Category: paleoart

Kubanochoerus

Pigs were once unicorns.

Kubanochoerus gigas lived about 15-7 million years ago during the mid-to-late Miocene, and ranged across a large portion of Eurasia with fossils known from both Georgia and China.

It was one of the largest known pig species to ever live, slightly bigger than the modern giant forest hog at about 1.2m tall at the shoulder (3′11″). But its most distinctive features were its horns, with a small pair above its eyes and a single large forward-pointing one on its forehead.

A few specimens lack the large horn, and so some paleontologists consider it to be a sexually dimorphic trait possessed only by males. But it’s currently unclear whether this was actually the case, since at least one “hornless” skull has been reported with the distinctive larger tusks also associated with male pigs – so it’s possible that the horned and hornless Kubanochoerus were actually separate species!

Glowing Dinosaurs

Many modern birds are capable of seeing into the ultraviolet regions of the electromagnetic spectrum, and some of their non-avian dinosaur ancestors might have had the same sort of vision. And much like their living relatives, that means various parts of their bodies and plumage may also have been UV-reflective and UV-fluorescent.

So here’s a Velociraptor with some speculative UV coloration – although this is just what it would look like to human eyes under a blacklight. What it would actually look like to a creature that can see extra colors is impossible to depict on a screen designed for trichromatic vision!

Panzhousaurus

Panzhousaurus rotundirostris, a sauropterygian marine reptile from the mid-Triassic of southwestern China (~245 mya), living just a few million years after the devastating Permian-Triassic mass extinction. This small marine reptile was only about 40cm long (1′4″) and is known from a single near-complete skeleton.

Although it was a distant evolutionary cousin to plesiosaurs (and even more distantly to modern turtles), it was actually most closely related to an early sauropterygian lineage known as the pachypleurosaurs – a group of small lizard-like aquatic reptiles with tiny heads, long necks, and paddle-like limbs.

It had an unusually short and rounded-off snout compared to its relatives, and since it would have lived alongside many other diverse marine reptiles it was probably specialized for a slightly different ecological niche.

Nanodobenus

Nanodobenus arandai, a pinniped from the mid-to late Miocene (~16-9 mya) of Baja California Sur, Mexico. Although it would have looked very similar to a sea lion, it was actually an early member of the walrus lineage that lacked the specialized long tusks that characterize its modern relatives.

At just 1.65m long (5′5″) it was only about half the size of living walruses, making it the smallest member of the group ever discovered and leading to it being given the nickname “smallrus”.

It probably occupied a similar sort of fish-eating ecological niche as true sea lions – which eventually replaced it in the region after its extinction – and since it lived alongside several other larger species of walrus it may have become dwarfed to avoid direct competition with them.

Conflicto

Conflicto antarcticus, a recently-named waterfowl bird from the earliest Palaeocene of Antarctica (~65-64 mya).

Standing around 50cm tall (1′8″), it had a slender body, long legs, a long neck, and a narrow goose-like beak. It also had an unusual pair of bony bumps on its skull which may have supported some sort of small crest superficially similar to the knob on the head of the modern magpie goose.

Temperatures in Antarctica at the time were much warmer than today, and the area where its fossils were found would have been a temperate estuary or river delta. It was probably an omnivorous wading bird, feeding on vegetation, small fish, and invertebrates in shallow freshwater.

Although it somewhat resembled a presbyornithid it was actually part of an even earlier branch of the waterfowl evolutionary tree – so its ancestors must have originated much further back in the Late Cretaceous – and their similar body shapes hint that the common ancestor of all waterfowl may also have been a rather leggy bird. Conflicto’s closest known relative might actually be the similarly-aged Anatalavis (which was previously though to be a primitive magpie-goose) from North America and Europe, suggesting that its lineage was quite widespread and already taking advantage of vacant niches in the immediate wake of the Cretaceous-Paleogene mass extinction.

Eons Roundup 2

  • California Channel Island pygmy mammoth (Mammuthus exilis) and Columbian mammoth (Mammuthus columbi)

And speaking of island elephants, I recently illustrated some for PBS Eons’ episode on the California Channel Island pygmy mammoths:

https://www.youtube.com/watch?v=dXwoKEDtdlM

Island Weirdness #31 – Tiny Elephants On Parade Part 2: Flores

Much like Japan, ancient Flores had a succession of dwarf stegodontids – close relatives of modern elephants that were capable of island-hopping through Indonesia by swimming.

A stylized illustration of an extinct dwarf elephant. It has curved tusks, small ears, and very proportionaly short stumpy legs.
Stegodon sondaari

Stegodon sondaari lived on Flores during the Early Pleistocene, about 900,000 years ago, and was the size of a small water buffalo at just 1.2m (3′11″) tall at the shoulder. It was probably descended from the larger Stegodon trigonocephalus, known from Java, and it had proportionally short legs which may have been an adaptation to clambering over rough terrain and steep inclines.

Around 850,000 years ago Stegodon sondaari disappeared from Flores, probably due to a large volcanic eruption, but a new wave of stegodontids quickly recolonized the island. The mid-sized Stegodon florensis probably originated from either Java to the west or Sulawesi to the north, and eventually evolved into a new dwarfed subspecies.

A stylized illustration of an extinct dwarf elephant. It has long gently curving tusks and small ears.
Stegodon florensis insularis

Stegodon florensis insularis wasn’t quite as small as its predecessor, standing around 1.8m tall (5′10″). It probably didn’t shrink quite so much due to the existing presence of various predators on Flores, since it was likely the main prey of large Komodo dragons, it was hunted by Homo floresiensis, and it may also have been occasionally targeted by giant storks.

It seems to have disappeared around the same time as several other unique endemic species, between 50,000 and 20,000 years ago, due to either climate change, another volcanic eruption, or the arrival of modern humans – or perhaps a combination of all of those factors.

And that’s all for this month… but Island Weirdness will be back later for part 2, with more giants, more dwarfs, and so many elephants.

Island Weirdness #30 – Homo floresiensis

The most surprising resident of ancient Flores would have to be Homo floresiensis, a species of archaic humans nicknamed “hobbits” due to their unusually small stature.

Standing at an adult height of about 1.1m tall (3′7″), they were smaller than any population of modern humans and are thought to represent an unusual case of insular dwarfism.

They also had much smaller brains than would be expected for their size, similarly to the miniature hippos of Madagascar, which was probably an energy-saving adaptation in an island environment with limited resources, since brains are metabolically expensive organs. An area of their brains associated with higher cognition was about the same size as in modern humans, however, so they weren’t necessarily less intelligent – stone tools and butchery marks on dwarf elephant bones suggest they were cooperatively hunting, and there’s also possible evidence of fire use for cooking.

It’s not clear exactly where they belong on the human family tree, and attempts at extracting DNA from the known remains have so far failed. They might be descendants of a population of Homo erectus who arrived on Flores about 1 million years ago, or they may even have been part of a much older unknown lineage that dispersed from Africa over 2 million years ago.

Although they were initially thought to have lived on Flores from 190,000 years ago up to about 12,000 years ago, more accurate dating of the cave where their skeletal remains were discovered suggests they actually disappeared about 50,000 years ago – about the same time that modern humans arrived on the island.

Island Weirdness #29 – Leptoptilos robustus

Indonesia is located at the junction between several tectonic plates, and as a result a large number of volcanic islands make up the region. While some of these islands have had land connections to Asia or Australia in the past, others are separated by deep ocean trenches and have been isolated with little movement of species between them.

The island of Flores in the southeastern Lesser Sunda archipelago was formed fairly recently – sometime in the last 15 million years – and has been home to some highly unusual endemic species, including dwarf elephants, giant rats, Komodo dragons, and diminutive “hobbits”.

Leptoptilos robustus was a huge stork, closely related to the living marabou and adjutants but estimated to have been at least 20% larger. It would have stood around 1.8m tall (5′10″) and had a chunkier build with unusually heavy thick-walled bones, suggesting it may have become functionally flightless. Only fragmentary arm bones were found, however, so its unknown whether its wings were reduced in size or not.

There were few large carnivorous mammals on Flores (possibly none), and Leptoptilos robustus would have had little competition for carrion and prey. It may even have filled an ecological niche similar to the giant Hatzegopteryx of Cretaceous Hațeg Island – a large terrestrial stalking predator eating any smaller animals unfortunate enough to fit into its mouth.

The known remains date to the Late Pleistocene, around 50,000 to 20,000 years ago, and this giant bird seems to have gone extinct sometime during that date range. It’s unclear what killed it off, but possible factors include a changing climate on the island, a major volcanic eruption, and the arrival of modern humans. 

Island Weirdness #28 – The Rodrigues Solitaire

Located to the east of Mauritius, the small island of Rodrigues is the geologically youngest of the Mascarenes, formed only about 1.5-2 million years ago.

And it also had its own large flightless bird – the Rodrigues solitaire, Pezophaps solitaria.

It was closely related to the dodo, although it wasn’t a direct descendant. Based on DNA studies their last common ancestor is estimated to have lived about 20 million years ago, so they must have each convergently evolved from separate pigeon lineages that arrived on each island at different times.

Standing 70-90cm tall (2′4″-2′11″), with males being larger than females, it had long legs, a long neck, and a slightly hooked beak with a black band described as resembling a widow’s peak. Its plumage was grey and brown, and it was reportedly aggressively territorial and capable of giving a strong bite.

It had large lumpy bony knobs on its wrist bones that were used as weapons to clobber each other while fighting. Due to this its wings were less reduced than the dodo, retaining stronger musculature, and it was apparently also capable of using them to create loud low-frequency sounds for communication – possibly in a similar manner to modern crested pigeons’ whistling wings.

The solitaire survived for longer than both its dodo cousin and the Réunion ibis, but only because its island was rarely visited by humans until the late 1600s. Once Rodrigues began to be exploited the story became the same as the other Mascarene islands: a combination of hunting, habitat destruction, and predation by invasive species rapidly dwindled its population. It likely went extinct sometime between the 1730s and 1750s, since an exhaustive search for a live specimen in 1755 failed to find a single bird.