If you happened to visit the swampy forests of what’s now Italy about 7 million years
ago, you might have crossed paths with a very strange ape.
It had a small brain - less than half the size of a modern chimp’s - and it also had
a puzzling combination of other features.
It had teeth with sharp cusps, adapted for slicing through fibrous plants -- much more
like we see in some of today’s Old World monkeys than in living apes.
And it had well-developed chewing muscles and a robust jawbone, suggesting that it ate
leaves almost exclusively, unlike its other ape cousins, which mostly lived on fruit.
But attached to that small skull with monkey-like teeth was a body that was much more ape-like.
It had a short lower back and a broad torso, like living apes do, with arms that were long
compared to its legs.
And it had long, curved fingers and toes, also like those of modern apes.
Now, we know a lot about this weird European ape, because anthropologists have found many
fossils of it, including a relatively complete one in a coal mine in Tuscany in the 1950s.
It was given the delicious-sounding name of Oreopithecus, or hill ape.
And despite some of its more monkey-like features, experts agree that it was a hominoid -- a
member of the superfamily that includes all living and fossil apes.
Which is interesting, and kinda strange.
Because, not only did Oreopithecus have an odd combination of features, it was also just
one of around fifteen species of apes whose fossils have been found throughout Europe.
And, I don’t know if you’ve noticed but, Europe isn’t home to any of our ape cousins
today.
And we know that hominoids didn’t originate on that continent.
So, what was Oreopithecus doing in the forests of Miocene Italy?
How and why did this ape wind up in Europe?
And, why aren’t there wild apes in Europe today?
Today, our closest evolutionary relatives, the apes, live only in small pockets of Africa
and Asia.
But back in the Miocene epoch, between about 23 million and 5 million years ago, apes occupied
all of Europe.
We find their fossils from Georgia and Turkey in the east, to Spain in the west, and almost
everywhere in between, including Hungary, Italy, and France.
Some we know only from teeth and jawbones, while others we have relatively complete skeletons
of, like Oreopithecus.
And we know that they’re apes, rather than monkeys, because they share many skeletal
traits with living apes, like having broad, shallow torsos; shoulder blades that are positioned
on the back of the rib cage rather than on the sides; and they don’t have tails.
They’ve also got what are known as Y-5 molars, a classic hominoid dental trait.
That means they -- including you -- have lower molars with five cusps on them, and the grooves
in-between form a Y-shape.
So, what allowed these apes to make it to Europe in the first place?
Well, our earliest ape-like ancestors had already evolved and diversified throughout
the woodlands and tropical forests of Africa back in the early Miocene, about 20 million
years ago.
We know this because we’ve found lots of their fossils at sites that date back to this
time, in Kenya and Uganda.
For example, there are Proconsul and Ekembo.
They both share some of the same basic features in their teeth and skulls with later hominoids,
and they probably didn’t have tails.
But they still clambered around on all fours in the trees, more like monkeys.
And there was Morotopithecus, which also had those same uniquely hominoid features.
But based on the bones in its lower back and legs, it probably held its torso more upright
and climbed more like living apes do.
But things started to change for these primates starting about 17 million years ago.
That’s when Africa’s climate started to become drier, and experience more seasonal
variation.
Over time, the environment became less tropical, and more open and grassy.
This left early hominoids with fewer of their preferred foods, like fruits, and more lower-quality
foods, like leaves, seeds, and bark.
But at the same time, up in Eurasia, the climate was becoming warmer and more forested.
So while Africa was getting drier, Europe was becoming more hospitable to these early
apes and other subtropical and tropical mammals.
Which is why it’s around this time, about 16 million years ago, that we see hominoids
first start to appear in Eurasia.
The first pioneer in Eurasia that we know about was called Griphopithecus.
It’s found at sites in Turkey, Slovakia, Austria, and Germany, from 16.5 to 16 million
years ago.
But it was only the first of many.
Once hominoids made it into the warm, humid forests of Europe, they diversified and spread
across across the continent.
So, soon after, in France, we find Dryopithecus fontani from 12.5 to 11 million years ago.
It was actually the first of the European apes to be discovered, named by a French paleontologist
in 1856.
And in northeastern Hungary, about 10 million years ago, Rudapithecus reigned.
It lived in forests that were swampy or maybe flooded seasonally, and its brain about as
big as a chimp’s.
Then, in Northern Spain alone, there were five different genera of apes, ranging in
size from Pierolapithecus at about 30 kilograms to tiny Pliobates at just four and a half
kilos.
But as the apes of Europe were enjoying their heyday, big changes were afoot.
And by “big” I mean, like, the size of the Himalayas.
Starting about 50 million years ago, in far-off Southern Asia, the Indian Plate of the Earth’s
crust had begun to crush into the Eurasian plate, slowly forming the massive Himalayas.
By about 10 million years ago, this slow-motion collision started to lift these giant mountains
even higher, and faster.
And these new mountains changed climate patterns all over the world.
In Europe, this meant that the once subtropical forests that apes had conquered began to transition
into cooler, more seasonal, deciduous woodlands.
Many of Europe’s apes found themselves unable to adapt to the loss of their subtropical
forests, and began to go extinct, around 9.6 million years ago.
Rudapithecus in Hungary and the many apes of Spain were likely among the casualties.
And as the cooling and drying trend continued, forests became more fragmented and grasslands
began to spread.
The few apes that survived to this point were either highly specialized or isolated in pockets
of suitable habitats, or both.
For example, Ouranopithecus from northern Greece seemed to have adapted to a more open,
grassy, and shrubby landscape with fewer trees.
The wear on its teeth suggests that it ate roots, tubers, and other hard, abrasive foods.
And some anthropologists have actually suggested that, based on its teeth, Ouranopithecus might
have been a hominin, a member of that group of apes that includes us and all of our extinct
relatives that existed after our last common ancestor with chimps and bonobos.
And the same has been suggested about another European ape: Graecopithecus
It’s only known from a partial jawbone found in Greece and a single upper premolar from
Bulgaria.
And some scientists have proposed that it, too, has some traits that are unique to hominins,
namely in the roots of two of its teeth.
But, as with Ouranopithecus, this claim is very controversial, mainly because we have
many more -- and more complete -- fossils of hominins from Africa, which is generally
agreed to be where hominins originated.
In any case, the final holdout among Europe’s apes was our old friend Oreopithecus.
It lived in forests that were cooler and wetter than the habitats of the other European apes,
which may have helped it adapt to the changing climate conditions that had doomed its contemporaries.
And the fact that it was so well adapted to its isolated environment might also explain
why it had those features that seemed more monkey-like than ape-like.
Oreopithecus lived long after the split between monkeys and apes, but over time it evolved
those teeth with sharp cusps, like those found in some monkeys, which were perfect for eating
leaves -- yet another example of convergent evolution in action.
Oreopithecus survived in isolated forests until about 6 or 7 million years ago, when
the chunk of Italy that it lived on - which was an island at the time - finally collided
with the rest of the Italian peninsula, which of course changed its habitat considerably.
By 6 million years ago, the reign of the apes in Europe was over.
But was that it?
What was their legacy, for other primates and for us?
Well, like all apes, the apes of Europe were hominoids, so they are part of our superfamily.
But whether they’re distant cousins or direct ancestors depends on who you ask.
Most anthropologists agree that our earliest ape-like ancestors -- early hominoids like
Proconsul and Ekembo -- evolved in Africa.
But they disagree about what happened next.
Some experts think the European apes are just an interesting side-branch of our family tree,
and that the hominoids that eventually evolved into us remained in Africa, and evolved there
Their reasoning is that the earliest ape-like primates are found in Africa, as are our earliest
definitive hominin ancestors, and our closest living ape cousins.
But the problem is, we haven’t found conclusive fossil evidence of those apes that gave rise
to the hominins.
These were the members of another subfamily, the Homininae, which includes all of the living
African apes as well as humans.
But we have yet to find fossils in Africa of the last common ancestors that gorillas,
chimps, and humans all share.
There are some potential candidates, but their fossils are fragmentary and isolated.
And the fact that we haven’t found them might just be an accident of geology.
After all, only some locations preserve fossils, and only some locations have been excavated.
But others propose that one of these European ape species might have returned to Africa
and given rise to our lineage.
Advocates of this hypothesis point, as evidence, to several features of the skull and teeth
that Eurasian apes share with later hominids.
Needless to say, there are lots of gaps in our understanding of human evolution, and
this question -- about when, where and exactly how the hominoids gave rise to hominins -- is
one of them.
But what we do know is that strange apes like Oreopithecus were just part of an incredible
radiation of apes that took place during the Miocene epoch.
And its remains, found in the fossil forests of Italy, remind us of that time when
apes, for a brief span of geologic time, conquered the European continent.
Thanks for joining me today, and special thanks to our Eontologists, Jake Hart, Jon Ivy, John
Davison Ng and let’s not forget STEVE!
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Now, if you’re interested in the origins of things, then you should definitely check
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came to be, like why so many religions have rules about head coverings, and what fake
conspiracy theories can tell us about our very real feelings about invasions, government
and war.
Check out the link in the description!
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