Welcome back to Nature League!
This month, we’re exploring the theme of extinction, and during our Lesson Plan we
covered the idea of mass extinctions and mentioned some examples.
When you mention mass extinction, most people think of the time when dinosaurs vanished
from Earth. This seems to be the mass extinction event we can all easily think of, most likely
because dinosaurs are super awesome and the whole story is totally epic.
It’s one thing to talk about a mass extinction...but another thing entirely to see where one took place.
For this month’s Field Trip, I’d like to share some footage from a special trip
I took last summer to the K-Pg boundary- the layer of Earth from the time of the dinosaurs’
mass extinction.
This past summer I got to help out with a paleontology course being taught in Makoshika
State Park with two good buddies, Dan and Chris. Makoshika is in the badlands of eastern
Montana- it’s where one of the opening scenes of Jurassic Park the movie is supposed to
have taken place, but I’m pretty sure they shot it somewhere near California. Anyways.
For starters, the badlands are completely stunning, and that’s even before you start
taking the dinosaurs into consideration. The exposed rocks show millions of years of geological
time, and during the sunset on our first night at basecamp, Dan and Chris explained the geological
formations visible from basecamp. I, meanwhile, got footage of this incredible landscape.
The summer nights in eastern Montana can be filled with thunderstorms that stretch as
far as the eye can see. We happened to catch a really great lightning storm one night,
and while I probably should have stayed indoors, I couldn’t help but grab some footage of
the skies. I wonder what the skies looked like for the dinosaurs that used to live here
and if they enjoyed these skies as much as I do...
We saved a surprise for the students until later in the week. We told them we were hiking
down to a location where we’d investigate rock layers. What they didn’t know is that
we were taking them to one of the few places on Earth where you can see and touch the layers
that form the K-Pg boundary. Chris was excited to show the students the layers but was not
impressed by my cinematography pursuits…
As we got to the end of the trail, we had the students examine the layers of rock and
take notes of anything that stood out. I, meanwhile, went into turbo mode and climbed
all over the rocks. When in Makoshika…
So a little bit more ab out this location. The K-Pg boundary is a geological signature
making the end of the Cretaceous Period and the beginning of the Paleogene Period. It
used to be called the K-T boundary, an abbreviation for Cretaceous-Tertiary boundary, but geologists
have since messed with the naming to reflect different divisions of geological time.
The end of the Cretaceous Period is of note because it includes and is sometimes defined
by the mass extinction that occurred approximately 66 million years ago. While geologists are
pretty certain about the transition from the Cretaceous to the Paleogene, it’s a different
thing entirely to see it in person.
Makoshika State Park in eastern Montana is one of only a few places in North America
where the K-Pg boundary is exposed and actually accessible. While there are many places around
the world where the boundary is apparent, this spot is up there in terms of total experience
and ease of access.
We revealed to the students that the layers we were looking at contained the K-Pg boundary-
surprise! After investigating the differences in sediment, color, texture, etc., we sat
down to discuss the extinction event in general.
[DAN:] The time that separates T-Rex from stegosaurus is even greater. So stegosaurus
was already a fossil when T-Rex was alive. Basically, all of the periods of time in the
Mesozoic - the Triassic, Jurassic, and Cretaceous - end with an extinction event.
Scientific consensus has changed over time, but at present the most likely mechanism for
this mass extinction event was an asteroid colliding with the Earth near the current
day Yucatan Peninsula. This collision disrupted climate and ecosystems globally and led to
the extinction of almost 3/4 of life on Earth at the time, including our favorite non-avian dinosaurs.
And yet, in the millions of years that followed, new life forms appeared on Earth, and groups
like mammals, birds, fish, and some reptiles radiated and diversified, leading to the incredible
biodiversity we see at present.
And now a word, not from our sponsors but from the dictionary...
Welcome to this month’s Wild Word! Once a month on Nature League we’ll look at the
etymology, or origin and history, of words related to nature.
This month’s theme is extinction, and we’ve discussed extinctions throughout Earth’s
history and a potential sixth mass extinction happening right now.
And the “right now” has a name, particularly in terms of geological eras. This month’s
Wild Word is “Anthropocene”.
The word “Anthropocene” can actually be traced back to Greek, but it has two separate
parts we should look at.
The first part, “anthropo-”, comes from the Greek word “anthropos”, which translates
to man, or human being.
The second part of the word, “-cene”, comes from the Greek word “kainos”, meaning
“new” or “recent”.
After the Cretaceous period and the extinction of the dinosaurs, geological epochs had the
ending -cene tacked on; for example, the Oligocene, Miocene, and Pleistocene. These epochs make
up Earth’s recent history, but geologists are considering naming the time period we’re
currently in after mankind.
Some have argued that by naming the current epoch after ourselves, we’re claiming some
kind of ownership over the Earth and its systems and that it sounds like we’re just saying
that we rule.
While human dominance is inarguable when you look at the sheer impact our species has had
on Earth, I like to think of the Anthropocene as being named for people not because we’re
in charge, but rather because we’re responsible for the drastic changes occurring on the planet.
So while a formal definition of “Anthropocene” is “relating to or denoting the current
geological age, viewed as the period during which human activity has been the dominant
influence on climate and the environment”, “Anthropocene” comes from two Greek words
that literally mean “new human”. And instead of an ego boost, I like to think of this as
a lovely reminder to consider the effects of our current choices.
It’s weird to say that one of my favorite places on Earth is this small layer of dirt
in eastern Montana that harbors a beyond depressing event, but I can’t help but love this place.
Our day to day lives move so quickly, and it’s hard to think about what I’m doing
next week much less in the timescale of millions of years.
Yet when I’m here, touching these pieces, I’m shaken with an overwhelming sense of
humility. This layer tells the story of loss of life on a scale unimaginable, and yet…
without the loss of the species living at the end of the Cretaceous, Earth as we know
it would be unrecognizable. Humans may not have ever come to exist. When I touch this
layer, I’m reminded that this lethal event led in part to my own living existence.
Extinction is never an easy thing to think about, and we’re facing major challenges
when it comes to conserving the species threatened with extinction today. By looking at a longer
timescale, however, I am hopeful that...well...life, uh...finds a way. I truly love this place,
and I hope that you too were able to enjoy it: the good and the bad, the mass extinction
and the recovery of life on Earth.