Adventure #5:
Ecosystems of the Past
Ecosystems of the Past
Though there may only be four ecosystems in Idaho today, the past has held many different types of ecosystems!
Together, let's take a look at Idaho's past environments, and especially what types of plants and animals use to live here.
On the right side of each blue bar, you will see the name of the time period that this was in earth's history! All of these time periods together make up Earth's geologic timescale!
Idaho was a shallow lake or a lagoon environment 4600 million years ago.
Precambrian
When we begin to think about Idaho's past, the furthest back that we have found is around 4600 million years ago!
Wait.....that's like a really long time ago. Even older than the oldest living people!
Let us imagine our home back in that time. There would have been very few living things, and there would be water everywhere! In fact, there would be almost no land in sight.
As evidence of this time in our past, we have found mounds of prehistoric bacteria that have fossilized for us to find today. These bacteria mounds are called stromatolites.
Say it with me! Stroe-mat-oe-lites
Taken by Paul Harrison from Wikipedia commons, CC license
540 million years ago, Idaho was an ocean home to many species.
Cambrian
From Wikipedia Commons, CC license
Moving through time, we saw our area become a deeper ocean around 540 million years ago.
Yes, still older than our old people!
Idaho at this time was covered with shallow to moderately deep oceans, and we saw an explosion of life. Imagine the biodiversity we see in our oceans today. There are what seems to be endless amounts of plants and animals down there!
That would be a lot like what our area looked like in the Cambrian time period, but the plants and animals would look slightly different.
One of the fossils we see a lot of from this time are trilobites. These were common in our ancient ocean ecosystem, and they look like hard shelled bugs with many legs underneath!
Say it with me! Try-low-bites
Idaho was still an ocean environment 290 million years ago, but it now has more complex animals.
Precambrian
Now we are entering a time of chaos for Idaho and the world! There is a large amount of tectonic plate activity, dramatic climate changes, and many extinctions that occur during this time. However, we are still an ocean.
Wait, if we're still an ocean, why are we talking about the precambrian?
This time, instead of many trilobites and small creatures roaming our ocean, we would see much larger and more complex animals.
In fact, this is the time of the ancient sharks!
Idaho is home to the worlds largest amount of helicoprion fossils. Helicoprion is an ancient shark that had all of its teeth in a big spiral similar to a saw. This spiral of teeth is the only fossilized evidence of our ancient shark.
Say it with me! He-li-cop-rine
From Wikipedia Commons, CC License
From James St. John, CC License
The environment of Idaho shifted into a freshwater lake 145 million years ago.
Cretaceous
From Wikipedia Commons, CC License
Say it with me! Lang-stone-ie-uh
As the water becomes shallower in our area 145 million years ago, we become simply a freshwater lake and no longer an ocean.
What's the difference?
Well, an ocean is a massive body of salt water, but a freshwater lake is not salty and much smaller. This freshwater lake environment created a whole new kind of life. This new life is even larger, more evolved, and reshapes life as the world knows it.
This environment allowed the opportunity for aquatic animals to evolve and live on the land!
One of these animals that steps foot onto land is Langstonia, a crocodile-like animal that lived long ago.
Idaho looked like it did today with some slightly different plants and animals 2.5 million years ago.
Pleistocene
Moving forward in time, we have the Pleistocene where life in our area greatly resembles life today. The only main difference is the types of plants and animals.
What was the environment like?
The environment 2.5 million years ago had a lot more oxygen than we do today, but there ecosystems were very similar. More oxygen just created larger organisms, many of which are extinct today.
In fact, Idaho has sloths and giant bison roaming our land! One breed of bison in particular was massive. It was named bison latifrons, and by looking at this fossil we can see that the environment in our recent past was not much different from today.
Say it with me! B-eye-son Lat-i-fronz
From James St. John, CC License
Now that we have explored our past, what is one common thing you noticed in these different time periods?
They all have water!
Even our Pleistocene period has some water present to create and sustain life.
Water is not only essential to our world today, it has been essential for nearly all of Earth's history.
I don't know about you, but I have been wondering something. The town I live in doesn't look like it is all natural ecosystems (like the images we've seen).
Why is that?
Do humans have an impact on ecosystems? Do we change them or what happens?