Hi everyone Ezekiel O'Callaghan with
Raptor Chatter here to talk about
all the finds for paleontology that
happened in May 2019
amber comes from trees
and some of the Burmese amber in
particular has been great at capturing
the life that lived during the time it
was created during the Cretaceous period
with a number of geckos birds and very
very unique arthropods being found in
this Burmese amber however now there's a
piece of this amber that's been shown to
have an ammonite and a few types of
marine snail in it.
the finding of these
marine animals in the Burmese amber
helps to show how this amber formed in
an area that had fairly large tides and
a lot of water being brought in from the
coast and being incorporated into the
soil and into the areas where the tree
sap would run and eventually hardened
into amber
additionally with the
ammonite being a puzosia ammonite it
helps us narrow down the time range that
the Amber formed being between 110 and
about 95 million years ago very much in
the dead center of the Cretaceous period
Archaeopteryx is the best known fossil
coming from the Solnhofen - limestone however
one of these Archaeopteryx fossils was
found not to be an Archaeopteryx but a
new genus called Ostromia
now there's another fossil of
Archaeopteryx that may not be an Archaeopteryx
Alcmonavis poeschli was
thought to have been in Archaeopteryx
but may be it's separate genus the wings
of this bird were slightly more robust
than those of the other Archaeopteryx
specimens we have and so may mean that
it is its own species separate from the
Archaeopteryx that we've previously known
this find indicates that flight
and birds may have already been well
developed by the time of the middle
Jurassic when we find Archaeopteryx and
that the first birds and flying
dinosaurs may have started even further
back than we had previously thought
there are still some questions though
about whether Alcmonavis is
archeopteryx because well these wings do
seem larger and slightly different than
those of Archaeopteryx it is a very
fragmentary fossil and so there is still
some debate as to whether or not Alcmonavis
isn't just a particularly large
individual of Archaeopteryx
Keeping on the subject of flight we're going to
look at Caudipteryx which had long
flight like feathers but definitely
couldn't fly its wings were just too
small to be able to lift it into the air
however that doesn't mean that they
couldn't have provided some lift while
the animal was running. In order to test
this scientists looked at the most
similar body plan of living animals to
caudipteryx, which is a juvenile ostrich
from there they used modeled caudipteryx
wings and attached them to the
back of the ostrich and had the ostrich
run with complex sensors they were able
to test the g-forces and the amount of
force and lift that was generated by
holding the wings outwards with
what the researchers found was not only that the
small wings did provide decent lift but
they also formed a pseudo flapping
motion with just the natural currents of
air going by causing them to lift and
fall and lift and fall very much like a
flapping motion. This could help us
understand where flight in the birds
first came from as there have been two
main hypotheses for where it came from
one hypothesis was from the trees down
with a few small dinosaurs hopping from
branch to branch then using their
feathers and wings to help glide further
distances between them and the other
being from the ground up being that some
of the dinosaurs while running would use
their wings to help them accelerate
faster or balance or help cause some
lift while trying to climb up steep
slopes this evidence from caudipteryx,
the most primitive dinosaur having long
flight feathers that we know of helps to
indicate that the ground up may be a
more likely scenario for developing
flight in the birds
When North and South America finally collided there was an event known
as the Great American biotic exchange
where animals from North
America and South America migrated to
each other's continents one of the most
important places for understanding this
event is the Yucatan in southern Mexico
where many of the species from both
continents interacted. Fossils from
underwater caves dating to about 35,000
years ago have helped to show how many
of these species began to interact and
migrate between the two continents.
Fossils from these caves include things
like giant ground sloths but also Arctotherium a bear that was even larger than
our modern-day bears. There's also the
canid Protocyon and a few human remains
found in some of these caves. Knowing
that humans were able to reach these
caves without going underwater thousands
of years ago should be somewhat alarming
as continued climate change is going to
alter the environments and not
necessarily in ways in which humans are
adapted for them and so we need to be
prepared to deal with climate change in
a real and meaningful way
Many types of fish from the very small sardines to
some varieties of shark have schooling
behavior and form Shoals at certain
times
however it's incredibly hard to show
that schooling behavior in fish
appeared anywhere in the fossil record
and that's because oftentimes even when
many fish die they aren't going to form
the same kind of formation that they
would have in life. A new fossil coming
from the Green River Formation
has shown them to preserve this behavior
this densely knit ball of over 250 fish
helps to show that there was
communication happening between
different individuals of the species as
far back as the Eocene over 50 million years ago
This kind of behavioral
communication between individuals of a
species wasn't thought to have been
preserved in the fossil record and while
we don't know exactly how this fossil
that is very unique was formed it does
help us lean into questions of what we
might be able to tell from other fossils
in the future
The megaraptorians are some of my
favorite dinosaurs and not because
they're incredibly unique but rather
because they don't seem to fit in
anywhere as far as we can tell just yet
many fossils of megaraptorians are
very fragmentary and new species that
are being found still have this trait of
being fragmentary and so it's hard to
narrow down where exactly on the
theropod line they lay whether they be
closer to things like Tyrannosaurus or
things like Allosaurus which while
superficially similar are very different
and took very unique paths in evolution
New fossils coming from Thailand helped
indicate that they may be closer related
to things like Tyrannosaurus laying on
the Coelurosaurs line of the theropod
family tree Phuwiangvenator
yaemniyomi is a new megaraptorian
and Vayuraptor nongbualamphuensis is a
newly found basal coelurosaur.
Together these two species help to illustrate the
variety of theropods that were living
during the early cretaceous with megaraptorians being found throughout
much of Eastern Asia, Australia, and South
America. However they did start to
decline during the Late Cretaceous. I
earlier mentioned that many of the megaraptorians
are very fragmentary in their
remains and the same holds true for
Phuwiangvenator as it is also very
partial and so more fossils of megaraptorians
need to be found before we can
definitively define which clade they do
truly belong in.
The Petrified Forest is
known for trees but that's not the only
thing that's found there. Among the
fossils that are found there are a few
very early dinosaurs the crocodile like
phytosaurs and massive Amphibians
known as the Metoposaurs. The most
common Metoposaur from the Petrified
Forest is Koskinonodon perfecta.
However as it turns out that may not be
a valid name for the fossils coming out
of the Petrified Forest
before the metoposaurs were discovered
in the Petrified Forest the fossils came
out of Wyoming in was called Anaschisma.
This Anaschisma may be the same species as
the fossils coming from the Petrified Forest
However Anaschisma was very
fragmentary whereas the fossils coming
from the Petrified Forest of Koskinonodon
were almost perfect lending to the
scientific name perfecta
and so after almost a hundred years it
turns out that Koskinonodon may not
be Koskinonodon but rather it may
be Anaschisma and that just
highlights how we need to go back and
look at all the formerly found fossils
and ensure that we aren't doubling up on
the number of species we found so we can
get a much better picture of what
exactly lies in front of us so that we
can better understand how to address
extinctions and biology in the future
And finally coming from New Mexico my
neighboring state we have Suskityrannus hazalae
This Tyranosaur was
fairly small as the fossils we have of
it are juveniles but it is the earliest
Tyrannosaur to show the arctometatarsalian
foot condition which is a
special adaptation in the foot of a few
different types of dinosaur which helps
them run longer distances. It's been
found in Tyrannosaurus and also in
things like the ornithomimosaurs like Gallimimus.
The initial discovery of the
fossils took place in 1998 meaning
there's been over 20 years of research
done  on these fossils in order to formally
describe them that doesn't mean that
they weren't totally unknown though the
documentary Planet Dinosaur used an
animal based off of these fossils to
create Zunityrannus in their film
however we do now know that
Zunityrannus is more accurately Suskityrannus.
Hi everyone thanks for watching
lots of stuff came out in May I'm moving
so the next time I film one of these
monthly reviews I will probably not be
standing in this same corner.
My next video is probably gonna be me packing up
all the rocks and going through some of
them while I do that but um you know, be
safe, take care, don't go extinct
