in 2011 a worker at an oil sands mine in
alberta canada made one of the most
exciting dinosaur discoveries of the
21st century
while digging up a cliffside the workers
excavator struck an unusually hard
object
peppered with large tan splotches he had
just discovered the remains of a 110
million year old nodosaur
nodosaurs were a group of armored
plant-eating dinosaurs that lived during
the late jurassic and cretaceous periods
and paleontologists have been studying
these dinosaurs since the 1830s but
nobody had ever found a specimen like
this one before
researchers at the royal terrell museum
named it borealo pelta mark mitchuli
after the technician who spent over
five years cleaning up the fossil it
represented a completely new
species and that was just the beginning
although the dinosaur's tail and a few
other parts were missing
everything that was left was amazingly
detailed there was a gorgeous skull
articulated neck vertebrae several leg
and foot bones and portions of the torso
and hip regions
but it was the rest of the fossil that
made international headlines
from the hips forward boriello pelta had
an almost complete set of osteoderms
osteoderms are bony plates that are
embedded in the skin
just like what alligators have today
nodosaurs and many of their relatives
had
backs that were covered in osteoderms
possibly for defense
better yet borealla pelta contained
super rare remnants
of softer body materials and even had
traces of pigmentation
giving us important clues about the
animal's color pattern
and the key to all this exceptional
preservation was
where borealis pelta ended up after it
died and
how it got there because the strange
thing is it was found
lying on its back in a marine deposit
in other words it was fossilized upside
down underwater
and a lot of other nodosaur fossils have
turned up in similar deposits
ones left behind by ancient waters so
how did these dinosaurs end up getting
buried at sea
the answer to this question is a growth
but also kind of cool
process of decomposition called wait for
it
bloat and float
nodosaurs belong to a larger group of
herbivorous dinosaurs called
ankylosaurus
scientists have found their remains on
most of the world's continents
including antarctica and they generally
divide ankylosaurus into two major
groups
the ankylosaurids and the nodosaurids or
the nodosaurs the ankylosaurus tended to
have
short wide skulls and many sported bony
clubs on their tails that were probably
used as weapons
but notosaurs didn't have these clubs
instead many of them
including borealopelta had long spikes
on their shoulders and narrower snouts
two of the oldest nodosaurs on record
are gargoylosaurus and mymora pelta
both were around 3 meters long and lived
in the western u.s during the late
jurassic period
but nodosaurs persisted throughout the
cretaceous period
sticking around right until the age of
dinosaurs ended 66 million years ago
and both nodosaurs and ankylosaurids
often turn up in marine fossil deposits
now you might remember from our video
when sharks swam the great plains that
from about 95 to 68 million years ago
a huge body of water called the western
interior seaway
split north america in half and earlier
in the cretaceous much of west central
canada
and the upper great plains were covered
by the maori sea
an extension of the arctic ocean so
there was a lot of available sea for the
armored dinosaurs to end up in
for example take the nodosaur known as
niobrarosaurus
it's known exclusively from the late
cretaceous marine deposits of western
kansas
and some of its fossils even bear the
tooth marks of ancient sharks
and lots of other armored ankylosaurus
including nodosaurs have been found in
marine deposits
from places like queensland australia
and james ross island antarctica
one species was even found in california
with fossilized oysters encrusting on
its bones
and then we have borealo pelta the
spectacular nodosaur that those albertan
miners came across
its remains were discovered in the early
cretaceous clearwater formation
where the fossils of marine reptiles
like plesiosaurs and ichthyosaurs often
turn up
but scientists had never found any
dinosaur material out there
until borealopelta so
what happened well after its death
borealis pelta's corpse hit the sea
floor around
200 to 400 kilometers away from the
closest shoreline
and it landed upside down which turns
out to have been
a common fate for nodosaurs computer
simulations suggest that these top-heavy
animals would have flipped over pretty
easily while floating in the water
so below the waves borealla pelta came
to rest in a layer of stagnant oxygen
poor mud
traces of burrowing sea creatures were
found nearby but paleontologists found
no
evidence that the dinosaur's body was
scavenged and when it was discovered
borealo pelta was encased in a tomb of
hard rock called a concretion
as its body decayed carbon dioxide and
other substances were released
which changed the chemistry of the water
inside the mud around the carcass
soon enough a tough layer of cytorite a
type of iron carbonate
formed protecting the dinosaur's remains
but
how did it get so far away from the
coastline after all
borealis pelta was heavily armored and
short-legged
so it was probably a terrible swimmer
and it lived on land anyway so there's
no reason to think that the nodosaur
swam to its watery grave it's more
likely that the dinosaur's body was
washed out to sea sometimes after an
animal dies and bacteria start breaking
it down
gases build up inside the corpse and if
the carcass ends up in a body of water
while that's happening
it might start bobbing around at the
surface scientists call this phenomenon
bloat and float eventually those gases
escape the body stops floating and it
sinks to the bottom
and no matter where an animal dies
there's a good chance its remains will
get
scattered around after death but the
concretion around borealo pelta
kept most of its skeleton together
better yet the rocky shell helped the
dinosaur retain its three-dimensional
shape
even as layers of sediment piled up on
the carcass over time
between the bloat and float process and
the seafloor environment where it landed
boriella pelta kind of hit the jackpot
in terms of preservation
for example along with those osteoderms
experts found that the fossil was also
covered with tiny
polygonal scales on much of its skin and
delicate skin structures were spread out
across the skull
neck back hips and even its legs plus
many of the dinosaurs osteoderms along
with other parts of the body
were coated in a dark gray material this
stuff has been identified as a kind of
organic film
and it's loaded with the chemical traces
and byproducts of
keratin keratin is a key ingredient in
fingernails hooves feathers
and hair and some modern reptiles like
alligators have keratin sheaths over
their osteoderms
unfortunately keratin often vanishes
without a trace during the fossilization
process
but the organic film on borealo pelta
preserved the original three-dimensional
structure of the keratin sheaths that
covered and lengthened the bony
osteoderms when the dinosaur was alive
the ones on boreala pelta shoulder
spikes are a centimeter thick in some
places
and make up about 25 of the total length
of each spike
so this gives us a clearer picture of
what the notosaur actually looked like
but wait there's more the film of
keratin wasn't even the most spectacular
aspect of this fossil
this dinosaur had preserved evidence of
coloration
and it came in an unexpected pattern
some of borealo pelta scales bear the
chemical hallmarks of a pigment called
pheomelanin judging by these traces it
appears that most of the dinosaur's back
was a reddish-brown while its underside
was pale
this means that borealis pelta could
have been counter-shaded or darker on
its upper side and lighter on its
underside
counter shading can make animals much
harder to see because of the way
shadows help us perceive objects when
sunlight hits a three-dimensional body
it tends to look light on top and dark
on bottom
so if these creatures are lit from above
they'll look almost uniform in color
their dark backs will be illuminated and
their light underbellies will look
darker
because of that predators might not even
recognize counter-shaded animals as
three-dimensional objects visually
they're harder to make out
this would have been really useful for
borealo pelta because
even though it was really big like 1300
kilograms
back in the notosaurs heyday massive
carnivores stalked north america
and one of them was acrocanthosaurus a
predator that measured 11 meters long
and could have weighed a little
over seven metric tons with enemies like
that on the prow
borealo pelta may have benefited from a
little camouflage
without the amazing preservational
environment created by the concretion
and the whole bloat and float thing in
the first place we wouldn't have
any clue what color this huge dinosaur
was
or what it ate and that brings us to a
soccer ball
sized lump found in borealis pelta's
abdominal cavity
in 2020 royal terrell paleontologist
caleb brown
and his colleagues recognized this lump
as a cola light
which is a hunk of fossilized intestinal
contents
even though boriella pelta had ended up
in a marine deposit this cola light was
loaded with bits and pieces of land
plants fossil sites in other parts of
canada tell us that central alberta was
home to a wide variety of terrestrial
plants in the early cretaceous
with conifer forest dominating the
landscape but it doesn't look like
borealis pelto was too keen on conifers
leaf tissue makes up 88 of all the plant
material that was identified
inside the cola light and the vast
majority of those leaves came from
ferns which is interesting because
scientists had always
assumed that nodosaurs with their long
narrow snouts were picky eaters
instead of chowing down on a mixed
foliage indiscriminately
the dinosaurs would have carefully
plucked their favorite plants
and borealis pelta's gut contents look
like evidence of this
but they also point to something
surprising about the environment that it
lived in
inside the colo light the researchers
discovered a few samples of charcoal
that the dinosaur apparently swallowed
in fact burned plant fragments represent
six percent of the botanical material in
the colalite
and perhaps that says something about
borealis peltis feeding behavior
researchers think wildfires were quite
common during the cretaceous when
borealopelta was alive
oxygen may have made up around 30 of
earth's atmosphere compared to just 21
today and when these natural disasters
happen ferns often bounce back faster
than other plants do
for a brief period ferns may actually
dominate a post-fire landscape as the
environment recovers
so if borealo pelta was a picky eater
with a taste for ferns then maybe the
dinosaur was attracted to
wildfire-stricken areas where these
plants were thriving
between the remnants of keratin and its
preserved dietary clues
borealis pelta might be the most
significant nodosaur fossil
ever found and just think the dinosaur
could have been lost to us forever if it
hadn't bloated and floated across an
inland sea
in death this creature beat the odds
evading scavengers and the ravages of
fossilization
before it survived the mining process
and caught an
equipment operator's eye by doing all
this
it's given us a bounty of dinosaurian
knowledge
so here's to boreala pelta mark michelai
an improbable ambassador from the early
cretaceous
[Music]
thanks to kayla brown and donald
henderson of the royal terrell museum in
alberta
and jacob vinther of the university of
bristol for their help with this episode
and thanks to this month's eontologist
for floating around with us
luke and curtis mahoney sean dennis jake
hart
john davison ing patrick seifert and
steve
you can become an eonite by pledging
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eons also thank you for joining me in
the constantine hosta studio
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