Schwäbisch-Fränkischen Alb: Little teeth and my European Ancestors

Since Germany was underwater for most of the Age of Dinosaurs (The Mesozoic Era), there is plenty of limestone underneath the country (limestone forms exclusively in aquatic settings where there are lots of little organisms generating calcite for their skeletons). When limestone is taken above the water line, it’s quickly dissolved (geologically quickly, I guess) by slightly acidic groundwater. These dissolved cavities are then called caves, as in stalactite bearing, blind fish holding caves. With all that limestone and all those cavities, much of Southern Germany is prime cave country. When caves open up, animals and sediment tend to fill the void. Our expedition moved into the Schwäbisch-Fränkischen Alb, a mountain range composed entirely of Mesozoic limestone to visit some of these cave sites where younger fossils have piled up as caves opened in the rock and local critters fell in, creating a tangled geological history for the region.

These cave fills are often the best source of fossils for terrestrial ecosystems since the caves create sink holes in the middle of the forest and animals who wouldn’t normally get deposited in a lake (rodents, monkeys, lizards etc.) get swept into the cave. One cave-fill contained rocks that were almost entirely composted of bones and teeth that were cemented together by the calcite that had seeped out of the cave walls (the same calcite that grows into beautiful cave forations):

Another cave was a chimney-like shaft where we sifted through sand for Oligocene teeth and bones. It’s always gratifying to collect where you actually find vertebrate bone (assuming you’re a vertebrate paleontologist). That site was especially exciting because it required some careful scrambling through briars and over outcropped rock. A cliff face and rock ledge will always make a geological expedition more fun.

We also examined a cave that hasn’t been filled in yet. It formed underground like a rocky bubble and lay unexposed for millennia until the surrounding rock finally winnowed away leaving a chamber just big enough for a family and the kids. And that’s exactly what it was used for. Cro-Magnon people (early modern humans) rolled into the area and liked the view overlooking the entire basin. It was probably a good spot to watch for mammoths, and even better for watching the sunset.

We ate lunch on the crest of a hill near the Cro-Magnon cave. Boulders protruded from the field of lush grass and wildflowers creating a gorgeous landscape in want of a henge or barrow. I dangled my feet over the edge of a boulder.

To my left was another hill and another outcrop where excavators had found a butchered wooly rhino skeleton from the Paleolithic (50,000 years ago), and a small encampment from the Neolithic (10,000 years ago). Mesozoic rocks, Oligocene fossils, human artifacts…this is Germany. This is why I came here.

We also stopped by a 15 million year old impact crater. When large rocks smack into the earth, the bedrock ripples like the surface of a pond, mixing up the layers and leaving an uplifted central platform; the earth’s frozen rebound to the power of the asteroid. The crater quickly filled with water and became a popular place to stop for a drink when horses were still sporting three toes.

A museum reconstruciton of Steinheim 15 million years ago.

The town of Steinheimer is nestled into the bowel now, sitting on top of a thick sequence of lake sediment. An observant Steinheimer scientist named Hilgendorf started to pay attention to the snail shells that were preserved under his feet. As he burrowed deeper, he noticed the shells were more standardized, more basic. By collecting shells from the beginning of the lake to the end, he demonstrated how one colonizing species gave rise to new species of snails through intermediary steps. He published his work in 1862 and is credited as being the first scientist to demonstrate Mr. Darwin’s crazy new theory of change through time and the emergence of speices. I collected some of those snails out of historical respect more than out of a need to add more mollusks to my luggage.

The classic branching of speciees outlined by Hilgendorf a few years after Mr. Darwin published his bright idea.

The sediment that holds the snails. All those little white dots are tiny freshwater snail shells.

That night we stayed in Sigmaringen, a Baverian town near the source of the Elbe River which eventually runs through Dresden, Prague, and Vienna. We walked to dinner, dodging past the massive slugs and even more massive snails that come out with the rain. (The snails are large enough to double as speed bumps for the absent-minded cyclist.) We crossed a modern bridge that looped over the road, rounded a bend and, as is want to happen in Europe, we were confronted with a castle. The massive Renaissance structure was built by a German lord in the 16th century. Of course, I didn’t have my camera on me so you’ll have to make due with these images borrowed from Sigmaringen’s tourism website.

This image of the castle is just too epic to let sit on only one website.

At a traditional inn next to the castle, we toasted the final night of the expedition with delicious Heles beer and happily stumbled home.

On the distant horizon you can see the Swiss Alps rearing their beautiful heads. I'm standing on a crater rim by the by.

Our final field stop was to another crater lake that was formed in an ancient volcanic crater. The animals were mostly early, mid-sized horses, but a few rhinos, and the odd beardog, the ancient relative of both carnivores, spiced up the fauna a bit. The site was introduced to us by a professor of geology at the university in the region. He struck me as a down-to-Earth (pun intended) hippie who just loves fossils, man. His beard was growing wild, his hair fell lower than his shoulders, and he seemed to prefer going barefoot. His lead excavator was the polar opposite. He was a good ol’ boy with a thick regional accent and a need to carefully explain every detail in a methodical drawl. His galoshes hiked up to his knees, and his upper lip hiked up to a large, well-groomed mustache. The two men have been working together for at least a decade, but I imagine most of their conversations come straight out of “The Odd Couple.”

A toe quiz. I rocked this one. Do you know which critters are on display here? Hint, they have hooves and are distantly related to each other by having odd numbers of toes.

And north we rode. I discussed American and German movies with my increasingly friendly seatmate and actually delicately touched on German between 1930 and 1945 with some frankness. And thus the Fulbright mission goes on.

After returning from the field I diligently worked on my fossils, attended a lecture on Creationism given by an angry Australian Geologist (more on that next week after I give my own talk on the history of American Creationism), and went to visit Marco for Japan Tag (Japan Day), a celebration of Düsseldorf’s Japanese population with heaps of street sushi, noodles, and Kirin Beer. The streets were packed with Germans demonstrating karate and dressed as their favorite Anime character in a mini-skirt. The night was rounded off with the largest fireworks display in Düsseldorf, which was vaguely disappointing after years spent at Riverfest and the Blue Ash Fireworks displays. Germany may have cavemen, but it doesn’t make things explode into brilliant colors quite like we do at home.

I hope you had a fantastic weekend and are mentally prepared for the coming week. I’m just getting back into town after a tour of Switzerland, the Rhineland, the Low Countries, and England with friends from Ohio State. Stay tuned for adventures such as cycling in Amsterdam, climbing in the Alps, and theater gooning in the West End!

Solnhofen: Archaeopteryx and coprolites

Last November I made a pilgrimage to see one of the most important relics in Germany. At the Berlin Natural History Museum I genuflected to get a better look at the Berlin Archaeopteryx. The animal is neither dinosaur nor bird, caught somewhere in-between. I can’t remember a time when I wasn’t aware of this animal and its significance in our understanding of evolutionary processes. Wrapped up with the image of a feathered dinosaur is the world “Solnhofen.” Since I was six I’ve known it was the name of a place in Germany, and was home to all the Archaeopteryx fossils that have ever been chipped out and described.

As the rain started to fleck the university van’s windshield, we parked in a small gravel parking lot. Behind the lot was a small quarry filled with slabs of tan rock and piles of limestone. This was the fine-grained, lithographic, Solnhofen limestone. The rock was used for decades as the source of lithographic stone. It’s grain is so fine that it perfectly took ink from minutely detailed images and faithfully trasfered them to paper. As I’ve said before, printing is in my blood, but fossils are close to my heart. It was time to find an early bird (or more importantly a mammal. No fuzzy critters have ever been found in the Solnhofen quarries, despite several fossils of small, terrestrial dinosaurs).

The finely bedded rock breaks along irregular bedding plane after a few hammer strikes. Ideally a chisel is used to pry the planes apart, but I only had my hammer and a cheap aluminum knife I swiped from the youth hostel (I’m an Outlaw in Wiesbaden as a result). But that was enough to discover a few ancient creatures.

Solnhofen isn’t packed with fossils, but I was able to collect more ammonite fossils (spiraled squid shells), a belemite, and I helped excavate a fish vertebral column:

It had been drizzling the whole time we were in the quarry, and the heavens finally opened wide and we all retreated to a shelter that was held up by towers of piled limestone. After eating our soggy lunch, we piled into the bus to see some of the treasures of the quarry in the Jura Museum in Eichstätt.

Paleontology requires an active imagination. The material paleontologists study is the empty hull of a once active organism. It’s hard to stay interested in a lifeless fossil. If the paleontologist’s imagination can conjure the animal from the few clues left behind, it becomes instantly more interesting. Then the paleontologist must use a few key clues to imagine the habitat that lead to this creature. I’m not suggesting paleontologists imagine or fabricate their research. Just that in order to pursue interesting questions, paleontologists have to maintain a picture of a long-vanished world, testing that picture empirically, ultimately revealing the story of life’s struggle to survive. It’s hard to conjure much of anything in the imaginaiton when you’re squatting in a wet quarry looking at squid shells. This is the beauty of a museum.

The Jura Mueusm is actually housed in a castle that was besieged by the Swedes during the Thirty Years War. Someday I'll lay siege to Union Terminal to give it that kind of historical distinction.

This is the fossil of a small fish who sunk to the bottom of the lagoon. His head was lodged in the sediment, but his tail was free to flop around, creating the gashes in the sediment you see surrounding the body. These are the stories that come from the Solnhofen.

The museum holds all the evidence of the extinct ecosystem with rare and unusual speciments that add a new level of complexity to the world of the Late Jurassic. The fossils of dragonflies, perfectly preserved with their multi-faceted eyes and delicate wings were on display:

Small lizards and early sea turtles demonstrate the coast wasn’t far away, a fact also revealed by the Stars of the Solnhofen: The Fliers.

Small pterosaurs recovered from the limestone were prize collectors items in the 19th century. The first Archaeopteryx was thought to be a pterosaur by the quarryman who smuggled it our of the pits and sold it to a local collector who recognized its real significance. The flying reptiles are often preserved with impressions of their leathery wings rippling the stone around the delicate finger bones that supported the wing. Most of the reptiles are small - about the size of a pigeon or seagull - showing they probably didn’t venture very far out to sea, and the coast offered a nearby roost.

The Jura Museum also houses its own Archaeopteryx fossil. This bird is smaller than the pterosaurs and its friend in Berlin. The animal is maybe the size of a robin, but is preserved in all it’s missing-link glory with a toothy bill and delicate feather impressions. I stopped and studied the fossil for several minutes, trying to remember every physical detail of this beautiful little bird.

Eventually I had to wrench myself away to hop back on the bus, but first I tried to take myself back 140 million years to a shallow lagoon rimmed with massive reefs that was a little too salty for most life to function happily. On the surface the waves crashed against the German coast, but below, the quiet, calcitic sediments were an undisturbed tomb for all animals washed into the protected lagoon. Tracks in the sediment reveal the activities of busy horseshoe crabs who took a wrong turn on the way out of the hypersalinated water. Their lazy path terminates with their carapace, preserved for posterity at the end of the trail. Coral and sponges formed the barrier reefs, while jellyfish and squids (some preserved with their ink-sacs intact) drifted through the water, evading marlin-like, ray-finned fish. Overhead pterosaurs rise on the coastal thermals and dive after dragonflies the size of my hand. A small dinosaur, Juravenator, darts through the tropical foliage after a small shrew-like animal who’s too quick to ever become a fossil…who needs a time machine when you have fossils like this?

A view from the battlements of the Jura Museum. Yeah, battlements. Now the castle and museum are owned by the Catholic Church. That's cool right?

Tschuss!

Holzmaden: Marine Reptiles and lots of squids

When I was in first and second grade, my favorite video series from the library was called “Dinosaurs!” The series was narrated by Walter Cronkite and took you through the history of paleontology from the naming of the “terrible lizards” through the 20th century where I was introduced to many of my paleontological heroes. The historic sections used Ken Burns-style pans over old paintings and photographs spliced with historical reenactments.

A display in the Holzmaden Museum that showed the fossils found at each successive layer. They forgot to include a mannequin of a shocked German miner.

Once scene showed a German miner diligently chipping away at a slab of slate. His lantern light catches a strangely colored rock embedded in the slate. He takes his chisel to the rock and reveals the body of a dolphin-like reptile. It caused a sensation. This was an antediluvian sea-monster! I remembered that excavation and fossil, but didn’t remember where exactly that scene took place. I walked into the Holzmaden Museum, and there it was: The dolphin-lizard. I had a weird feeling of déjà vu.

A massive Ichthyosaurus trying his derndest to be a whale.

160 million years ago, South-western Germany was part of a huge inland sea, something like the seas of the Caribbean or Southeast Asia. The tranquil water was filled with squid, both the modern fleshy kind that get turned into calamari and shelled squids called ammonites that formed the base of the Mesozoic Marine ecosystem. All this tentacled protein brought in the sea monsters. Ichthyosaurs were fully committed marine reptiles. That look almost exactly like modern dolphins and are a classic example of convergent evolution. They mastered the art of live-birth (as revealed by fossils that preserve juveniles stuck in the birth cannal!) and were able to transform their limbs into fins and tails into flukes. Their enormous eyes indicate animals that relied on keen eyesight to track down their prey.

The glare is terrible, but if it wasn't you would be able to see a neophyte marine reptile a little south of her stomach.

Also splashing around Germany were the plesiosaurs, long-necked, four-flippered animals that are usually brought into discussions of the Loch Ness Monster. Presumably these ungainly animals had to haul themselves onto the beach to lay their eggs, making it impossible for them to become as perfectly adapted to the marine environment as the Ichthyosaurs. No one is really knows how they used that long neck to snap up food, but it must have worked out for them since they thrived throughout the Mesozoic.

A plesiosaurs missing his squishy parts. There's no scale, but this guy is about the size of a dolphin.

A plesiosaurs put back together going after a small squid. No one is quite sure how lashing your neck around like that affects your hydrodynamic abilities.

He smiled for the camera.

The seas also supported marine crocodiles with diminutive forelimbs and powerful, finned hind limbs. Sharks were on the scene, but they didn’t achieve their mega-carnivore status until the reptiles left some open niches 65 million years ago. In the Jurassic they looked more fish-like with stubby noses and wide, multi-finned bodies. One of the fossils in the museum’s collection shows a primitive shark with dozens of squid shells piled up in his stomach. Modern squids their shells inside their bodies. This is a dense piece of calcite that resembles a 22-caliber bullet. The shells that killed the shark are piled up in his gut, a fossil telling the story of some pretty awful indigestion.

Sharks have carilage skeletons, so they usually don't fossilize very well. You're looking at it's stomach (ventral view). The mouth of this guy is to the right, the gill slits V towards the top and bottom and the shells that killed him are piled up in his stomach to the left.

The most spectacular fossil in the museum is a log roughly 30 yards long. Anchored to the Jurassic driftwood are over one hundred crinoids (Sea lilies). Crinoids are like starfish on sticks. They anchor themselves to the substrate and collect food as it passes through their fans. These crinoids decided to go for a ride, latching onto every available spot on the log that eventually ran aground burying everyone on board (It’s unclear if the captain went down with the ship). The fossil takes up an entire wall and took 15 years to prepare (always remember every pretty fossil you see took hours of delicate work from a preparation specialist who carefully removed the obfuscating rock).

A mess of crinoids. A crinoid salad if you will. All log of boyant freedom run aground.

When we went to the shale quarry we were once again set loose on an uninspiring landscape where spoil piles of chipped shale were heaped on the edge of the industrial pit. As I walked towards the chipping group I saw the yellow gleam of a shell. I had found an ammonite squid and I hadn’t even swung my hammer! After an hour of chipping I discovered the shells were ubiquitous and you would need good luck not to find one. I also found bullet like squid shells, but no vertebrate pieces. The shells sit in my room, waiting to be added to the collection in my parent’s garage.

We had taken this excursion during a school holiday and the pit was filled with children and their parents smacking away at the rocks. The sight of four year olds wielding hammers might have been cute if I didn’t fear for my digits every time they drifted near my small excavation area.

A six-year old doing some serious fossil hunting. My money says he finds a squid.

With new insight into the Jurassic high seas where sea monsters apparently risked constant headaches thanks to millions of drifting, shelled mollusks, it was back to the road. Soon we would be examining a very different Jurassic ecosystem…

The business end of a Mesozoic squid roughly the size of a semi-truck tire.