Messel: Tiny Horses and World Heritage

47 million years ago, the world was pretty toasty. The planet was blanketed in lush jungles and forests as far north as Greenland. Think about that for a second. Jungles in the Arctic, complete with tapirs and crocodiles. Germany was just as balmy. It was also tectonically unstable. One awful day, a magma chamber that had been simmering under Paleozoic bedrock had finally pressurized subterranean water beyond it’s comfort level, sending an explosive cloud of rock and steam over the European jungle. A vast crater was left in the middle of the forest. This crater started to behave itself and water flooded the site, leaving a large standing lake, a rarity in many Jungle ecosystems. Animals flocked and herded to the site and everyone proceeded to get nice Eocene suntans.

One of the earliest bats ever found. What's especially crazy is there were multiple species with different wing spans and ecological niches. Well I think that's crazy anyway...

The first couple meters of water were fresh and a happy home for fish and crocodiles, but near the bottom of the lake the water was stagnant. Organic material was swept in and settled in the noxious environment that few organisms could penetrate. The combination of limited biological turbation and slow sedimentation formed perfectly smooth oil shales as the organic material imbued the rock with precious carbon energy that engineers would later unearth to fuel VW Bugs. Every now and then the same tectonic forces that caused the crater to form would shake the contents of the lake, releasing the noxious fumes trapped in the sediment. Birds flying over the lake and terrier-sized horses at the water’s edge would suffocate and contribute to the next round of organic chemistry experiments.

A little early horse (Propalaeotherium) giving his little hooves a work out. This reconstruction is the size of my dog, a terrier mutt.

The Messel Pit was discovered in the 1870s, but wasn’t mined in earnest until the mid 20th century when the Germans figured out how to use the oil shale. People had been finding incredible fossils in the pit for decades, but formal scientific excavations of the site didn’t begin until the ‘70s. After most of the valuable oil shales were exhausted, city planners moved to turn the pit into a landfill. German paleontologists stepped in and had the place declared a UNESCO World Heritage Site in 1995, formally protecting the remaining rocks for future studies and opening the pit to the public.

Dr. Martin explains the mysteries of Messel (all scientific errors in this post are my faulty German's fault, not his explaination's).

There are a lot of World Heritage Sites that may not be literally vital to a Global Heritage. Arguably Angkor Wat, or the Roman Limes reflect someone’s heritage, but not everyone’s. But Messel concerns everyone. It is a time capsule of the world in transition. The stories its rocks tell are the basis for the modern ecosystem.

The unassuming entry to the Messel Pit.

Ancient, strange organisms, holdovers from the time of the dinosaurs like bony-scaled fish and primitive, hopping relatives of hedgehogs and shrews mingled with the first horses, rhinos, bats, and primates (the lemur-like Darwinia massellae recently caused a publicity stir). There is also a weird mixture of continents in the rocks of Messel. Animals from South America like the pangolin were crawling around in Europe and Asian birds snuck in without explaining how they got to Germany.

A pangolin, relative of armadillos and sloths, who really doesn't belong in Messel, but wound up in Germany anyway. What can I say, he's a free spirit.

An early primate that would have behaved a lot like a lemur. In other words, it would have been a lot of fun to watch.

Basically everything was swept into the lake, and paleontologists have been able to piece together entire food webs based on preserved stomach contents and geochemical sampling of the bones and soft tissue preserved in the rocks. Bat wings are darkly outlined and fuzzy tails are preserved forever. Or, were preserved until we started digging them up. The shale is 50% water and as soon as you start to chip away at it, it starts to dry and curl like the pages of a drying book. This desiccation causes the delicate fossils to fracture or disintegrate, so all unprepared rocks need to be preserved in oil or water. To study the fossils, a layer of resin is poured over the fossil and all the shale is chipped away. Then resin is poured over the newly exposed side. Now all the bones are cemented together and can be studied without getting your hands wet. The resin imbues every display with an amber-like glow.

A small fish fossil that soaks in oil and comes out to show visitors what your most likely to find in Messel.

An early relative of deer, cows, and antelope. Only it's roughly the size of a chinchilla.

At the site we had a UNESCO guide along with us to explain the significance of the pit which, honestly, doesn’t look like much. It’s a big hole with shrubs and weeds struggling to make a living. She showed us to a secluded spot, away from the eyes of school groups, and let us get out our rock hammers. The hammers weren’t completely necessary. A spackling knife is the favorite tool of the Messel excavator. You lop off a few layers of material then lift off the layers with the knife. The layers tend to split where anomalies – read fossils – are located. I managed to find a few leaves and little spirals of sediment that I was told were fish droppings. My luck continues to hold.

The uninspiring view over the excavation site.

Oil Shale slowly drying in the baking sun. The slant to the beds is due to the bowl-like shape of the crater the rocks were deposited in.

After visiting the displays in Frankfurt and the fossil site in Messel I could check a destination off my list of things I have to see before I die. I wouldn’t mind coming back to look a little harder for bones, or to study the exquisite animals that have already been collected, but I “Split the Shale” and can rest easily.

A fountain in the middle of the pit that was drilled when a geological research team cored under the pit to put together the explosive history of the locality.

That night we stayed in Tübingen, one of the oldest college towns on the planet. Dr. Martin did his graduate work there and gave a tour of the ancient castle that looms over the Necker River and explained the fencing culture of old German fraternities (you would spar with rival fraternities, packing your sliced cheeks with butter to make the scar more noticeable). After a few drinks along the peaceful river and some rousing discussion about Mesozoic rocks in Siberia, it was time to go home. The next day we would be spending some time below the waves…

A beautiful view of the Necker River from our hostel in Tübingen.