Hi everyone, this is Ezekiel O'Callaghan with Raptor chatter.
We finally got our actual somewhat set set up
So that's really exciting
We are gonna be going over what happened for December 2019 and paleontology
and if you are waiting for the year in review...
shouldn't be much longer
So let's begin our review
So in November there had been a leak about a dinosaur that was mummified.
And while this study isn't on that dinosaur
It does help show just how valuable mummified dinosaurs can be to the sciences
Specifically the fossilized soft tissue that isn't skin
can still help show some of the proteins that would have existed in dinosaur flesh  and essentially ...
dinosaur meat
By looking at a mummified hadrosaur,
researchers were able to show that some of the proteins from the original meat and flesh of the animal
could have been preserved
And this is different than from the skin, which is where most of the study in mummified dinosaurs has occurred
What the study shows, is that the flesh and meat of dinosaurs, even hadrosaurs,
which were very distantly related to birds
very much resembled the chemical composition of birds
Meaning that yes, dinosaurs might have tasted like chicken
This is very important because as I have mentioned the hadrosaurs were very far separated from the birds
By over 180 million years of evolution
What this means is that all of the dinosaurs may have had this kind of chemical composition in their meat and muscle
Which is very unique and helps the birds become so successful with flight today
and while hadrosaurs didn't fly
That same kind of very efficient muscle type may have helped to become as successful as they were
The early theropods are very diverse
But finding something that can be defined as an ancestor
or close to an ancestor of one of the later groups
That was more dominant during the Jurassic or Cretaceous is very hard
Even Cryolophosaurus,
only seems close to the base of where the split would have been between things like
the coelurosaurs and the allosauroids
which isn't very specific
and that makes this new find coming from Argentina even more special
Astolfovenator vialidad is one of the most primitive known allosauroids
Or at least it's probably an allosauroid
it has a large mix-up of different traits that are found in many of the other groups of early theropods and
this helps to show just how diverse and
Exactly how related some of those groups may have been
The combination of traits that are very similar to both the allosauroids and the Megalosaurs
Helps to mix up our understanding of how exactly many of these early theropod groups were related
Previously, before Astolfovenator had been discovered
It was thought that the Allosaurs and coelurosaurs  were more closely related than the Megalosaurs
which would have been a separate group
That was also very successful throughout the Jurassic and parts of the Cretaceous
However, Astolfovenator having this mixture of allosauroid and megalosaur traits
really does mix this up
What it suggests is that the Spinosaurs aren't within Megalosaurs as was previously thought
and were their own distinctive group
But then also it shows that the Megalosaurs and the Allosaurs were much more closely related
with Metriacanthosaurus somewhere in between that
This entire clade has been grouped within Carnosauria
Which was previously just for the things like Allosaurus and then the later Carcharodontosaurus
What this means is that the coelurosaurs, which would lead to eventually the birds
but also raptor dinosaurs and Tyrannosaurs,
are much more separated from animals like Allosaurus and giganotosaurus than previously thought
And that the evolution towards the birds was very distinct from the rest of the clade that made up the theropods
For a single fossil to so revolutionize our understanding of how different theropods were understood
is going to be controversial
However, a few other researchers have stated that they have entered data from Astolfovenator
into their own datasets for their own studies
and that what they're finding is in agreement with what the researchers found in this study
meaning that it does seem very promising that more research done on this species and this specimen
Will help reinforce the idea that the Megalosaurs and the Allosaurs
were more separate from the coelurosaurs than previously thought
Very, very occasionally and only in the best preservation
the central nervous system of certain arthropods
May be preserved
The reason I say 'may' is because there is still a lot of debate about it
A new paper looks at two different Arthropods coming from the Cambrian
and suggests that yes, This is the central nervous system of the animal
However, this will still be debated
What some other researchers are suggesting is that rather than being the central nervous system of the animal
That it's actually the gut cavity leaking some of its fluids and causing the dark staining on the rocks
Which some people are interpreting as a central nervous system
rather than being a true central nervous system as we wouldn't be as likely to expect in the fossil record
However, what the researchers of this paper suggest
is that the we do see certain traits that do align with what we know of the nervous system of even modern-day arthropods
and this is a few different things
First that the gut in the esophagus of the animal actually passed through the central nervous system
Essentially when it goes up to the eyes it makes an entire loop
and then the gut cavity goes through that loop and lays on top of the nervous system of the animal
And this is something that is found in modern arthropods as well
From butterflies, to ants, to even grasshoppers
They all show this same kind of thing where the gut cavity passes through the nervous system
before continuing along the rest of the body
There's also what appeared to be ganglion
which are essentially smaller bundles of nerves that exist in each segment of modern-day arthropods
and also appear to exist in certain segments of these primitive arthropods
Meaning again, this may be a central nervous system
The main issue with these papers is that it's very hard to prove definitively that it is indeed that nervous system
And so more study with many more specimens is going to need to be done
Ceratopsians often have elaborate headgear
and Triceratops is the most famous of these
But it's separate from the group that we're going to be talking about today
Which is the Centrosaurs
Of the Centrosaurs,
Styracosaurus is one of the best known of this clade
with it's very very elaborate frill being one of the most distinctive features of the species and of the genus
However, where most depictions of it show a very even presentation with
both sides of the frill being very symmetrical
a new fossil shows that wasn't necessarily always the case
The fact that at least one specimen of Styracosaurus shows asymmetry
indicates that at least the ceratopsians with more horns
may not have been a symmetrical as the ones with fewer horns, like Triceratops,
may have previously indicated about the entire clade
With the same find may indicate for the species and the genus is far different
What it may indicate for the genus
is that Styracosaurus may have even cross bred with something like Centrosaurus
Which was very closely related and may have been the direct ancestor to Styracosaurus
They are both found in the same formations after all
Problem with this idea though,
is that different specimens of Centrosaurs and Styracosaurus
don't necessarily line up in the time frame of the different formations
to make it likely that they would have been an anagenic series
essentially one species evolving directly into another
Rather, the authors suggest that instead of this
Styracosaurus had a diverse breeding pool
and that would have been more likely to cause this kind of asymmetry that we see in this fossil specimen
rather than cross breeding. Which would be more difficult and more unlikely to happen
Another new paper suggests the oldest parental care in the fossil record
coming from the Carboniferous period
The find consists of two specimens of a new species of amniote
Dendromaia unamakiensis
The two specimens were found within very close proximity of one another
with the smaller specimen appearing to be within or under the arm of the larger specimen
The two specimens are fossilized within what appears to be a hollowed-out, Carboniferous tree stump
Which to me, at least, doesn't indicate parental care
Rather, what it indicates the me
is more likely both specimens attempted to seek shelter within the tree stump
from something else in the environment. that would have been a greater hazard
And this could have been something like a flood
as you would need to bury the tree stump in order to get these specimens to fossilize
So as much as the researchers are trying to suggest this is the oldest evidence of parental care
There's still gonna be a lot of debate about this find and it's not necessarily gonna be all one-sided
Depending on what other researchers feel
Personally again, I don't feel it's necessarily completely
definite that this is parental care
Rather, I think it was just a very opportune and very unique fossil
That is very interesting, but not at quite as interesting as the researchers suggest
This find though, again like I said, is unique
and so will help inspire a lot more discussion on when exactly parental care evolved in the fossil record
and it is a very good indication of how paleontology works
with a lot of discussion happening from many different people
So feel free to leave your opinions down below as well
Complex forests are very well known from the carboniferous period
In fact the word 'Carboniferous' comes from the amount of coal that was found
coming from this time period in the fossil record
But these Carboniferous forests weren't the oldest forests
New fossils coming from the Devonian of New York
showed that even some of these older forests from the Devonian
had incredibly complex trees with very complex roots
The roots have been associated with fossils of Archaeopteris,
which isn't to be confused with Archaeopteryx, which was a dinosaur closely related to birds
Archaeopteris was one of the most dominant trees of the Devonian
and from these new fossils had very complex and seemingly very modern roots
Within the area of this discovery, are other roots from other trees
which show that they weren't nearly as complex as these other more modern roots were
and that these more modern trees were able to become more successful into the Carboniferous
and were able to very much change the environments and the atmosphere around them
These trees became very successful
and created so much oxygen that it was at almost 35% during certain parts of the Carboniferous
And it all started from these Devonian trees
which were already preparing to have very modern roots much like today's trees
Which brings into consideration how much forest can change the environments today
And why we should be sure that we are protecting and managing them in a safe and sustainable way
In order to become a fossil, the animal needs to be buried rather quickly
and this often requires a lot of water
as you need to be able to have a lot of water moving sediments in order to cover the animal
before it starts decaying
And there's a lot of water in the oceans...
What this means, is that the oceans preserve a very good record of different fossil life
during different times of the earth
What this means in mammals, is that the whales are one of the best-preserved lineages
of evolution over time
As the whales were already going into the water as early as 50 million years ago
Just a few million years after the extinction that killed the non-avian dinosaurs
However, later than this, there's still a lot of other Transitional forms that we can still study
The animals that are the best examples of this are often things like pakicetus
Which show some land-based adaptations and some water-based adaptations
However, even once the whales became fully aquatic
there are still new studies showing more transitional forms
as they became the modern whales that they are today
As an example of this, a new study looks at a new species of whale
Aegicetus gehennae
Coming from the late eocene about 35 million years ago of Egypt
This species shows the reduced hip proportions
that would have led to a more tail powered swimming condition
rather than leg swimming condition as found in earlier versions of the whale
In Aegicetus,
we see the reduction of the hind limbs which previously would have been used for a paddling swimming motion
and the enlargement of different tail vertebra
which would have helped the tail become more dominant for swimming
much like it is in modern whales today
This new species is just one of a long list of different transitional whale species that we know of
But they do help show how we got the whales that we have today
and just how complex the evolution of whales from pakicetus
into modern day animals like the blue whale or sperm whale has been
The Pseudosuchians  were some of the most dominant predators of the triassic in the American Southwest
Animals, like Poposaurus, Arizonasaurus, or Postosuchus all were very dominant
and even out-competed many of the dinosaurs in the region at the time period
and this was because many of the theropod or early theropod dinosaurs
that existed in the Southwest of the United States during this time period
were very small and very fragile such as Coelophysis
which was very hollow boned
and wasn't necessarily going to be taking on something as bulky as a poposaurus
A very well-preserved Poposaurus is a great example
of how these animals were able to out-compete the dinosaurs for most of the Triassic
Poposaurus would have been about 6 to 7 meters long
making it much larger than the contemporaneous dinosaurs that would have lived alongside
Such as Coelophysis.
While the skull of this fossil is missing
the hips help to show how they were still bipedal much like the dinosaurs
with greatly reduced forelimbs
and this would have helped them to more rapidly catch prey when hunting
The find places more emphasis on the hip differences between dinosaurs and Pseudosuchians
as being one of the main reasons that led to the dinosaurs' success
The more efficient running in walking gates of the dinosaurs
would have helped them become more successful in this small and medium sized carnivore niches
up until the end of the Triassic
where the Triassic-jurassic extinction allowed them to become the most dominant predators on the land
The reason I want to specify on land is because a lot of the Pseudosuchians
did become much more aquatic
and by that, I mean many of them evolved in the crocodilians we see today
While not all of them did stay in the water
such as Baurusuchus from the kem kem beds of Cretaceous, Morocco
They did dominate the water and very few of them did leave it
But the fact that they did do so well on land during the Triassic
and even the Cretaceous and parts of the Eocene
Shows that the crocodilians aren't necessarily limited to just water
especially when they have a few million years of evolution on their side
Hang on
Dani I don't think we can record in here...
(Dani) Too echo-y?
(Zeke) It is so echo-y! Like... just my voice
(Dani) How does it sound with the door open?
(Zeke) Hello?
(Dani) Better?
(Zeke) No.
(Dani) ARRRRGHHHH!!!
(Zeke) Like, listen to this
(Dani) I know... I was hoping it wouldn't be too echo-y...
(Dani) DAMN IT! IT WAS GOING TO BE SO COOL!!
(Zeke) It was.
