Another Anomalocaris

I don’t know! You wait ages for a new Anomalocarid, then two come by in close succession! First Schinderhannes bartelsi and now Hurdia.

Yes . . . well . . . another Anomalocarid,

Another weird Anomalocarid.

Allison C. Daley, Graham E. Budd, Jean-Bernard Caron, Gregory D. Edgecombe,, & Desmond Collins (2009). The Burgess Shale Anomalocaridid Hurdia and Its Significance for Early Euarthropod Evolution. Science, 1597-1600 DOI: 10.1126/science.1169514

Where to start! When I first saw it, I thought is was an Anomalocarid caught in flagrante delicto with a phyllocarid!

This is a bit of déjà vu, as with the original identification of Anomalocaris from the Burgess Shale, here’s another case of a number of isolated fragments being found previously (mouthparts, frontal appendages, body, and those weird frontal carapaces - a total of 8 Cambrian taxa) and given separate names, now being brought together into one complete specimen – just like the original Anomalocaris.

While the body, eyes and great appendages are similar to other Anomalocarids, the major difference here is the strange, and very large, carapace or shield-like structure on the head.

It is unlike any other Anomalocarid, with the possible exception of S. bartelsi which has a structure at the back of the head, which may be a funky posterior-flaring carapace-like structure (although that structure could be a pair of trunk appendages).

Fig. 2. Paratype specimen and isolated components of H. victoria. (A) ROM 49930, paratype, lateral view showing lateral flaps. (B) ROM 59258, frontal appendage morph A. (C) ROM 59259, frontal appendage morph B. (D) ROM 59260, mouthpart with extra teeth rows. (E) ROM 59261, lanceolate gill blades showing attachment at one end (arrow). (F) ROM 59262, paired P-elements. (G) USNM 57718, holotype of H. victoria. Scale bars, 1 cm. Abbreviations are as in Fig. 1. B, Banffia; ex, extra teeth rows.

Firstly the head. This is by far the most bizarre Anomalocarid, by virtue of the head, which is the first Anomalocarid identified with a carapace. At almost 50% of the length of the animal, it's huge, and made of two different "elements", a single “H” element and a paired “P” element. There doesn’t appear to be anything below this carapace, so it’s function is something of a mystery.

Why on earth is it there?!

Sexual selection maybe?
There are certainly examples of other arthropods that have an exaggerated body part used to attract a mate – think of the fiddler crab, but all seven fully articulated (with all the bits in the right place) specimens show this remarkable carapace, and it’s unlikely that all seven would be all one sex (if the structure was confined to one sex). Although it would be interesting to see if the size of the carapaces shows any bimodal distribution which may indicate a size differential, possibly based on sex. But as arthropods generally keep growing, maybe there are two sets of growth trends.

Prey capture maybe?
Perhaps Hurdia trapped small prey below the carapace and then advanced so that the appendages could grasp the prey. Or maybe it was used to dig into soft sediment after prey. Or perhaps it contained sensing apparatus to detect prey in the sediment

Who knows?

The rest of the beast conforms pretty much to the standard Anomalocarid body plan, including the circular jaws. This time, however, there are more teeth just for added effect.

Hurdia does have a fine set of gills though. And they appear to be free hanging gill structures, and similar to crustacean and chelicerate gill structures, rather than the modern arthropod biramous limb (where the leg and the gill are part of the same structure). This is interesting because it is thought that the Cambrian arthropod biramous limb formed by the fusion of a uniramous leg (just the leg) and a respiratory exite (gill), whereas the modern biramous limb is formed by a split of the main axis of the limb. The presence of separate filamentous gills in Cambrian Anomalocarids pushes the structure below the crown group arthropods and into the stem group arthropods, supporting the fusion theory.

An analysis groups Hurdia along with Anomalocaris and Laggania as a sister group, outside of the Euarthropods, or crown group arthropods.

Schinderhannes bartelsi fits in between Hurdia and Fuxianhuia.

Incidentally the reconstruction of Hurdia was done by Merrianne Collins, who did the reconstructions for Steve Gould's book on the Burgess Shale fossils, "Wonderful Life".

Allison C. Daley, Graham E. Budd, Jean-Bernard Caron, Gregory D. Edgecombe,, & Desmond Collins (2009). The Burgess Shale Anomalocaridid Hurdia and Its Significance for Early Euarthropod Evolution. Science, 1597-1600 DOI: 10.1126/science.1169514

New Scientist - It just gets worse

Having put out a highly misleading cover and story claiming that "Darwin was wrong" when in fact Darwin never discussed the topic, and the tree of life is still very much a solid analogy for metazoan evolution, New Scientist just can't let a bad decision go.

They now have that cover on an adverting poster.

Having antagonised a lot of scientists with their cheap sensationalism to generate sales, re-using the cover is simply giving the finger and saying 'we don't care about accuracy, sales are the thing'.

Jerry Coyne is calling for a boycott, PZ agrees. So do I.

But it should also be a science boycott. High profile scientists who contribute to NS should refuse to continue to do so. Scientists who are approached for stories should refuse to cooperate and make sure the editors know the reason. Tell the reporter why, and ask that the reporter tell the editors the reason why.

But there is another thing scientists can do, and that is assist other science publications such as Discover, and Seed with contributions. If these publications can get a series of high profile stories, the circulation of these publications will rise. That way then the science message can get out, while snubbing NS.

If I were an editor of Discover or Seed, I'd be on the phone to some leading scientists now, to line up some contributions.

Anti-Science Science Minister?

The recent statements by the Canadian Minister for Science have left the impression that he does not understand evolution and he does not accept evolution. The reason? When asked about whether he believed in evolution, he refused to answer saying that is was a religious question.

Actually, I have to say that, in part, he is right. I do not believe in evolution. I accept evolution is one of strongest scientific theories we have, because of the overwhelming scientific evidence that supports it, from a myriad of scientific disciplines. I do not believe in evolution. Belief is a religious question.

However, the Minister clearly wasn't talking about that when, in his response, he conflated evolution and religion. That, frankly, is a creationist response. His subsequent clarification also showed that he doesn't understand evolution.

As a consequence, he has been tagged, with justification, as anti-science.

So? After all, there is no requirement that the Minister for Science has to be a scientist, or accept one of the fundamental basics of modern science?

Well, having a science minister who doesn't accept one of the fundamental basics of modern science, is like having a health minister who doesn't accept that HIV causes Aids. Wait a miniute, we've had one of those in South Africa.

How did that turn out?

Umm, not well.

Oklahoma legislator admits human life does not start at conception

Mike Reynolds, an anti-stem cell research, anti-abortion, Christian fundamentalist, Republican (though you guessed that last one, right?) in the Oklahoma State legislature, has introduced a bill to thwart President Obama's removal of Bush's restrictions on stem cell research.

In part Bill 1326 reads, in part:

B. No person shall:
1. Knowingly conduct nontherapeutic research that destroys a human embryo or subjects a human embryo to substantial risk of injury or death;
2. Transfer a human embryo with the knowledge that the embryo will be subjected to nontherapeutic research; or
3. Use for research purposes cells or tissues that the person knows were obtained by performing activities in violation of this section.
C. Any person or any business entity recognized by the laws of this state that engages in, or is associated with a business entity that engages in, the actions prohibited by subsection B of this section shall not be eligible for any Oklahoma income tax credits. No state agency or retirement system shall invest in a business entity that engages in the acts prohibited by subsection B of this section.
D. Any person found violating the provisions of subsection B of this section shall, upon conviction, be guilty of a misdemeanor.

But wait a minute. Anyone that destroys a human or subjects a human to substantial risk of injury or death, would attract for more substantial penalties than a misdemeanor. Therefore, it logically follows that Reynolds does not consider an embryo as human, and that, therefore, human life does not start at conception!

Does his constituents, and more importantly, his parishioners (yes, he is an Ordained Deacon) know his views on when life starts?!

More at ERV.

Religious Ghouls - Pope Lies (Shock, Horror)

Ratzinger's brave new world apparently now includes bald-faced lying.

In comments that have been reported widely, Ratzinger, on his way to Camaroon, said that HIV/AIDS

was a tragedy that cannot be overcome by money alone, that cannot be overcome through the distribution of condoms, which can even increase the problem.

That's a flat out lie, see here, here, the FDA, the Center for Disease Control, and how about the UNAIDS Position Statement on Condoms and HIV Prevention, July 2004, which says in part:

The male latex condom is the single, most efficient, available technology to reduce the sexual transmission of HIV and other sexually transmitted infections.

If he had stopped at "was a tragedy that cannot be overcome by money alone, that cannot be overcome through the distribution of condoms", then he would have been on safer ground. HIV/AIDS cannot be overcome by money alone, nor through the distribution of condoms alone. HIV/AIDS needs a multidisciplined approach that includes education, treatment and prevention. But Ratzinger couldn't resist the opportunity to lie.

He's supposed to be a 'fisher of men'. What kind of catch do you get with bait like that?

Never forget these people want to control female reproductive rights.

Red Dwarf - Update

The British cable channel "Dave" has released the schedule for the 3 new episodes of Red Dwarf, "Back to Earth parts I, II, and III. The will be shown each night from Friday April 10 at 9.00pm, along with other classic episodes and a "Making Of" documentary, and finally all three episodes and the "Making Of" together on April 13.

Friday, April 10th from 9pm
Back to Earth - Part One
Gunmen of the Apocalypse
Quarantine
Tikka to Ride

Saturday, April 11th from 9pm
Back to Earth - Part Two
Smeg Ups
Polymorph
Emohawk - Polymorph II

Sunday, April 12th from 9pm
Back to Earth - Part Three
The Making of Back to Earth
Back to Reality
Marooned

Monday, April 13th from 9pm
Back to Earth - Part One
Back to Earth - Part Two
Back to Earth - Part Three
The Making of Back to Earth

If, like me you can't make the UK in April, there is even better news. The DVD of all three episodes, plus the documentary and additional content, is scheduled for release on July 15th

Now THAT'S a spacecraft

Finally! A cool looking spacecraft.

The European Space Agency's Gose satellite is due to be launched from the Plesetsk Cosmodrome in north-west Russia on Monday.

But just look at it!

It's beautiful.

It's what a space vehicle should look like. It's got an ion engine. It's even got FINS!

The Goce satellite will measure tiny variations in the pull of gravity experienced across the planet.

The fact that the Earth is not a perfect sphere, but is flattened at the poles, and as the composition of the Earth varies from place to place (varying the density), results in a variable density, which in turn varies the pull of gravity.

As the measurements are so small, Goce must fly very low, 270km, which means that it will interact with the slight atmosphere still present at that height. Hence the fins.

It also has a cool xenon ion propultion system to ensure smooth flight through the traces of amosphere.

NASA? Are you watching? Next time you put a sattelite up, at least shove some fins on it!

Full story at the BBC.

More info on Gose can be found on the European Space Agency site. Including this cool video.

Addicted to Adduction

The inability of creationists to deal honestly with scientific evidence is legendary, especially when it comes to human evolution. Answers in Genesis and the Institute for Creation Science are the standard bearers of disingenuity.

Jim Foley has a post up at the Panda's Thumb about the latest creationist effort, this time concerning the recent find of 1.5 million year old fossil footprints from Illeret, Keyna.

One thing caught my attention was a neat story concerning the hallux, or big toe.

Discussing the different characteristics of modern, Illeret and Laetoli footprints (and hence exposing the claims by creationists that they are all the same, and so human), Jim mentions the hallux and abduction. Abduction of the hallux can be explained as the 'movement' of the hallux away from the line of the foot.

Compare your left hand and foot. Draw an imaginary line through the length of the foot. The hallux is set slightly off that line (taking in to account changes to the big toe caused by a lifetime of wearing shoes). Now, compare that the your left hand. The thumb is at a much greater angle to a line along the length of the hand. The thumb is abducted to a much greater extent that the hallux.

The foot of our distant ancestors would have had been more like our hand in terms of the position of the hallux - for prehensile reasons. But as our ancestors moved to be primarily ground dwellers and upright bipedalists, the shape of the foot evolved. The big toe adducted (moved closer the the line of the foot - the opposite of abducted) and the footprints at Illeret and Laetoli show this rather neatly.

The angle of abduction in modern humans is around 8 degrees (see figure showing abduction angle for the left foot). The angle of abduction of the Laetoli prints (at 3.7 mya) is 27 degrees. The angle of abduction for the Illeret prints (at 1.5 mya) falls neatly in between these two values at 14 degrees.

Now, what is another name for something that falls somewhere between two conditions? . . . Umm . . . Oh yeah, . . . intermediary.

Palaeoporn 11 - again

OK, back by huge public demand . . . err of one. Palaeoporn 11 is back with mark-ups.

The photo is of a portion of an Anomalocaris appendage, and shows the typical preservation style of fossils in the Emu Bay Shale.

In the photo (click to enlarge) there are three segments (S) and two segment boundaries (SB) the segment boundary is doubled because the original appendage was roughly circular, and when you flatten a tube, you don't get the appendage boundary matching up when squashed.

The specimen has been re-crystallised during an episode of overthrusting. The surface of the fossil is normal calcite, but in the centre the calicite is in the a fibrous form (FC). The matrix where the fossil was, is smooth (M2), the normal matrix is M1.

There is no phosphatisation of muscle tissue, and so this is probably a moult. But that's another story . . .

Palaeoporn 11

A slightly different Palaeoporn this time, as there's a bit of a theme this week, on preservation. A bit later I'll be discussing how to fossilise muscle tissue. This, and other specimens helped in coming up with the process.

This is a fragment of an Anomalocaris appendage from the Cambrian Emu Bay Shale. The interesting thing is the preservation. The outer layer preserves the impression of the appendage, together with segment boundaries. Inside, is a layer of fibrous calcite crystals. The specimen has been re-crystallised after a metamorphic event which included overthrusting. The crystals are, in fact aligned to the stress field, as they 'lean' towards the north - the thrust direction was south to north.