Month: October 2024

Spectember/Spectober 2024 #09: Big Bad Wild Dogs

@poshtearexdoodles asked for “African wild dogs evolved to fill the larger pack animal niche of lions”:

Although in this particular timeline the endangered and fragmented wild painted dogs in Africa didn’t survive far past modern times, that wasn’t the final extinction of the species – captive groups persisted, and after the [REDACTED] of humans an escaped population managed to carve out a niche for themselves in the grasslands of southern North America.

A shaded sketch of a speculative descendant of painted dogs. It's a large wolf-like animal with short thick hyena-like jaws, a mottled shaggy coat of fur, and and small hoof-like nails on its feet.

Their most notable descendant is Megainolycos poshtearexi. At nearly 1m tall at the shoulder (~3’3″) it’s one of the largest canids to ever exist, comparable to present-day lions in size and general ecology, with short thick bone-crushing jaws convergent with those of hyenas.

It also retains the complex variable coat coloration of its ancestors, with each individual having a unique disruptive pattern of black, white, and brown blotches.

Much like its ancestors it’s a highly social pack predator specialized for endurance hunting. Along with some surprisingly horse-like limb ligament morphology, its feet now sport hoof-like nails rather than claws, and it pursues prey over long distances to the point of exhaustion – mainly targeting the larger ungulates across its prairie habitat such as hogs, horses, bovids, and deer.

Spectember/Spectober 2024 #08: Saberatel

Roy (@roygattero) requested “ratel becoming the new african big predator”:

A shaded sketch of a speculative descendant of honey badgers. It's a somewhat cat-like animal with a short snout, long saber-teeth, small ears, semi-digitigrade limbs, a mottled coat, and a short tail.

Perforictis royi is the latest in the long and venerable tradition of various synapsid lineages discovering the ecological niche of “big stabby saber-teeth“.

A descendant of the modern ratel/honey badger, it stands around 80cm tall at the shoulder (~2’8″), and convergently resembles the feline-like build of some of its more ancient relatives. Inhabiting the tropical forests of the rifted-off island continent of East Africa, it’s an ambush predator specializing in tackling larger prey – primarily ungulates and primates, but also occasionally giant rodents and hyraxes.

Usually cooperatively hunting in mated pairs, these mustelids stalk close to their targets before attacking, with one individual focusing on toppling and immobilizing their target while the other positions itself to deliver a swift precision killing bite to the throat with its saber-teeth and powerful neck musculature.

Perforictis scent marks its territory using extremely pungent secretions from its anal pouch rubbed onto vegatation, along with making loud scream-like vocalizations.

Spectember/Spectober 2024 #07: Mole Dino

Today’s spec creature is a combination of a couple of submissions – James P. Quick asked for “a post-K/Pg relict dinosaur from pre-glaciation Antarctica”, and an anonymous asked for “a subterranean (like, say, Talpa or Spalax) burrowing dinosaur”:

At the time of the K/Pg mass extinction some of the small ornithopods that inhabited Late Cretaceous Antarctica had been developing increasingly complex burrowing behavior and a more generalist omnivorous diet than most other ornithischians – and, along with their ability to endure the long dark cold polar winters, this was juuust about enough for them to survive while the rest of their non-avian cohorts vanished.

They were very briefly a fairly successful disaster taxon in the devastated polar forests, but they were quickly displaced by other diversifying survivors and never really got another ecological foothold to regain anything close to the non-avian dinosaurs former glory.

Instead the little ornithopods specialized even further for burrowing, spending more and more of their lives underground to avoid the increasing competition and predation from mammals and birds.

A shaded sketch of a speculative descendant of small ornithopod dinosaurs in Antarctica. It's a fuzzy little mole-like animal with a hoked beak at the tip of its toothy snout, no eyes, a keratinous shield on its head, large shovel-clawed forelimbs, a chunky body, stocky legs, and a fat bristly tail.

Now, well into the Cenozoic at the dawning of the Miocene, Cthonireliqua quicki is the very last representative of the non-avian dinosaurs. Small and stocky and mole-like, just 15cm long (~8″), it has muscular forelimbs with large shovel-like claws, a keratinous shield on its head, and a thick bristly tail where large fat reserves are stored.

Its eyes are almost completely absent, only vestigial remnants present under the skin of its face, and it navigates its extensive burrows using sensitive whisker-like filaments and its keen senses of hearing and smell. Still omnivorous like its ancestors, it feeds on whatever it comes across while tunneling – mainly worms, insects, smaller vertebrates, roots, and tubers.

Unfortunately for Cthonireliqua, and the rest of its Antarctic ecosystem, time is running out. Over the last few million years Antarctica’s climate has been steadily cooling and drying, the continent has become fully isolated, and the Antarctic Circumpolar Current has formed. Glaciation is well underway in the continental interior, and the once-lush forests are shrinking away and being replaced with tundra.

Soon all evidence of these dinosaurs’ existence will be buried under the ice.

Spectember/Spectober 2024 #06: Death Ray

Yeah, I’m keeping this stuff going again for another round of Spectober!

An anonymous request asked for a “big macropredatory ray”:

A shaded sketch of the head of a speculative descendant of pelagic stingrays. Its a large ray with triangular wing-like fins, a slightly shark-like pointed snout, protrusible sharp-toothed jaws, and a vaguely skull-like pale marking on its underside.

Speirobatis thanasima is a large ray found in open oceanic waters, reaching sizes comparable to the modern giant manta ray at around 3m in length (~10′) with a wingspan of over 5m (~16’5″).

But despite its body shape closely resembling that of mobulids or myliobatids, its closest present-day relative is actually the pelagic stingray. Already being active hunters with mouths full of sharp pointed teeth, these ancestral rays gradually evolved bigger body sizes and began occupying an apex predator niche similar to that of large sharks and toothed whales.

Speirobatis is a strong swimmer, using flapping motions of its triangular wing-like pectoral fins to travel at high speed and make acrobatic jumps out of the water. Highly intelligent and social, it lives in family groups that hunt cooperatively – encircling and herding schools of fish tightly into bait balls, taking turns stunning prey with slaps of their fins, and then grabbing incapacitated individuals with snaps of their protrusible jaws.

Groups will also tackle larger prey such as marine mammals and sharks, harassing and chasing targets to exhaustion while taking quick opportunistic bites out of them.