It’s 70 million years ago, and you’re
in northwestern Madagascar. The climate is subtropical, and very seasonal,
with long periods of drought broken up by stretches of heavy rain. Rivers dry up, leaving only ephemeral pools
behind. It’s a hard place to live, for you and even
for your average amphibian. But this place is home to one hell of a weird
frog. Paleontologists call it Beelzebufo -the so-called
devil frog. And it may have been the largest frog that
ever lived. Beelzebufo thrived in this environment, possibly
because of adaptations that it had in common with some modern frogs that still live in
these kinds of habitats. For one thing, its proportions were just ...weird. ‘Cause it had a disproportionately big head,
and a really wide mouth. And it probably had an incredibly powerful
bite, making it a serious predator for smaller animals. It also had these flanges of bone on the back
corners of its skull that were so big that they may have overlapped with its shoulder-blades
and even affected the movement of its arms. Now, the thing is: There are frogs around
today that look a lot like this, with big bumpy skulls and huge mouths. And you wanna know what they’re called? Because it’s really awesome. When scientists are trying to be all serious
about them, they refer to these modern frogs as ceratophryids. But they’re more commonly known as … wait
for it … Pac-Man frogs! And phylogenetic studies group Beelzebufo
with modern Pac-Man frogs. But here’s the problem: Pac-Man frogs only
live in South America. And Beelzebufo is only known from Madagascar,
around 70 million years ago. And Madagascar and South America haven’t
been connected for like 115 million years. So, if these frogs are related, paleontologists
have to explain how they ended up in totally separate places, and figure out where and
when their ancestors lived. And if it turns out that they aren’t related,
then why do they look so similar? Untangling the origins of Beelzebufo -- the
giant frog that lived alongside the dinosaurs -- turns out to be one of the most bedeviling
problems in the history of amphibians. The first fossils of Beelzebufo were collected
in 1993 in the Mahajanga Basin of Madagascar, and more bits and pieces were found each field
season after that. But this odd frog wasn’t fully described
until 2008, once there was enough of it to compare to other living and extinct frogs. And that comparison to living frogs is where
the trouble started. Even before the discovery of a partial cranium
in 2010, it was clear that Beelzebufo really looked like a Pac-Man frog that had somehow
ended up on the wrong continent. And the devil frog also turned out to be,
just, really big. The biggest modern frogs live in Africa and
are known as goliath frogs. These chonky bois can get up to just over
30 centimeters long and weigh more than 3 kilograms. But the largest estimates put Beelzebufo at
around 40 centimeters long and 4.5 kilograms. And based on its features, we can get at least
some insights into what its ancient habitat was like, and maybe even its behavior. For example, based on its limb proportions,
the devil frog probably walked on land, rather than hopping from tree to tree like some frogs
do. And its big, blobby shape and short limbs
would’ve helped keep it from drying out as quickly as a smaller frog would have. It also may have been a burrower, using its
back legs to dig into the soil and make a nice, cool place to hang out during the hottest
and driest parts of the year. This is something that frogs and toads still
do if they live in seasonal environments. But where things start to get weird … is
its head. Beelzebufo had what’s called a hyperossified
cranium - meaning that it had extra bone tissue that formed a series of pits and ridges over
most of its skull, giving it a bumpy texture. It also had an extremely wide mouth and was
probably capable of biting really hard. In a study published in 2017, researchers
measured the bite forces of living Pac-Man frogs, then scaled those measurements up to
estimate the bite force of Beelzebufo. And they found that the devil frog may have
had a bite as strong as a snapping turtle with a similar head size, and -- pound for
pound -- could even have rivaled that of a lion or tiger. Living frogs with morphologies like Beelzebufo
tend to be aggressive ambush predators, so the devil frog probably was one, too. Its powerful bite may even have allowed it
to prey on small crocodilians or even juvenile dinosaurs. A frog that hunted baby dinosaurs!?!?! It’s possible, ‘cause several dinosaur
species have been found in the same formation where Beelzebufo was found! OK, but so, all of its weirdness aside, the
thing that really perplexes us about this frog is where exactly it came from. The key question is: Did Beelzebufo just look
like a Pac-Man frog, or was it actually related to them? Pac-Man frogs live in places a lot like where
Beelzebufo lived -- in warm, arid habitats with pools of water that dry up seasonally. And modern Pac Man frogs -- and Ms. Pac Man Frogs -- are also
large predators with hyperossified skulls. Now, it’s possible that this is a case of
convergent evolution, where species with similar lifestyles develop similar adaptations -- in
this case, giant mouths, and body shapes and sizes that allow them to survive dry spells. But if they are actually related, we have
a problem. Because, then we have to explain how Beelzebufo
ended up only in Madagascar, while Pac Man frogs are found only in South America. In order for the ancestors of Beelzebufo and
Pac-Man frogs to have spread to both places, there would have to have been a connection
between Madagascar and South America, by way of Antarctica. But we now know that Madagascar was fully
separated from Antarctica by around 115 million to 112 million years ago. So this means that the group of frogs that
was ancestral to Pac Men had to, first, evolve into its own distinct group, and then, migrate
to Madagascar before 112 million years ago, assuming they got there by land. But, so far, the science says that wasn’t
the case. Molecular clock studies suggest that - at
the earliest - those ancestors of Pac-Man frogs didn't evolve until 88 million years
ago, long after Madagascar had already broken away. Now, the fossil record may provide some evidence
that this group originated earlier, but the record is still really spotty. So the timing doesn’t work for these ancestors
of Pac Man frogs to get to Madagascar by land. Ok but what about … rafting? We know other animal groups made it to the
island by riding on random, naturally formed rafts of plant material. So could the ancestors of this giant, scary
frog have done the same thing? Well, even if they did got to Madagascar after
it split off by rafting, the molecular clock estimates for when Pac-Man frogs originated
are still too recent. Their origin is generally estimated at sometime
after 65 million years ago - which is 5 million years after Beelzebufo was already terrorizing
Madagascar. So, there’s a lot about this frog that science
can’t quite explain. Yet. We’re not sure where it came from. And we’re not sure where it went. All of the fossils that we’ve found of it
come from sites dated to the late Cretaceous, and there are no frogs closely related to
it on Madagascar today. So it’s possible that Beelzebufo went extinct
during the extinction event at the end of the Cretaceous Period. But we can’t know for sure until we find
more sites and more fossils that are more recent than that. Now, even though we don’t have a lot of
answers, this weird amphibian can still teach us a lot about the patterns of evolution. Like, if Beelzebufo and Pac-Man frogs aren’t
related, and they just converged on the same adaptations, that tells us there’s something
about being big, mean, and extra bumpy that gives a frog a selective advantage in a dry,
seasonal environment. And if they are actually related - then that
tells us that there may be gaps in the fossil record of frogs that’s used to set the molecular
clock, and that frogs were probably much more widespread back then than we thought. But hey, if nothing else? You and I learned today that Pac Man frogs
are a thing! And that makes me pretty happy. Goliath thanks to this month’s Eontologists:
Lucan Curtis-Mahoney, Sean Dennis, Jake Hart, Jon Davison Ng, Patrick Seifert, and Steve! Become an Eonite by pledging your support
at patreon.com/eons. Also thank you for joining me today in the
Konstantin Haase studio. Be sure to subscribe at youtube.com/eons. Thank you!
A foot and a half long doesn't really seem that impressive compared with the biggest ever from most other taxa. When you look at Arthropleura, Archelon, Teratornis, or Meganeura, you'd almost expect the largest frog to be the size of a VW Bug.
This would have been a strong tough frog the size of a dog. Don't accidentally step on it, though. It might not recover from that.
Ampheebus Christ, the biggest frog ever lived.
Yeah, but what happened if you kissed it?