Among fossils: How very old things remind us of our youth

The earth is 4.54 billion years old. That’s a big number to wrap your head around. Spending time among very old things helps, but even then it’s easy to forget that not only the fossils themselves are ancient; so is the rock they came out of, the planet circling a sun that has been around a long time.

Since my childhood, dinosaurs have arrested my imagination like nothing else in science, and what better place to witness the majesty of these ancient animals than the Houston Museum of Natural Science, displaying some of the oldest things on Earth? When I walk through the Morian Hall of Paleontology, I see the bones of creatures that lived millions of years ago, preserved naturally by the processes of geology, like mummies, but embalmed by mud, pressure, and minerals. These aren’t bones, really. They’re rocks, no different from petrified wood or the crystals in the Cullen Hall of Gems and Minerals. They were once creatures of flesh and bone, but the organic molecules and chemicals that made up their bodies, if they didn’t decay, were replaced atom by atom while the rest of life on Earth developed.

Triceratops

Lane, the most complete fossil specimen of Triceratops in the world. 65 million years old.

Mine is a problem of scope, I think. It’s a strange feeling to understand that Lane the Triceratops, the most complete specimen of this dinosaur, was under our feet during the fall of the Roman Empire, was still buried in the time of King Tutanhkamen, and remained undiscovered while Shakespeare wrote his sonnets. This animal died, and life went on as it always does. Its life among presumably millions of others like it was common. Undistinguished. But that specimen is no longer a Triceratops; it’s a skeleton made of rock. Not even a skeleton, but an impression of it. A three-dimensional photograph dug out of the album that is the many-layered dirt of our planet. This animal has become a symbol of history. Now that is rare.

Icthyosaur

Icthyosaurus mother. At least 146 million years old.

It’s remarkable, this action of preservation that the Earth is capable of. And it’s remarkable that we have developed the science to identify and understand these stones. We had to consider both the life cycle of rock and the taxonomy of life before we could begin to speculate what these samples could mean. But really, so what? They’re just rocks.

It’s the feeling of humility they deliver that makes them fascinating. It’s like walking through modern Rome after living in developing Houston, surrounded by buildings a thousand years old that stood before the United States was even imagined. We’ve been walking around these seven continents for millenia, in the dark about what was under our feet until the birth of paleontology in 1666, when Nicholas Steno identified “tongue stones,” known then only as triangular rocks, as fossilized shark teeth. Dinosaurs were around whether we knew they existed or not. They are as old as the rock we walk on.

Icthyosaur Baby

Impressions of Icthyosaurus pups in the rib cage of this rare specimen suggest this animal died in childbirth.

Now consider this. In 2011, biologists identified 20,000 new species, a large number of them beetles, and most of them invertabrates. That was in a single year. Now take that diversity and multiply it by the age of the Earth. I’m not going to do the math, but that’s the number of species paleontologists have yet to discover. That’s the amount of life we potentially have yet to search for in the rock.

After early hominids, fossils of the first humans date back 1.8 million years, along with mammoths, mastodons, and saber-toothed cats that appear in the rock alongside them. Triceratops lived in the late Cretaceous, discovered in rock at least 65 million years old. Icthyosaurus swam the oceans and gave birth to her young between 245 and 146 million years ago, in the Jurassic and the Triassic. (Their era lasted 100 million years. Again, we’ve been around for 1.8.) Trilobites in our collection have been preserved for between 540 and 360 million years, and the stromatolites, layered rocks formed by ancient bacteria, date back to 3.4 billion years. Not million. Billion. They appeared in the Archaeozoic Eon, about a billion years after Earth solidified out of molten space-rock.

Trilobite

One of the best preserved and most intricate trilobites in the world. At least 360 million years old.

What will the occupants of this planet find after the next million years? We’ve been around for a while, but not nearly as long as these fossils. What will paleontologists of the future, if they still exist, find in another 65 million years? 146? 540? 3.4 billion? The Earth will still be here by then; humanity is another story. Will we still cling to the crags in a different form, the maps unrecognizeable to the once-dominant species of 2015 CE, if they could see them? Will we have preserved our history as well as the rocks have preserved the dinosaurs?

Stromatolites

Stromatolite formed by layers of ancient bacteria preserved in rock. At least 3.4 billion years old.

In another 3.4 billion years, the sun will be nearing the end of its life, having expanded into a red giant and swallowed Mercury and Venus. According to many estimations, by the time the sun is 7.59 billion years old, it will engulf the Earth. We are living in our planet’s middle age. It took half the Earth’s life for humanity to arise and build its cities. For the United States to claim its sovereignty.

Lucy

Lucy, Australopithecus afarensis, the most complete skeleton of this hominid in the world. 3.18 million years old.

The Earth is old, dude! We never pay this age any mind until we identify something to date it against. Here we have Triceratops, say, a creature that lived in the time when this rock was young, just a pile of sediment on the floor of the ocean or a river. Paleontologists owe a lot to the power of speculation and theory. We may never know for sure what life was like in the era of these ancient creatures. But if we have anything in common with the dinosaurs, ancient mollusks and archaebacteria, it’s that we all grew on this same rock.

In a way, we’re just as old as they are. Our bodies are made up of the same elements that have always been here in some form or another, buried under the crust in a molten mantle, or exposed to the light of the sun that has fueled life on Earth for as far back as the imagination will stretch. As Carl Sagan said, “We are all made of star stuff.”

Note: heat from active volcano may damage running shoes.

at the base of the volcanoRecently I went on a trip to Antigua, Guatemala and had the opportunity to go to the top of an active volcano just a short distance away from the city called Pacaya. One of the main reasons we chose to visit Antigua was the proximity to active volcanoes because ever since I saw the Ring of Fire IMAX when I was a child I have been fascinated by volcanoes and lava.

So we reserved our spot to go to the volcano and they gave us a slip of paper that told us to pack snacks, water, a flashlight (we signed up for the afternoon/night hike) and wear running shoes or hiking boots. The tour group picked us up at our hotel and we were off for our one and a half hour ride in a van packed with people on winding roads – for a girl like me who gets a little car sick, keeping the window cracked was important on this drive.

When we arrived at the base of the volcano, we were immediately met by the children who live in the village at the base of the volcano, with hands full of walking sticks and “ponchos” telling us to buy these things from them.  The “ponchos” mostly turned out to be garbage bags but it was rainy and the thought of a long hike in the rain for those in our group who did not bring rain gear probably made garbage bags look like a reasonable idea! The children demonstrated how sturdy and good their walking sticks were and said “stick for you?” One man (pictured) did not want a stick but this little boy followed him for about the first 10 minutes of the hike. You might also note that this man was not wearing appropriate footwear – socks and sandals seem like a very bad choice on a rainy day up a volcano – but maybe that’s just me.

Our guide told us that the trip to the top of the volcano was going to be at most 1 hour and 45 minutes. The rain decided to stop a few minutes into our trip so we were able to pack up our rain gear and continue on our journey. The first hour or so of the hike was on steep, narrow dirt paths in the forest; as you can imagine it was pretty muddy after the afternoon rain. It was at this point that I knew it was going to be my fate to have very muddy pants before our ride home. With no lighting along the path the journey back down the volcano was sure to be a slippery adventure.

With about 30 minutes left in our trip up to the top we walked out of the forest and the landscape changed completely – suddenly there were no more trees or life of any kind – only black lava rocks as far as the eye could see. The path we took across was mostly made of tiny tiny rocks, which is very much like trying to climb uphill in a sandpit or on a treadmill – you use a lot of energy without making much progress. The altitude change made it harder to breathe and I kept having to take little breaks, but with a glowing river of lava in sight it was definitely no time to quit.

When we reached the top, the heat radiating from the lava beneath the thin crust of cooled lava felt a lot like the beginning of a sunburn on my skin. We used our trusty sticks to tap the surface in front of each step to be sure the crust would not crack beneath our weigh – sometimes the tap would cause a whole patch of crust to fall in – yikes! Certain cracks exposed glowing lava flowing beneath – it was incredible! I’m including some photos below but I realize now it’s pretty difficult to get the sense of the lava flowing from any of the photos – but believe me – it was an awesome experience and I would recommend it to anyone who has the opportunity to see an active volcano up close. It was completely worth the wacky van ride and trying uphill journey!

A WORD OF ADVICE FOR ANYONE INTERESTED IN TAKING THIS TYPE OF JOURNEY – When we made it back to the bottom of the very muddy mountain in the dark of night (and yes, I did manage to slide down a bit of the trail on my rear end) I realized that my running shoes were a slightly different shape! The heat of the surface near the flowing lava heated the puffy layer of rubber in the soles of my shoes and as I tromped down the mountain the softened layer shifted and my shoes were newly lopsided. Perhaps hiking boots would have been a better choice. Oh well, I guess you learn something every day! Also, note that the stick you may “purchase” at the bottom of the volcano will likely be more of a “rental” when you return to the bottom and the same children who 3 hours earlier had sold you the stick will be welcoming you back to the village by saying “stick for me?” It probably wouldn’t fit in your luggage anyway.


there are a lot of rules when visiting Pacaya.

There are a lot of rules to know about when visiting Pacaya!

A diorama of the volcano and our path up to the top.  

I was laughing while sliding backwards down the slope trying to pose for this one!

look! that's real lava glowing under there!!

Look! That’s real lava glowing in there! It was very interesting to see the folds of the surface of the cooled lava flows.

one place I decided it would not be safe to step...

One spot I tapped with my walking stick and decided not to step.

This guy in our group was close enough to the river of lava to set his walking stick on fire – it was incredible!

Our guide brought a bag of marshmallows to the top and handed them out so that people could roast them over the lava.