Hello everyone, Zeke O'Callaghan with Raptor Chatter here
and I'm going to first point out that you don't see my cabinet with the fossils behind me
Because my wife and I are moving so that I can go to university
However, hopefully we'll have that set up in the next few months
As for the subject matter
We're going to be going into June 2019 in paleontology
Some dinosaurs had very strange feet
The Tyrannosaurs had a bone in the foot that pinched up to become very narrow
and this helped them in long distance running
The Raptor dinosaurs such as Velociraptor had the iconic a sickle clawthat they could use to help
grapple onto prey while hunting
This meant that the dromaeosaurs
essentially would just run on two toes while the other would be lifted up and above
However, now there's a dinosaur found coming from South America that used only one toe when it ran.
Vespersaurus paranaensis
was the species of abelisauroid more closely related to animals like Carnotaurus than to the Raptors such as
Velociraptor or Deinonychus
It had the unique adaptation of raising up the two flanking toes on each foot and running on only the larger
singular middle toe on each foot making it functionally mono-pedal using only one toe
While this is the first time this has been found directly in a dinosaur
there has been some trace evidence that suggested this type of behavior
coming from not too far away
A slightly older formation of rocks nearby
showed trackways which contain tracks that appear to have only one toe being used
indicating that a slightly older relative of Vespersaurus  may have lived in the area
and in a very similar environment
as both of these formations, the one where the track comes from
and where Vespersaurus was found
are very scrubland desert-y types of environments
Well the exact reason for the dinosaur becoming mono-pedal isn't known
It does indicate that there's a lot of variety in the dinosaurs that we don't necessarily know about
and how even looking at track ways
we can start to understand different things that we may find better clues to later in the fossil record
The Cambrian explosion is famous for giving rise to many of the complex forms of life
that we see even to this day
It's exact cause hasn't always been known though
A new paper, however, it suggests an earlier cause to the Cambrian explosion
coming from the Ediacaran Period
The paper suggests that during the Ediacaran, there were large volcanic arcs being formed by plate tectonics
When two plates of oceanic crust meet one will begin to sink
It will then begin to melt and rise up as magma
Causing volcanic arcs to form as that magma reaches the surface and becomes lava
This process can be seen today in
places like the Aleutian Chain in Alaska or in the Philippines
where subduction causes large volcanoes to arise
The production of these types of volcanoes during the Ediacaran period
would have been much greater than that of today and the eruptions from these volcanoes
would have released nutrients into much of the water supply
and this then would have caused an increase in the amount of photosynthesis and
oxygen being produced
Therefore allowing larger animals to begin evolving
as there is more oxygen for them to begin attaining a larger body size
while it isn't definite it is a good step and educated guess towards what exactly caused the Cambrian explosion
and how life began to reach the many complicated forms it has today
Large birds such as the Moas of New Zealand and Elephant Birds of Madagascar
did quite well up until human arrival on the respective islands
However, earlier humans still interacted with large birds
Specifically, Pachystruthio dmanisensis, a new species of fossil bird
coming from the Crimea region of Ukraine
The time in which Pachystruthio lived in mainland Europe
coincides with the arrival of some of the earliest humans to the continent
Meaning that it very likely interacted with humans
potentially as a food source for them
And when we talk about this predator to prey dynamic,
we need to understand that Pachystruthio was not predator like the earlier terror birds of South America
But rather was much more closely related to animals like the modern-day ostrich
Meaning that it would have been much more likely to have been predated upon by early humans
rather than the other way around
Jurassic Park has instilled and promoted the idea in many people that we can get DNA from fossils
if only they are preserved well enough
And a new study presents that that may be true but not necessarily the DNA were looking for
Instead the DNA that some scientists have been able to find is that of bacteria
Bacteria living in the soil where many fossils are found is free to move through it
However, it risks more damage from things like acid rain and the elements if it remains in the soil
That's where a slightly harder dinosaur bone can provide a refuge for it
This means any DNA that we find from dinosaur bones is much more likely to be that of the bacteria
and a false positive as to being true dinosaur DNA
With this in mind, we need to be very very very understanding that dinosaur DNA
likely won't survive the fossilization process. It's just too old
DNA is designed to fall apart in part of this self replicating process that all animals need to function
That also means that once the animal dies, one of the first things that DNA does is fall apart
Because of this, it's much more likely that any traces of DNA we find in dinosaur bones
are that of the bacteria that have moved into the bones seeking refuge
I will go on to continue to say that some more modern fossils
such as those of some mammoths and giant ground sloths do still contain DNA
because they fossilized much more recently and the full decay of the DNA hasn't had enough time to take place
and that'll be important going into our next article.
So sloths are weird.
There's the two-toed sloths and the three-toed sloths that are found today
And while they are superficially very similar- being slow-moving tree-climbing animals
They really aren't that closely related.
And that's something we've known for a long time
The closest known relatives that we know of to each of the respective tree sloths
are different genera of ground sloths separated by many millions of years of evolution
However, a new study suggests that what we had thought they were set up as
isn't exactly accurate
Now, the two modern tree sloths are still very much separated
but the groups that they're most closely attached to and related to have changed
and this is because we've been able to look at DNA of many of the fossilized ground sloths
and modern sloths in order to make a more accurate family tree for this group
And so this has thrown a lot of our understanding for the evolution of sloths out the window
as we begin to understand with better evidence what exactly happened that led to some ground sloths
becoming tree sloths.
And with the graphic from the papers showing this just how much change there was among these groups
just based on DNA evidence
And so if it is possible that DNA from animals
especially the ones that are more modernly preserved
It can help our understanding of their evolution and potentially causes of extinction
as we can begin to compare which species today are doing well,
and which ones they are most closely related to that have already gone extinct
Modern hyenas live in Africa, but they once ranged much further than that
particularly Chasmaporthetes which were running hyenas
Having a much straighter back and longer back legs than are modern-day hyenas
These animals were built more like a cheetah than our modern hyenas
And could be found across Eurasia and even as far as Arizona and even further south into Mexico
They were quite successful animals for their time
In order to get into North America
these hyenas crossed the Bering Land Bridge a bridge which formed as the ice age worsened
As the glaciers expanded across the continents, they would take in and freeze some of the sea ice
lowering sea levels and revealing the land bridge that is now covered between Alaska and Russia
As for the hyenas, it's been thought that they moved through the northern parts of the area fairly quickly
But a new fossil shows that they were there for at least some time
And how long that is... we don't know
The fossil that was found that shows that they were this far north in what is now the Yukon Territory of Canada
was found many decades ago and resided in one of the Canadian museums until its rediscovery this past year
After a description, it becomes more clear that that site
may be more able to provide more evidence that hyena stayed there
and whether they stay there for a longer time or
were just simply passing through the area moving south to warmer climates
where they may have been better adapted
Understanding the arm movements of dinosaurs and particularly theropods
can be very important for understanding how flight evolved
In order to better understand the arm movements of the early dinosaurs
researchers looked at one of the best preserved and largest of the early theropods
coming from the early Jurassic
Dilophosaurus wetherilli
Some of the postulations and idea is for the flapping motion of modern birds
has come from the idea that early theropods
and some of the later Coelurosaurs, would use their hands to snatch prey out of the air or off the ground
reaching forward and not being adapted into the flight motion
This new research, though, suggests that Dilophosaurus did not use its hands in that way
Rather primarily using its mouth when it was hunting and just using its arms and hands to clutch
prey close to the chest in order to control it rather than actively hunting using its arms
The authors do hold some caveats though
Particularly, that this Dilophosaurus was injured before it died
In fact, there's an entire paper on just the injuries of this Dilophosaurus and to read directly from the paper:
The petrified pectoral limbs are peppered with a plethora of Paleo pathological peculiarities
that point to a plenitude of potentially painful problems that plagued the poor prehistoric predator.
Which well on one hand, yes
It is just a bit of fun alliteration for the authors
also is something that is noted about the specimen that one of the arms was very very badly damaged
and had a number of broken bones that had partially healed or not healed at the time of death
The authors do also point out that
Dilophosaurus had a significantly less flexible elbow joint than those of animals such as the Coelurosaurs
Some of which would eventually evolve into the birds
This shows that not all dinosaurs would have had the ability to evolve
into something resembling our modern-day birds.
Rather, it took the Coelurosaurs' evolution to take that very derived trait
which is that flexible elbow
to begin attaining flight and beginning to become more bird-like
Trilobites are a very commonly found fossil
because for a long part of Earth's history, they were pretty much everywhere
However, where exactly they evolved from and which animals they are most closely related to
has been up for debate
Many have suggested that they were closely related to animals such as horseshoe crabs and the eurypterids
both of which were very closely related to the arachnids
However, a new study of trilobite eyes suggests otherwise
A new study looking at Trilobite eyes
shows that they aren't that similar to the eyes of animals like the horseshoe crabs
but rather they're much more similar to animals such as the lobsters and other crustaceans
This would put the trilobites in the group, Mandibulata
Again much closer to crustaceans and then eventually the insects
This month has gone to show that very small pieces of evidence
such as the DNA of certain ground sloths or just some eye cones in a trilobite fossil
can help revolutionize and better our understanding of the natural world
Just because a find is big and grand like that a Vespersaurus, which is a very unique dinosaur
doesn't mean that we should overlook other types of fossils that are smaller
Alright everyone, it's been a while getting this out
Again, we're moving
So hopefully we'll be able to keep up with getting these out getting everything sorted
it's nice not being in the greater Phoenix area where it's
114 degrees Fahrenheit right now
Again still moving
So we'll be getting out getting our own place eventually and having our normal set up
and hopefully get something a little better set up for recording  depending on what we find too
because I know there were some audio issues in the old house
Be safe
take care of each other and
Let's not go extinct
