle, and distinct curved traces indicating motility—point to similarities with modern nematodes. The team was especially excited to find trace fossils, as unlike many of its squishy contemporaries, which were not especially mobile, Uncus was quite active. It wasn’t until the researchers moved to a different section of the site in 2019 and found a shift in the composition of the microbial mat that they were able to see the ecdysozoan fossils and traces that revealed this ancient species and its motility.
“It’s a remarkable find, as it places Ecdysozoans in the Precambrian Eon, supporting the theory that this lineage predates the Cambrian explosion,” said Hughes. “Ecdysozoans are so diverse and occupy so many niches, that to actually identify an early one and see what Ecdysozoans were doing is just amazing.”
Preserving a Historic Site
Nilpena Ediacara National Park (NENP) is more than a field site for Hughes and the team – it’s been a part of Hughes and his family’s lives for 25 years. After so many years of working there, Hughes and his family have built a deep relationship with the indigenous community and the cattle ranch owners who sold part of their land to develop NENP and preserve the Ediacaran fossils. Hughes and his team are very careful to not disturb the structure and layout of the park, as no rock is allowed to be removed from the site.
With a grant from NASA, they were able to secure a 3D laser scanner that provides high-resolution images of all of their findings in the field. “We do everything we can to make sure every rock stays on site,” said Hughes, “The only exception is if we discover and describe a new species. Then, we deposit a holotype in the Museum in South Australia. This is really important to our work ethic, to not disrupt the land that belongs to the indigenous people.”
Moving forward, the researchers plan to use the laser scan data to study the curvature and movement of this species. “Uncus body fossils and associated trace fossils give us a really unique opportunity to look in detail into the sinuosity and curvature to model the potential musculature of this ancient species,” Hughes said. “Moreover, because these fossils are preserved on fossil bed surfaces, we can investigate the ecology of this taxon and try to understand whether its distribution on the seafloor might correlate with another species or a particular type of microbial mat structure.”
Uncus dzaugis is named in honor of Mary, Matthew, and Peter Dzaugis for their past and continuing contributions to fieldwork at NENP.
Reference: “An Ediacaran bilaterian with an ecdysozoan affinity from South Australia” by Ian V. Hughes, Scott D. Evans and Mary L. Droser, 18 November 2024, Current Biology.
DOI: 10.1016/j.cub.2024.10.030
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39 Comments
On the cliff edges at Lake Maraboon, Queensland, there are a multitude of different sea animal fossils. There was no deliberate damage to the fossils 3 years back, but now, unfortunately some ridiculous people are trying to destroy the fossils and others that are just imprints. Trying to make believe these never existed. This area should be restricted and preserved. I can send photos I took in the past.
Professing themselves wise they became fools.
That is a unique privilege that’s owned by scientists only.
Only thing that belong to scientist like you is what’s in my pants will fill you good enough since it’s Like Really Huge(^^)
Reminds of the organized superstition that tears down statues of competing groups. No morals that can stand in daylight.
Everything in the earth and universe demonstrates the reality of intelligent design! A carpenter reveals himself by the house that he built. His skill, his knowledge. A painter reveals himself by the lovely portrait or seascape he painted. Even looking at our own body we can see God’s masterful design. Our ribcage protecting the vital organs. 2 eyes located in the front of the skull not in the back of your head. And the internal structure allows you to see in color. And muscles that allow to look left and right, up and down. 2 hands with 5 fingers that you move with a thought. DNA. The highly complex , genetic, digital , chemical code. This code provides the instructions to the cells on how to fabricate proteins from a selection of 20 amino acids. Then tissue, then organs and systems such as the heart. With its 4 chambers taking blood in by vacuum, the pumping blood out by contraction caused by an electric pulse. The DNA also provided the instructions to fabricate the sinus node. That bundle of nerves that generate a 60 millivolt pulse to the heart. 60 to 100 times per second. Ir the pulse was weaker or not the right interval we would not survive. Nothing never has created anything. In the electronic world we engineer and build circuits that generate an electric pulse. Such as the clock pulse used in a microprocessor.
Paul. It’s called evolution. Not intelligent design. Please try to get that through your non-intelligently designed head.
What I can’t seem to get through my own thick skull is…. How is it possible that there are still so many people out there who just can’t seem to be able to grasp the well established fact that evolution has been the chisel and hammer that has shaped life on Earth through the ages. It can either be utter ignorance or blatant unwillingness to accept reality as it is!
Religion and the belief in magical divinities living in the sky were established centuries ago, at a time when scientific knowledge was at the value of just about zero, and in its place existed only conjecture and superstition. Since then, science has unearthed incredible amounts of physical evidence that should have been sufficient to convince all of those thick skulled religious people that their theistic ideas didn’t have a snowball’s chance in hell to have any veracity or scientific validity!
Wake up and smell the flowers, people!!!!
Science fiction coming alive; mans imagination a blueprint to becoming reality. Development of technologies made possible by the collective steps of human scientist. Those who think they know, know nothing, your conclusions based on somebody else’s discovery built on the collective over time. For you to look down on and criticize anybody’s understanding or belief in whatever scientific information, creation or religion identifies by your own self-placement, you
to be low on the totum pole of evolutionary understanding and intelligence, your understanding is blinded in arrogance We evolve with the help of each other, every theory and scientific concept subject to correction and under constant change, if you do not believe today we shower you in love for tomorrow
Anyone who favours evolution over intelligent design is a numpty
People who favour evolution over intelligent design don’t probably want to believe in God , how sad when God sent his only begoten son Jesus Christ to suffer and die so that we can be saved.
You are correct. They tell you in the article that it’s like someone covered the area all at once “like cement” or maybe the worldwide flood of Noah’s day instantly buried everything in sediment. Why is it people deny the truth when it is blatantly right in front of them. Archaeologists around the world are finding the truth that supports what is written in the scriptures.
Bend your knee while you can, acknowledge the king of kings.
“The fossil’s unique features—including its cylindrical body, a consistent length-to-width ratio, remarkably rigid cuticle, and distinct curved traces indicating motility…”
Where does the similar fossil called Grypania spirals fit? It’s 1.3 billion year old. Long before these Eadiacarans appeared.
Where are the remaining 100000s of these fossils??
A valid estimate is that 1 in every 1000th species fossilize. They may come in clumps though, depending on conditions. But essentially you ask for what average as fossils from up to 100 million species of animals.
Gryphania is too old to be an animal. Wikipedia lists suggestions: “a giant bacterium, a bacterial colony, or a eukaryotic alga.”
Always “ground breaking” vaguely blends into irrelevant, gotta keep that grant $$$ coming…!
I found some fossilized democrats lol
The oldest US president, a republican, will take his position this spring. Fossils are old; you do the math.
You should realize biden is 82 democrat
Jimmy Carter was blessed with 100 years of life.
proof of the reward for right decisions
Rep or Democrat your decision to vote makes you part the whole, and guilty for the sins and decisions made in office by that President, called share of the blame, put those sins under your arm to be counted on judgement day, Diminished capacity is no longer a defense for Republicans or Democrat alike
MAGA !
The groundbreaking find remains groundbreaking and is relevant for eluci9dating the tree of life. The grants that enable the hard work of scientists are paid by willing donators.
You are correct. They tell you in the article that it’s like someone covered the area all at once “like cement” or maybe the worldwide flood of Noah’s day instantly buried everything in sediment. Why is it people deny the truth when it is blatantly right in front of them. Archaeologists around the world are finding the truth that supports what is written in the scriptures.
Bend your knee while you can, acknowledge the king of kings.
ID proponents are the most dishonest, opportunistic liars on the planet. Your book of fairy tales is ludicrous at best. Religion was created to enslave the weak minded and ignorant, it’s ideology was based on scientific illiteracy to provide explanations for phenomena that science now provides. Your faith is archaic and preposterously illogical, yet you continue to be enslaved by it’s moronic teachings. There is no messiah, there is no judgement day. Treat people with kindness and respect. There is no afterlife. Wake up and realise you’ve been conned by the largest cult in human existence.
A little illustration would make more clear what we are seeing or not…frankly I am unimpressed. Let’s see more.
They look like worms. Not very interesting looking.
Absolutely love the ethos here, of not taking rock away unless totally necessary (for the holotype). I lead and attend geology field trips (in the UK) and I like to try to get folks to leave their hammers behind, and to “take photos not specimens”. I will reference this work to encourage them to conserve.
👏👏👏
It’s definitely vermiform (paywalled, but the images isn’t search walled).
For a younger example of a putative ecdysozoan, there is a new find of what could be the embryos of a Saccorhytus [Tiny Fossilized Embryos Reveal Stunning Details of Life Half a Billion Years Ago, Michelle Starr, Science Alert, 27 December 2024].
Y’all must be stupid 555 million years ago they still can’t crasp the concept of time lies lies and more lies there is no such thing as 555 million years ago
Crasp??
Truth!!
Being a scientist gives them somehow the right to spread any kind of BS around, being accepted a truth by a vast majority of people. However, when scientist predict future events, this BS owned privilege always reveals itself. Why, because they’re always wrong. But in this case, there’s also everytime an excuse for their mistakes. Scientists believe technology is able to change climate change. Another of those BS proclamations. Earth will eliminate humans to survive and recover our wrong doings and scientist’s mistakes about almost everything.
The Earth is only 6,000 years old.
Intriguing article
Billions of years old, BS, carbon dating proved wrong many ways, many times. These fossils could maybe be from Noah’s flood. Waisting our tax dollars spreading more lies. There is no proof that evolution exists. You would still see every stage of every animal., you couldn’t stop it. We can’t even get muels to bread. Stupid people.
Carbon dating is not used on fossils older than 50, 000 years old. Radiometric dating is used for fossils older than this. Your flood theory had been disproved numerous times, due to the fact the geologic column has no spread of fossils in the sediment that would be the result of a large flood. Not a single layer shows the type of fossils that would be expected to be seen, why do you think that is? The only lies being spread here are the ones by ID proponents who were brainwashed into believing that a Magic Sky Fairy, who incidentally ignored all other civilizations on the planet that had been surviving for over 100,000 years prior to this magical revealing, did so to a group of illiterate goat herders in the remote Middle East. The story is ridiculous. You clearly misunderstand or misrepresent Evolution, no surprise there. Try again bud, maybe this time do some actual research instead of parroting classic ID misdirection.
Ah okay, so when did the cell turn into a bunch of cells that turned into plankton that turned into swimy things that turned into fish that crawled onto shore that turned into dinosaurs that turned into monkeys that turned into humans again? Every year I am more and more convinced the theory of evolution was created while on shrooms. There is no way that is legit… it makes absolutely zero sense. You have three options. God. We’re in the matrix or aliens put us here. I choose God but that didn’t happen until later in life. I stopped believing in the evolution ridiculousness about the same time my balls dropped. There was and is an intelligent designer.
“Muels to bread” … how embarrassing!!