Mammalia

Since this is a common misconception, I feel like destroying it.

If you’ve ever read a dinosaur book from the early 2000s or the late 1900s, then you’re sure to have heard of “Mammal-like reptiles” , the apparent transitional form between reptiles and mammals. Famous examples include Dimetrodon and Lystrosaurus. There’s one problem with Mammal-like reptiles, they don’t exist! Well not exactly.

To truly understand this we must go back to the 1800s, when scientists first discovered these creatures, they thought “oh, it looks like reptile, it must be one.” So they defined the group Synapsida, which, at the time, was a subclass of Reptilia, and can you really blame them for thinking that?

Synapsida/mammal-like reptiles basically included any reptile that was closer to living mammals than any living species, some being very mammalian, like Thrinaxodon.

But there’s a problem here, mammals clearly evolved from these creatures, and mammals were definitely more closely related to certain species of Synapsids than others.

Then, in the early 2000s, a new form of taxonomy was being introduced, Cladistics. Unlike previous forms of taxonomy that was based purely on characteristics, Cladistics revolved around grouping animals based on their evolutionary relationships and shared common ancestry. Basically, if you evolved from a group, you’re a part of that group (with the exception of species). This is why cetaceans are Ungulates (the clade that includes most hoofed mammals), because they evolved from them and are closer to hippos than anything.

So mammals obviously weren’t considered reptiles at the time, but synapsids were, despite evolving into mammals. So there was a problem, Reptilia was paraphyletic (including some, but not all, descendants from a single common ancestor). So taxonomists decided to remove Synapsids from the class Reptilia. This wasn’t a problem since Synapsids were never more closely related to a certain group of living reptiles than others.

So Synapsida became an unranked clade that includes modern mammals, and the term “mammal-like reptile” became invalid, but still is commonly used and the idea that mammals evolved from reptiles lives on. But in reality, mammals evolved from non mammalian synapsids, or stem-mammals, but not reptiles.

Thank you for reading, remember to like share and subscribe.

October 1st, 2023, outside of Richard’s Landing. Told from the perspective of Scout Richard.

“There’s adventure to be found in Richard’s Landing!” My dad said before we took the long drive up to this small town in Alaska, right by Denali National Park. I knew he was just saying it to cheer me and my brother up. We were only going here because we technically own a lot of land in the town, and we have no where else to go. It all happened after my mom died, in a fiery car crash. It was so sudden and mysterious. Apparently my dad was going to pick her up from the airport for his work (he’s a park ranger), but he couldn’t make it in time so she rented a car and tried to drive to him, but crashed. Her parents blamed it on him and he ended up loosing custody of my twin sister and two of my three younger brothers, but was able to keep custody of me and one of my younger brothers whose younger than me by about a year.

We came to Richard’s Landing because we basically own it. In 1921, my great great grandfather, Lewis Richard and his friend started an airfield up here in Alaska. Alaska didn’t have that many airfields back then, and sled dogs were the primary transportation of getting supplies around the state. With airplanes coming and going, a whole town was started. To this day my family is well respected by the other citizens. But at the same time, it’s only known because tourist books list it as a place to see Alaskan cryptids, demon bears and birds of horror they call them. It’s honestly just a bunch of nonsense in my opinion, my dad agrees and when he graduated from high school, he immediately left because at than time the town was capitalizing on the hype of those crypids with all sorts of merchandise, made him sick.

Just as we were about a mile outside of Richard’s Landing, we heard a police siren. When we got close, we discovered that a police officer was standing by a burning truck. My dad pulled over and started to get out of our car.

“c’mon dad, do we need to stop?” I said, but it was too late, he’d already gotten out of the car, so I got out too.

“Hey officer, what happened?” My dad asked.

“Car crash, just found it, the fire department is on there way to put out the flames, although, as you can see, they’re not that big.” The officer said, “wait, do I know you?” He asked.

”Lewis Richard Jr, and you are…” my dad said.

”It’s me, Dave from high school,” the officer said.

“Yo, Dave, it’s nice to see you again, how you doing man?” My dad said.

“Great, you?” Dave said.

”wait you two know each other?” I ask.

”oh, this is my daughter; Scout,” my dad said to Dave.

”Nice to meet you Scout, me and your old man were best friends in high school,” Dave said, “Anyway…” Dave continued talking to my dad.

I knew it would be a while before my dad was done talking to Dave. So I decided to walk over to the woods and check them out. I stopped to inspect a tree. On it were some white fluff, some kind of animal fur by the looks of. When I picked it up, it felt almost like… the feathers of a bird, not fur. I slipped it in my pocket.

All of a sudden I heard a twig snap behind me. A part of me thought “oh no Scout, you took from nature, now you’ll pay the price,” but the more reasonable part of me thought “it’s probably just a squirrel.” Sure enough, behind me was a squirrel, although a very strange one. When it opened its mouth, it showed its teeth, which were unlike any kind of rodent tooth I’d ever seen. I pulled out my phone and snapped a picture of the strange “squirrel”. The sound of the picture being taken must’ve scared it because it ran off.

At least first I thought it was the picture being taken that scared the squirrel off, but then I suddenly felt a chill go down my spine, and the sudden sensation of fear. But that didn’t make sense, there was nothing to be scared off. Yet I still felt like some force was there with me, causing me to panic…”

”Scout!” I heard my dad say behind me. I jumped in shock.

“you okay? You looked a little pale there,” my dad said.

”I’m fine, just saw a squirrel,” I said.

”Okay, but Dave said you can’t be wandering off like that, not by a car crash,” he said.

”okay, sorry,” I replied.

We walked back to the scene of the crash.

”okay, I’ve been inspecting the crash, and something’s not right,” Dave said, “the position the lane the truck is in, isn’t the direction the guy was driving when he crashed, judging by those tire park over there. But here’s where things get weird, the tire marks don’t show signs of turning into the lane, they just stop. The driver stopped, and then something else knocked over their car. And the body wasn’t with the wreck, being whoever, or whatever did this, it took the body.”

”that makes no sense, we’d know if another person did this, there’d be evidence to prove it. It would have to be an animal, but no animal in Denali is large enough to do this, not even a Grizzly,” my dad says.

”What makes it even weirder is that this morning, farmer Tom reported seeing what he thought to be a bear kill on of his pigs. He said what he thought to be a bear actually was a bipedal monster, at least 25 feet in length,” Dave said.

“What did you tell him?” I asked.

” I told him he was probably sleep deprived or drunk, and it was just a bear,” he responded, “still weird nonetheless, but hey there’s a more logical explanation just waiting to be found, I’ll keep you updated as we find out more. Nice running into you.”

”see you soon Dave,” my dad replied.

After that we continued driving into Richard’s Landing. I looked on my phone to try and identify the “squirrel” I saw. I couldn’t match the teeth with any rodent, but oddly enough, they resembled the teeth of a multituberculate, which were members of the extinct mammal order multituberculata, but they’ve been extinct since the Eocene, nearly 34 million years ago, or at least they should be.

Something tells me I was going to have a very interesting time in Richard’s Landing, and maybe, just maybe, that something was the fear I felt when I saw that creature in the woods.

[WARNING: THIS IS FAKE, NONE OF IT HAPPENED, IT DOESN'T EXIST]

Have fun while Sparx and Alpha clean up the art before Beasts from our Past can finally release.

In 1976, Antarctic explorers found something shining through the ice. After breaking and chipping the ice away. They found a mysterious skeleton. It was developed, with... 8 legs... it for sure wasn't an arthropod because there was a skeleton, with ribs, a vertebra, and a complex limb structure. They analyzed a sample of the ice, and took an air sample out of the bubbles in the ice, and found the carbon and oxygen percents put it at the mid-to-late Cenozoic Era. They carefully excavated the skeleton, and analyzed it. they found the spine was fused at one point, with obvious stacking, meaning it didn't have 8 legs, it was two, four-legged tetrapods that were fused together.

They analyzed a chunk of ice with similar chemical structure found 68 miles away, and put it on. The animal had an oversized head and was an obvious carnivore. Wait. "How Scientists Did A Second Brontosaurus", turns out they slapped a Cryolophosaurus skull on it. Back to basics, I guess...

They eventually found a skull impression left on rock deep below the ice. They carefully considered every possibility, it fit. This changed the story completely. It had 2 temporal fenestra on each side of it's head. With its approximate age, this would've put this specimen as the very first mammalian Diapsid, throwing off all theories of Diapsids restricted to lizards and birds. But it was also a confirmed herbivore, as evidenced by it's flat, small, and numerous molars.

So, they carefully split the spines apart, giving them their two creatures. And that's when it all came together. The skull shape, the second set of temporal fenestra, it meant, the horses, zebras, giraffes, donkeys, okapis, they aren't Synapsids... they came from this creature, which was a diapsid. At some point, they must have evolved to lose that second set of temporal fenestra.

So, the paleontologists just kept digging... and digging, and digging. The later found a completely preserved specimen. I mean, it was dead, and starved, and it's eyes were gone, but, the skin, the hair, the bones, the flesh, it was all there. And boy was this boy BIG. 29 feet long and 18 feet tall?

Okay, so, it was indeed four-legged, not eight-legged like some paleontologists thought (See Jack Horner's "Evolution of our Past: The Eight-Legged Tetrapod"). The animal had a boastful neck, long as a giraffe, and a long body with a tail that'd make Diplodocus jealous.

However, it was discovered that the animal had much denser femurs than it's forearms. This led to the Kangaroo Theory, which said that this animal, while using it's long tail as support, they could rear up on their hind legs, and look much bigger than they already were, scaring any predators.

It was likely to live in pairs, as any bigger would've caused overgrazing of the trees.

Eventually, in 2008, a man digging for fossils found another specimen, but this one had a shorter neck, intact skull, and shorter tail. At first, it was thought that this was a result of sexual dimorphism, but as later proved that these two were of two separate subspecies. Also, later in 2008, the species was finally named, Armatemi epizon. The long necked version was given the title Armatemi epizon diutius, while the newer, shorter version was given Amatemi epizon brevior.

It’s up until now that you realize that every prehistoric segment seen in the show is already featured in all 3 trailers. This episode is about how mammals rose to global power. Scenes not shown in the trailer will be censored or not covered in detail.

The scene opens up with the Jurassic, when mammals were insignificant until the asteroid impact. After, the world became covered in forest. To show you what mammal life back then was like, the scene transitions to the present where two tree-climbing mammals, the [REDACTED] and the [REDACTED] live in the Amazon. Their mammalian adaptations and intelligence are highlighted.

Afterwards, the forests started to dry out. Flash forwarding to 34 Mya, a giant Megacerops is shown in a remarkably accurate habitat. Several start [REDACTED] for the [REDACTED], showing how powerful mammals have become. Then the Eocene dried up and grass took over.

Back in the present, animals adapted to grassland life are shown. A deadly cheetah starts a high-paced chase to hunt down a [REDACTED]. Then mammals adapted to living in the mountains are shown, including the extremely well-adapted [REDACTED] that can balance on the narrowest cliffs. Unfortunately, a tragic scene happens.

Grassland animals in the past are shown from 2 Mya. A group of Doedicurus are shown messing around, 4 adults and a very cute innocent-looking baby. Then a juvenile Smilodon arrives and tries to investigate. The following scene is extremely satisfying, but will not be covered.

Finally, mammals shown to adapt to the seas and the skies are shown. A giant flock of [REDACTED] try to escape a [REDACTED] in the present.

Then we see the first whales to evolve during 47 Mya, the [REDACTED], a coast living whale whose CGI is so good that from a distance they perfectly resemble sea lions. One jumps into the ocean to find prey, but finds itself under attack from a ferocious [REDACTED], resulting in a high-stakes chase that will not be covered. The episode closes with modern whales, a group of male [REDACTED] that try to entice a female by chasing her and attacking one another.

Then, humans evolve and the world starts to burn.

Overall review: 75/100. While both prehistoric and modern day segments are good, the prehistoric segments are too few, only 3 out of 8 segments focus on ancient mammals. There is nothing else to look forward to in Chapter 8, which will most certainly only have one prehistoric segment.

Now let's be clear, I love all prehistoric animals, or really all animals in general. All critters are amazing and cool. But if I had to do a top 10 then this is what it would be. Here are my favorites of all prehistoric creatures. Some are dinosaurs but others aren't, and all of them are still fascinating and spectacular animals.

10. Gastornis

What I have first of all is a very interesting dinosaur. Gastornis served a similar purpose as the herbivorous Ornithischians after they kicked the bucket at the end of the Maastrichtian. Unlike the Terror Bird wannabes in WWB, Gastornis was an herbivore that used its powerful beak to grab and crush plant life, much like the beaks of the ceratopsians. It may have also hunted small animals like horses, but I think an herbivorous diet is a little more likely at the moment.

9. Archaeopteryx

The superstar bird of the Jurassic. Archaeopteryx is a fearsome looking blue bird with teeth and a long, raptor-like tail. It's teeth were probably only good for killing insects and maybe small lizard and mammals. It probably couldn't fly super well, but nonetheless seeing one of these in the air would be a dream. Also, it's type specimen is so well preserved and looks pretty awesome.

8. Omnidens

This bizarre predatory Arthropod was as long as a human, and has scary appendages at the front. Omnidens certainly makes up for Anomalocaris being small, and I wish it got featured in documentaries like WWM. Scary look, cool name, and overall a spectacular animal.

7. Cymbospondylus

This 60-foot giant eel-like reptile is an awesome sight. Cymbospondylus is one of the early icthyosaurs from the Mid-Triassic, but it already grew to massive sizes. Despite its huge length, Cymbo was long and thin like a snake or eel, instead of bulky like a whale. It's straight, conical teeth meant it probably just fed on smaller animals like fish, placodonts, and squids. But still, it's one unique ichthyosaur.

6. Gigantspinosaurus

Not a spinosaur, but an awesome bizarre stegosaur. Gigantspinosaurus was built like a Kento, and had spikes on its shoulders and thagomizers on its tail tip. It lived in Asia during the Mid-Jurassic, where stegosaurs first came to be. Overall, this stegosaur is just a super exciting creature with a great name.

5. Timurlengia

I don't know why, but I just love this cool tyrannosaur. Timurlengia lived in the Southern Caucasus, namely Uzbekistan, during the Early Cretaceous. It was mid sized, and probably looked similar to a young Tyrannosaurus. Timurlengia had a relatively long snout, fast speed, and likely some down. Certainly one if my favorite dinosaurs!

4. Griffinfly

The Meganeuridae were giant relatives of dragonflies that inhabited the swamp forests of the Late Carboniferous and Early Permian. The largest and coolest, Meganeuropsis, was also the largest insect ever. Instead of hunting mosquitoes like dragonflies, the griffinflies hunted small lizards and synapsids. The first truly draconic flyers!

3. Arambourgiania

The azdarchids were the tallest and largest flyers ever to exist, and the tallest of them all was Arambourgiania. On par with Hatzegopteryx in size, Arambourg would've been a truly scary sight - a stork taller than a giraffe walking toward you with long stilt-like legs. It's head was smaller than Hatzeg's, so Arambourgiania probably hunted smaller or different prey. But either way it was still an apex predator and a fascinating real-life dragon.

2. Baryonyx

My top dinosaur, Baryonyx is a massive and fascinating spinosaur. It is known mainly for its massive, 1-foot claws that it used for hooking and killing fish. It is also probably the most well known spinosaur, and it's remains are sometimes used to determine the look and lifestyle of spinosaurs who don't leave behind as complete skeletons, like Spinosaurus. Baryonyx ate fish for certain but it also could have hunted Iguanodon at times, and I think it should've been featured in WWD Episode 4 instead of Utahraptor (especially since Utahraptor isn't even from England).

1. Smilodon

And finally, the legendary sabre-toothed cat! Smilodon, the largest of the sabre-tooths, was a lion-sized apex hunter of the Americas during the Pliocene and Pleistocene. Unlike lions, cheetahs, and other modern big cats, Smilodon hunted large megafauna like Toxodon and giant ground sloths, instead of fast-running antelopes and deers. It used its superior bulk to wrestle large animals, and then used its legendary fangs to deliver a death vote the throat, severing arteries and veins and killing almost instantly. Smilodon was one powerful animal, and it's a pity it kicked the bucket just 10,000 years ago.

So, yes, you guys can create creatures for my Speculative Evolution project! Extinct groups aren’t shown. They can be descriptions, and you don’t have to make images. A few notes though:

Rules:

You must make everything make phylogenetic sense(no 6 limbs on a vertebrate as an example), so everything must be grouped into a common ancestor/group with plausible traits.

It is VERY useful for you to make behaviors for your creature, so I have a higher chance of picking you as the winner.

You do NOT have to make images, but you get 1 bonus point if you do.

Each person can only name ONE species after themselves, so choose wisely.

Each person can create 3 genera(not species, so it’d be something like Triceratops as one genus, and Triceratops prorsus and Triceratops horridus are two species)

All genera need AT LEAST one species name

Creatures can only be placed in the following environments,

You can only make creatures evolved from the following groups.

No land carnivore can be bigger than Mortitan imperator, which is at 20 tonnes.

No land herbivore can be bigger than 150 tonnes.

No megaraptoran can be bigger than 15 tonnes

Environments:

Equator Continent: Desert, Heavily Volcanic Area,

Northeastern Continent: Savannas, Jungles, pretty much Africa

Archeon: Island chain with unique life(only place Nothosaurs are)

Isla Borbtile: No non-avian dinosaurs. Think of it like Madagascar

Polar Continent: Tundra, Ice, Frozen Rainforest(the trees form a canopy that stops cold air from coming in, so it’s hot in the inside), Temperate rainforest

South Continent: Unsure. Choose environments

West Continent: Unsure. Choose environments.

Ocean: Open Ocean, Deep Ocean, Coral Reefs

Creatures:

Dinosaurs:

Sauropodomorphs are mainly survived with true sauropods, but none of them live in the Northeastern Continent

Tyrannosauroids are the strongest land predators, but they don’t live in the Northeastern Continent

Megaraptorans are widespread and trying to get the top predator niches. They are the top predators of the Northeastern Continent. They are in 2 groups, the Grappling Kings, which use their arms a lot, and the Scythe Claws, which use their jaws often

Allosauroids are rare, but do still survive, though are not apex predators.

Megalosauroids are only survived in spinosaurids

Noasaurids are fine and doing well in all continents.

Ceratosaurs and Abelisaurs are mesopredators that don’t have many major species compared to the apex predators.

Dromaeosaurs: The most common small carnivore group, but still has lots of competition with synapsids and smaller pseudosuchians

Ornithomimids: only Deinocheirus-like animals survive

Scanscorioptyids or however you spell them aren’t common, and only are in the Equator Continent

Ankylosaurs are better then the Mesozoic. They’ve got a filter feeding population settled as well as some omnivorous ones.

Stegosaurs are similar, but just are much less common

Ornithopods are some of the most common large herbivores through EVERY continent.

Ceratopsians have weird horn shapes, and are very common. There’s a genus on Archeon

Birds are very fine and no danger

Other Reptiles:

Tailed pterosaurs(not sure what specific group) are extremely common in the Equator Continent and Isla Borbtile

Azdarchids have become flightless in some genera, but large flying ones are still going and are common

Tapejarids, Nyctosaurids, and Pteranodonids(or whatever) are the most successful groups.

Anurognathids are crepuscular feeders since birds took day and bats took night

Rauisuchians are desert specialists that are common in deserts

Sebbecids are large pursuit predators that appreciate dense areas

Other crocodylimorphs are as successful as ever

Mosasaurs are mesopredators for the reptiles

Plesiosaurs are common with the long necked dudes, but pliosaurs are barely surviving

Nothosaurs are only survived with a few arboreal species in Archeon

Turtles are fine

Large ichthyosaurs are very strong and somewhat fast apex predators. Smaller ichthyosaurs still exist.

Other reptiles: They’re fine

Synapsids:

Gorgonopsids are part of the ever lasting conflict of “who can control the small predator niches the best”, and are doing well

Therocephalians are in that contest, but are very effective with their venom

Herbivorous non-mammalian synapsids aren’t that common, but are still ok

Entelodonts have become the largest true mammalian predators, reaching max sizes of 5 tonnes, but are aiming for larger sizes

Canines and felines are still successful, but are facing competition they’ve never had before

Pinnipeds are doing very well, and they caused the extinction of most Nothosaurs.

Bears are common omnivores that have reached sizes of more than a tonne.

Rhinos are successful by following in the path of ceratopsians and sauropods

Afrotheres have lost most elephant diversity, but they still live.

Horses are the most common small(ish) prey

Chalicotheres are actually more successful than during the Cenozoic.

Cetaceans are the dominant ocean life

Some species of Sloths still exist, ground sloths and south american Ungulates also exist and are quite successful

Fish, Amphibians, and Invertabrates:

Their usual successful selves. You don’t me to explain much more.

With the rules, groups, and environments done, there’s one more thing we need to say before we start:

Whoever makes the best creature(in my opinion) gets sneak peeks of creatures and can suggest creatures whenever they want.

May the best creatures win! Also, I will be taking the top 5 creatures I see

Also, I’ll try to keep this open until next week Wensday

Prompt: An Abelisaurid sits on a rocky ledge not too far away from its kill. While it has eaten its fill, the scavengers of the area now fight to eat theirs.

REQUIRMENTS

• An Abelisaurid of your choice.

• A carcass of any animal (Ain't even have to be an herbivore).

• One or more species of pterosaurs (One larger than other).

• 2 species of small scavenging dinos.

• One or more birds.

OPTIONAL

• Species of bird hunting pterosaur in the sky.

• Large carnivore ready to barge in and steal the kill lion style.

• One or mammals.

UP-TO-YOU!

• The setting.

All works will be judged by me. You have until the end of the month.

https://scitechdaily.com/new-species-of-mammal-related-to-manatees-elephants-and-hyraxes/