Josephoartigasia monesi, the largest rodent known to science. Weighing more than a ton, it reached up to 1.5 *meters* in height. It dwelled in South America during Pliocene and Pleistocene.
Art by James Gurney.
Today I bring you something peculiar. Meet *Tupilakosaurus*. It is an amphibian that dominated western Laurasia in early Triassic, as the biosphere struggled to recover after the Permian extinction.
Tupilakosaurus was a small - just under a meter long - creature, with a long, powerful tail, short limbs and (apparently) external gills, like those of an axolotl. These fine animals lived in rivers without going ashore and hunted small fish or other amphibians.
Tupilakosaurus is a curiosity due to its particular circular vertebrae (pictured below), which is uncommon for their kind of amphibians. Indeed, when first discovered they were originally believed to be fish, and later to be ancestors to Ichthyosaurs.

Despite their short existence, Tupilakosaurus had quite a sizeable habitat, ranging from modern day Greenland to western Russia, such as Vladimir oblast, Nizhny Novgorod region, and all the way to Arkhangelsk and Vyatka. It would take later amphibians millions of years to carve the same range.
Today I bring you *Benthosuchus* - a relative of the Wetlugasaurus from the other week. Another Temnospondyli amphibian, its name translates to "crocodile of the deep". It's skull was ~70 cm long with overall body length reaching 2.5 meters. As with many other amphibians of this order, its eyes were closer to the top of the skull, aiming them upwards. This indicates that the animal was an ambush predator, waiting patiently just underwater until it was ready to strike.
The typical species, *Benthosaurus sushkini*, was logged by Ivan Efremov in 1929, with overall genus classified in 1936.

Rhyniognatha is an extinct genus of arthropod of disputed placement. It has been considered in some analyses as the oldest insect known, as well as possibly being a flying insect. Rhyniognatha is known from a partial head with preserved mouthparts from the Early Devonian aged Rhynie chert around 400 million years old, when Earth’s first terrestrial ecosystems were being formed. The type, and only species is R. hirsti, which was named and described in 1928. Other analyses have interpreted the specimen as a myriapod.
Fossil:


Another possible reconstructions:


Possible centipede reconstruction, probably as larva, this is suggested, highly speculative interpretation of Rhyniognatha hirsti as a Crussolumlike centipede. Note that the depicted morphology refers to a fully grown adult, while the fossil itself was more likely an early immature.

Head reconstruction:

Coming to ARK soon

Recently there has been a study on Spinosaurus legs that shows that he couldn't support the weight he has on such short legs and that legs must have been 4 times bigger in order for him to function properly. So the small legs were probably from totally different species mixed with Spino skeleton or a juvenile.
Finally he is back to normal.
Thus I bring you **Vetlugasaurus**. Despite the *-saurus* in the name, it is in fact an Amphibian of the Temnospondyli order, which lived in what is now Russia and Greenland during the early Triassic period.
Originally discovered and categorized in 1920-s, it is named after river Vetluga - on the shores of which the first fossil was found. The skull measures ~22 cm, with overall body length ranging from 75 cm to 3 meters.
In 2018, a full skull was found.

The gorgonopsid was named after the river Vyatka in the Kirov oblast, near which it's been found. Kirov, of course, has been named after Sergey Kirov.

Analysis of the bone structure of Multituberculata demonstrates that they gave birth to relatively large babies, with a fairly short period of milk feeding - similair to modern day rodents.
This is in contrast to Marsupials, who birth tiny babies and milk feed them for quite a long time.
  
[Pterodaustro](https://wikiless.org/wiki/Pterodaustro) was a genus of pterosaurs that is believed to have filter-fed with a "tooth comb". Like flamingos (who also filter-feed), the Pterodaustro's proposed color would be caused by its diet, which likely consisted mainly of crustaceans and other small creatures
Because of its tiny focken legs, it might've had some difficulty flying, unlike other pterosaurs

despite the recreation's similarity to the greatest extant rodent, the closest living relative of this genus ([Josepho~~stalinia~~artigasia](https://en.wikipedia.org/wiki/Josephoartigasia)) is the [pacarana](https://en.wikipedia.org/wiki/Pacarana)
approximately 500kg and 2.6m long
here is a possibly inaccurate depiction next to some guy and my cousin

My personal top 10 all time favorites are:
1.Velociraptor(actually Utahraptor/Dakotaraptor/Deinonychus/Achilobator) doesn't matter: they are all just awesome, the fact that they hunted in packs, were vicious killers with their deadly claws, were so fast and agile that someone couldn't possibly escape from them is just fabulous at the least, truly a six foot turkey... And I don't know if they could really open unlocked doors tho...

2.Spinosaurus: it was literally the largest theropod ever, bigger than T-Rex and even Giganotosaurus! It could swim, eat huge fish, hunt larger dinosaurs, hunt on land, hunt in water, just pure badassery!

3.T-Rex: I don't really think I need to explain this one...

4.Dilophosaurus: not small and not too large carnivore with signature crests on it's head perfectly capable of hunting and killing anything middle-sized creature, it has really grown on me with of course Jurassic Park since I was 3 years old and with ARK in 2015, even without the frill and venom, still totally amazing. If they ever succeed in ressurecting a dinosaur, they really should use Chlamydosaurus lizard DNA on it tho... Baby and fully grown:

4.Mosasaurus: the biggest marine reptile ever, it hunted other Mosasaurses, sharks, turtles, everything It could get it's huge jaws on, was 17 meters long!

5.Pteranodon: bigger than any bird alive today, dive-bombed into the water to eat fish, truly an iconic creature!

5.Tylosaurus: once again, huge marine reptile,14 meters long and also hunted everything Mosasaurus did, always wanted to have one roaming in Danube!

6.Compsognathus: just a cute little vicious carnivore fellas that everyone would want as a pet and you should not mess with!

7.Dimorphodon: very cute little bird from the Jurassic, really has a special place for me and I love it, even if it would probably attack you in an instant lol

8.Giganotosaurus: literal gigachad of Cretaceous period bigger than T-Rex!

9.Quetzalcoatlus: biggest bird ever with 12 meters wingspan bigger than my building where I live, what else do you need?

10.Carnotaurus: a vicious and fast predator with an iconic horns and smol arms!


[Jaekelopterus rhenaniae](https://wikiless.org/wiki/Jaekelopterus) (410.8-402.5 Ma) is the largest known species of arthropod. It's classified as a [chelicerate](https://wikiless.org/wiki/Chelicerata), which also includes sea spiders, horseshoe crabs, arachnids, and various other extinct groups. They're called "sea scorpions", but they likely didn't actually live near the sea, so someone screwed up there

**^** The horseshoe crabs are close extant relatives. (As a side note, I just learned that horseshoe crabs' blood (which is blue btw) is used for pharmaceutical development since it can detect toxins, and now you also have to deal with that knowledge)
It's [Ambulocetus natans](https://wikiless.org/wiki/Ambulocetus), folks. They could move around on land using contraptions called "legs" -- as you may have noticed, modern whales typically don't have these. Known from a single fossil found in Pakistan, they existed 48-47 million years ago and then literally disappeared into thin air (confirmed by witnesses at the scene)

This particular skeleton was discovered in Mongolia in late 1940's - early 1950's. At the time USSR had organized a number of paleontological expeditions into the region - with great success. One of the most famous paleontologists of the expeditions was Ivan Antonovich Efremov (photo below), although he is better known as a science fiction writer, depicting a bright, socialist future of peaceful space exploration.

They're basically just like any other arthropod. Don't even know why I bothered to post this

They varied in size from around 5-55 cm and were around during the Cambrian to middle Devonian (around 500 to 400 million years ago, give or take a few million years)
Or maybe I'm thinking of a giraffe
---

It's actually a [pterosaur](https://wikiless.org/wiki/Pterosaur), which was a clade of non-dinosaur flying reptiles (228-66 million years ago)
   It's named after this lad
- Closely related to modern monitor lizards
- 12-14 meters in lenght
- Carnivore
- Used snout to locate prey
- Eated: fish, sharks, squids, turtles, Plesiosaurs, Hesperornis, and other Mosasaurs

- Unfortunately extinct at end of Cretaceous period, since I was little I want that we have one in Danube so bad

- Here is JP one cause it's badass:

This is the Paleontology Museum in Moscow. The current building (pictured here) was created in 1965, after Academician Yuri Orlov petitioned the government that the old building was becoming too cramped and unfit for the vast collection. The museum currently bears comrade's Orlov's name.
Their website: https://www.paleo.ru/museum/about/
More pictures inside.
### Platybelodon

### Moeritherium

### Stegodon

Can we have these back, please
An artist's rendition of an early human village, with some freshly-domesticated dogs at the forefront. At the back, a cave lion is hesistant to approach the strange place.
Sadly, I have lost any information on who the artist is, so if you know - please share.
This is an Olorotitan - a type of hadrosaur, found in what is now Amur oblast in Russia. At approximately 12 metres long it was one of the largest species of its family. It is also notable for some unique characteristics, such as having 18 vertebrae in the neck, instead of the usual 15. Some scientists consider this to be a hint at the potential evolution of the hadrosaurs, had they not gone extinct - a drift towards sauropod like adaptations.