Hi everyone
this is Ezekiel O'Callaghan with Raptor Chatter
And firstly, I would like to apologize for not uploading. My wife and I were on vacation and so weren't able to get videos done
However, now that we're back ready to start the month with April in review
This April had a lot of really big finds including the find of one of the biggest things to ever live in our ocean
An Ichthyosaur jawbone from the late triassic
came from a creature that was estimated to be almost 25 meters long or 85 feet
The only thing that we know if that would be larger than this in the fossil record
Would be things like our modern-day blue whales and other baleen whales.
Being so large and so new to science
it's given new ideas as to just what these Mesozoic reptiles could do and how large they might have evolved
According to one paper published this month
there are about 5 million years between the end of the Permian extinction and the recovery of the marine species
And this is specifically due to anoxic events in the oceans
That is not having enough oxygen in the oceans to support life
Looking at oceanic sediments from the Early Triassic of Iran
Scientists were able to correlate the anoxic events with the extinctions of several different types of ammonite in the early triassic
showing how these later anoxic events help to stunt and
slow down the progression and recovery of marine life after the Permian extinction
If you were to imagine a lizard with four eyes
this probably isn't what you'd imagine
A species from 49 million years ago was found to have two different
pineal eyes. And while some species today are known for having that third eye, a pineal eye,
this species had the two holes in the skull which showed there were two, helping to lead
understanding and development of how reptile skulls evolved and helping to say that reptile skulls aren't
necessarily the best analog we have to other species like amphibians, which also have pineal eyes
Dinosaurs were just one small part of the group called Archosaurs during the early and mid Triassic
Before expanding and dominating the planet during the Late Triassic
This dominance and diversity from that dominance seems to stem from the Carnian Pluvial Episode
A period where Earth's environment went from very arid to very humid and then back to arid again and
This just helps us to understand how the dinosaurs were able to gain dominance over their relatives
Which were also doing very well at the time and then dominate the planet for a further
140 million years helping to shape much of the history of life on Earth
For a different look at paleontology, we're going to look at the International Journal of Astrobiology
Which asked the question
Would we be able to tell if there is an industrial culture 420 million years ago during the Silurian?
They came up with the answer that no, you wouldn't be able to tell
Any sort of leftover sediments from that time period would be indistinguishable from all the background events that already happened on a normal
basis on earth
And that means for our time period the Anthropocene
We may not leave behind a major mark in the sediments and the rocks of the earth
At least compared to the normal behaviors of the earth
On the other hand normal behaviors on the earth have also killed off 90% of life at times
So we should temper this with caution and still do what we can to limit our impact on the global climate
Another study looked at the teeth of coelurosaurs, one branch of the theropod group of dinosaurs
to try to understand how exactly they ate
It found that the puncture and pull tactics work best
Meaning that they would puncture and then pull right back out
This study looked at a wide variety of species including the Tyrannosaurid: Gorgosaurus,
the dromaeosaurus: Dromaeosaurus and Saurornitholestes
and the troodontid: Troodon
Based on what they found
Troodon would have had the weakest teeth for this method of eating
Meaning that it may have filled a different niche in the environment which many of these species are found
Meaning it could have been anything from a scavenger to just eating smaller
prey rather than the larger prey that it seems the Dromaeosaurs and the Tyrannosaurs ate
Further study of teeth, looked at the calcium isotopes found in certain species
particularly in North Africa
so this would be species like
Spinosaurus
Carcharodontosaurus, and sarcosuchus all very large
40-foot long plus
predators in North Africa during the early and mid Cretaceous
By analyzing the calcium content and the chemical makeup of the teeth
The scientists are able to compare that to modern-day species to get a better understanding of what exactly the preferred prey was
so for things like
Carcharodontosaurus and some of the abeilisaurs which also looked in the area. It was found that they had teeth most suited to eating land-based prey
where something like sarcosuchus had teeth that was suited to both fish, aquatic prey, and land-based prey.
And meanwhile, Spinosaurus
potentially had a diet consisting entirely of fish based on the chemical analysis of the teeth
And this shows the potential for
resource partitioning in an environment to allow multiple
very large predators to survive alongside one another just as it may have shown with Troodon in the previous study
The extinctions of the megafauna like mastodons, mammoths, and ground sloths
at the end of the last ice age has been under question as to its exact cause with many scientists suggesting
human hunting caused many of these extinctions
However, there's been little direct evidence of human hunting on some of these species
Footprints from white sands national monument, New Mexico
Have shown the pathways that a giant ground sloth took 15,000 years ago
And also the same pathways that a human hunter took during the same time
Some of the human footprints were found inside the footprints made by the giant ground sloth
Meaning these were made in a very close time proximity to one another
Additionally there seemed to be flailing circles where the sloth would rear up and try and flail at other hunters approaching from another direction
Showing some inherent self-defense in the ground sloth as it knew this was a predation attempt
And so the idea that human pressures are causing extinctions is gaining momentum still
and it could even still be happening today
Thank you everyone for watching. I want to apologize one more time for not having videos up for a while
We will have a video over the vacation we took because we did stop at the Fukui prefectural dinosaur museum in Japan
And so I'll do a review of that cuz it was a fantastic museum. And me being me: Take care. Be safe. Don't go extinct
