Worm-like creature with legs and spikes finds its place in the evolutionary tree of life

Aug 17, 2014
A reconstruction of the Burgess Shale animal Hallucigenia sparsa. Credit: Elyssa Rider

One of the most bizarre-looking fossils ever found - a worm-like creature with legs, spikes and a head difficult to distinguish from its tail – has found its place in the evolutionary Tree of Life, definitively linking it with a group of modern animals for the first time.

The animal, known as Hallucigenia due to its otherworldly appearance, had been considered an 'evolutionary misfit' as it was not clear how it related to modern . Researchers from the University of Cambridge have discovered an important link with modern velvet worms, also known as onychophorans, a relatively small group of worm-like animals that live in tropical forests. The results are published in the advance online edition of the journal Nature.

The affinity of Hallucigenia and other contemporary 'legged worms', collectively known as lobopodians, has been very controversial, as a lack of clear characteristics linking them to each other or to modern animals has made it difficult to determine their evolutionary home.

What is more, early interpretations of Hallucigenia, which was first identified in the 1970s, placed it both backwards and upside-down. The spines along the creature's back were originally thought to be legs, its legs were thought to be tentacles along its back, and its head was mistaken for its tail.

Hallucigenia lived approximately 505 million years ago during the Cambrian Explosion, a period of rapid evolution when most major animal groups first appear in the fossil record. These particular fossils come from the Burgess Shale in Canada's Rocky Mountains, one of the richest Cambrian fossil deposits in the world.

Looking like something from science fiction, Hallucigenia had a row of rigid spines along its back, and seven or eight pairs of legs ending in claws. The animals were between five and 35 millimetres in length, and lived on the floor of the Cambrian oceans.

A new study of the creature's claws revealed an organisation very close to those of modern velvet worms, where layers of cuticle (a hard substance similar to fingernails) are stacked one inside the other, like Russian nesting dolls. The same nesting structure can also be seen in the jaws of velvet worms, which are no more than legs modified for chewing.

"It's often thought that modern animal groups arose fully formed during the Cambrian Explosion," said Dr Martin Smith of the University's Department of Earth Sciences, the paper's lead author. "But evolution is a gradual process: today's complex anatomies emerged step by step, one feature at a time. By deciphering 'in-between' fossils like Hallucigenia, we can determine how different animal groups built up their modern body plans."

While Hallucigenia had been suspected to be an ancestor of velvet worms, definitive characteristics linking them together had been hard to come by, and their claws had never been studied in detail. Through analysing both the prehistoric and living creatures, the researchers found that claws were the connection joining them together. Cambrian fossils continue to produce new information on origins of complex animals, and the use of high-end imaging techniques and data on living organisms further allows researchers to untangle the enigmatic evolution of earliest creatures.

"An exciting outcome of this study is that it turns our current understanding of the of arthropods – the group including spiders, insects and crustaceans – upside down," said Dr Javier Ortega-Hernandez, the paper's co-author. "Most gene-based studies suggest that arthropods and velvet worms are closely related to each other; however, our results indicate that arthropods are actually closer to water bears, or tardigrades, a group of hardy microscopic animals best known for being able to survive the vacuum of space and sub-zero temperatures – leaving velvet worms as distant cousins."

"The peculiar claws of Hallucigenia are a smoking gun that solve a long and heated debate in evolutionary biology, and may even help to decipher other problematic Cambrian critters," said Dr Smith.

Explore further: Brain of world's first known predators discovered

More information: Hallucigenia's onychophoran-like claws and the case for Tactopoda, Nature, DOI: 10.1038/nature13576

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ratrodcattleprod
1.2 / 5 (19) Aug 17, 2014
This story is a great example of how pseudo science has crept into the arena of real science.
Other then this makes a nice picture and those who can't think for themselves would accept this as evidence for evolution.
Vietvet
4.3 / 5 (16) Aug 17, 2014
This story is a great example of how pseudo science has crept into the arena of real science.
Other then this makes a nice picture and those who can't think for themselves would accept this as evidence for evolution.


Look, we have a new science denying troll!
ratrodcattleprod
1.2 / 5 (19) Aug 17, 2014
so vietvet accepts pseudo science as real science?
Try sticking with real facts little one.
Vietvet
4.4 / 5 (13) Aug 17, 2014
so vietvet accepts pseudo science as real science?
Try sticking with real facts little one.


Science overwhelming confirms the truth of evolution. How do you explain the millions of extinct and living species?
ratrodcattleprod
1 / 5 (16) Aug 17, 2014
So you think an extinct specie is proof of evolutionism? I may have some ocean front property for you to consider buying.
Science does not overwhelmingly do anything of the sort except in the creative imagination of evolutionary scientists.

Vietvet
4.3 / 5 (12) Aug 17, 2014
@rat

You haven't answered the question. What is your explanation for the diversity of life?
kochevnik
5 / 5 (8) Aug 17, 2014
JVK prefers asexual reproduction, not diversity. He has cloned himself as atrodcattleprod

jerryjbrown
5 / 5 (2) Aug 17, 2014
They could have used a better picture for the article. There a dozen better pictures on the first page of a search. Definitely a freaky creature.....
TheGhostofOtto1923
4.2 / 5 (14) Aug 17, 2014
So you think an extinct specie is proof of evolutionism?
No, evidence does this. Similarly, a total lack of evidence for, and an overwhelming amount of evidence against the bible stories, means they didn't happen.

And since they are found in the same book where you get all your notions about creationism, we can conclude that that is false as well.
Vietvet
4.1 / 5 (9) Aug 17, 2014
JVK prefers asexual reproduction, not diversity. He has cloned himself as atrodcattleprod

Got to disagree about ratrod being a JVK clone. JVK can't post without his inane word salad. Ratrod is just someone without an education and an attitude that explains why.
malapropism
5 / 5 (7) Aug 17, 2014
so vietvet accepts pseudo science as real science?
Try sticking with real facts little one.

Well see, the thing is, your god-dude has made all this sciency-evidence stuff that looks like evolution is just RIGHT! you know? And then he kinda forgot to put in any evidence at all in his book for any of the stuff that he said in it and other people wrote down for him. And what's with that anyway, can't he write? What are we all to think, then huh? So is he just like totally forgetful or what. Or is he maybe just some kind of one of those bastards who likes to mess with people for the hell of it.
Steve 200mph Cruiz
5 / 5 (7) Aug 17, 2014
This story is a great example of how pseudo science has crept into the arena of real science.
Other then this makes a nice picture and those who can't think for themselves would accept this as evidence for evolution.


You're an idiot, science is just a methodology.
They found a structure in this organism that happens to be only represented in one living organism: The velvet worm. I bet you don't even know what a velvet worm is.
Yeah, it's most likely not a direct ancestor of them, but this article didn't make that claim, but they are undoubtedly related and velvet worms are a particularly archaic organism and were actually very likely to be the first creatures to walk on land, at least from the fossils we have found.
Just shut up, the dictionary entry on science would disprove you, don't even bother trying to argue semantics.
Captain Stumpy
5 / 5 (6) Aug 18, 2014
This story is a great example of how pseudo science has crept into the arena of real science
@ratroach
feel free to read this: http://www.nature...576.html

now, please show me WHERE the pseudoscience is? thanks
Other then this makes a nice picture and those who can't think for themselves would accept this as evidence for evolution
science has a methodology that requires EMPIRICAL data and evidence in order to continue, which means that the article above is based upon a study that has been peer reviewed and has empirical evidence supporting its conclusions.

Now, you say that this is not science and pseudoscience... that is called CONJECTURE without evidence (think "BS" or "talking out your butt without a clue" but said nicely)

IF you have some EMPIRICAL EVIDENCE that you can present disputing the above study, please present it for review and allow us to make informed decisions

otherwise shut up and troll elsewhere
c0y0te
5 / 5 (4) Aug 18, 2014
I find those reversed drawings simply hysterical. How the heck could anyone think that those spikes were the legs?!? I mean, of course, it's natural that the creature would walk on hard, non articulated spikes and offer its soft back with something that resemble wiggling baits to potential predators. (yes, this was sarcasm...)
OZGuy
5 / 5 (4) Aug 18, 2014
@Vietvet
atrodcattleprod is a fitting playmate for Verkle. Of course it's possible Verkle created a sockpuppet and he's once again just playing with himself.
alfie_null
5 / 5 (5) Aug 18, 2014
So you think an extinct specie is proof of evolutionism? I may have some ocean front property for you to consider buying.
Science does not overwhelmingly do anything of the sort except in the creative imagination of evolutionary scientists.

You don't know how to argue, let alone argue science. Your skill at composition is mediocre. And it seems you don't even understand this. Is your intent to portray what we should understand is the intellectual caliber of those who share your beliefs? You are, you know.
thingumbobesquire
5 / 5 (4) Aug 18, 2014
"Worm-like creature with legs" -- sounds an awful lot like many creatures in Washington DC to me.
krundoloss
3 / 5 (4) Aug 18, 2014
Are there really people that still don't believe evolution? God and the bible are not the same thing. One could even say that Science is used to study God's Methods. But it doesn't matter, really, ignoring truth is the real problem. Don't Ignore Truth! Science seeks the truth, and if you believe a religious text over proven scientific facts, you have your head up your a$$!
TheGhostofOtto1923
3.8 / 5 (6) Aug 18, 2014
God and the bible are not the same thing.
Yah one exists the other one doesn't.
One could even say that Science is used to study God's Methods
If there is any evidence for your deistic god then only scientists are capable of finding it. But they haven't found anything yet.

Which doesn't seem to faze you as you are sure he exists despite evidence. I think you are still clinging to the possibility of escaping death which is an entirely religious notion. Absolutely no evidence supports it.

When you die you simply end. As hitchens paraphrased, you don't have a body, you are a body.

Deal with it. Live with it. This is the only life you will ever have.
jscroft
4 / 5 (4) Aug 18, 2014
Oh look! Trolls feeding trolls!
krundoloss
2.5 / 5 (2) Aug 18, 2014
Ha, You assume so much about me. My only notion, is that there is probably a god of some type, only if that "god" is merely a name for the force that caused creation, nothing more. You assume I seek answers to scary questions with religion, yet I am perfectly content to not know for certain about many things. If I cease to exist when I die, that would only increase my life's value. I feel that all religions are just a crutch for the weak-minded, filling in the holes in our conception of reality. So we are in agreement sir, However I do not feel the need to lash out at others on forums....

supamark23
5 / 5 (3) Aug 18, 2014
This story is a great example of how pseudo science has crept into the arena of real science.
Other then this makes a nice picture and those who can't think for themselves would accept this as evidence for evolution.


Go crawl back under whatever rock you came out from, worthless troll.
kochevnik
4 / 5 (5) Aug 18, 2014
that "god" is merely a name for the force that caused creation, nothing more.
Um YOU have the power of creation, unless you're gay or underage. You imaginary friend only has the powers you imagine him to have, and besides they're imaginary powers. Indeed this worm-like creature with legs and spikes also has the power of creation, if lacking the power of volition
TheGhostofOtto1923
4 / 5 (4) Aug 18, 2014
My only notion, is that there is probably a god of some type
No, evidence and the lack thereof suggest that there is no such thing. And there is certainly no reason to conclude that one 'probably' exists.
only if that "god" is merely a name for the force that caused creation, nothing more
Then dont call it god. Scientists wouldnt call it god. I think you are just backpedaling.
krundoloss
2.5 / 5 (2) Aug 19, 2014
Man, yall are vicious! Don't call it God then, just call it Big Bang Theory or whatever. Point being, that if Time is Real, then there had to be a beginning, and if there was a beginning then something had to cause it to begin. This is a philosophical and logical argument, not a theological one. Im a freakin atheist.
kochevnik
not rated yet Aug 19, 2014
Man, yall are vicious! Don't call it God then, just call it Big Bang Theory or whatever. Point being, that if Time is Real, then there had to be a beginning, and if there was a beginning then something had to cause it to begin. This is a philosophical and logical argument, not a theological one. Im a freakin atheist.
Big bang created spacetime. Discussing time prior is no more sensical than discussing space before the big bang. Space and time are one thing called spacetime. Also time is very ephemeral and not be observed directly. Some things are numeric and only manifest by conservation laws, like energy. Also note big bang theory was posited by believers and is not universally accepted. At least they were believers who were more interested in questions than canned answers
krundoloss
1 / 5 (1) Aug 19, 2014
Big bang created spacetime. Discussing time prior is no more sensical than discussing space before the big bang. Space and time are one thing called spacetime. Also time is very ephemeral and not be observed directly. Some things are numeric and only manifest by conservation laws, like energy. Also note big bang theory was posited by believers and is not universally accepted. At least they were believers who were more interested in questions than canned answers


Ok, well let just not have any ideas are not supported by Epirical Evidence. And since you cannot prove you love people, you may as well not believe in that either. Do you enjoy pointlessly disagreeing with people on discussion forums?
kochevnik
1 / 5 (2) Aug 19, 2014
Ok, well let just not have any ideas are not supported by Epirical Evidence. And since you cannot prove you love people, you may as well not believe in that either. Do you enjoy pointlessly disagreeing with people on discussion forums?
Empirical evidence is the weakest form of science. It is subject to confirmation bias. Cosmology has deep underpinnings in maths and make testable predictions, which religion cannot do. Testing love is measurable. There is evidence it corresponds with theta wave and may be implemented by force-carrying bosons at the quantum scale. Proofs are part of maths not science in general. It seems you don't know what you're talking about. Discussions are only pointless if one of the parties chooses to be an ignorant fool. That is your prerogative
PhotonX
5 / 5 (4) Aug 20, 2014
This story is a great example of how pseudo science has crept into the arena of real science.Other then this makes a nice picture and those who can't think for themselves would accept this as evidence for evolution.
A Creationist railing against pseudoscience. Ya gotta love the irony.

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