The Forgotten Story of the Beardogs


When you think of the world’s most fierce,
numerous, and dominant meat-eating mammals, you probably think of animals like the big
cats, or wolves, or bears. But long before any of those animals existed,
there was another predator that prowled North America. And it was neither cat nor dog nor bear, but
it was their distant relative. It had the tapering snout and long tail of
a dog. But it walked on the soles of its feet and
had a large body, like a bear. Its name was Amphicyon, and it was one of
the largest predatory mammals ever to walk the Earth. And it was just one of a very diverse group
of ancient meat-eaters that ruled the northern hemisphere for over 30 million years! Some of these creatures were fox-like forest
dwellers; others were fast, long-legged predators; and others still, like Amphicyon, were nearly
as big as polar bears. Scientists refer to this group of extinct
beasts as the Amphicyonids. But because of their strange combination of
bear-like and dog-like traits, they’re sometimes confusingly called the beardogs. And even though you’ve never met one of
these animals, the beardogs are key to understanding the history of an important branch of the
mammal family tree. Because, at the height of their reign, the
beardogs played a pivotal role in outcompeting another group of early dominant predators
— a group we’ve told you about before, which has also since gone extinct. And by getting rid of them, the beardogs paved
the way for their own relatives, the carnivores we know today. Natural history — like all history — is
full of overlooked characters, figures that quietly shaped the world around them. And if you ask me, the saga of the carnivores
could never be complete without the forgotten story of the beardogs. Now, most of the meat-eating mammals that
you know today — like cats, dogs, and bears — are members of the same group, the order
known as Carnivora. And it might sound like, to be a member of
this group you just have to eat meat. But Carnivora isn’t synonymous with carnivore. Carnivora includes animals with diverse diets,
not just meat-eaters. They range from the bamboo-chomping Giant
Pandas to more omnivorous animals, like raccoons, and even walruses! So, a carnivore is any animal that eats other
animals, but Carnivorans are a specific taxonomic group of placental mammals. And some of the earliest members of this group
were the beardogs. Beardogs first appear in the fossil record
around 40 million years ago, during the Eocene Epoch. They probably originated in North America
and spread into Europe before the two continents slowly became separated. Because of that, fossils show that two distinct
lineages of beardogs wound up evolving in isolation for millions of years. One of the oldest-known species is actually
a tiny creature from North America called Daphoenus demilo. It lived in the late Eocene, from Wyoming
to Saskatchewan, where it survived on a diet of plants and small animals in the dense forests
that covered the continent. And it, like all beardogs, belonged to a group
of mammals known as Caniformia — the same group that includes today’s bears and dogs,
along with other familiar mammals like seals and skunks. Scientists think that beardogs diverged from
other Caniforms early on, forming their own branch of the mammal family tree. Both bears and dogs evolved later, but today
they are the beardogs’ closest living relatives. And because of that, beardogs share a lot
of similarities with both animals. For example, beardogs tended to have longer,
pointier snouts, like dogs and bears do. And many beardogs were large-bodied and walked
with their feet flat on the ground like bears, but also had a long, dog-like tail. Now, after the North American beardogs became
separated from the Eurasian species, the two groups found themselves on very different
evolutionary paths. In North America, beardogs diverged into two
subfamilies, each of which played a big role in shaping the predator-prey dynamics of the
continent. The first group appears in the fossil record
about 40 million years ago, in places like Texas and Wyoming. Early species in this group were well-adapted
for hunting in dense forests, like our friend Daphoenus, which was probably about the size
of a swift fox, or maybe as big as a coyote. But when these first beardogs came about,
there were bigger dogs on the scene. Though they weren’t actually dogs, either. The fiercest apex predators in Eocene North
America were the Hyaenodonts — bigger, stronger carnivores which we’ve talked about before. Hyaenodonts had big, powerful jaws filled
with blade-like teeth. Plus, we can tell from their heel bones that
some of them could make powerful leaps, suggesting that they probably used an ambush hunting
strategy, hiding in the forest undergrowth and tackling their prey with brute force. Now, those first little beardogs might not
have seemed like much of a threat to the hyenadonts, but circumstances soon swung in their favor. As the Oligocene Epoch began about 33 million
years ago, North America was beginning to go through a major cooling and drying phase. And this opened up the landscape, turning
forests into savannas. This new, open environment spelled trouble
for the specialized hunting style of the hyenadonts. And they had another problem to deal with, too: their teeth. Hyaenodont teeth were all adapted for ripping
and tearing flesh — great when you’re only eating meat, but less so when your food of
choice suddenly declines. Beardogs, on the other hand, had more varied
teeth. Their front teeth were used for tearing, but their
molars had different shapes and sizes. Some could be adapted for crushing, puncturing,
or holding prey, depending on what was selected for. And these differentiated teeth proved to be
a key advantage for the beardogs. Plus, by the start of the Oligocene, some
beardog species had gotten big — big enough to compete with hyenadonts for the same food,
while maintaining more of this adaptability. The combination of direct competition from
beardogs and an unforgiving new environment spelled the end for the Hyaenodonts. By about 30 million years ago, they had vanished
from North America. Soon, beardogs were on the rise. By about 23 million years ago, several large
beardogs appeared, with long legs that gave them a more efficient stride — perfect for
chasing down prey like three-toed horses and early camelids. But the North American beardogs were about
to face much stiffer competition, and from their own kind. About 18 million years ago, a new threat crossed
the Bering Land Bridge: even larger beardogs, the ones that had evolved separately on Eurasia. And over there, the beardog story had played
out differently than it had in North America. At first, the Eurasian beardogs struggled
to thrive, in part because there too, they faced competition from the hyaenodonts. But when those bigger carnivores started to
decline, the beardogs had their moment. They quickly spread across the continent and
began to fill niches that hyaenodonts had left empty. But rather than adapting to become sleek and
long-legged like their American relatives, Eurasian beardogs became heavier and more
robust. They were also probably more opportunistic
and adaptable, hunting or scavenging on large prey like hyenas do today. In fact, we have direct evidence of this! In 2006, researchers described a rhino jaw
from Portugal that had bite marks matching the teeth of a Eurasian beardog called Amphicyon
giganteus. So when the large beardogs arrived into North
America, it spelled trouble for the locals. And they were just one part of a whole wave
of Eurasian carnivores that came over, shaking up the dynamics of whole ecosystems. These new carnivores outcompeted the North
American beardogs, and by about 17 million years ago they were extinct. The Eurasian beardogs however, thrived in
their new habitat. They grew even larger, reaching sizes that
put them among the biggest mammalian land predators of all time. Two species of these giants were ambush predators
the size of polar bears that roamed Western North America. They had powerful forelimbs, massive clawed
feet, and muscular jaws that could deliver a crushing bite. But these beardogs were about to meet the
same double-threat as the hyaenodonts that came before them — new competition and climate
change. However this time, the situation was reversed. Beardogs had outcompeted the hyaenodonts in
part by being adaptable generalists, able to eat more kinds of food when conditions
changed. But then those beardogs were replaced by more
specialized hunters — members of their own family: the modern Carnivorans. Some of these new Carnivorans included hyenas
in Eurasia and borophagines in North America; you may know them as the bone-crushing dogs. Both of these animals could shatter bones
with their teeth, something that beardogs couldn’t do, which made them more efficient
scavengers. Plus, there was also the arrival of the cats,
which began to compete for the niche of hypercarnivore, with their razor-sharp teeth and retractable
claws. Meanwhile, bears — actual, real bears! — had
diverged and spread, with teeth that were adapted to a more omnivorous lifestyle. All of these new Carnivorans were doing everything
that beardogs could do, but better and in more targeted ways. Clearly, the days of the beardogs were numbered. The North American beardogs had already been
outcompeted by the giant Eurasian beardogs. And with only huge ambush predators left on
both continents, they couldn’t stand up to the more specialized cats, dogs, and bears. Some of the last species we find in the fossil
record belonged to the genus of the mighty Amphicyon. By about 9 million years ago, beardogs on
both continents were gone. But we shouldn’t forget the role they played
in shaping predator dynamics in the Age of Mammals. Their rise helped the carnivorans outdo their
competitors, the hyenadonts. And their fall was accompanied by the rise
of the modern cats, dogs, and bears we know today. When the last of them vanished, the beardogs
had formed a kind of bridge between old and new: a missing puzzle piece in the 45-million-year
saga of the meat-eating mammals. Hey big thanks this month’s Eontologists:
Patrick Seifert, Jake Hart, Jon Davison Ng, and Steve! Become an Eonite by pledging your support
at patreon.com/eons! And also high-fives for joining me in the Konstantin Haase Studio. Be sure to subscribe at youtube.com/eons.

100 thoughts on “The Forgotten Story of the Beardogs

  1. what we all wanted to know.

    "is this a i ride you we go out hunting together… each ov us have a mate and litter at home https://youtu.be/xbmLqrnxH2w?t=395'

    or a

    " you me and 8 ov our best friends that look like you chase deer all day. https://youtu.be/xbmLqrnxH2w?t=152 "

    situation.

    also sorry to ruin it but they where big rodents 🙂 sleeker hunter driven biggo raccoons. or swifter badgers.

  2. The beast of Gévaudan must have been from either a pack of Beardogs or Hyaenodonts that had been hiding out in the forest of Lozère in France for a few million years until the rampage in 1764. Obviously! 😉

  3. I love your program – any chance you could do one on cactus and it succulents and how the evolved – what were the first succulents? You could even talk about the convergent evolution of cactus vs other succulents!

  4. We call Our blue heeler baby bear…he looks just like one, people who first meet him say it too…can’t imagine if he were 400 lbs… yikes…

  5. Just think, in thousands or millions of years from now some lady is telling people about this weird cat thing (bc now they're in 2 different groups)

  6. While watching this video, I suddenly realized how limited my knowledge on ancient mammals is, compared to dinosaurs -.-

  7. Go to the channel, “Dogman Encounters Radio.” Listen to a few episodes and you will discover there is no way all these people are making this stuff up.

  8. How could you possibly know how long this predator lived on earth.. 30 millions years is impossible for you or anyone to know,,utter rubbish,

  9. Could you guys do an episode about the atlantogenata and maybe laurasiatheria would also like to see a video about the split of the sauropsids and synapsids.

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