Hallucigenia

[China Doll]

Hi All,

What is Hallucigenia and what makes it special?

(There may be a free drink for the first correct answer)

Cheers,
China xx

[dawkins]

its a fossil of a strange critter from the cambrian found in the burgess shale. It apparently had two arses and no head but the scientists had probably put it back together in the wrong order.

[China Doll]

Thanks Dawkins... It certainly sounds rather special!

(Perhaps it's a way of tracing George Bush's ancestory?!)

[ugly_bob]

I thought it was the state of mind caused by drugs such as LSD - but that may cause you to see things with no head and 2 arses I suppose!

[China Doll]

Nah Bob.... you wouldn't see that but you could wake up with it in the morning ;0)

[theprof]

Brilliant answer dawkins and spot-on.

I'd like to that if I remember rightly, the paleontologists were even more confused as to where its arse was as it was found to have a dark stain at both ends!

[theprof]

Oops should be " I'd like to add that"...

[China Doll]

Erm... without meaning to sound too incredulous, how on earth did scientists (who I've always figured were really rather bright,) think that something that had two arses and no head could exist? Or have there actually been other creatures like this that have existed?

[dawkins]

That is why it is special China.

I don't think they thought it really had no head they just didn't know where the head would go. At one point they thought it fed through its toothpick like feet. Anyway, they flipped it over and it made a bit more sense but some people think that it is just a part fossil of a larger animal. It is very easy to make a mistake reconstructing a blurred 500 million year old fossil of a worm like creature.

[China Doll]

Thank you all.

While you're here and to save asking in another thread - does anyone know what a Cealocanth (I'm not sure I've spelt that right) is and if there's anything special about that too?

Thanks again!

[dawkins]

Coelacanths are living fossils. 5 feet long pale blue fish that was though to have gone extinct before the dinosaurs untill somebody saw one swimming off the coast of south africa in 1938.

So again very special. Where are you getting these questions from?

[China Doll]

A friend of mine studied geology and keeps baffling me today if I'm honest Dawkins.

Basically I have a lot of questions when it comes to science anyway but they're usually a bit more phillosophical in nature. (Today I've been flummoxed completely and because I'm not sure that I'm spelling all the names correctly I didn't think a search engine would be very useful.) I looked up the burgess shale you mentioned earlier but didn't really have time to have a very good look at it.

I've only very recently started using the Science category as I was a bit scared my questions would be laughed at but everyone has been really very helpful and informative.... which unfortunately for you all has encouraged me so I guess I'll be hanging around here a bit in the future.

[theprof]

Glad to have you here China Doll. Don't be afraid of posting any question. We're all glad to help and won't laugh - honest.

[China Doll]

Thanks very much Prof.... I think I'm going to like it here.

[brachiopod]

I remember chatting to Simon Conway-Morris about Hallucigenia and the Burgess Shale fauna.
He described the moment of revelation when he inverted his Hallucigenia model (well, drawing as it was).

I can't recall him using the phrase "it's got two arses", though !!

:o)

[dawkins]

brachiopod

I used a bit of creative licence on the two arses, i'm afraid, to liven things up. i'm quite proud of my new description and will be using it again in the future.

D

[steviep165]

if i remember my degree course correctly china me old doll (lovely too see you here by the way), the burgess shales turned up many species which had never been seen before.
the venerable Stephen J Gould had a good butchers at that them and based a lot of his work on the punctuated equilibrium theory of evolution upon these new species.
how many of the fossil remains where actually correctly reassembled and categorized however, is open to debate.

and here's a hallucigenia for ya petal!!!......

http://www.karencarr.com/Images/Gallery/2004_g allery_hallucigenia.jpg

[theprof]

Furthermore, if you want to see an animation that's had us all in stitches in the lab this morning, have a look here:

http://evolution.berkeley.edu/evolibrary/artic le/_0_0/cambrian_13

[China Doll]

Thanks Stevie... Looks a lot better than the one drawn on a post-it for me last night.

Lol @ Prof.... very good!

[brachiopod]

Fantastic! I love the link, theprof, though I nearly broke my moniter turning it upside down "so as I could see it right proper, guv'nor"

" 'ho does them Burgess Shale fauna finks they is, eh? Bleedin' arthropod wannabe's, that's what! ".