(Temnospondyls are a large group of early tetrapods!)

Trematosaurus

Trematosaurus is a genus from the early Triassic, and was described in 1849!

They are found in what is modern day Germany and Russia

They have a slender skull with an elongate snout and probably preyed on fish

They are sometimes compared to modern day crocodiles

Art Credit: Dmitry Bogdanov

A preface and first week

This isn't the first time I've done so, but it is the one I have done to such a consistent degree.

When I saw the prompts for a full month of PREHISTORIC mermaid designs, I immediately jumped into the challenge. The prompt choices were varied, and also filled with plenty of obscure genera. Many of which I probably would not have drawn otherwise, I mean, have you heard of Cycleryon? Eretmorhipis? Yawunik??? Die hard paleonerds probably have, but even I was unfamiliar with some of these prompts..

With so many different and varied creatures with different forms, body types, and biological families, it proved quite the interesting challenge to portray them as unique and coherent mermaid designs. But this is part of what made it fun to do, I've had to think outside the box for some of them, and even for the more straightforward ones, I've done my best injecting my own creative juices in making interesting Prehistoric Mermaids.

Credits to the prompt by Subjectively on YouTube, or @magik_jack_art on Instagram. I have been following him along for some time for both his fakemon and creature designs, and they are just genuinely creative and fascinating.

With that out of the way, let's get on to the first round of Mesozoic Merms:

Week 1: Triassic

Day 1: Conulariida

The Conulariida are a group of shelled cnidarians that lived from the Edicaran period; some 545 million years ago, all the way through the late Triassic period. They were sessile animals that likely possessed tentacles to capture prey.

My first thought when I saw this prompt was "what the hell is this?" And then afterwards "It's a marine flowerpot." Flowerpot or not, this was what I had to work with. I went with a gorgon-inspired look, and she turned out pretty cute for a day 1 piece. Looking back, she did end up looking a lot simpler than many of the later works in both concept and execution, but I still like her regardless.

Day 2: Cycleryon

Cycleryon was a crablike decapod that lived in the Jurassic period (not Triassic! I didn't make the prompt!). Anachronism aside, My design for it was fairly straightforward. At first I didn't quite know what to make of this creature, but after looking through many species of crustaceans and the like for color reference, something suddenly clicked:

Tokusatsu crab.

It's probably the least human-like of my Mesozoic Merms, but they're an interesting one to me.

Day 3: Eretmorhipis

Eretmorhipis is a marine reptile from the Triassic of China known for its broad, fan-like fins (its name literally means "oar fan").

You can clearly see where the influences lie, now :]

Her color scheme is personally one of my favorites. A little bit of Chinese water dragon, and a touch of lotus flowers, all wrapped up in an elegant assemblage of flowing fabrics, fans and bows.

Day 4: Cyamodus

While it looked like a turtle, Cyamodus was actually a Placodont, and a member of Sauropterygia (for non paleonerds, Sauropterygians included animals like Plesiosaurus). It was a durophagous, feeding on hard-shelled organisms like shellfish.

This one partly inspired by ancient Chinese armor, which some of them did use turtle shells! (I know it isn't a turtle, but close enough.) I still went in with the details though, including the hair tied in reference to the segmented shell, and all that damn armor detailing..

Day 5: Chinlea

Chinlea; named after the Chinle Formation, was a freshwater coelacanth, not unlike the modern day genus Latimeria, though it did go extinct by the end of the Triassic.

I was suggested by @temoti to give her a lil meat on her bones, and thus, we have ourselves a chubby Coelacanth for this week!

I'll be honest she might be one of my favorites I've done for this week. The colors, the personality, even the little freckles sprinkled on her.

Better watch out for that Saurichthys though..!

Day 6: Trematosaurus

Trematosaurs were large temnospondyl amphibians. Uniquely for amphibians, they were tolerant of saltwater, and as a result, one of the few fully-marine amphibians.

My design was.. certainly an interesting take on the animal. I was looking for a way to somehow integrate the creature's long snout as part of her design, and I eventually landed on a long cap. It took several redos of the sketching and color scheme before eventually deciding on a fire-bellied newt, and leading into a spunky streetwear-inspired girl by the end of it.

This month's designs were all originally planned to be 'one shots', but I like to think that she and the Chinlea gal would make a cute duo. A spunky, hotheaded gal and her more laid-back companion. Might make art of the two in the future, we'll see!

Day 7: Prosaurosphargis

Capping off the Triassic week, Prosaurosphargis was a fairly recent discovery (2023 at the time of writing).

It is a member of the Saurosphargidae (another family in the Sauropterygia) from the early Triassic period 250 MYA, only 1-2 million years after the Great Dying that wiped out

On to the Mermaid — or I suppose Man in this case, I don't have much to say, but I did reference leatherback turtles, and free divers. Oh, and I can't forget the cute little ammonite.

By Scott Reid

Etymology: Hole Reptile

First Described By: Burmeister, 1849 

Classification: Biota, Archaea, Proteoarchaeota, Asgardarchaeota, Eukaryota, Neokaryota, Scotokaryota Opimoda, Podiata, Amorphea, Obazoa, Opisthokonta, Holozoa, Filozoa, Choanozoa, Animalia, Eumetazoa, Parahoxozoa, Bilateria, Nephrozoa, Deuterostomia, Chordata, Olfactores, Vertebrata, Craniata, Gnathostomata, Eugnathostomata, Osteichthyes, Sarcopterygii, Rhipidistia, Tetrapodomorpha, Eotetrapodiformes, Elpistostegalia, Stegocephalia, Tetrapoda, Temnospondyli, Eutemnospondyli, Rhachitomi, Erypoiformes, Stereospondylomorpha, Stereospondyli, Trematosauria, Trematosauroidea, Trematosauridae, Trematosaurinae 

Referred Species: T. brauni, T. galae, T. thuringiensis?  

Status: Extinct 

Time and Place: Between 251 and 247 million years ago, in the Olenekian of the Early Triassic

Trematosaurus is found in the Buntsandstein Member of the Solling Formation of Sachsen-Anhalt, Germany; as well as the Lipovskaya Formation in Volgograd, the Yarenskian Formation in Komi, the Gostevskaya Formation in Orenburg, and the Petropavlovskaya Formation in Orenburg, all in Russia.

Physical Description: Trematosaurus was a large, long-headed amphibian that, in general, greatly resembled living crocodilians - but, again, it was an amphibian, and an ocean going one at that. Because the Triassic is always - always - extra. The skull was triangular and fairly long, greatly resembling that of the modern gavial. It had a long, wedge-shaped tail, very short and stubby limbs, and a long and streamlined body. Its feet were probably used as flippers, aiding it in swimming, and the wedge tail would have been extremely useful in propelling the animal forward. As an amphibian, it would have been covered in slippery, slimy skin, rather than scales - which was fine, since it spent all of its time in the water. It had small, sharp teeth, in a skull that was even somewhat hooked - increasing its general crocodile-like appearance. It also had its eyes, very clearly, on the top of its head; its nostrils were at the front of its snout, once again at the top, so it could surface and breathe easily. The skulls of these animals ranged between twenty and forty centimeters long; though the body size is unknown, we could guess somewhere between 2 and 3 meters in length. 

Diet: Trematosaurus was decidedly carnivorous, feeding on a variety of fish and other animals in its aquatic habitat. 

Behavior: This amphibian would have been extremely mobile and active, swimming around in its environment, hunting food, and searching for new places for feeding. The tail would have been useful in helping Trematosaurus to propel itself forward, while the limbs may have been helpful in steering. It probably wouldn’t have gone to land very much - honestly, those legs were small enough to be useless, so if it went on land it was to rest and maybe to mate. It would have laid its eggs in the water, probably close to the shore in secluded and hidden habitats like in flotsam and other murkey areas, as there were many animals that would have enjoyed some tasty squishy amphibian eggs. Whether or not it was social is difficult to tell; it was certainly common, in fact, one of the most common animals of its area, and it may have hunted or traveled in small groups, much like how frogs are usually found in congregations today - as are crocodilians - though they probably would have been loosely formed ones. 

Ecosystem: Trematosaurus lived, in general, in the ocean and near sandy beaches, though it would also venture into aquatic habitats that were more of a mixture of salt and freshwater (ie, brackish water) in river channels and sandy deltas along the sea. This makes sense, as such habitats would have been safer locations for it to lay its eggs. That said, it lived alongside a very wide variety of animals in its norther ocean habitat right after life finally began to recover from the extinction. It lived with the Mastodonsaurid Amphibian Parotosuchus and the giant Lycophyte tree Pleuromeia in the sandy shorelines of Germany. In the oceans of Russia, however, Trematosaurus was surrounded with other animals - sharks such as Hybodus and Lissodus; other fish such as Saurichthys, Watsonulus, Ptychoceratodus, Holophagus, and the lungfish Ceratodus and Arganodus; Parotosuchus again as well as other amphibians like Batrachosuchoides and Dromotectum (a survivor from the Permian); the mystery Synapsid Putillosaurus; and a fun variety of early reptiles. There were tons of Allokotosaurs such as Doniceps, Vitalia, Kapes, Coelodontognathus; the also very crocodile-like but not a crocodile Chasmatosuchus; a Parareptile, Orenburgia; the potential tuataras Scarschangia (which would be one of the oldest tuataras known); a Sauropterygian Tanaisosaurus; the Tanystropheid Augustaburiania; and even ridiculously early Suchians such as Vytshegdosuchus, the Poposaur Bystrowisuchus, and the Rauisuchian Scythosuchus. There were mystery reptiles too, such as the Archosauriform Tsylmosuchus, making the northern oceans of Pangea a fascinating location for the study of the early radiation of Triassic life. Also, indicating that Trematosaurus sure did have a lot to eat - and a lot of competition! 

Other: Trematosaurus is one of the Trematosaurids, a group of amphibians that evolved right after the end-Permian extinction for a high level of adaptation for aquatic life. They honestly look very similar to modern gavials, but were completely marine - living in oceans and seas across the Triassic. Trematosaurus itself actually had a shortner snout than some of its cousins like Wantzosaurus and Cosgriffus, though it still was a very crocodilian-like lad despite being an Amphibian. One could really call the Triassic the Age of Crocodiles - if you weren’t a relative of modern ones (ie, a Pseudosuchian), you were either weird - or trying to be one. And Trematosaurus definitely was trying to be an ocean crocodile. 

~ By Meig Dickson 

Sources Under the Cut

Bellerophon 

By @iguanodont​

Versus 

By @drawingwithdinosaurs​ 

Trematosaurus 

Click on the above links to refresh your memory about these animals! And feel free to use this post to debate and argue on what people should vote for!

Amphibian August #15 -- Trematosaurus

The terrestrial temnospondyls began to decline during the Late Permian, affected by changing climate and the continuing diversification of reptiles and synapsids. But the semi-aquatic and fully aquatic forms continued to thrive, dominating freshwater ecosystems, and survived through the massive Great Permian Extinction to make a quick recovery into the start of the Triassic.

One group, the trematosaurids, even ventured into the ocean -- and may have been the only amphibians to ever become fully marine. A few modern amphibians are fairly salt-tolerant, and the crab-eating frog makes brief excursions into seawater, but no other known amphibians have ever taken it quite to the extreme that the trematosaurids did.

Trematosaurus lived during the Early Triassic of Germany and Russia (~251-257 mya), and grew to around 1.2m long (3′11″). Convergently crocodile-shaped, it had a relatively short snout compared to some of the other more gharial-like trematosaurids, and was probably a shallow-marine predator feeding on fish, invertebrates, and other small animals near the shoreline.