From Estonia…..with fish?

It has to be said that sometimes international research collaboration is underrated and if I’m being honest I was not sure what to expect from my trip to Estonia. I will return to what I got from it at the end of the post.

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Figure 1. Location of Estonia

So first off where is Estonia and why did I go out there, Estonia is just below Finland on the map (fig.1)

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Figure 2. Dr Tiiu Märss

and the capital Tallinn is located on the coast of the Baltic sea. I went there for a very simple reason….knowledge, you see I have been at this PhD for a year and bit now, and all my knowledge about the fish in my bone bed is self-taught. The reason for this is that although the University of Portsmouth has experts in both vertebrates and the Silurian neither have worked on Agnatha, so this is why I have had to teach myself.  Now luckily for me, my supervisors know all sorts of researchers including Dr. Tiiu Märss (fig.2)

who for a number few years has worked on Palaeozoic fish so she was going to give me first-hand knowledge on these groups so that I could identify the disarticulated material in my bone bed. So the way I’m going to do this post is tackle each day and what I got up to.

Monday  

BEEP BEEP BEEP, oh god its 3am I didn’t even know this time existed! So two trains and a 2 hour and 45 minute flight and I find myself in Estonian….Tallinn to be exact and once I have located my bag I headed for the door, where I was met by Tiiu (holding up a sign saying “LUKE” very rock & roll).

After a bus ride across the city I reached my home for the next four days the Academic hostel, which was very good and I would highly recommend it, any who so after a spot oflunch we made it to the department which as you can see in (fig.3) is located next to a

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Figure 3. no it’s not Narina

forest! The first thing we did was chat in her office about my project and I showed her my samples I brought from the UK.  After this I was shown to my work area (fig.4) which was all very swish and I started going through her UK material.

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Figure 4. The office and my work place for the four days

Tuesday

So day 2 begins with where I left off the previous day, sat at the binocular microscope (fig.5) and as mentioned looking through the loose samples that Tiiu has collected over the years and this was useful as I could get a sense of what certain scales look like and ask Tiiu questions about the material. I felt very lucky to be looking at all these different localities that I have read about in papers and places I know are historically important like some of the Scottish sites. Another interesting point was the variety of preservation in the denticles, browns, blacks and whites colours, and of all qualities. While looking, every so often I would stop and draw a denticle of interest and identifying them, I had a great many slides to through at least 60 so this was going to take some time. It was also great to know that the denticles in my sample which I had already identified as Paralogania ludlowensis was correct as Tiiu confirmed this (this is not surprising as this is expected to be the most common genera in my bed…but time will tell).

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Figure 5. My set up with Microscopes and note pad oh yeah and the samples (far left)

Wednesday

Now Wednesday was an interesting one as I was able to look at a large number (some 20 drawers) of articulated agnatha and gnathostomes (that’s animals in this case fish with jaws). Before that I did finish off looking through those disarticulated specimens….partly because I had not finished looking through them as there were so many and well partly because I had over slept on the Tuesday oops!

So I descended into the basement of the institute (the natural home of the palaeontologist) where their fossil collection is located, then as with the disarticulated material I sat down with a microscope and slowly went through each one stopping to draw ones of interest. Now one thing some of you readers may not realised is that there is a very good reason why they call people like myself a micro-palaeontologists and that’s because you spend most of your time strapped to a microscope of one type or another and this certainly was the case in Estonia. In term of the material it was a mixed bag some of the specimens were to be honest a little grotty while others were insanely beautiful, of particular note was the Canadian artic specimens which I was told by Tiiu were the “rubbish” bits that Wilson did not want when they were collecting in the 1990’s. So I know at this point I would normally saying here “see fig.1” I will be 100% honest folks I did have a chance to take pictures at this point, however this photo taken in Tiiu office (fig. 6) shows an articulated specimen of Phlebolepis elegans and the coolest part of this is that I have seen this actual specimen in the flesh….or denticles I guess.

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Figure 6. A photo of a photo of Phlebolepis elegans

After that there was a quick coffee and cake break, the coffee was great and served in their own mug! (fig.7) How cool is that, the poppy seed and chocolate bun was lovely as well. Back to work and I was looking at a “small” section of a mass mortality bed from one of the Islands of Estonian (Saaremaa in particular) and to describe it, well think of those Green River Formation slabs covered in fish it’s like that except with Phlebolepis elegans in the Silurian!

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Figure 7. Yes the institute has thir own mugs!

Thursday

The last day before flying home on the Friday was mostly made up of three things, looking through the Estonian material like I did with the UK material, which was excellent, seeing the differences between the two areas….oh I should probably explain, ok so back in the Silurian Earths continents looked rather different (fig.8.) The UK was known as Avalonia a series of small islands…not Scotland though as it was part of America….until it slammed into Wales and England while Estonia was part of the continent known as Baltica. The second thing was getting a load of papers……some in Russian…..still the pictures are nice the translation will come later I think. Finally, what I like to think as a bit of a highlight is some thin section photography I did with my thin sections on her microscope and camera (that’s the one on the left in fig.5) and as you can see in (fig.9) the results were excellent with all manner of details seen.

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Figure 8. Map showing the Silurian paleocontinents of Avalonia and Baltica

So what are my final thoughts about my first international research trip, well overall excellent it was really good chatting to a fellow thelodont researcher and gives me a real sense of what I need to do and how to do it. I recommend to my fellow researcher if you can go out to another part of the world and learn from others and to see other stuff to very much go and do it, as it’s so very useful. Also a final note I am stood in down town Tallinn and waiting for a bus to the airport when who should I bump into but my friend Charlotte from my local college back in my home town…..it truly is a small world.

Luke.

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Figure 9. A denticle from cut through horizontally, you can see the dark borwn in the centre which is the pulp cavity and the thin brown lines which are the dentine tubules and the ornimentation on the sides of the denticle

Well there you are I hope you have enjoyed this first year of Ancient anglers we are very sorry we have not posted more but we hope this will change next year. To all our readers, followers and causal browsers Merry Christmas and a happy new year.

from the Ancient Anglers

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References

Figure 2 is from http://www.gi.ee/index.php?page=30&staff_id=36 and figure 1 and figure 8 comes from Google images.

Better late than never – the other ancient angler speaks!

Hello all, Chris here.
I think it is about time for me to join the blog and start posting. This post will be quite short and aims to introduce myself to you all, and outline what I am researching.
Like Luke, I am also a PhD student at Portsmouth University, and for my sins I aim to be a fish worker too, or Palaeoichthyologist to give us our posh title! However, despite graduating with Luke in 2011, my personal circumstances meant that my PhD research has begun a year later so I am a little behind the work that Luke has done to date.
My research concerns a group of fish known as the Actinistians, the Coelacanth family. These are a fascinating group of fish that until 1938 were thought to have gone extinct at the KT boundary along with the (non-avian) Dinosaurs, 65 million years ago.
They first appeared in the fossil record in the Early Devonian – c.400 MYA, and we still have 2 species swimming in our oceans today. They survived both the Permo-Triassic major extinction and the KT (Cretaceous/Tertiary) extinction, left no (yet found) evidence of their existence for 65 million years, and were then discovered alive in the 1930s (fig.1).

Figure 1. latimeria chalumnae (The living coelacanth)

I will be studying some Late Jurassic Coelacanth fossils, found by Steve Etches, the world renowned collector of Kimmeridgian (Late Jurassic from mostly Kimmeridge Bay) fossils, and aim to ascertain their relationship with other Coelacanths. It is possible that these fossils represent new species, new to science.

Future posts will detail the family, what we know so far and will include some pictures!
In addition to the Coelacanth related posts, I am a keen fossil hunter, so I will indulge myself with the occasional post to show off my finds and explain what I have found and where it came from.
Yours piscatorially
Chris

References

Images taken from Google images

So what are doing with your time exactly Mr Hauser?

Hello Luke here, here it is then my first post on fish related to my research, sorry it’s so late folks but it’s been quite hectic. But before I introduce the cast of characters I will just mention what my PhD is on. I am looking at the Downton bone bed from the welsh borders; some of you may be wondering “Downton bone bed? Well I have heard or the very famous Ludlow bone bed”. This is kind of the point of my research, when you look at the Ludlow bone (fig.1) you can see this grey lithology and all those black grains…their fossils and in particular fish fragments. This is also true of the Downton bone bed however if you were to see it you would not clearly see the fossils, this is because all the fossil grains are of a similar colour to the lithology (a tan/brown colour) and this is why it has been missed for full investigation for the last 150+ years. So the next few sections for you delectation are some brief summaries of the types of fossil fish that I will come across, of course one the most exciting aspects of my PhD is the potential of finding new things, now this does not necessarily mean new species but possibly fish that are not known from this part of the world or at this time or who knows what. So without further ado here are the cast of characters I will become familiar with over the next possible 6 years and hopefully you guys will learn to love them, these odd bunch of early fish.

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Figure 1 Ludlow Bone Bed

Condonts

So these little jawless beauties appear in the Cambrian and make it all the way to the end Triassic! That is very impressive when you consider a lot of these fish don’t make it past the P/T mass extinction let alone animals getting past the Devonian. While on the subject of “animals” let’s clear things up about condonts and conodont animals, now condonts have been know about since 1856 when Christian Pander a Latvian embryologist and palaeontologist first identified them but, they were not the whole animal. They are calcium phosphate (or to be all fancy like calcium carbonate fluroapatite) microfossils known as conodont elements (fig.2)

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Figure 2. Conodont elements: (a, b) coniform elements, (c, d) ramiform elements, (e, f) pectiniform blade elements, (g, h) pectiniform platform elements, (i) bedding-plane assemblage.

which would have been found in the mouth of the animal (fig.3) Now these elements can be categorised by shape into different types protoconodonts, paraconodonts and euconodonts and due to taxa like Ozarkodina whose apparatus has been found complete and articulated we know how they looked in the living animal (fig.4).

So what about the living animals well the conodont animal or as some

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Figure 3. (A) Dorsal view of the reconstructed, closed apparatus of Novispathodus.(B) Orientation of the apparatus within the conodont’s head.

researchers are suggesting they should be called Conodontophora (conodont bearers), either works for me. These were eel like fish (fig.5) ranging from a less than a centimetre to those gigantic Ordovician monsters of the Soom shale which were 10’s of centimetres. Now it is at this point I should explain some of the many controversies with conodonts, so first off; what are these chaps (and chapettes) eating, well the main idea is that these were filter feeders using that complex apparatus in the mouth to filter out plankton from the water column. However in more recent years researchers have found that the elements have microwear patterns and this tells us that these guys are grasping prey so they are more likely swift little hunters.

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Figure 4 (a) natural assemblage of conodonts from the Carboniferous of Illinois (×24); and (b) the conodont animal from the Carboniferous Granton Shrimp Bed, Edinburgh, Scotland, with the head at lefthand end (×1.5).

Other blog posts in the works for these critters are; Conodonts: are they vertebrates? (yes and here’s why) and were conodonts venomous?

Thelodonts

Ah thelodonts or to translate their name ‘nipple tooth’, these jawless fish (agnatha) ranging from a few centimetres to meter in length and make up the bulk of the bone bed fauna so far seen. Now I apologise if I wax lyrical about these guys but in terms of my project I have come across hundreds of these guys but like 4 conodont elements so you can understand if these get a tad more press but worry not fans of conodonts they will get their own post.

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Figure 5. Reconstructions of Conodontophorans in life

So let’s get into them, they appear in the Middle or Late Ordovician and sadly bit farewell and join the choir invisible in the Late Devonian. We find their fossils can be found all over the world and we can find them as complete articulated specimens but the majority of their fossils (and certainly this is the case with my material) they are found as isolated micro fossils (fig. 6). I should at this point explain what thelodonts are; they are fish with an endoskeleton of cartilage and then there skin is covered in dermal denticles (fig.7) in a slightly analogous way with sharks. The denticles, as the dent part of the word suggests are related to teeth…that is for want of a better word they are teeth in the skin (hence the dermal bit). In the fossil record they usually “rock” (no pun intended) up as isolated denticles in sediment most famously in the Late Silurian bone beds but occasionally as entire articulated specimens found in places like Canada, Scotland and Scandinavia with all their denticles in place. While on the subject of places we find their remains add to the list Russia, Australia, South East Asia, Europe and finally North and South America. They are a monophyletic group although one group the Furcacaudiformes from Canada are morphologically very different and there is debate on their position in thelodonti and represent a new order of thelodonts (Märss, 2006a).

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Figure 6. thelodont fish in life

Overall thelodont affinities remain somewhat unclear, it has been suggested that they are the sister taxa to the osteostracans and could also be close to chondrichthyes but the way thelodonts have their micromeric squamations (scales) is different from both. Ultimately when it comes to where these fish fit one must remember there we are talking about a group of animals mostly known from there isolated dermal denticles in fact in most decent phylogenetic analyses only contains24 to 25 taxa because that’s how many we have articulated. Now that’s not to say that that makes it invalid I am unsure how many characters were generated but 24 taxa is quite a small selection but does once again highlight the challenges one faces when dealing with the fossil record.

On a final foot note for now diet wise these chaps are probably eating plankton, algae and rubbish (well deposit and suspension feeding on sediment) in fact the Furcacaudiformes with their deep bodies and large eyes were suggested to be predators. Right well not top of the line predators but still taking on small prey items however it is more likely the large eyes were used to help select only the tastiest bits of detritus….also helps in spotting predators, like giant sea scorpions.

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Figure 7. thelodont denticles Loganellia scotia

Acanthodians

The final group of fish that I will be looking at and discussing here are the “spiny sharks” or acanthodians (fig. 8) named in 1844 by Agassiz (for more information about Agassiz’s life and work click here). This group gets its name from the Greek word akanthos which means spine and it’s well placed as they are the only fish that processed spines on all their fins. They appeared in the Silurian which is handy for me and disappeared when coprolite hit the fan with end Permian extinction. However one of the most notably features of the acanthodians are jaws…yes these are some of the first jawed vertebrates but at the time of my research (roughly 420 ma) they are not the dominant fish fauna it’s still the agnathans. There found in the fossil record like thelodonts both as, in my case isolated fragments of denticles or as articulated specimens and they are found in all corners of the globe. In terms of there relationships with other early fish we rule out early sharks (although the spiny sharks  name came from morphological similarities) placoderms and early actinopterygians, but of the jawless ancestors only thelodonts come close to a similar micromeric squamation but it is unlikely the two are that closely related. It now seems that they share a lot of specialized characters with osteichthyans compared to other groups, some of the characters are: similar shaped brain case, nature of the gill filaments (hemibranchs) along the gill arch and the presence of brachiostegal rays. Although (Davis et al 2012), found that they are somewhat split between the osteichthyans and the chondrichthyans, so once again this shows that with dealing with fish this far back getting a complete resolution of their origins can be difficult.

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Figure 8. Example of an acanthodian Climatius reticulatus, Illustrator Arthur Weasley

There are three subgroups of acanthodians the first is the Climatiiformies which were I guess the “standard” acanthodian although were more heavily armoured than the other two. The next it is the Ishnacanthiformes which had robust jaws and big teeth and assumed to be the predators of the group and finally the Acanthodiformes which were the most successful of the groups and despite developing jaws became filter feeders (turns out have jaws is not just handy for grabbing food items). The final bit of classification is the scale morphology there being two types, one is the Acathodes type which is a crown made of true dentine and a thick acellular bone base and Nostolepis type that has a dentine crown penetrated by vascular canals and a base of cellular bone.

Others

Now there have also been chondrichthyan scales found in bone beds of this age in the welsh borders but apart from saying “there are sharky things in them there hills” I can’t expand really, I also may come across material from other types of agnathans and as soon as the thesis or paper is accepted I will be blogging about it, I also plan to do more in depth posts on these groups but all in good time.

So yes there we are that’s the sort of fish I will be working on hopefully Chris will tell you about his fish soon so until next time (which will be a special post) take care.

References

Davis, S. P.; Finarelli, J. A.; Coates, M. I. 2012. “Acanthodes and shark-like conditions in the last common ancestor of modern gnathostomes”. Nature 486 (7402): 247.

Janvier. P, 1996. Early Vertebrates, Clarendon press. Oxford. Pp.393

Long. J.A, 2010. The rise of fishes: 500 million years of evolution, Johns Hopkins University Press. pp.304

Märss, T. Turner, S. & Karatajūtė-Talimaa, V. 2007. Handbook of paleoichthyology Volume 1B “Agnatha” II Thelodonti, pp.141.

Märss, T., 2006a. Exoskeleton ultrasculpture of the early agnathans and fishes. – Journal of vertebrate paleontology. 26(2), p.235-252.

All taken from Google images apart from figure 4 taken from http://www.blackwellpublishing.com/paleobiology/figure.asp?chap=16&fig=Fig16-5&img=c16f005.