The Formation and Preservation of the Solnhofen Fossils

Our new Archaeopteryx exhibition has stunning complete fossils of fish, turtles, crocodiles, shrimp, sharks and much more, all from Solnhofen, Germany. In this blog, Dr. Bakker explains why Solnhofen produced and preserved so many spectacular, intact specimens.

The Mystery of Tropical Germany

From the first diggings in the late 1700’s,  Solnhofen presented a profound puzzle: Why was  Germany tropical in the Jurassic?

The fossil evidence was perplexing:

Fish
Amiopsis Lepidota

Big, long-lived reefs grow only in the tropics – how could northern Europe have supported the Solnhofen reef?

Large crocodiles thrive only in the warmest climate – how could giant sea-crocodiles flourish at Solnhofen?

Huge tree ferns today are emphatically warmth-loving plants – how could tropical ferns grow luxuriously at Solnhofen?

The mystery was world-wide. In the Jurassic, big crocodilians, tree ferns and reefs had spread all over Europe, Asia and North America. The tropical belt must have extended into Alaska and far south into Argentina.

Solnhofen was part of the proof that the Jurassic was one of the warmest periods in the history of life. Since the end of the Jurassic, on average Europe and North America suffered a gradual decrease in winter warmth.

Solnhofen – A Real Jurassic Park

Big-Budget movies have made the Jurassic Period  the most famous sector of geological time in our modern world. But in fact, the Jurassic was already world-renowned by the 1830’s. The first carnivorous dinosaurs known from good skeletons came from the Jurassic of Oxford. The first dinosaur tracks discovered in abundance were from the Jurassic of Massachusetts. The first complete skeletons of giant sea-reptiles were excavated from the Jurassic of southern England.

But no locale has gave finer fossils from the Jurassic than Solnhofen, Germany. Beginning in the mid 1700’s, Solnhofen has provided a never-ending stream of petrified animals and plants.

Fish
Liodesmus Sprattiformis

The exquisite skeletons lie in lithographic limestone, a rock that records not only bones but  impressions of skin and other soft tissue. Vertebrate bodies are preserved in exceptional detail. The pterodactyls at Solnhofen often have fossilized wing membranes. Crustaceans and mollusks are often fossilized as complete bodies. Even the most delicate  parts of squid – tentacles, eyes, and ink sacs – are recorded as high-resolution impressions.

Solnhofen lithographic stone has captured a more complete picture of Jurassic life than any other kind of sediment. Fossils are not common – hundreds of rocks slabs must be split to expose a single animal. Fortunately, the discovery of fossils is encouraged by commercial interests. Beginning in 1798, the lithographic stone has been quarried to make stone plates used to print high-resolution images of paintings, etchings and, later, photographs.

Many scientific publications about Solnhofen fossils have been illustrated by drawings of specimens reproduced via lithographic limestone plates.

Why are Solnhofen fossils so magnificent? The environment  around a tropical reef  was perfect for preservation. Reef-building organisms – sponges, microbes, corals – built up an arc of hard calcium carbonate that shielded a quiet lagoon. All manner of salt-water fish and invertebrates hunted for food in the upper warm waters. Land-living animals came to the beach to search for washed-up carcasses. In the air flew ‘dactyls and, on occasion, a  bird.

When an animal died and sank to the bottom of the lagoon, the water chemistry offered protection from  the forces of decay and dismemberment. The hot tropical climate concentrated the salts in the quietest part of the lagoon, so that most decomposers – organisms that would destroy the carcass – were kept away. Salt-loving microbes spread a thin film over the bottom, and this film functioned like a death-shroud, further protecting the body of dead animals. Perfect fossils were formed when the microbial mat excluded every crab, snail and  bottom-living shark that would otherwise destroy the body.

Extinct Sea Turtle
Eurysternum Wagleri

Solnhofen brings to us a picture of half-way evolution. The rich fish fauna was being modernized by natural selection. Old-fashioned armored fish were going extinct. New styles of jaws and fins were being developed among what would become the dominant fish families in the modern world. Many Solnhofen fish were living-fossils in their own day, representing evolutionary designs that had first appeared two hundred million years earlier. Other Solnhofen fish were the first successful members of clans that dominate today.

Pterodactyls and sea-reptiles too were about half-way in their Darwinian trajectory. Sea-turtles had not yet evolved their specialized flipper. Sea-crocodiles were about to suffer extinction and replacement by the new ocean-going species of the Cretaceous Period. Crustaceans were starting the wave of evolution that would continue as modern crabs and shrimp and lobsters.

There collection displayed here in our exhibit is one of the finest samplings of the entire Solnhofen biota. The Archaeopteryx at the center of the exhibit is the only Archaeopteryx in the New World.

Science Doesn’t Sleep (8.14.08)

Granny Smith
Nutritous and delicious.
Creative Commons License photo credit: Steve Navarro

So here’s what went down after you logged off.

For the 2008 Olympians, what’s nutritious and delicious? Powdered apple peel.

Humans and wild elephants in Indonesia have come into repeated conflict over habitat - resulting in property losses for humans and deaths of wild elephants. So, locals have developed a squadron of trained “flying elephants” that patrol the perimeter villages and warn their brethren away.

Insects that dive underwater create an “underwater lung” – an air bubble they carry with them as they swim – in order to breathe. Scientists have just figured out how it works.

Don’t forget to sleep on it: sleep plays a sophisticated role in what we remember – and what we forget.

Geographic profiling: what works for bees also works for serial killers.

Ready the wonderment: the Moon goes into partial eclipse this Saturday night.

Where have all the sea monsters gone? A variety of factors are transforming Earth’s oceans into “simplistic ecosystems dominated by microbes, toxic algal blooms, jellyfish and disease.”

Paul’s Fourth of July Picnic Piñata

A Smörgåsbord of Alternative Energy Treats à la Carte Sure to Set Off Some Fireworks!

Algae
Creative Commons License photo credit: Sarah Camp

Independence Day is here, and it’s time to fire up the grill with a few tasty bites from the overflowing pantry of alternative energy. For an appetizer, dig into some ocean algae that may one day soon be a superior producer of biofuels, at least according to researchers from Kansas State University. Well, don’t actually eat them, because they are probably not too tasty, and that’s good news, because using algae to make fuel could leave more corn (that would otherwise be used for biofuels) on the market for much-needed food supplies.

Another way to use tiny living things to make energy for us is to let microbes turn hard-to-reach oil into easier-to-extract natural gas. That is the goal of a group of Canadian and British scientists. If their research goes well, injecting microorganisms into wells formerly deemed depleted could renew production. And when will this exciting development get those gasoline prices below $4 a gallon again? Well, let’s see, the original biological process took tens of millions of years, so….

previous ms
Creative Commons License photo credit: atomic0x

What better way to have fun in the sun on Independence Day than with a solar powered car. A group of students from Iowa State University are planning to compete in 2,400-mile race from Texas to Canada in a $400,000 sun-powered vehicle that looks like a souped-up ping-pong table-but hey, that’s a zero emissions ping-pong table that can cruise at over 30 miles per hour. More (solar) power to them!

You may one day declare your independence from less efficient chemical batteries to power your stuff as fuel cells become more efficient. Researchers in Germany are working with carbon nanotubes to make components for fuels cells that are ten times lighter and weight far less than conventional amorphous carbon structures used now. Even more impressive, these tiny-only several atoms thick-tubes boast 1000 times the electrical conductivity of their conventional counterparts.

For something a little more practical for you, the average American celebrating the quintessential summer holiday, you can get your very own fuel-cell-powered car and its solar-powered hydrogen production plant (which makes fresh fuel for the fuel cell)-and the whole package is only $99.99! Well, the model car is only about six inches long, but the science is real-and very cool. You’re sure to be the hit of the picnic.

PICT1015
Creative Commons License photo credit: s2art

As the warm July breezes whisk away your paper plates and blow that BBQ smoke right back in your face, rather than complain about the weather, celebrate the fact that Texas has the fastest-growing wind power industry in the USA. An ultra-clean, and only somewhat noisy, wind turbine-or a whole farm of them-may soon be coming to a desolate hilltop near you. The question is, “What’s the next big thing in Texas energy?” and the answer, my friend, is blowing in the wind. Big time oilman T. Boone Pickens is betting $10 billion on that.

Another hot topic (aren’t they all?) for this hot month is geothermal energy-producing steam with the natural heat from the earth’s interior. I just got back from Iceland, where that clean and renewable source provides 90% of home heating energy-and allows for really long hot showers. Here in the US, we could supply the electrical needs for over 260 million Americans if we tapped in to only 5% of the geothermal potential available in our own underground. There are plenty of challenges to make this work, but you can bet that as hydrocarbon prices soar, those obstacles won’t seem quite so big.

As that sweet smelling smoke from the wieners and burgers on the grill wafts into the upper atmosphere, don’t overlook the contribution that it adds to your carbon footprint, and how that footprint contributes to global warming and climate change. Scientists are realizing just how hard it is for individuals to influence those numbers significantly-even the austere lifestyle of a Buddhist monk produces about 1/3 the carbon emissions of a typical energy-hungry American. So do we just give up? Of course not-we need to think more about alternatives already mentioned here-and walk more. The person who comes up with the carbon-free barbecue that still delivers that smoky flavor might be up for a Nobel Prize, at least in my book.

When you finally get back to the crib, your belly full of beef (or veggie burgers) and your eyes glazed from too many red, white and blue exploding chrysanthemums and Catherine wheels, you can settle back into your chair and read up on more energy topics the old-fashioned way-by the cozy glow of a zero-emissions gravity-powered lamp. Now, that’s a down-to-earth solution!

Happy Fourth of July!