Critter of 27/04/2010

I've had a break over the last few days from posting. Not intentionally, as there have been numerous distractions.  Normal university commitments continue, but on top of that the weather has been glorious, resulting in a lot more outdoor activity, particularly barbecues. When I have been indoors I have the distraction of the snooker world championships on BBC2 and 6 songs to learn for a friend's band by Friday. Obviously I don't have time to write any of the longer pieces I have planned, but there is certainly time to squeeze in a beautiful critter. I have chosen another trilobite, this time Sphaerocoryphe which is closely related to Cheirurus which was mentioned in my pokémon blog.

The above picture shows Sphaerocoryphe robusta from the Ordovician period.

This one is likely Sphaerocoryphe cranium. Though not pictured here, Sphaerocoryphe thomsoni can be found in Ayrshire. Isn't it beautiful, even for a detritivore?

More From the Zechstein Basin

It isn't every day that a specific area of interest comes up in a lecture multiple times. I was already paying quite a lot of attention during this particular sedimentology lecture, but managed to pay even more when the Zechstein sea was brought up. I thought I would share the information I got from it.



The first mention simply came with the mention of commercial uses of evaporite deposits, as salt from the Zechstein sea is mined for industrial purposes and human consumption. Boulby mine in East Yorkshire is apparently the deepest in the UK and extends a mile out to sea.

The Zechstein basin is a saline giant, extensive marine evaporite deposits (deposited when sea water evaporates and leaves minerals) thousands of metres thick in what are known as intracratonic basins (a craton is a part of the Earth's crust that has not been split or merged). There are no modern equivalents of saline giants. Below is a picture of major Phanerozoic evaporite deposits.

Saline giants present a conundrum for geologists as evaporating sea water in the laboratory does not produce natural evaporite minerals and produces them in the wrong volumes (not enough anhydrite, too much sylvite/carnallite). Evaporating a 300m column of sea water only produces less than 5m of salt, yet in Jurassic marine deposits in America the desposits are 3500m thick, which would require the evaporation of a 240km deep marine basin!

On the left is the data predicted compared with the actual amounts found in the Zechstein basin. Below is the same data plotted in a graph. As can be seen, the predictions do not match what is produced.

The explanation for this seems to be that these basins were repeatedly replenished with sea water, possibly before the sea had fully dried out. Doncaster during the Permian was in a sea which was constantly evaporating and being refilled. This required special conditions. There needs to have been a barrier to the open ocean permitting replenishment of sea water (which could be continual or episodic); there needs to have been prolonged subsidence; and there needs to have been prolonged aridity and thermo-haline stratification (this relates to the temperature and salt content of the water).

There are different types of saline giant basins. The Zechstein was a deep barred basin, as shown on the left. These have the same mineralogy across the basin at any given time, overlying anoxic muds, with a straitified water column in 10s to 100s of metres cycles.


Hopefully future lectures will reveal more about the Zechstein basin, though I suspect that I will have to apply information from other examples in order to work out more about it.

Pokémon Palaeontology I

There are a few parallels between pokémon and palaeontology, both have the collecting aspect and both give the desire to discover new species. On top of this there are fossil type pokémon, which I will be looking at here, and also many are based on extinct organisms. I do feel I should point out that the evolution seen in pokémon is nothing of the sort, it is metamorphosis. If the pokémon gave birth to the next "evolution" then it would be an extreme case of saltation (a large leap) similar to the hopeful monster approach of Goldschmidt, which is known not to occur. As it occurs within a single generation and is repeatable by other members of the species, it is definitely metamorphosis.

I always liked pokémon, I played the Gameboy game (I bought red at first) and had a love of fire type pokémon, so naturally I picked charmander. I also collected the trading cards, which I still own. I played gold when it came out, but after that slowed down. I last played diamond, though I lost it for a while and now that I have found it again I have nothing to play it on. I can't buy the new game for the same reason, so I thought that instead I would indulge myself by looking at the various palaeontology influenced pokémon and come up with my own ideal team (in the form of a gym leader with a theme and not simply the sort you would challenge the elite four with).

Kabuto and Kabutops are  favourites of mine. I naturally chose the dome fossil while playing red in order to get these. Kabutops was often a member of my team on the Gameboy game and I often select it when playing Pokémon Stadium too. They are a combination of both rock and water type, making them quite versatile in battle. In contrast with Omanyte and Omastar, they have a more attacking style which they sacrifice some defence for. Kabuto is based on the living horseshoe crab and of course the extinct trilobites. Kabutops is based on the eurypterids, though its cephalon and pleural segments connect it to trilobites and genus Cheirurus  seems to be the preferred comparison.

Next up are Omanyte and Omastar, which are resurrected from the helix fossil within the game. Both are also rock and water type and quite clearly are based on ammonites. 

Also from the original games comes another which I used to use often, the flying and rock type Aerodactyl. Aerodactyl is another obvious one, both the appearance and name suggest that it was based on some sort of pterosaur, often labelled pterodactyls. More specifically it could be a Ramphorynchoid as it had teeth and a tail.

A big jump through the pokédex now to Anorith and Armaldo. These are a mixture of rock and bug type (though oddly not water type considering their basis) and Anorith is resurrected from the claw fossil. Anorith for me is the interesting one as it was based on the Cambrian beasty Anomalocaris for which the tale of discovery is fascinating.  Originally Anomalocaris  was believed to be three different species; the mouth part was thought to be an unusual jellyfish called Peytoria; the front appendages were thought to be the back end of a shrimp; and the body was thought to be a sponge.

Armaldo is rather different as it is a bit of a mish-mash of different prehistoric organisms. It is supposed to be based on Anomalocaris,  but seems to have features thrown in which fit the thyreophorans (the dinosaur group containing stegosaurs and ankylosaurs). Below is a picture of the awesome Anomalocaris  for comparison:

The root fossil brings back Lileep, which evolves into Cradily. Both are rock and grass type, though it is again odd that they are not water type, considering the habitat of what they are based on. Both of course are based on Crinoids, also known as sea lilies. It is a tad annoying that they are plant type, as their superficial resemblance to flowers cause many to think of them as plants, when they are actually animals, more specifically echinoderms. Personally I think Lileep is quite cute, whereas Cradily looks demented.

Shieldon and Bastiodon are next, coming from the armour fossil. Both of these are based on ceratopsian dinosaurs, with Shieldon resembling a Protoceratops to an extent, while Bastiodon is apparently based on Zuniceratops.

These two are both rock and steel type, making their head shields tougher than any ceratopsian ever managed.

Last for now are Cranidos and Rampardos, resurrected from the skull fossil and they are the only fossil pokémon to be only rock type. Both are obviously based on pachycephalosaurs, though apparently Rampardos is more specifically based on pachycephalosaurs such as Dracorex or Stygimoloch. I find the name Stygimoloch amusing as it means "horned devil". 

For now I will leave it there, having covered the specifically fossil type pokémon. There will be more to come though, as many pokémon are based on prehistoric critters and I also intend to list a gym leader type team. I will go easy on the images next time, they have messed with the format too much and the amount of blank space is annoying.

Science Humour

Whilst searching for the images to my last post I stumbled on somebody else's blog from a couple of years ago containing some amusing science-themes images. I thought I would steal a couple of them to post here.

That honestly did make me laugh a fair bit.

Though this one did even more so, it was the "maybe" that did it. There was also this quantum mechanics themed joke, which I rather liked:

Q. Why was Heisenberg no good in bed? A. Because when he had the position he never had the momentum, and when he had the energy he never had the time.

This one is predictably my favourite, and how could I not post a palaeontology themed one? Now, how can I steal this for my palaeodoodles?

And to finish, a good message about science:

Palaeontology in Popular Science

I thought I would recommend a few books which give good insight into the world of palaeontology that are not too technical and are interesting to read.

Neil Shubin's book Your Inner Fish is a fantastic read, the sort where you absorb a lot of information without realising. It is very easy to follow and does not bombard the audience with complicated ideas and jargon. It begins with a palaeontological story, in which Shubin talks about how he learnt the trade and how he used palaeontological principles in order to discover the now famous transitional fossil Tiktaalik roseae,  aka the "fishapod". Shubin aptly demonstrates how this applies to us by crossing disciplines into developmental biology and genetics, something palaeontologists are doing more and more often. Personally for me this book was very useful. I almost didn't buy it but am so glad I did as it helped me make some big decisions. My life was hitting a dead-end and I had become heavily drawn to palaeontology. Reading this book helped confirm that I would like to go into the field of palaeontology during a time when I was having to make the decisions leading to it.

I was going to avoid books about dinosaurs, but I felt that Grave Secrets of Dinosaurs  by Phil Manning was worth mentioning. It presents the more glamorous side of palaeontology, the sort which grips the imagination of the public. It centres around the discovery of a Hadrosaur called Dakota, which is rare in that it has the soft tissues preserved in a 3D structure and can potentially tell us a lot about dinosaurs which we didn't already know. In other areas of palaeontology soft tissue preservation is quite common, but not with dinosaurs. I was going to avoid dinosaur books simply because people mistakenly equate palaeontology to the study of dinosaurs, when really dinosaurology is a small subset which gets a lot of attention. I chose to list this book as it also crosses disciplines, this time into geochemistry, and it also mentions a lot of hi-tech approaches which may contrast with the other books.

If I could only recommend one of these books, it would probably be Trilobite  by Richard Fortey. Not because of a fondness for trilobites (which pretty much emerged due to this book anyway) but because it is both superbly written and highly informative. Fortey applies the study of trilobites to a broad range of areas including evolution, biostratigraphy, continental drift and more. Not only does he demonstrate many different aspects and applications of palaeontology, but he also elucidates the world of trilobites, unveiling numerous wonders. This book has also been a personal help. I was beginning my journey into palaeontology at the time I read it (I am still a long way off of fully achieving it) and it gave me the comfort of feeling that I was on the right track and that this is what I want to do. I could not recommend this book more.

I recommend this book because it gives a good overview of the fossil record, documenting many excellent fossil transitions. It contains many images and is easy to navigate if you ever want to use it for quick reference. The title says it all really, Evolution: What the Fossils Say and Why it Matters. Donald Prothero, the author, does at times get a little repetitive and shrill with his criticisms of creationism. Nearly every fossil example is followed by an example of how creationists distort or ignore the data. I often found myself hoping that he would stop doing that and focus on the fossils, as that is where this book shines. I've not seen any other books for the general public which match this one for its coverage of the fossil record and the study of evolution, so for this I recommend it.

Last but certainly not least is Wonderful Life as no list of books on palaeontology would be complete without the work of Stephen Jay Gould and this book is near enough a masterpiece. Quite a lot about palaeontology is presented in this book, demonstrating the techniques used by palaeontologists and the issues they face when interpreting fossils. Gould also puts them into a wider context in a way few could manage so effectively. He eloquently elucidates the weird wonders of the Burgess Shale Cambrian fauna, though for this it is sadly now out of date in many ways (science does progress, after all). To accompany this book I would recommend The Crucible of Creation  by Simon Conway Morris as it updates some of the findings, expands on some of the themes, and at the same time comes to the opposite conclusion to Gould, making for gripping reading. However, Conway Morris' book is also ageing and gets a bit shrill when criticising Gould, so if you just want to know more about Cambrian fauna, perhaps something more up to date is required.

Microdictyon Again

Yesterday I did not post a new critter and today has been the same, however, I do want to say more about Microdictyon. The small shelly fauna (left) of the early Cambrian are a group of fossils which are isolated hard parts, all small as the name suggests, and all are difficult to classify. Many of them are still mysterious, though occasionally discoveries are made which put some of them into context, often throwing up surprises. Microdictyon  means "little net" and was the name of a phosphatic microfossil in the early Cambrian. The microfossils have a distinct net like structure, hence the name.

It wasn't until fossils in 1989 were found with soft tissue preserved. Nobody could have predicted that it would turn out to be an armoured lobopodian. The sclerites were found to sit just above the lobopods, on each side, looking like shoulder pads. It is likely that they were used for defensive purposes, though it has even been suggested that they were compound eyes like those of trilobites.

Words Just Cannot Do Justice To My Incredulity

If you don't know who Kent Hovind is then I suggest you run a mile every time you see his name, he is perhaps the worst creationist apologetics has to offer. However, if you, like me, are building up an immunity to his drivel somehow, then try reading this. It turns out Kent posts imaginary conversations, usually quite self-aggrandising, on a blog site, which he writes whilst in prison. In this example he discusses with Ardi (if you don't know about Ardi then you are on the wrong site here). I don't want to say more, just read it: http://www.cseblogs.com/2010/04/19/knee-mail-“if-ardi-could-talk”/

Thaumaptilon - Today's Critter

Today I decided to look at an organism called Thaumaptilon (wonderful soft-feather)  as it is believed to be a survivor from the Ediacaran fauna which was found in the Burgess Shale of the mid-Cambrian. This superficially leaf-like animal is considered to be a cnidarian and lived its life attached to the sea floor by a holdfast. It grew to around 8 inches and was covered in spots on one side which may have been zooids, suggesting it was a colonial animal.

These animals were once thought to be sea pens, like the one in the image on the right, however, this has been strongly questioned on numerous lines of evidence. So why have I chosen something which is similar to a sea pen and didn't really do much? Well, Thaumaptilon was linked to Ediacaran forms such as Charnia which had long been tricky to classify (it still is). If Thaumaptilon was indeed both related to Charnia and to modern pennatulacean cnidarians (sea-pens) then it would be strong case against the concept of the Vendobionta of Adolf Seilacher. Seilacher proposed that the Ediacaran organisms were an evolutionary experiment in multicellularity which left no descendants. He also proposed that these quilted forms, of which Charnia  was one, had a hard outer layer which explained why they fossilised so well. Modern sea-pens do not have this outer layer and so the link would have dealt a heavy blow against it.

This image shows Thaumaptilon  along with the Ediacaran forms Charnia  and Spriggina. Charnia is named after Charnwood Forest in Leicestershire where it was initially discovered (so I have managed to keep most of the critters British so far). Spriggina is quite fascinating as it has been classified as an annelid worm, a rangeomorph frond, an arthropod (possible trilobite ancestor), and a proarticulate. In this image is another Cambrian form, Stromatoveris, which has been classified as a ctenophore. The image below shows a potential phylogeny on which both Thaumaptilon  and Stromatoveris can be seen.

I wouldn't like to comment on the potential relationship with Charnia  at the moment. Current popular opinion seems to be that we just don't know. The Ediacaran and early Cambrian fauna are some of the most difficult to study enigmatic organisms known to palaeontology. Thaumaptilon may not have been doing much when it was alive, but from a palaeontological perspective it is fascinating.

Politics

For the record I am not really interested in politics, though I really should register to vote. Anyway, I have found my ideal party, who I hope I can vote for.

Trilobite Tattoos?

As I have tattoos already, the thought of a trilobite tattoo would be quite tempting. I found this website which shows some trilobite tattoos on others.

I am seriously going to look into this properly now...

Crinoids of the day

For today's critters it seems only fitting that they are crinoids. They have been mentioned a couple of times on this blog, but today brought a surprise with two (and now three) blogs on crinoids. The following is Protaxocrinus from the Ordovician. Protaxocrinus girvanensis can be found in Ayrshire.

The next is Diabolocrinus,  also Ordovician in age and found in Ayrshire.

A Crinoid Coincidence

Earlier today I posted about the crinoid poster I did for a uni project. Coincidentally I have just found an article on Science Daily which is not simply about crinoids, but about their evolution in response to predation. This information would have been useful for the poster as it was about the adaptive evolution of Palaeozoic and Mesozoic crinoids. The article in question is about the evolution of motility in Mesozoic crinoids in response to predation by sea urchins.

Evolutionary arms races are often postulated as the cause of rapid evolutionary escalations, however, they are not always easy to demonstrate. In an excellent study of both living examples and fossils, researchers from the University of Michigan have demonstrated that crinoids evolved their defensive strategies in response to being preyed upon by sea urchins (Baumiller led the research, who also led the research in one of the papers we cited in our poster).

Modern crinoids were quite recently found to be able to crawl away from stressful situations and reattach to substrate in a new location. Palaeozoic crinoids were unable to do this and so invested in stronger "armour" in order to provide protection. The researchers placed sea urchins in a tank with both crinoid fragments and living crinoids. They observed the sea urchins feeding on the fragments and the living crinoids. This confirmed that sea urchins do feed on crinoids and also provided the necessary clues for scrutinising the fossil record. The undigested parts bore characteristic teeth marks from the sea urchins.

The palaeontologists then analysed 2,500 stalked crinoids from the Triassic period, looking for the same bite marks and scratches. Over 500 had such markings, suggesting that predation by sea urchins was a strong ecological presence for early Mesozoic crinoids and the likely driver behind the evolution of motility.

The timing of the occurrence also has significance, as most examples of evolutionary arms races comes from the Mesozoic Marine Revolution, which occurred around 75 Ma later. For crinoids it appears that the arms race had long been raging due to the evolution of stronger, more active feeding apparatus in echinoids.

The journal article can be found here.

Adaptive Crinoids: Palaeontological Poster Presentations

A few months ago we were set the task, in groups, of producing a poster to be presented in front of the rest of the people on our course. At conferences scientists often do poster presentations of their recent work and display them so that other scientists can browse them and easily find out more. Our task was to produce the same sort of thing, albeit it on a smaller scale as there are only 11 of us on our course. The poster I co-produced is titled A Comparison of the Adaptive Strategies of Palaeozoic and Mesozoic Crinoids, however, on the day it tended to be referred to as Adaptive Crinoids. Our poster came joint first, which is why I feel it is worth sharing. As my prize I chose the superb book Wonderful Life  by Stephen Jay Gould. The picture may not be brilliant quality as I currently only have a trial version of powerpoint and so can't edit it to make it suitable. I can't even copy and paste the writing.

So there it is. There are a couple of mistakes, but nothing major. We seemed to get a good balance of information and aesthetic value. The poster should not be so wide, the black edges need trimming back in this image. If it is too hard to read that may be because it was made for A1 sized paper.

The critter of the 17th of April

In a break from trilobites found in Britain, I think it makes sense to present the organism which is currently my profile picture.

This is Microdictyon, an armoured worm from the early Cambrian. It is often classed as a lobopod, though this phylum is not well defined. It is well known from fossils of its sclerites, with some soft-bodied fossils found in China. It has ten pairs of sclerites on its side, matching its pairs of tentacles, and the anterior and posterior are featureless (this image makes the sclerites look like eyes). There are 11 species of Microdictyon, one of which is amusingly called M. anus. 

I am becoming quite fascinated by early metazoan evolution, right up to the Cambrian explosion. Microdictyon  is one of the small shelly fossils of the post-Tommotian Maotianshan shales. 

Critters of 16/4/10

tesFor today I have gone for more trilobites, both of which are agnostids. Most agnostid trilobites are eyeless and have a similar sized pygidium as the cephalon, making it difficult to determine which end is which sometimes.

This first agnostid trilobite is Lotagnostus which is from the Upper Cambrian. Lotagnostus trisectus can be found near the Malvern Hills. It is sometimes known as Agnostus trisectus. 

This agnostid trilobite is Eodiscus punctatus, from the Middle Cambrian. It can be found in Wales and is sometimes referred to as Microdiscus punctatus. 

Critters of the *blank*

I am surprised that I did not have this idea sooner as it is the sort of thing found on many blogs. I have decided to update more regularly, though mostly images and not too much writing. I shall be doing the "animal of the week" sort of thing, but a week seems like too long. Daily might get tedious, so the time period is irrelevant (hence the *blank* in the title). Of course, this being the Palaeobabbler it is only fitting that they are extinct critters. I'll probably post a mixture of fossil images and reconstructions, depending on what I find really. Some will follow themes (the first lot will likely be species taken from British Palaeozoic Fossils as I just got it out of the library) and some may be quite random.

This first specimen is Olenelloides, a gorgeous trilobite from the lower Cambrian. Olenelloides armatus can be found in British Cambrian rocks. I will apologise in advance for anyone who happens upon these posts who is not fond of trilobites, I am likely to put up a few pictures of them. Trilobites are incredible fossils and have such diversity that I could keep posting a new interesting one for quite some time.The most striking feature of Olenelloides is clearly the cephalon (the head part at the anterior), which is almost star shaped. I would love to find a fossil of this some day.