it's 70 million years ago and you are a
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 your average amphibian but this
place is home to one hell of a weird
frog
paleontologists call it bielsa buffo the
so-called devil frog
and it may have been the largest frog
that ever lived beal zabufo 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 because 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 want to 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 serato friads
but they're more commonly known as wait
for it
pac-man frogs and phylogenetic studies
group bielsa buffalo with modern pac-man
frogs
but here's the problem pac-man frogs
only live in south america and bielsa
buffo 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 bielsa buffo
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 majunga 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's 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 bielsa
bufo 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 chunky boys can get up to just
over 30 centimeters long and weigh more
than three kilograms
but their largest estimates put bielsa
buffo around 40 centimeters long and
four and a half kilograms
and based on its features we can get at
least some insights into what his
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 his big blobby shape and short limbs
would have 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
beal zabufo 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 beals of bufo
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 a tiger
living frogs with morphologies like
bales of bufo 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 because several dinosaur
species have been found in the same
formation where biezel buffo was found
okay but so all of this weirdness aside
the thing that really perplexes us about
this frog
is where exactly it came from the key
question is did biel zabufo just look
like a pac-man frog or was it actually
related to them
pac-man frogs live in places that a lot
like rabiela bufo 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
hyper-ossified 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 well we
have a problem
because then we have to explain how
bielsa bufo ended up only in madagascar
while pac-man frogs are found only in
south america
in order for the ancestors of bielsa
buffo 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-man frogs 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 just
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 just doesn't work for
these ancestors of pac-man frogs to get
to madagascar by land
okay 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 get 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 some time after
65
million years ago which is 5 million
years after abiel zabufo 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 beelzebub 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 bielsa bufo and pac-man frogs
aren't related and they just converged
on the same adaptations
then that tells us that there's
something about being big and 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
[Music]
goliath thanks to this month's
eontologists luke and curtis mahoney
sean dennis jake
hart john davidson ing patrick seifert
and my boy steve
become an ianite by pledging your
support at patreon.com
eons also thank you for joining me today
in the constantine haza studio
be sure to subscribe at youtube.com
thank you
[Music]