synapsida

Hey, look. It’s that Megaloceros giganteus portrait I started in April 2015… and finally finished.

Commonly known as Irish elk* or giant deer, M. giganteus lived in Eurasia during the Middle Pleisotcene and Early Holocene. It had the biggest antlers of any known cervid: it could reach up to 40kg in weight, and up to 3.64m across. In body size, it was similar to the Alaskan subspecies of moose, reaching on average between 540 - 600kg, with large specimens weighting 700kg or more.

It’s closest living relative is probably fallow deer (Dama dama)

*elk in British English is exactly the same animal as moose in American English. Don’t ask me why. Elk/moose live in Eurasia as well as North America, so it really doesn’t make any sens to me, but there you go.

Castorocauda lutrasimilis catching breakfast. I’m not sure about the hind leg, but I was too lazy to change it.

Castorocauda was a semi-aquatic docodont that lived about 164 million years ago, during the Jurassic period, in what today is Inner Mongolia. It was a piscivore, that also supplemented its diet with invertebrates.

It was mammaliaform, but not a mammal.

It could reach a little over 40cm in length, and between 500 to 800g in weight.

The name Castorocauda lutrasimilis means beaver-tail similar to otter.

The holotype preserves extensive coat of fur, and also small scales/scutes on the tail. The tail was also covered in sparse hair.

I don’t have time for anything lately, so here’s a silly drawing of a Thylacosmilus atrox I did about two weeks ago and didn’t have time to upload it until now. Inspired by the jowls cat/chin cat discussion, and also by my dog :P

I’ve decided to combine big jowls with big chin, because the idea of sabers covered entirely by really long, floppy jowls doesn’t strike me as very comfortable for the animal, and sabers covered only by sort of flesh-sheaths on the mandible also don’t seem comfortable, so I went with somewhat floppy jowls covering the top part of the teeth, and partial sheaths on the lower jaw covering the rest.

And also, by looking at today’s predators, I’d guess that Thylacosmilus spent a lot of its time doing what predators do best: being lazy.

Thylacosmilus lived between the Late Miocene to the Late Pliocene in South America, and I’d be very surprised if they didn’t flop on their backs at least from time to time.

So, I’ve made an anatomical study of everyone’s favourite giant hornless rhino.

Paraceratherium lived in Eurasia during the Oligocene epoch, and was one of the largest land mammals ever - its skull alone could reach 1.3m in length*. Exact size of Paraceratherium isn’t known due to lack of complete specimens, but it’s been estimated to be up to 7.4m long, 4.8 to 5.25m tall at the shoulder, and weight between 11 and 20 tonnes.

It was a browser, feeding on relatively soft plants.

I used modern rhinos’ and horses’ muscle systems for reference. And I’ve learned that there exist a shrink-wrapped reconstruction of Paraceraherium, with matchstick legs that in no way would be strong enough to carry animal of that size. Honestly, it’s the stuff of nightmares.

* for reference, I’m 1.58m tall. Sure, that’s not much, but it’s still pretty mind-boggling to think about something’s head only 28cm shorter than me.

I think this guy is finished… I’ll have to check tomorrow, when I’m actually somewhat awake. I have two versions of this, with one minor difference, but I’m just to tired to decide now which one is better (or if I still need to fix something, add some shadows, and so on).

But anyway, 2 pictures done, 10 more to go!

And a little bit about Haptodus: it’s the most basal sphenacodontian, and member of a lineage that eventually led to mammals. It lived during the Late Carboniferous and Early Permian (299 - 296.4 Ma). It was about a medium-size predator, with individual sizes varying between 60cm and 1.5m in length. It fed on arthropods and small vertebrates. I based my reconstruction on H.garnettensis ( or H. baylei, depending on whether baylei is a valid species or not.)

It’s lying on Cordaites leaves.

Next one will be Pantelosaurus or Tetraceratops.

Dimetrodon grandis, a large Sphenacodontid from the Early-Middle Permian. Despite being a reptile, Dimetrodon is actually more closely related to us than to any contemporary reptile group. It used its large sail for thermoregulation, turning to the sun when it needed to warm up. The sail also may have had a role in sexual reproduction, as well as a threat display.