#tetrapod

[lowpolyanimals]

Tetrapod from Cell to Singularity

[alphynix]

Despite being named after the famous Muppet frog, Kermitops gratus here wasn't actually a frog itself. Instead it was a close relative of the common ancestor of all modern amphibians, part of a grouping of amphibian-like animals known as amphibamiform temnospondyls.

Living in what is now Texas, USA, during the mid-Permian, about 275 million years ago, Kermitops would have resembled a chunky salamander. Only its fossil skull is known, so its full body size is uncertain, but based on the proportions of related amphibamiformes it was probably around 15-20cm long (~6-8").

Although its discovery helps to fill in the very sparse fossil record of the early evolution of modern amphibians, it's also complicated matters more than expected. Previously it was thought that the characteristic skull anatomy of modern amphibians evolved in a clear sequence, but Kermitops has a unique mix of features that doesn't fit this idea – suggesting that there was a lot of convergent evolution going on in amphibamiformes at the time.

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NixIllustration.com | Tumblr | Patreon

[amnhnyc]

Happy Fossil Friday! This boomerang-headed critter is Diplocaulus magnicornis. It lived some 275 million years ago during the Early Permian in what is now Baylor County, Texas. Like other nectrideans (an extinct order of tetrapods), this species had two projections at the back of its skull, creating its signature boomerang shape. Scientists aren’t sure what its exact function was, but it was presumably related to the way the animal swam. Diplocaulus probably lived in ponds and streams. 

Photo: M. Pelczar / © AMNH

[koshigurajumy]

Jumy-M Tetrapod vs. Raging waves / 消波ブロック対荒波

[somethingusefulfromflorida]

My mom bought me this book for Christmas

The Resurrectionist by EB Hudspeth, a fantasy field guide full of anatomical illustrations of monsters and cryptids.

The musculoskeletal systems are fun to look at, but not nearly as in-depth as I would have liked. If you have more than a passing knowledge of taxonomy (or in my case, access to Wikipedia), a lot of the details fall apart under scrutiny

The harpy has four upper limbs connected to one shoulder girdle; it shouldn't have arms, only wings

The sphinx is not classified as a mammal, but is still somehow in the family Felidae with cats (and like the harpy is also drawn with only two girdles despite having six limbs. I will give the author credit for giving the sphinx a keel for the wing muscles to attach to)

It lists the Hindu deity Genesha as a cryptid, which is a no-no.

Cerberus is also explicitly not a mammal, but somehow still a canine (literally in the species Canis with wolves, dogs, and coyotes)

Both mermaids and dragons are listed as members of the order Caudata; the only extant members of Caudata are salamanders, which kinda makes sense for dragons, but not so much for mermaids (also, the author keeps playing it fast and loose with cladistics; both mermaids and dragons are in the same order despite being in different classes, and while dragons are explicitly said to be amphibians, mermaids are given the fictional class mammicthyes, which means mammal-fish. At that point, why not just call mermaids amphibians? Why make up a fake latin hybrid name?)

But what bugs me most of all is the classification of the Minotaur as its own order of mammal when in mythology it is explicitly described as a hybrid of two known species (made possible only by the cruel machinations of the divine, but still)

To use actual taxonomical nomenclature, the minotaur's species would be B. taurus × H. sapiens (specifically B. taurus♂ × H. sapiens♀; there are, to my knowledge, no legends of H. sapiens♂ × B. taurus♀). That's how ligers, tigons, mules, zorses, pizzly bears, narlugas, etc., are described.

If I had written this book, I would have leaned more into evolutionary biology. Most land animals have four limbs because they all evolved from boney lobe-finned fish, which split off from the boneless sharks and rays millions of years earlier, so any six-limbed vertebrates would need to be descended from a fictitious category of six-finned fish which would either be an offshoot of boney fish/tetrapods (I guess they'd be hexapods, though that term refers to insect arthropods), OR a precursor to boney and cartilaginous fish that both clades split away from much earlier (it's easier to lose structures than to gain them, so it makes more sense for a six-limbed ancestor to spawn four-limbed descendants than the other way around).

Think about how different elephants are from humans, and humans are from aligators, and aligators are from penguins, and remember that they all evolved from the same ancestor tiktaalik, an amphibious fish that existed some 375 million years ago. Imagine a precursor six-limbed species and how diverse all its descendants would look after 400 million years. Save for the occasional instance of convergent evolution causing two unrelated species to independently evolve similar body plans to fill the same niche, tetrapods and hexapods would look nothing alike. There would be very little recognizable overlap between the two. A six-limbed "pegasus" would not look like a real world horse, and a six-limbed "dragon" would not look reptilian/dinosaur-ish, for much the same reason that giraffes don't look like frogs; they're just too distantly related. Bonless sharks and boney fish and whales/dolphins all have similar looking bodyplans only because their environment requires the same hydrodynamic shape, while terrstrial vertebrates are much more physically diverse.

[velespaleoart]

Early tetrapod paludarium

[firstlawcedarprairie]

Seduced by the blue of the sea...

[neanderthalfakemon]

A convergent pokemon with relicanth - this fella’s a sort of stem-tetrapod.

[pix4japan]

Mt. Fuji Towering Over Coastal Concrete Barrier

Location: Miho Peninsula, Shizuoka Prefecture, Japan Timestamp: 15:19 April 5, 2023

Typically, when people think of Mt. Fuji, they imagine a breathtaking snow-capped mountain set as a backdrop of natural beauty. This may include freshwater lakes, rows of flowerbeds, expansive beaches, or high-elevation shots of city lights. However, for me, the scene has a distinct street-photography vibe.

As I gaze upon the majestic mountain, I am struck by the juxtaposition of man-made structures that have contributed to the destruction of the once white sands of this particular beach. It's a stark reminder of the impact humans have on the environment, and how our actions can last for centuries to come.

Despite this destruction, Mt. Fuji remains one of Japan's most important symbols of natural beauty and is revered by adherents of the native belief system of Shintoism, where the mountain is considered one of the more important gods.

The scene before me is a testament to the complexity of human-nature interactions and the importance of respecting and preserving our natural surroundings. It serves as a reminder that we must strive to strike a balance between our modern way of life and our responsibility to protect the planet for future generations.

Pentax K-1 II + DFA 28-105mm F3.5-5.6 63 mm ISO 100 for 1/200 sec. at ƒ/11

[reubenyeoart]

Artillery Mech

Had more mechs on the mind, this time inspired by the designs of the Gen 5 Armored Cores (from V and Verdict Day)!

[ostracartderms]

Permian sunset with Peltobatrachus and an early arachnid

[rlephant]

concrete tetrapods

[alphynix]

Keraterpeton galvani here was part of a group of amphibian-like early tetrapods called lepospondyls.

Living in what is now southern Ireland during the Late Carboniferous, about 318-314 million years ago, this 30-40cm long (~1'-1'4") fully aquatic animal was the earliest known member of the diplocaulid lineage (although its skull was much less elaborately modified than its famous boomerang-headed relative Diplocaulus).

It had a broad short-snouted head with eyes set far forward, and a pair of backwards-pointing bony "horns" at the back of its skull. Its forelimbs were smaller than its hindlimbs, and unlike most other diplocaulids it had five fingers on its hands instead of four.

Its vertically flattened paddle-like tail was also around twice as long as the rest of its body, and was probably its main source of propulsion in the water.

Keraterpeton seems to have been quite numerous in the coal swamps it inhabited, representing the most common species preserved in the Irish Jarrow Assemblage site – a location where fossil specimens were uniquely "cooked" and partially replaced with coal during the fossilization process.

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NixIllustration.com | Tumblr | Twitter | Patreon

[typhlonectes]

As life was first struggling to set foot on land in the Late Devonian Period, there was a predator waiting to snatch it back to the depths: the recently discovered Hyneria udlezinye, a toothy prehistoric fish estimated to have reached up to 9 feet long.

It represents the largest monster fish yet uncovered from this period and appears to have lurked in the brackish waters of the modern-day Waterloo Farm site in South Africa, in wait for its prey. 

An excavation exposed a wall of fossils there in 2016, during road construction, and led to this and a number of other discoveries, including the fossil of an early tetrapod, the massive fish’s likely prey. These early genetic forebears of modern human resembled large salamanders or small alligators and walked on four feet (thus tetrapod)...

[umbrasdoodles]

More of the Alternate Form Project - here is Turpis the totally not demon's monster form. I based it off an old sketch of him plus prehistoric amphibian relatives, with a side of Toothless from the How To Train Your Dragon movies

[unofficial-sean]

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A post shared by Hiromu。 (@hiromumaru_maru)

Sky Coelacanth, if you please