#spectember

Another anonymous request asked for a "terrestrial placoderm":

Keluphichthys pezoporus is a descendant of Bothriolepis-like Devonian placoderms. Inhabiting shallow freshwater environments, they often used their rigid jointed fins to scramble short distances over land to reach new isolated ephemeral pools, and they developed convergently lung-like structures that could exchange gases directly from air, allowing them to survive in poorly-oxygenated waters and make even longer terrestrial journeys.

While the end-Devonian extinction devastated all other placoderms, this odd lineage survived into the Carboniferous, eventually raising themselves up to walk fully on their two limbs using a heavily scaled tail for balance.

Due to the relative weight of its bony carapace Keluphichthys is a fairly small animal, standing about 10cm tall (~4"). Its high domed body shape allows it to right itself when overturned, and resists the bite forces of larger predators such as the early tetrapods it lives alongside.

Its jaws are protrusible, with bony blades fused into a serrated "beak" used to snatch up invertebrate prey.

It's still reliant on wet environments, needing to stay moist and returning to pools of water in order to reproduce. Juveniles start out aquatic and gradually transition to terrestrial habits as they mature.

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What if... (HUGE ORIGINAL SKETCHES SPOILERS AHEAD)

For 2020's "Spectember", I came up with the "shrøøp" - a future elephant shrew descendant that's taken a page from the book of platybelodon (who's often nicknamed "scøøp" or "scööp" in paleo memes) and become something of a shovel-tusker.

So since this IS spectember, I've been doing a lot of explorations of what kind of megafauna in my worldbuilding project of Beast Fables. Urvara is basically kinda of like an "Earth but more" place. The continents are roughly in similar places, but there's a LOT more wildlife to go around, from ground sloths to toxodons (here called rhippo) to sebecids and even a singular Eurypterid.

set in an alternate Middle Jurassic where marine reptiles never dominated, mammal-like synapsids descended from forms such as the real life Castorocauda fill the seas. Here we have Castorocauda, a real-life extinct mammaliform synapsid with a beaver-like tail:

its descendents, the Pelagocaudids (informally Aquadonts) diversify into whale and sauropterygian-like niches with a few primitive twists

with primitive lips, and fish-beaver like tails being ancestral to the family, i'm having a lot of fun designing the transitionary forms. i'm unsure if it's actually certain whether castorocauda's paddle was horizontal like whales or vertical like fish, so for an interesting and possibly? speculative element i've opted to design them with vertical paddles and retaining long frontal limbs to grapple and grasp

A very late Spectember entry, but I was inspired by @alphynix 's "Dicyny World" where archosaurs and cynodonts never got to take over and the planet was instead dominated by the descendants of the dicynodont Lystrosaurus (which was famous for dominating in the aftermath of the Great Dying that ended the Permian).

So here's a bunch of random species, playing around with the idea of dicynodonts having superficial or convergent features of mammals, squamates and birds to fill niches similar to all of those, as well as the idea that drab coloration and color-blindness in mammals were a side effect of their nocturnal Mesozoic ancestry so other synapsids could probably be quite colorful.

Clockwise from top:

• The Tookey, an arboreal species adapted for climbing, similar to primates, squirrels and the arboreal synapsid Suminia, that feeds on leaves, seeds and insects in the treetops, using prehensile paws and a balancing tail to navigate among the branches.

• The Tuskbird, part of a pterosaur-like flying clade. This species is mostly ground-dwelling, however, similar to galliform birds, with males sporting brightly-colored iron-rich tusks for display. They eat primarily seeds, which they crack open with their short, blunt bills, as well as other plant matter.

• The Goliphant, a megafaunal herbivore that grazes on low-lying vegetation such as ferns and shrubs and grass-equivalents. Older bulls sport bright colors on their faces to display to conspecifics. Populations at different latitudes have differing amounts of body hair, being furrier in colder regions.

* The Puffrus, a semi-aquatic omnivore that spends most of its life at sea, feeding on marine plants and shellfish, but returns to land to breed as it is oviparous like most other non-therian therapsids, forming colonies on the shore where they guard their eggs in densely-clustered nests until hatching.

* The Spearbill, a plains-dwelling omnivore with a long beak that can be used to probe into burrows for small animals, break into insect nests like an anteater and pick up seeds and fruit-analogues. Its comb-like tusks are used for grooming, and its long limbs make it an adept runner.