Excavation with the University of Warsaw, Poland

[Italo40]

Dear members,

It’s time for another “review” of a palaeontological site I had the pleasure to excavate in. However this one is quite different from the others I already posted about: those were outcrops in Ohio, USA, where you could collect fossils freely or by signing a disclaimer. This time, instead, I had to operate alongside the institution that holds the concession to excavate and study the material. For fifteen days in August 2019 I excavated in the Late Triassic beds of Krasiejów, southwestern Poland, alongside the Institute of Paleobiology of the Polish Academy of Sciences, based in Warsaw. It is not the only “official” dig that I took part in, but, alas, the only I’m allowed to post pictures of!

Krasiejów’s site has been exploited for the extraction of clay since the beginning of the XX century until 2002; the first scientific excavations took place in 1993 and the first publication was issued in 2000. Since then dozens of students and palaeontologists from all over the world have visited the site.

The assemblage dates to the Late Triassic, but a more precise dating (Carnian or Ladinian) has not been assessed yet. Back then Poland was situated much southern on the Northern hemisphere, under subtropical conditions. Rivers formed extensive backwaters and swamps, separating islands from the dry mainland. Occasionally, intensive rainfall led to flooding that washed out skeletal remains and transported them to their final site of burial. Bones were then scattered and damaged, but rapid deposition led to their preservation. Krasiejów can therefore be classified as a Konzentrat-Lagerstätte. A section of the Bonebed is open to the public and it’s a truly mind-blowing sight! Dozens of skulls, mandibles and isolated bones of amphibians (later I’ll tell you exactly of which species) can be seen lying there since 220 million years ago. I pictured a small section of the bonebed, circling in yellow the skulls and in red the mandibles.

The lithotypes that make up the outcrop are red claystone and grey pelites. Tools needed for excavating are geological hammers, pickaxes and shovels. That's what an usual day on the site looked like:

The flora and invertebrate assemblage is not very rich: conifer cone scales and branches, freshwater bivalves and small arthropds. Fish were scarce and poorly preserved. In the case of lungfish, instead, toothplates were common: 

The most interesting aspect is represented by tetrapod bones: they are countless, even in my wildest dreams I could not have hoped of finding so many as I have!

Metoposaurus was a temnospondyl amphibian characterized by a dorsoventrally flattened body up to 2 m (6,5 ft) long. Its bones are the most common remains in Krasiejów. It probably lived at the bottom of shallow-water reservoirs, as ambush predator hunting for fish and other small vertebrates. For air it had to resurface regularly, but it may not have been able to enter land. The bones on the bonebed belonged to it. Here you can see a close up of a mandible ramus from two perspectives, two ribs, a vertebra and interclavicle. 

Ciclotosaur, another temnospondyl amphibian, hunted on both water and land. It’s not easy to differentiate its bones from those of Metoposaurus on the field.

Paleorhinus was a phytosaur, a 3,5 m (11,5 ft) long semi-acquatic predator superficially resembling a gavial. I have found a couple of teeth that belonged to it.

Stagonolepis was a herbivorous, 3,5m long archosaur with a heavily armoured body. Its skull was small and equipped with conical teeth and a horny beak on the mandible and a fleshy snout on the upper jaw. It may have used them to dig food out of the ground. Osteoderms and teeth (not pictured) were rather common. We also found a femur of Stagonolepis:

 

And a bone of the hind limb, that in order to be extracted and protected was covered with a field jacket of gypsum:

Finally, a rauisuchian and dinosaur species make up the assemblage, but we didn’t find any of their bones since they are extremely rare.

If you'd like to know more about Krasiejów, I suggest you to read these two papers:

- Gruntmejer, K., Konietzko-Meier, D., & Bodzioch, A. (2015). The Triassic world of Krasiejów. FIELD GUIDE, 17.

- Dzik, J. and Sulej, T. 2007. A review of the early Late Triassic Krasiejów biota from Silesia, Poland. Palaeontologia Polonica 64, 3–27.

 

 

Well, that’s it! This excavation was an incredible experience for me, I met some great people and found amazing fossils!

I hope you enjoyed and leave a comment if you have any question for me!!

Fabio

 

[RuMert]

Very nice report, pics and finds

[digit]

Wonderful trip report!

 

There are a few volunteer opportunities to dig fossil rich sites with the Florida Museum of Natural History (FLMNH) that my wife and I enjoy participating in when the digs are active. You don't get to keep any of the specimens but you do get to take all the photos you want. It's an incredible experience to learn and develop field skills digging on sites that are loaded with fossil material. It's fun to shift gears from amateur fossil hunter to playing professional paleontologist for a short while.

 

The sites we volunteer at have fossil material that is very distinct from the surrounding matrix making it easy to see when you happen upon a specimen while digging with flat-blade screwdrivers and dental picks (for detail work near a specimen). From your photos above it seems the specimens and the matrix are virtually the same color and other than some subtle textural differences, the fossil specimens seem more difficult to distinguish from the surrounding clay matrix. Looks more challenging to work through without damaging specimens. A Triassic tetropod Lagerstätte would certainly be an interesting place to be able to volunteer.

 

 

Cheers.

 

-Ken

[Italo40]

12 minutes ago, digit said:

Wonderful trip report!

 

There are a few volunteer opportunities to dig fossil rich sites with the Florida Museum of Natural History (FLMNH) that my wife and I enjoy participating in when the digs are active. You don't get to keep any of the specimens but you do get to take all the photos you want. It's an incredible experience to learn and develop field skills digging on sites that are loaded with fossil material. It's fun to shift gears from amateur fossil hunter to playing professional paleontologist for a short while.

 

The sites we volunteer at have fossil material that is very distinct from the surrounding matrix making it easy to see when you happen upon a specimen while digging with flat-blade screwdrivers and dental picks (for detail work near a specimen). From your photos above it seems the specimens and the matrix are virtually the same color and other than some subtle textural differences, the fossil specimens seem more difficult to distinguish from the surrounding clay matrix. Looks more challenging to work through without damaging specimens. A Triassic tetropod Lagerstätte would certainly be an interesting place to be able to volunteer.

 

 

Cheers.

 

-Ken

Thank you for the appreciation! 

I read about the Florida excavation and it is definetely in my bucket list! I hope sooner or later to be able to join it.

Indeed in many circumstances it was not easy to spot the fossils, especially teeth due to their small size and lungfish toothplates that had exactly the same colour of the matrix. Ribs were much more abundant and easy to find, but it was hopeless to recover them intact. I can't remember how many flasks of glue we employed! Vertebrae were preserved in concretions and at the beginning I didn't know it so I threw them away! I had to go through a large amount of excavated rock to find them back.

Hope I explained everything clearly,

fabio

 

[digit]

You explained perfectly!

 

Some fossil hunters hunt because they enjoy building a collection (which is perfectly fine).   Working at a site where all you can keep is photos tends not to be of great interest to those who enjoy the hobby because their passion is in constructing their private collection. I enjoy the experience of fossil hunting more than the fossils themselves and so the opportunity to work with scientists to volunteer on scientifically important sites is a no-brainer for me.

 

If a trip to Florida ever materializes for you, please let us know about it here. Our "fossil season" in Florida tends to be the dry (non-hurricane) season when rains are less frequent and groundwater levels (and waterways) are down. The volunteer digs tend to be during these times as well--generally between about November and May. If you make it to our corner of the States during that time and the conditions are right, we might be able to host you for a fossil hunt or direct you to where you'd need to sign-up for one of the volunteer digs if any are active at the time.

 

 

Cheers.

 

-Ken

[Italo40]

18 minutes ago, digit said:

You explained perfectly!

 

Some fossil hunters hunt because they enjoy building a collection (which is perfectly fine).   Working at a site where all you can keep is photos tends not to be of great interest to those who enjoy the hobby because their passion is in constructing their private collection. I enjoy the experience of fossil hunting more than the fossils themselves and so the opportunity to work with scientists to volunteer on scientifically important sites is a no-brainer for me.

 

If a trip to Florida ever materializes for you, please let us know about it here. Our "fossil season" in Florida tends to be the dry (non-hurricane) season when rains are less frequent and groundwater levels (and waterways) are down. The volunteer digs tend to be during these times as well--generally between about November and May. If you make it to our corner of the States during that time and the conditions are right, we might be able to host you for a fossil hunt or direct you to where you'd need to sign-up for one of the volunteer digs if any are active at the time.

 

 

Cheers.

 

-Ken

I totally agree with you! Sharing your experiences with other and knowing that you are helping the progress of science is the ultimate goal for me.

As for Florida, I am very grateful with you. 100% when I'll get to travel there I'll be in touch with you. Same if you want to organize a trip to Italy

Cheers

[Ludwigia]

Thanks for this report. I don't know all that much about this period and learned quite a bit through your post.

[Tidgy's Dad]

What a wonderful experience! 

Thank you very much for sharing it with us. 

[Jeffrey P]

Thanks for sharing your story about this fossil site which I, and I'm sure other TFF members are unfamiliar. It must have been such a privilege to have access to such a unique and wonderful site. Congratulations.

[FossilNerd]

Great report as always Fabio! What a wonderful opportunity for you to be able to experience this. Thanks for sharing with us and for the very informative post. 

[Monica]

A wonderful post about helping to find amazing fossils!  Thanks for sharing, Fabio!