Here’s a very strange fossil from the Chengjiang Lagerstätte, an early Cambrian fossil bed from 525 million years ago. It’s a collection of Waptia-like arthropods, nothing unusual there; these are ancient creatures that look rather like headless shrimp. What’s weird about it is the way the individuals are locked together in a daisy chain, with the telson (tail piece) of each individual stuck into the carapace of the animal behind. It’s not just a fluke, either — they have 22 fossil chains, and just one animal all by its lonesome.
(Click for larger image)
Waptia-like arthropod, Lower Cambrian, Haikou, Yunnan. (A) Individual with twisted abdomen, part of chain, Yunnan Key Laboratory for Palaeontology, YKLP 11020a. (B) Chain, about 20 individuals, various dorsoventral-lateral orientations, composite image (joined at cpt/p arrow), YKLP 11020a and YKLP 11020b. (C) Individual linked to carapace behind, lateral view, part of chain of nine individuals, YKLP 11021. (D) Isolated individual, subventral view, YKLP 11019. (E to G) Reconstruction shown in dorsal, ventral, and right lateral views, respectively. Scale bars in (A), (C), and (D) indicate 1 mm; in (B) and (E) to (G), 5 mm. b, s, and t indicate bent, stretched, and telescoped individuals, respectively; cpt, counterpart; f, facing direction; p, part; and tw, twisted.
They do not look like animals that were constrained in a burrow, or that were crawling over the surface. Rather, they had been swimming together in a chain at death, and the whole chain fell to the sea bed, bending and kinking but still remaining firmly locked together.
Why were they doing this? My first thought was of sex; everyone knows how dragonflies and damselflies lock together for mating, but of course that would predict pairs of individuals, not 20 at a time. It also reminded me of the Drosophila mutant fruitless, in which male flies court other male flies, and they spontaneously form conga lines in the culture bottles. That’s also unlikely, since that kind of behavior doesn’t lead to a consistent pattern of successful reproduction, but maybe if these animals were hermaphroditic, it might work. It’s not a behavior that any modern arthropods show, however.
The authors consider the possibility it is a feeding strategy, but that’s even worse: they’re locked basically mouth to anus, which would mean the fellow at the end of the line gets a very unpleasant diet. They conclude that the most likely explanation is that this represents a migratory behavior, perhaps involved in daily vertical migration. It may have been that strings of these animals would link up and paddle together to move to new feeding sites, where they separated and dispersed until the time came to move elsewhere.
Hou X-G, Siveter DJ, Aldridge RJ, Siveter DJ (2008) Collective Behavior in an Early Cambrian Arthropod. Science 322(5899):224.
Blogging-on-peer-reviewed-science tag missing?
Cool wossnames, too.
I see Jesus in that picture. right there, in the middle.
see the long hair (b), two red eyes (c), and well defined mouth (d)?
It’s fossil Jesus, I tells ya!
:P
Why’d they all die at once though?
Weird. (but cool!)
Social arthropods, maybe?
there is always the possibility that they were connected in other ways, like those angler fish where the males parasitise the females.
The authors consider the possibility it is a feeding strategy, but that’s even worse: they’re locked basically mouth to anus, which would mean the fellow at the end of the line gets a very unpleasant diet.
Interestingly, maybe it’s just coincidental but modern lobsters also migrate in a head-tail chain at times.
…
ah, in doing a quick search, I see there has already been some discussion about that:
http://groups.google.com/group/talk.origins/browse_thread/thread/b2c07831607a8851/c208fc2f166d7eb7?lnk=raot
actually, I would disagree with Siveter, in that I actually have seen them literally “link up”, antennae to telson, in certain places.
still, I’m going for it being coincidental to this; probably just a superficial resemblance.
What’s great is that they say that such an ordering is not seen in organisms today.
True, that makes answers all the harder to come by, but it also provides a window into life as we do not observe now.
Glen D
http://tinyurl.com/2kxyc7
Why’d they all die at once though?
good question. I think some have proposed this to be a case of some kind of linear “egg case”, and these were just about to hatch when it got buried or whatever.
Social arthropods, maybe?
damn, would THAT be cool.
there are modern social crustaceans, btw. There is a species of small shrimp that live in sponges that approach the kind of thing you see in eusocial insects.
let me see if I can find the reference.
To use a highly scientific term, this is way cool! It’s amazing that these little critters wouldn’t let go of each other even when they were dying (reminds me of a former boyfriend, now that I think of it).
Off topic just a little bit – Empirical Infidel has written an amusing rant about “Fossils from the Flood” http://www.empiricalinfidel.blogspot.com/
Maybe the creatures shown above died while dancing the Conga at an “Oops, I missed the Ark” party.
Just a thought…
*bing*
available as PDF:
http://www.vims.edu/bio/mobee/Duffy_IUSSI_2002.pdf
The first thing I thought of were salps. The second thing I thought of were lobsters migrating.
Hm, that seems to contradict what I wrote (“they say”) at #6, or more to the point, the source I had read. Well, apparently the point is that it’s a “chain”, not a “train”. Anyway, here’s what was said:
I don’t know if that’s such a great difference or not.
Glen D
http://tinyurl.com/2kxyc7
You mean I’m the only one whose first thought was of kinky group sex?
I thought of migrating lobsters as well, Ichthyic. Also birds such as geese and pelicans. While these birds are not in physical contact, it is known that the passage of one bird generates vortexes that a following bird can take advantage of and lessen their personal energy expenditure.
These birds, the lobsters and the arthropods in question are all moving through a fluid environment. It would seem to be an advantage to be able to travel in formation in order to conserve energy. An additional advantage may be to confuse predators by concealing the outline of an individual. This ploy is also used by birds that fly in dense flocks like starlings and by fish such as anchovies.
At any rate, image the delight of finding such a perfect fossilization of behavior! Especially from so deep in the past! I still get jazzed by the wonder of it all.
I don’t know if that’s such a great difference or not.
*shrug*
pretty hard to say without actual motion video to compare (not going to happen, obviously).
I’m sticking with “superficial resemblance”.
@PZ
With a title like that? It was my first thought, too.
You mean I’m the only one whose first thought was of kinky group sex?
It appears you are unique.
:P
It reminds me of birds (ducks, esp.) that are migrating. Although the birds are in a flying “V” or “A” depending on how you are looking at them.
Safety in numbers you know.
An additional advantage may be to confuse predators by concealing the outline of an individual.
hmm, that makes sense.
or even just increasing relative apparent size.
That’s really cool! I like the idea of the vertical migration, but what do I know, I’m a chemist.
I wish I could link my car up to a chain for my daily migrations, then I could sit back and read or something.
Have they named these social bugs?
Isn’t it just delightful to observe something, and be at the stage of considering different hypotheses? To start evaluating the possibilities, and not decide upon an answer?
Wouldn’t be (brain-)dead for quids!
The newly acquired Jehol Fossils by Chang et al. really whet my appetite for the less celebrated side (dinosaurs à la Jurassic Park and shit) of paleontology.
Great stuff, PZ, and a pleasant relief from the inanity surrounding a certain election */grunt grunt/*
Ok, how does this sound:
initial selective pressure for improving migration efficiency (I bet there are some modern midwater euphausids that might be worth looking at for comparison), which lead to anti-predator benefits as individuals moved closer and closer together.
weak swimming strength/direction control lead to selection favoring actual physical attachment in order to maintain advantages.
plausible?
Have they named these social bugs?
Second Crudely. An aerodynamic explanation seems reasonable at least. The energy savings from being in the peleton, so to speak, is quite a bit larger than you probably think it is. Don’t quote me, as I’m neither a physicist nor a biologist, but I believe the energy savings can be between 50-80%.
Another reasonable explanation, would be as a defense against predators similar to herding behavior. Make yourself look bigger combined with ready availability of other targets, to be your sacrificial lamb.
Interesting, whatever the reason.
As I suspected, there IS some data on grouping behavior in migratory euphausiids:
http://icesjms.oxfordjournals.org/cgi/content/full/60/4/885
though it appears that the data do not support the idea of social congregation in midwater crustaceans:
A playful cuttlefish, he locks
The headless shrimp like LEGO blocks
In chains from tiny to colossal,
Just to make a funny fossil.
Creationists, of course, believe
That Adam made, to give to Eve,
A necklace out of arthropods
(The real design, of course, was God’s)
A strange behavior this complex?
It almost has to mean it’s sex:
The overwhelming urge in life–
Unless, of course, you are my wife.
(it’s a joke, people…I was looking for a rhyme!)
I blame the bad influence of Rev BDC for not having closed my blockquote tag in that last post.
:p
It sounds plausible to this amateur scientist. I like the idea of apparent increase in size, which would be a large factor where most predators are are not of some much greater size.
But. It does occur to me that there is probably little know about the inner anatomy of these critters, and this would include knowledge of just where their reproductive parts are located. Snicker. Maybe they were making Cambrian whoopee.
Does anyone else but me have a fleeting image (from a Discovery or NatGeo or Nature program) of jellyfish or some other ocean denizen moving in an orchestrated manner with very close proximity? Wish I could recall more clearly.
Cuttlefish, OM – wonderful. Absolutely wonderful.
@Stanton – Social bug?? How about “bobby”. ;-)
I bet they got “squashed” by something. If you look real close – you can imagine the direction that the damaging item came from.
How are the 22 fossils distributed? It’s sort of surprising that only migrating groups would be preserved if it was some sort of migratory behavior. You’d expect to find more individuals, unless all of the preserved examples are from one location and happened to end up there during migration.
Maybe they were making Cambrian whoopee.
you mean PZ was right?
that will teach me to discount sex as the first and foremost explanation for just about everything.
;)
though it appears that the data do not support the idea of social congregation in midwater crustaceans:
thinking about that more, however, the particular midwater euphausiids in question live pretty deep, and rely mostly on bioluminescent patterns and misdirection (diagonal swimming motions, etc.) to avoid predation.
Might be better to look at ones living where daylight could affect the visual acuity of predators; where the apparent size/outline issues might make more of a difference.
that will teach me to discount sex as the first and foremost explanation for just about everything.
Weellll, when you really think about it . . . I mean in terms of biology . . .
At least one arthropod, Panulirus argus, the Caribbean Spiny Lobster, migrates in a chain-like formation. Though not locked mouth-to-anus, when they migrate en masse, they do so in a head to tail, follow-the-leader chain. Maybe those fossil arthropods had really bad eye sight, so the only way to know they were following anyone was a firm clamp down on the ass in front.
PZ Myers (#13):
Hardly.
My second thought, however, was of this.
Biological entomology, evidence for the proverbial ancient truism, “Eat shit and die”, or the modern adaptation: “Eat shit and die, motherfucker”
At least one arthropod, Panulirus argus, the Caribbean Spiny Lobster,
IIRC, many species of lobster do this. I’ve seen it in CA spiny lobsters as well.
Yes, I AM a doofus, should have read the other comments first.
One problem I can see is that the critters have all their appendages inside the carapace, as the abdomen appears to be free of appendages. Having someone else’s telson shoved into that area would seriously impair your ability to swim and breathe (each gill is attached to the top of the leg).
However, it may be that the frontal appendages could grip (no description of appendages is given) and it was these that held on to the back of the telson, but the telson has moved further into the carapace during/after death.
Maybe they gripped each other during periods of inactivity on the sea floor and succumbed to low oxygen levels.
Blake @ 37
WOW that was cool, that colony actually moves like a snake? I think my brane just fell out
Blake, at first I thought they were tent caterpillars. I used to watch them as a boy. Then it occurred to me that my memory was of them moving along tree branches. Their movement was thus not one of innate behavior but physical constraint.
There goes another (mis)inspired hypothesis. The floor around me is littered with them!
…as another pattern example, there are colonial cnidarians that also form very long chains.
example:
http://www.mbayaq.org/efc/living_species/default.asp?hOri=1&inhab=164
these guys grow over 100′ long.
The clutching, mating dragon fly thing is a SORE subject with me!
Last year the GOB and I were riding two up on the old shovelhead, cruising with some of our friends, through the Washington grand canyon to Glenwood, Washington. We rode through the national refuge there. Holy shit! The dragon flies were at it hot and heavy. The husband ducked & I got splattered with the damned things – which when they are mating it is like hitting a cigar butt at 50 miles per hour.
Any chance that this could be some type of survival tactic? It could be similar to fish schooling to appear larger or like one large animal. They may have needed to lock together due to currents or the turbidity of the water. Anyway, it’s a kick ass fossil!!!
Hey. I’ve posted two comments in a row without the Submission Error window!
Is ScienceBlogs getting back up to speed?
The colonial cnidarians might be that “fleeting image” I mentioned in #29. If not, the image is very similar. Thanks for the quick searching skills, Ichthyic. Impressive.
And with that many organisms involved, it may well have resulted in a Cambrian explosion.
:|
Apologies.
Is ScienceBlogs getting back up to speed?
this is a new thread; it seems to be a bit quicker. the older threads are still fubar.
can’t believe this has gone on this long.
If it was a DOS, it would have been resolved far more quickly; it’s gotta be something else.
btw, anyone else notice another somewhat interesting recent Science article:
http://www.sciencemag.org/cgi/content/abstract/322/5898/58
OT, but interesting.
Fossil. Yeah, right. I have this really cool trilobite, wire wrapped in copper, strung on dark leather as a pendant – and I can’t tell if I’m looking at it’s ass, or it’s smiling face! The thing looks sorta like this
()(..)()
That ‘drawing’ really sucks.
The jeweler had fun wire wrapping the fossil, but she had no idea of which end was which either.
By the way teachers – you are doing something right, because when I wear my fossil to the farmers market, little kids freak out over it, and they know what it is. (Though not the head from the hinney.)
heh, also in issue 322:
http://www.sciencemag.org/cgi/content/summary/322/5898/47
Ruse comments on Fuller’s latest claptrap.
should be interesting.
Hey. I’ve posted two comments in a row without the Submission Error window!
But I couldn’t make it three in a row.
It will make an interesting tale when this problem is finally diagnosed and corrected; probably instructive, too.
Getting back to reproduction, could such swarming or schooling behavior be useful in protecting the young? I’m aware of many modern species, including arthropods, that use some complicated behaviors to see their offspring through their early days, though not through the behavior exhibited in the fossil. Still, the range of behaviors is quite broad. Some fish literally inhale their fry; wolf spiders and scorpions carry their kids piggy back; musk oxen form a protective ring around their calves. What advantage might the fossil behavior have for the young, if any?
In regards to the host post,
I too thought it could be a instinctive survival response to ward off a predator(creating a larger mass and differing movement pattern) only this time the predator was not carnivorous but was instead a natural detrimental phenomena.
I think the whole damn blog needs a good enema.
It’s still doing batshit kick backs on my end.
If PZ is paying these guys to fix the trouble, they aren’t up to the task.
What advantage might the fossil behavior have for the young, if any?
if it’s anything like other midwater crustaceans, they all have planktonic larvae, so none that I can see.
OTOH, I hardly know what this critter’s spawning strategy is.
IIRC, there are species that exhibit some differences in spawning behavior dependent upon local predator strategies.
hmm.
might try starting with something like this:
http://www.springerlink.com/content/h144581v5877qp14/
This is proof that God likes it when creatures go ass-to-mouth.
This is proof that God likes it when creatures go ass-to-mouth.
O.o
I’ve seen Clerks 2 one too many times.
Ichthyic, You’ll have to post stick figure examples of your points for us dumbass hillbillies to understand.
You are going passed the laws of scripture, and we cain’t understand that. Thare ain’t nothin’ before creation, and Adam & Eve!
You silly shark!
(This ad paid for by damned fools for McCain)
The first thing that came to my mind is anomalocaris and its identification. There is no way that this this might actually be a single large organism and me misidentified its segments as separate organisms, is there?
Hells bells, I can’t even tell my creatures ass from it’s mouth.
You’ll have to post stick figure examples of your points for us dumbass hillbillies to understand.
sorry, I never was very good with ASCII art.
;)
I’m thinking pretty fast here, but if there’s something specific I could help with, just say so.
In general, the way my mind is working on this particular problem is by looking for comparatively similar organisms to the fossil one under discussion here.
they remind me, both in shape and behavior (free swimming crustaceans) of euphausiid shrimps, so I was comparing what I know about those things to what might work to explain these fossil critters.
Euphausiids are these guys, btw:
http://www.geocities.com/jgomez64/euphausiids.html
as an undergrad, I used to work with Jim Childress, who was studying the physiology of one particular species, so I picked up a few things here and there.
#62 – Patricia – Sorry, I can’t either.
You might want to choose someone else. I’m not that much fun.
if it’s anything like other midwater crustaceans, they all have planktonic larvae, so none that I can see.
Ahh, right. I hadn’t thought of that. Of course, they may have had a different reproductive strategy. In any case, this fossil is bound for fame and the attendant controversy.
But I still can’t see the Jesus in it (re: #2). You say the mouth is at b?
Thanks for the links and the replies. I’d like to continue but tomorrow’s customer expects me early. Must unwind from chair and stretch out on bed.
But I still can’t see the Jesus in it (re: #2). You say the mouth is at b?
no, no… d.
imagine if you flattened his face into two dimensions.
b (the chain) is the hair
c (linked couple) are the eyes
d (individual) is the mouth.
see it now?
… because if you can’t, I’m gonna have to start thinking you’re a heretic…
:P
Weeeelll – Except for not showing pinschers or some legs, the fossils look like Oregon crawdaddy’s.
Boil em’ up and dip em’ in a dill sauce and you got some real fine eatin.
Yeah, maybe they’re just grouping up to look like a large sea snake to make predators wary, like how fish swim in schools or how the robot lions connect to form Voltron.
imagine if you flattened his face into two dimensions.
Oooohhh. Yeah. I see. Flattened out.
When the stone rolled away he musta got caught by surprise. Like those critters in the Burgess Shale. Boom. Lights out. Tough world out there.
G’night.
Oooohhh. Yeah. I see. Flattened out.
actually, the more I look at it, the more I’m starting to think it looks like “Dumb Donald” from the ancient “Fat Albert” show.
This was before sea-snakes. Way, way, way before sea-snakes.
But there might have been something else large that they could imitate/intimidate.
Shit, I get a personal troll when I’m all tuckered out & ready to snuggle up to the husband for the night.
Ya’ll can insult away tonight troll. I’ll get back to you in the morning West Coast, USA time.
Goodnight sweethearts. :o)
I’m thinking this is a classic case of several things happening at one time. The arthropods are going about their business in a social group (school for want of a better term) and are passing through a ditch/canyon/depression when an undersea landslide occurs that catches a goodly part of the school. Suppose this slide occurs because of an earthquake. Suppose further that the arthropods in question are denser then the mud that buries them. Since they are already in an “open tube” so-to-speak, with aftershocks provide a shifting of individuals to the lowest point in the trench thereby “lining” these critters up. The “head-to-tail” formation is due to the direction the group was going plus semi-random forces of the mud/sand/sea bottom rippling during the seismic activity. Add to that scenario some fossil formation quirks and this find could be more geologic then biologic.
As for any evidence of the preceding: this is just me breaking wind and is no more factual then any other hypothesis . . . and possibly less then some. I just want to wave the there-may-be-more-then-a-single-cause flag in this discussion.
Since they are already in an “open tube” so-to-speak, with aftershocks provide a shifting of individuals to the lowest point in the trench thereby “lining” these critters up. The “head-to-tail” formation is due to the direction the group was going plus semi-random forces of the mud/sand/sea bottom rippling during the seismic activity.
also good, if less exciting to a biologist.
:)
However, look at the figure “c” which shows them linked up.
not so sure post-mortem positioning would give that result.
also, i would expect that similar post-mortem positioning would be evident elsewhere (other fossils), and be an obvious first thing that would be eliminated.
could be wrong, but that would be my first thought on that idea.
@ Patricia; Now theres somthing I could sink my teeth into, I remember my days down in norlins(New Orleans) drinkin beer and suckin down da crays.Kinda makes me want to travel back in time.
also, wrt to the post-mortem positioning idea, there is this that PZ noted:
It’s not just a fluke, either — they have 22 fossil chains, and just one animal all by its lonesome.
I would think that wouldn’t be the case if it was due to localized geologic factors.
?
Meh, I’m worn out on this for tonight. going to the gym for a workout.
cheers
Interesting explanation.
Obviously, I’m not a biologist, so I don’t get to do the whole “peer review” thing.
I thought that the feeding method made some sense, though, assuming that the flies were incapable of draining out the entire nutritional content individually.
Collective camouflage?
They’re all hanging together to look larger than they are?
Some insects do this, in caterpillar stage.
Ichthyic @ 52:
Ooh, I missed that one! Here are some choice quotes:
“[Fuller’s case is that] Darwin did not give a cause for evolution. He certainly did not unify the field. At most he gave lists of facts. Moreover, today if we feel that advance has been made, it is primarily in the molecular field, and this owes little or nothing to traditional evolutionary thought….The important thing is that all of this is completely wrong and is backed by no sound scholarship whatsoever.”
“As a historian and philosopher of science, I can only hope that the science community does not judge us all by Fuller’s example.”
Don’t rule out the reproductive explanation offhand – consider the slipper limpet and their stacks of mutual fornicators.
Non-scientist speaking, having a minor boom de yada moment:
Can creationists not realize how cool something like this is? They always act as though science’s non-omniscience — scientists’ openness about saying, “We don’t know why this is”, or “We don’t know how this happened”, or “We don’t know why it works this way” — is a failure. They seem incapable of realizing that “We don’t know” is the hook on which all science hangs, because the obvious follow-up to “We don’t know” is “How can we find out?”
And something like this — really, only one fossil not found as part of a chain? — just strikes me, the non-scientist, as wonderfully exciting. Because it means that even if I never learn about it, there are whole new things to be discovered, whole categories of information we’ve never even suspected existed.
Heres what my fellow creationists might say.
First the way this fossil was fossilized was by a sudden event. This event was the biblical flood. Before this by hours/minutes these creatures were in distress and so linked up to preserve themselves. You are seeing creatures in fear for their survival. They lost.
Blessed is the Maker and His water;
Blessed are the coming and the going of Him.
(This has GOT to remind more people than just me of Shai-Hulud’s coalescence into its adult body plan.)
Maybe its to ward off predators who’d otherwise think them small enough.
Fixed.
Fixed, dammit.
http://i262.photobucket.com/albums/ii119/DonExodus/motivator7761838.jpg
The problem with looking in modern equivalent environments is that he predation risks are manifestly different. For a start in Cambrian seas there were NO fish, not even a primitive shark. Just pikaia. So their predators would either have been other crustacians or being caught by crinoid type organisms. Thinking of which if capture by crinoid/cnidaria was a major problem perhaps this was a predator avoidance behaviour but not for an active predator.
guys: everyone knows these things were planted by god to make it look like the earth is only as old as sarah palin tells us it is.
Robert @82:
You’ve already been told off, let’s try something different.
I understand that you’ve imagined a reason for this strange, preserved animal behavior, that it seems plausible within the confines of your particular worldview, and that speculating plausibly is enough for you.
The scientists studying these animals want to do more than speculate; they want to come as close as is possible to knowing the truth. Toward that end, they study for years to be able to answer questions like:
Could pre-Cambrian arthropods feel fear?
Did they act in the interest of mutual preservation? How can we know these things? Is it useful to study their descendants to find out?
If they were clinging to one another in fear, why would they line up single-file, anus-to-mouth, instead of clustering together or forming a branching structure?
For that matter, why would a population of proto-shrimp be traumatized by a flood? If your hypothesis is that the fossilizing event, not the flood itself, is the cause of the distress that grouped them, how did they survive long enough to organize? Why did they stay in formation while they died?
Since we have limited attention and resources to spend on research, is this hypothesis worthy of consideration? Who is the source of this hypothesis? What is his (your) background in arthropod behavior, pre-Cambrian biology, or any other discipline?
To somebody accustomed to methodical scientific problem-solving, these questions immediately spring to mind, probably in something like the reverse of the order I have them in or in one head-rushing fit of skepticism. Since your speculation doesn’t offer anything that could actually be called an explanation (because such an explanation would be grounded in principles which you are ignorant of, but which people like PZ have spent their lives studying), and many of the points raised call the overall plausibility of your hypothesis into question, they will dismiss your suggestion out of hand. Furthermore, they will wonder why, if you don’t actually know anything about the subject, you would presume to offer a hypothesis about strange behavior among pre-Cambrian arthropods. If they’re particularly kindhearted, they might pause to correct the most glaring errors in your reasoning.
The reason I don’t really think it’s fair to mock you or hurl insults is because you, Robert, can’t possibly know what you don’t know. You have no idea how anyone would actually go about determining why these animals linked up like this, and you may not even believe it’s possible to know. The fact is, even if the explanations that are offered by the original research team, PZ, or other reviewers amount to a type of speculation, it’s educated speculation that can be held against a known standard of likelihood. Science is about continually updating and calibrating that standard.
I hope this all made sense. Good luck.
I thought of kinky group sex too. At the Monterey Bay Aquarium one time I saw some sea hares, which are indeed hermaphroditic. They mate in long lines and circles with each one being male to the one in front and female to the one in back.
Our alien overlords Grail tripping as in Philip José Farmer’s “Image of the Beast/Blown”.
;-)
All this idle speculation… pfffttt…
This is obviously the unintended consequence of a practical joke gone awry… a prehistoric version of ‘chickens-on-a-string’.
It is whispered (around the edges of the cow-tipping culture) that bacon fat transits a chicken’s digestive tract in less than 5-minutes flat. So… if you tie a little wad of bacon fat to the end of a 50 foot piece of kite-string, and chuck it into the chicken-yard, before too long, you end up with chickens-on-a-string… maybe up to half-a-dozen or so, beak-to-butt.
This is said to really piss-off farmers.
Anyway… critters’ digestive systems were a lot simpler in the Cambrian, and these are a lot smaller than chickens, so… I expect that the process was a lot quicker, and I doubt that 22 arthropods-on-a-string is anywhere near the record.
Sure, there are some mysteries here. First, the fossil needs to be examined for evidence of fossilized kite-string. And obviously, this occurred way long before bacon fat… so that’s right out… must have been something else.
Of course, we may never know the answer to the really big question… who was the trickster? He obviously ran away, when the Cambrian arthropod rancher came out to see what was causing all the racket.
Here’s a very strange fossil from the Chengjiang Lagerstätte, an early Cambrian fossil bed from 525 million years ago.
I was very concerned about this article. I was expecting at least a fossilized rabbit!
Thank Jebus it wasn’t. Darwin still rules!
Not necessarily; think of the big amphibian orgies you get when male frogs start indiscriminately amplexusing each other and every other decently-large object.
Maybe the 18 guys at the back are all crazed with pheromones and just latching on to whoever they can find–which of course would have the added benefit of exhausting the lucky guy in the #2 position and forcing him to drop off earlier.
Or anomalocarids, no?
I see Jabba the Hutt in that picture.
Is… is he our saviour now? If so, I may have a problem with being at his right hand, considering what happened to that dancer girl.
The pictures remind me the migration of the pine procesionary moth (Thaumetopoea pityocampa). Not that I think that there is anything common. Just an impression…
Why are they saying there is no similar behavior in modern animals? I dunno about lobsters, but I’ve seen such behavior in my back yard many, many times. In caterpillars.
http://flickr.com/photos/negora/2452767698/
Sometimes you can lift two or three from the line in the air, by grabbing the cartepillar in front. I know because I was quite the brat during my childhood years, and that was always a good way to scare a girl.
I saw some jellyfish-like creatures in this formation off Bonaire in May of last year diving. I very scientifically tested their toxicity by getting a “chain” of them wrapped around my head during a night dive. The results were positive.
They moved much faster than individuals and they died off in great numbers in formation a few days. Wouldn’t this suggest a reproductive event? It is still plausible that together they are no longer of the appropriate size for a meal.
Also:
http://www.vimeo.com/bubblebum/videos/tag:freaksofnature
Works for ducks too. Our halls at Uni were next to the Botanical Gardens and the duckpond. Two guys did this, they got the bacon fat on a string through Duck A but could not get any potential Duck Bs to eat it and there the experiment ended.
Dammit the quote didn’t work. The first paragraph above is a quote from DuckPhup.
Stephen Couchman @ #83:
Kull wahad!
Ichthyic @ #2, et al:
Jesus the Hutt?
And thank Dog for Cuttlefish, OM (blessed are his holy tentacles), now and forever!
@101: Peter i have to confes I have done what you wrote about and got 3 mixed ducks and a single goose on one string of bacon fat. My wife banned the proceedure thereafter.
My ducks had the disgusting (to me) habit of waiting for my corn fed Jersey cows to drop ‘manna from heaven’ aka a fresh turd, and even taught their ducklings how to rapidly beat their feet on said fresh turd as it would cause the most undigested pieces of corn to float to the top, easily scooped off by their beaks.So they had no problem eating the ‘recycled’ fat.
However;none of this has anything to do with this shrimp humpathon forever preserved in rock.
OK, here’s my bluesky idea from a non-biologist…
Suppose these guys/gals are all hermaphroditic. They swim around til mature, make some eggs, then go looking for a chain like this, or a single if no chains are about and start one. New addition goes to the start of the line and gets latched on by the one at the head. Eggs move from new head of the line and get fertilized by number 2 in the line, who then effectively dies… larvae get incubated, protected and fed by the chain of dead as they move back down the chain. This would explain why they’re all the same size, why most of the fossils are found in chains. I think I’ve heard of weirder reproductive strategies.
It was Cambrian Gomorrah: they were all rimming so God killed the lot.
Ockham’s Razor, works every time.
they’re locked basically mouth to anus
Sounds amazingly like America’s news media.
Those guys are real shrimps, only 1 1/2 cm or about 3/5 inch long. The whole chain wouldn’t be much longer than 25cm (approx 2/3 foot). Not much bigger than brineshrimp individually. There’s no sign of legs/feet so I would say they are probably pelagic. The chain formation may make it possible for them to move along the bottom, like a snake would, but their ‘tail lobes’ seem to be oriented for up and down movement, like a modern shrimps and a snake-like movement would require side to side movement, unless they turned on their sides. So I think pelagic swimmers is probably more likely when in chains. There’s no obvious mouthparts visible, they could easily be filter-feeders, taking in water through their mouths and screening the plankton out somewhere inside.
Modern shrimps/prawns have all their feeding bits, antennae and stuff comming out of their front ends, so maybe these fosils had claspers near their mouth-end that enable them to form the chains and keep their ‘mouths’ free to feed as they move through the water. The chains may give them better mobility and control of direction when swimming in moving water than individual swimmers would have. Could be the chains is just a travelling strategy and when in calmer water they separate to feed.
I don’t know enough about life back then to know, if enough of the predators were that small, that a chain of these tiny protoshrimp would be too big a mouthfull to bother with, thus making the chain formation a defensive strategy.
Peter Ashby said:
Sorry to be a paleontology pedant but I think your information is out of date Peter. Although Pikaia are the nearest thing to vertebrates found in the Burgess Shale (at least as far as I know) primitive fish (agnathans, the same order as hagfish and lampreys) did exist in the Lower Cambrian Chengjiang Lagerstätte. They were first discovered in 1999 and described in Nature here, and you can see the relevant fossils here.
Apologies again for the pedantry!
ID hypothesis: The Designer was grilling shrimp for dinner after all the work of the “explosion” and a few kabobs fell into the mud. The skewers must not have fossilized, though.
They formed a Conga line. Conga!!!!
Ichthyic isn’t making the connections at all here. First we read, “It’s fossil Jesus, I tells ya!”, then later we read, “lobsters also migrate in a head-tail chain”.
Clearly this is a Jesus and Mary Chain….
Robert Byers, You are a complete ass. Fossilization and a 6000 year old earth make sense how?
Yes, I remember the papers describing the *lower* Cambrian agnathans. Can you suck a shrimp to death? I’ve seen the pictures of hagfish going at a whale carcass on Blue Planet. Hard to get that sort of traction on a shrimp…
You are seeing creatures in fear for their survival. They lost.
ah, Robert Byers really telling us about creationists.
IOW, projecting again.
Yes, Byers, you creobots are obviously desperate to survive at this late date, and will lie, cheat, steal, and ? in order to do so.
There’s no sign of legs/feet so I would say they are probably pelagic.
yes, but I started thinking about ostracods, most of which are benthic.
Can you suck a shrimp to death?
most assuredly. you just “inhale” it. most fish are in fact, suction feeders and have no jaw teeth (though most have pharyngeal or glossian teeth).
as to whether fish in the cambrian (IIRC, there is still argument as to whether they were true agnathans or not) actually actively hunted, I couldn’t say.
WWDAS*
I wonder how many holiday parties will now have a Cambrian conga line.
Personally, I find it disgusting. (Mainly because I tend not to get invited to those sorts of parties.)
*What Would Douglas Adams Say?
#61
That is an interesting idea, but the close-ups do seem to show multiple organisms linked together.
All of the migratory and the like hypotheses, it seems to me, don’t seem to adequately explain *why* the chains are the predominant form we find the organisms in. These animals couldn’t’ve been migrating 95% of their lives. And what factors could cause some kind of preservation bias?
I wonder, could they have been colonial organisms that were in such chains their entire lives, for whatever reason (Of course, this leads to the question of what advantage such a colonial lifestyle would bring)? The single solitary example could be simply an accident, similar to the way that the various parts of anomalocaris fell apart giving the impression of different species. Or, perhaps that wasn’t actually the same species, but rather a related, non-colonial one?
Kel, is that poster you linked to at #86 a genuine quote from Conservapedia? Volcanoes spreading animals? That seems too insane even for creationists
I’m not sure it’s still there now, but I’m fairly certain it was there at some stage.
This just popped into my head. There is a deep sea denizen known as the Angler Fish. The females are much larger than the male. Think your head and your thumb. The male seduces the apple of his eye by latching onto her with his jaws and remains there while they literally become “one flesh.” He loses his ability to let go or engage in any independent action (including feeding or even independent metabolism). She gains an uninterrupted source of sperm. They thus survive.
Perhaps this fossil shows an earlier version of such a strategy, though I cannot guess how it would work in a large linear grouping.
Never a dull moment when you look closely.
Kel, is that poster you linked to at #86 a genuine quote from Conservapedia? Volcanoes spreading animals? That seems too insane even for creationists
I’m not sure it’s still there now, but I’m fairly certain it was there at some stage.
It was still there a moment ago and it is still monumentally stupid. And funny. And sad.
doh! Should read:
Kel, is that poster you linked to at #86 a genuine quote from Conservapedia? Volcanoes spreading animals? That seems too insane even for creationists
I’m not sure it’s still there now, but I’m fairly certain it was there at some stage.
It was still there a moment ago and it is still monumentally stupid. And funny. And sad.
Preview is useful.
It’s an early manifestation of a prayer circle.
She gains an uninterrupted source of sperm. They thus survive.
another interesting thing is that sometimes you get multiple males attaching themselves to a single female. Would be a wonderful model organism to study sperm competition in, if they were easier to keep alive in an aquarium.
I actually managed to collect a free-swimming male once. I had no idea how rare that was. They practically forced me to donate it to the Ichthyo collection at UCSB when i returned from the trawling trip.
Paperhand said:
I’m wondering if the chains had multiple uses – easier migration and defence rather than one or the other.
Could the chains have had multiple uses – a handy adaptation for migration and good for defense, may they only dechained to feed and/or mate but spent most of their lives in the chain because it was just so much safer and quicker than living as an individual?
However we need to remember that we only know that they were all in chains when they died, we don’t know how long they were in chains for the rest of their lives. Maybe they just got killed and fossilised during the time of year or even the time of day when they normally formed chains for whatever reason (if the reproductive theory is right whatever killed them may just have happened to catch them during mating season for example or if it is a defensive/migratory adaptation many planktonic creatures migrate up and down the water column all at once at very specific times of day – maybe they died at just such a time) – for all we know had they lived they might have all gone their separate ways a few days or even hours later.
Anything published on those pre-Cambrian, Australian sponge fossils yet?
I can’t help thinking that the feeding strategy reason was dismissed too soon.
A Just-So story that created this could be the development in their food source of the ability to get through the digestive tract unscathed – by growing a tougher cell wall, for example – which could quickly make shrimp-poo into concentrated rations for others. Daisy-chaining shrimp and tough-walled plankton would soon be in an evolutionary arms race that would also make all the other prey and predators step up their game until better strategies for dealing with this intransigent food source had time to evolve.
A migratory and/or mutual defence explanation suggests that the conga line would break up and reform regularly. Hence, the event that killed them must have happened fairly quickly but without causing much damage.
If each individual were feeding from the waste of its predecessor in the chain, then it was more likely to be a fairly permanent arrangement, at least if you had a good seat.) There would be no advantage to having someone else biting your tail but no way to get it off without losing your place. The guy at the front of the queue would actually be in a pretty bad spot. He gets first bite of the cherry but only a fraction of the nutrient. It also suggests how the fossil remains intact. The leader eats something poisonous – or perhaps just dies of malnutrition – but the next guy doesn’t want to give up his spot, until its too late, and there is no evolutionary advantage to warning the parasites behind him and a strong disincentive to letting go and getting to the front of the queue. Number 2 is good in all senses.
Either that or its a missing link in the evolution of the prawn shish kebab.
The evolution posters here are missing the big point. Its fossilized. this is not a ordinary event. It means the vreature was suddenly encompassed by sediment etc that held it place and allowed it to be turned to stone.
This never happens today.
This special event therefore is reasonably the origin of their pre-death reaction. They knew there was chaos in the envirorment by movement or sudden loss of directrion/sight etc and held on to each other for safety or sheer desperation.
Its most likely this was a rare reaction due to a special case. Being fossilized in this position was a rare event and showing the dramatic nature of the short time before.
It takes a creationist to explain what fits best with creationist frameworks.
It takes a creationist to explain what fits best with creationist frameworks.
IOW, it takes a creationist to project creationist idiocy?
so we’ve noticed.
thanks for your brilliant observation.
*rolleyes*
go away robert, your stinkin’ up the thread.
They found a bunny in the Cambrian?
Bullshit.
What would stop sediment from holding organisms in place and (eventually) allowing them to turn to stone?
Just as one minor example: There are very well-preserved bodies many thousands of years old pulled from bogs; if those bogs were to sink deep enough and be buried under additional sediment, any bodies they contained would become fossils.
Bullshit. They were attached to each other before they were buried in sediment.
[…]
Fixed.
Have these babies been formally named yet?