…and this is a 
Fossil daisy-chain
Category: Fossils • Organisms • Science
Posted on: October 13, 2008 9:52 PM, by PZ Myers
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.
Life Science
Comments
Posted by: Owlmirror | October 13, 2008 9:59 PM
Blogging-on-peer-reviewed-science tag missing?
Cool wossnames, too.
Posted by: Ichthyic | October 13, 2008 10:04 PM
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
Posted by: robbrown | October 13, 2008 10:05 PM
Why'd they all die at once though?
Weird. (but cool!)
Posted by: wazza | October 13, 2008 10:08 PM
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.
Posted by: Ichthyic | October 13, 2008 10:09 PM
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.
Posted by: Glen Davidson | October 13, 2008 10:10 PM
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
Posted by: Ichthyic | October 13, 2008 10:12 PM
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.
Posted by: Ichthyic | October 13, 2008 10:14 PM
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.
Posted by: hubris hurts | October 13, 2008 10:15 PM
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...
Posted by: Ichthyic | October 13, 2008 10:16 PM
*bing*
available as PDF:
http://www.vims.edu/bio/mobee/Duffy_IUSSI_2002.pdf
Posted by: mus | October 13, 2008 10:17 PM
The first thing I thought of were salps. The second thing I thought of were lobsters migrating.
Posted by: Glen Davidson | October 13, 2008 10:22 PM
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
Posted by: PZ Myers | October 13, 2008 10:23 PM
You mean I'm the only one whose first thought was of kinky group sex?
Posted by: Crudely Wrott | October 13, 2008 10:24 PM
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.
Posted by: Ichthyic | October 13, 2008 10:25 PM
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".
Posted by: Anon | October 13, 2008 10:27 PM
@PZ
With a title like that? It was my first thought, too.
Posted by: Ichthyic | October 13, 2008 10:27 PM
You mean I'm the only one whose first thought was of kinky group sex?
It appears you are unique.
:P
Posted by: S.Scott | October 13, 2008 10:29 PM
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.
Posted by: Ichthyic | October 13, 2008 10:30 PM
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.
Posted by: Brad D | October 13, 2008 10:32 PM
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.
Posted by: Stanton | October 13, 2008 10:34 PM
Have they named these social bugs?
Posted by: shonny | October 13, 2008 10:35 PM
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/*
Posted by: Ichthyic | October 13, 2008 10:35 PM
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?
Posted by: Stanton | October 13, 2008 10:35 PM
Have they named these social bugs?
Posted by: Fuodd | October 13, 2008 10:37 PM
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.
Posted by: Ichthyic | October 13, 2008 10:41 PM
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:
Posted by: Cuttlefish, OM | October 13, 2008 10:43 PM
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!)
Posted by: Ichthyic | October 13, 2008 10:44 PM
I blame the bad influence of Rev BDC for not having closed my blockquote tag in that last post.
:p
Posted by: Crudely Wrott | October 13, 2008 10:45 PM
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.
Posted by: hubris hurts | October 13, 2008 10:45 PM
Cuttlefish, OM - wonderful. Absolutely wonderful.
Posted by: S.Scott | October 13, 2008 10:45 PM
@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.
Posted by: Zombie | October 13, 2008 10:51 PM
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.
Posted by: Ichthyic | October 13, 2008 10:51 PM
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.
;)
Posted by: Ichthyic | October 13, 2008 10:59 PM
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.
Posted by: Crudely Wrott | October 13, 2008 10:59 PM
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 . . .
Posted by: Mike | October 13, 2008 11:02 PM
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.
Posted by: Blake Stacey | October 13, 2008 11:04 PM
PZ Myers (#13):
Hardly.
My second thought, however, was of this.
Posted by: scooter | October 13, 2008 11:04 PM
Biological entomology, evidence for the proverbial ancient truism, "Eat shit and die", or the modern adaptation: "Eat shit and die, motherfucker"
Posted by: Ichthyic | October 13, 2008 11:05 PM
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.
Posted by: Mike | October 13, 2008 11:06 PM
Yes, I AM a doofus, should have read the other comments first.
Posted by: Chris Nedin | October 13, 2008 11:08 PM
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.
Posted by: scooter | October 13, 2008 11:16 PM
Blake @ 37
WOW that was cool, that colony actually moves like a snake? I think my brane just fell out
Posted by: Crudely Wrott | October 13, 2008 11:32 PM
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!
Posted by: Ichthyic | October 13, 2008 11:33 PM
...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.
Posted by: Patricia | October 13, 2008 11:34 PM
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.
Posted by: Another Primate | October 13, 2008 11:38 PM
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!!!
Posted by: Crudely Wrott | October 13, 2008 11:42 PM
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.
Posted by: s1mplex | October 13, 2008 11:46 PM
And with that many organisms involved, it may well have resulted in a Cambrian explosion.:|
Apologies.
Posted by: Ichthyic | October 13, 2008 11:52 PM
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.
Posted by: Ichthyic | October 14, 2008 12:01 AM
btw, anyone else notice another somewhat interesting recent Science article:
http://www.sciencemag.org/cgi/content/abstract/322/5898/58
OT, but interesting.
Posted by: Patricia | October 14, 2008 12:04 AM
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.)
Posted by: Ichthyic | October 14, 2008 12:08 AM
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.
Posted by: Crudely Wrott | October 14, 2008 12:08 AM
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?
Posted by: Sphere Coupler | October 14, 2008 12:12 AM
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.
Posted by: Patricia | October 14, 2008 12:13 AM
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.
Posted by: Ichthyic | October 14, 2008 12:14 AM
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/
Posted by: Kel | October 14, 2008 12:15 AM
This is proof that God likes it when creatures go ass-to-mouth.
Posted by: Ichthyic | October 14, 2008 12:18 AM
This is proof that God likes it when creatures go ass-to-mouth.
O.o
Posted by: Kel | October 14, 2008 12:23 AM
I've seen Clerks 2 one too many times.
Posted by: Patricia | October 14, 2008 12:31 AM
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)
Posted by: TheBlackCat | October 14, 2008 12:34 AM
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?
Posted by: Patricia | October 14, 2008 12:35 AM
Hells bells, I can't even tell my creatures ass from it's mouth.
Posted by: Ichthyic | October 14, 2008 12:44 AM
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.
Posted by: Patricia | October 14, 2008 12:46 AM
#62 - Patricia - Sorry, I can't either.
You might want to choose someone else. I'm not that much fun.
Posted by: Crudely Wrott | October 14, 2008 12:49 AM
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.
Posted by: Ichthyic | October 14, 2008 12:52 AM
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
Posted by: Patricia | October 14, 2008 12:58 AM
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.
Posted by: H.H. | October 14, 2008 1:02 AM
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.
Posted by: Crudely Wrott | October 14, 2008 1:08 AM
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.
Posted by: Ichthyic | October 14, 2008 1:13 AM
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.
Posted by: Owlmirror | October 14, 2008 1:13 AM
This was before sea-snakes. Way, way, way before sea-snakes.
But there might have been something else large that they could imitate/intimidate.
Posted by: Patricia | October 14, 2008 1:17 AM
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)
Posted by: Robert J. Grieve | October 14, 2008 1:18 AM
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.
Posted by: Ichthyic | October 14, 2008 1:24 AM
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.
Posted by: Sphere Coupler | October 14, 2008 1:26 AM
@ 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.
Posted by: Ichthyic | October 14, 2008 1:32 AM
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
Posted by: JStein | October 14, 2008 1:54 AM
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.
Posted by: Paul G. Brown | October 14, 2008 2:28 AM
Collective camouflage?
They're all hanging together to look larger than they are?
Some insects do this, in caterpillar stage.
Posted by: James F | October 14, 2008 2:34 AM
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."
Posted by: Peter Ellis | October 14, 2008 3:02 AM
Don't rule out the reproductive explanation offhand - consider the slipper limpet and their stacks of mutual fornicators.
Posted by: Cactus Wren | October 14, 2008 3:22 AM
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.
Posted by: Robert Byers | October 14, 2008 3:31 AM
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.
Posted by: Stephen Couchman | October 14, 2008 3:51 AM
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.)
Posted by: Jake | October 14, 2008 3:53 AM
Maybe its to ward off predators who'd otherwise think them small enough.
Posted by: Owlmirror | October 14, 2008 3:54 AM
Fixed.
Fixed, dammit.
Posted by: Kel | October 14, 2008 4:00 AM
http://i262.photobucket.com/albums/ii119/DonExodus/motivator7761838.jpgPosted by: Peter Ashby | October 14, 2008 4:24 AM
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.
Posted by: moother | October 14, 2008 4:42 AM
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.
Posted by: Stephen Couchman | October 14, 2008 5:12 AM
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) backgr