A Week in the Triassic: Wild Areas Network Poland Palaeontological Dig 2019
In early June I was contacted through my university email with a volunteering opportunity in Poland with Wild Areas Network; an opportunity to take part in a real palaeontological dig. A month later, myself and four of my fellow University of Birmingham Earth Sciences students (find some of them here) were boarding a plane from East Midlands Airport to Wrocław. We spent the day exploring Wrocław and the University of Wrocław’s Museum of Natural History and, the following day, travelled by train to Opole. There, we met with the two other volunteers who would join us for the week and Joanna from Wild Areas Network; a woman whose passion is to expose the secret wild side of Poland.
Krasiejów, population approximately 2,000, is a small village lying about 30 mins by train to the east of Opole, Opole County. Its train station has a single platform. Most people grow their own vegetables or keep small numbers of livestock. Thirty minutes walk from the train station and you will arrive at a place that stands in stark contrast to the quiet village with its garden chicken coops and colourful detached houses. The JuraPark at Krasiejów was established in 2010 and is the closest thing to a real world Jurassic Park you will ever find. The largest of its kind, the park aims to bring the Mesozoic to life with true-to-life reconstructions, 5D cinema, 4D prehistoric aquarium and “Time Tunnel”. However, these are not the only things that make the Krasiejów JuraPark unique. Built at the base of a discontinued cement quarry, the park is the only one of its kind to be situated on an active palaeontological dig site.
During the Triassic, the location was drowned by a lake that extended far into the centre of the Germanic Basin (a large area of sedimentation in central Europe). 230 million years later, in 1974, the cement plant Strzelce Opolskie began mixing the mudstone of the area with water to be pumped to their nearby cement works. Amateur fossil collectors began to find bone fragments within the mudstone layers and in 1993, the first proper excavations of the site began. Since then, it has become one of the best places in Europe to see palaeontology in action.
A number of factors had worked together in the area during the Triassic to allow the fossilisation process to occur. Seasonal monsoon flooding periodically washed terrestrial animals from the surrounding land into the lake, where they settled to the anoxic bottom. The lack of oxygen in the lower water layers meant that they could not support the scavengers or microorganisms that would usually cause organic decay, ensuring that the bones of these ancient animals would be left for us to find. Water inundating the lake from the monsoon flooding would not only have picked up organisms, but also large volumes of debris and mud, resulting in the rapid burial of these carcasses, acting as a further barrier to natural decay. Finally, predominantly alkaline chemical conditions in the environment protected the bones from acidic chemical decay, but prevented soft tissue preservation. This is why the site only yields the bones of terrestrial tetrapods, and none of their soft parts, like skin or flesh. The nature of this process of preservation, however, means that the site does not yield articulated skeletons; monsoon flooding can be a very active and violent process, disturbing bones in the process of burial.
Arriving at the JuraPark was a really surreal experience. We’d been travelling for more than 24 hours by that point (rarely is the cheapest way to get somewhere also the fastest, and we were all poor undergraduates after all!). Our home for the week was a one room cabin owned by the University of Opole, whose space was mainly dominated by a long table that ran the length of the room whose top you could hardly see for all the fossils and microscopes and palaeontological equipment on its top! Two minutes into arriving and we already felt like we were immersed in a real dig! I think Joanna could sense our excitement and pretty quickly offered to show us the actual excavation site and we jumped at the chance. The site was hardly five minutes walk down the dirt track, and it was a place we were to become very familiar with over the next week.
We spent the first half of our first morning in Krasiejów in the lecture theatre of the Human Evolution Museum that was also on the site. We were introduced to the academics who would accompany us for the week and the Belgian Palaeontology Association volunteers who we would share the site with. The lectures introduced us to the Triassic ecosystem we were about to become very familiar with. but also to the research that would be happening on-site around us: one group was collecting microvertebrates, while another was working on fossil histology. I had never ever heard of palaeo-histology before, so I really enjoyed learning about how the Krasiejów fauna was being used to look at bone growth and development in fossilised vertebrates.
Searching for microfossils down the microscope
The second half of the morning was spent at Krasiejów’s Muzeum Paleontologiczne, in the village. The building is easily identified by two large model dinosaurs in its garden and the cranes nesting in the lamp post on the street directly outside! Inside, it’s like a treasure trove of local palaeontology. Opened in 2005 by the Krasiejów Lovers Association, the exhibit is a testament to the pride that the local people have in their geology. Artwork of local prehistoric fauna covers every wall, and every case is full of local specimens from the Silesia region, most of which are borrowed from the University of Opole.
When we got back to the park we began a full tour, taking in the 300 models of 70+ dinosaur/reptile species. We went through the “Time Tunnel,” which involved us all piling into a trailer and wearing funky 3D glasses so we could watch a strange video explaining the first four billion years of life on Earth compiled into eight minutes, complete with models and steaming volcanic vents. It was just as surreal as it sounds.
How big were the biggest sauropods? Big enough to walk underneath!
I think my favourite part of the tour was the Palaeontological Excavation Pavilion. The Pavilion had been build on the excavation site itself. Inside, most of the floor had been left as exposed rock, which had been excavated to show the density of the fossils on the site. Every metre of it was packed with metaposaur skulls, disarticulated limb bones and vertebrae. There was a glass walkway so you could stand over the site and get a close look at what was right beneath your feet. A moving glass platform had also been built over the exposed bed, meaning that palaeontologists studying the fauna could move over the area without risking damage to the exposed material.
The Palaeontology Pavilion
The Triassic Krasiejów fauna is diverse. Along with the collection of bivalves, gastropods, plants, insects, and other invertebrates found at the site, a range of vertebrate skeletons have emerged over the last 26 years. The most common of these is probably the amphibian Metoposaurus, the skulls of which litter the exposed floor of the Palaeontology Pavilion. A similar species, Cyclosaurus, is larger but significantly less common. Phytosaurs, resembling modern crocodiles with long, thin snouts have also been found, and even a few pterosaurs!
Probably the most famous find from the site, however, is the region’s only dinosaur relative; Silesaurus opolensis is a small dinosauromorph (early dinosaur relative), standing about 60cm tall at the shoulder. Named for the region it was found in and its closest town (Silesia and Opole, respectively), Silesaurus is suspected to have been facultatively bipedal, meaning that while it normally walked on four legs, locomotion on two legs was possible. Coprolite (fossilised poo) samples coupled with anatomical studies have revealed that the species is likely to have had remarkably bird-like feeding methods and a diet composed mainly of insects. The anatomical data suggests that the animal was likely picking through the foliage for insects, and regurgitating larger food parts and plants in much the same way that owls do today.
The dig site, with Palaeontological Pavilion and Educational Trail in background
We spent the majority of the rest of the week digging through the mudstone, with our eyes peeled for any black fragments that might indicate a bone. The excavation site sits just off the Educational Trial with all the dinosaur models, so every time we turned around another family or group of school children was stood on the corner of the walkway watching us from a distance. I have got to admit that there is something slightly unnerving about having a group of school children sing at you from about 100m away while you're digging around in the dirt! We even had a visit from a German TV crew filming a documentary about the best palaeontological sites in Europe and a local radio show who interviewed one of my companions about what we has been doing.
In three days of digging, I found absolutely nothing but bivalves, but I had so much fun that I didn’t even care. Even though none of us made any major discoveries, there was still plenty of palaeontology everywhere we looked to keep us busy! Digging is done roughly like this; all the topsoil is shovelled off and removed from the site with wheelbarrows. When the first bone layer is exposed, the shovels are exchanges for hammers. Using the back, pointed end of the hammer, rock is removed in layers, forming a step that is continuously worked down to floor level, which is where the bottom bone layer ends. The super high-tech tool of a sweeping brush with the handle broken off was used to clear debris from the area you were working on. As you remove rock, your eyes are constantly searching for anything that stands out as black against the reds and greys of the mudstone. Smooth areas appear and you get excited, only to pry your palaeontology prize out of the rock and find it is simply another bivalve that crumbles away in your hands.
So, what happens when someone does find something? Well, more solid bones, including things like vertebrae, can normally by pried from the rock with just a pick and your fingers. Limb bones and skulls, however, tend to be more delicate and require more support to be removed. First, the fossil is exposed from the top and sides. Next, the top and sides are coated with multiple layers of plaster of Paris, to stabilise the bone. Finally, the sediment underneath the bone is removed. You end up with a sort of plaster “egg” containing the bone and the sediment surrounding it. This is taken back to the lab so that the bone can be extracted much more carefully, using fine tools.
Photo by Adam Manning
We spent quite a bit of time in the lab with cases that had been extracted in previous years. The lab was composed of two rooms; the back room acted as storage, while the front room was for preparation and had a wall of glass so that members of the public could watch fossils being prepared. The museum lacks the manpower to clean them all up, so there were plenty there to pick from. The casings were so old that no one actually knew what was in any of them anymore, so everything we found was a surprise better than Christmas day! Working in pairs, the first task was to remove the upper most sediment layers, mostly done with our fingers, small picks and fine brushes. A saw was kept on hand to remove plaster regularly as it began to overhang as sediment was removed.
Samples from the lab (from left to right); ammonite with dirty hand for scale, trilobites, shrimp
My partner and myself soon began to find tiny circular fragments of loose bone material in ours and, after asking one of the professors, we were soon told that they were pterosaur bones, which were quite rare in these beds. Unfortunately, their fragility meant they were basically impossible to remove whole, no matter how much glue we used. We set about trying as best we could to get the tiny bones out, but soon came across something less delicate. Underneath the pterosaur bones were three metaposaur vertebrae and a clavicle (collarbone)! These were much easier to excavate and we managed to get all three of the vertebrae out! If only we’d had more time in Poland to finish our work!
The plaster 'egg' my partner and I worked on for the week (from left to right); the capsule as we first received it, the first vertebrae we retrieved from it, the very fragile pterosaur bones we managed to reveal.
My time in Poland was one of the best and most unique experiences of my life. It was done through Wild Areas Network, and you don’t have to be a palaeontologist to join done of their digs. Anyone, no matter how little experience they have, is welcome! Wild Areas Network was founded and is run by Joanna Chmielewska as a way to show people the hidden wilderness of Poland, and I definitely feel like it has opened my eyes to a whole new world of nature in a previously unexpected place.
A collection of photos from the Education Trail in the JuraPark
A massive thank you to Joanna for such an amazing opportunity, and to Dr. Elena Jagt-Yazykova and the University of Opole for accommodating us and filling our week with the most amazing things!
Some of my fellow travellers have their own palaeontology blog: https://www.darwinsdoor.co.uk/
If you think you might be interesting in discovering the wild side of Poland with Wild Areas: https://www.wildareas.net/
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Qvarnström, M., Wernström, J. V., Piechowski, R., Tałanda, M., Ahlberg, P. E., and Niedzwiedzki, G. (2019). Beetle-bearing coprolites possibly rebeal the diet of a Late Triassic dinosauriform. Royal Society Open Science. 6(3).