Phosphatherium

Phosphatherium escuillei was one of the very earliest known members of the proboscideans, a lineage today represented only by the three living species of elephants.

Living in what is now Morocco during the late Paleocene and early Eocene, around 56 million years ago, it would have been about the size of a cat, roughly 30cm at the shoulder (~1′) and 60cm long (~2′). It had a fairly low flat head with a proportionally short snout, while the back end of its skull behind it eyes was elongated, supporting large powerful jaw muscles.

Wear patterns on its teeth suggest it ate a lot of tough vegetation, and it may have been a semiaquatic animal behaving somewhat like modern tapirs or pygmy hippos – spending a lot of the daytime lounging in water, and emerging onto land to forage during the night.

Spectember/Spectober 2023 #10: Tree Goat

An anonymous submitter asked for an “arboreal goat with grasping sloth-like claws”:

A shaded sketch of a speculative tree-climbing descendant of goats. It's a hairy sloth-like animal, clinging to a tree trunk with long chunky limbs that end in large hooked claw-like hooves. Its head is proportionally small, with fleshy giraffe-like lips, forward-facing eyes, and small stubby horns.

Cluraix cephalula is a distant descendant of feral goats in a tropical forest environment, representing a small tree-climbing offshoot of a specialized chalicothere-like lineage.

About 70cm long (~2’4″), it clambers around in the high tree canopies, with its forward-facing eyes providing good depth perception in this complex three-dimensional habitat. Its long hooked claw-hooves are used both to cling onto branches and to hook-and-pull clumps of foliage towards itself, stripping the leaves with its flexible fleshy lips.

Spectember/Spectober 2023 #09: Things With Wings

(Apologies for the abrupt absence – I’m okay, just having everything break down at once. This is fine.)

So— back to the speculative evolution request list!

TheBigDeepCheatsy requested a “cactus-dwelling/germinating evolution of introduced rosy-faced lovebirds”:

A shaded sketch of a speculative symbiotic relationship between lovebirds and saguaro cactus. The lovebird is shown on the left, a small parrot that looks very similar to modern rosy-faced lovebird except with hints of a more mottled color pattern. The cactus is shown on the right, a large fasciated saguaro with its top fanning out into a wide "crown", with several nest holes dug into it and multiple lovebirds occupying them.

While Agapornis cheatsyi is still quite physically similar to its introduced ancestors, this lovebird has developed a close symbiotic relationship with the cactus Carnegiea ornipolis, a descendant of the modern saguaro.

Naturally fasciated, this cactus grows a splaying fan-like crown which the lovebirds excavate their shallow nest burrows into. Feeding on the cactus’ fruit in early summer, the lovebirds then disperse the seeds via their droppings – a process that significantly improves propagation chances, both due to the birds commonly foraging and defecating around suitable nurse plants and the passage through their gut speeding up germination.


Someone calling themself “LB” asked for some “flying afrotherians”:

A shaded sketch of a speculative flying tenrec. It's a bat-like animal with membranous wings supported by three elongated fingers, and a large shrew-like head with long toothy jaws and an elephant-shrew-like nose.

Elbeitandraka venenifer is a descendant of tree-climbing Malagasy tenrecs that developed gliding membranes – and its lineage is now just about achieving true powered flight.

About 25cm long (~10″), its proportionally short broad wings require it to fly very fast to generate enough lift for its weight. It mostly only actively flies when traveling between roosts and feeding sites (or when escaping from threats), alternating between gliding to save energy and flapping to recover altitude.

It’s an opportunistic omnivore, crawling around in the tree canopy foraging for vegetation, fruits, fungi, invertebrates, and the occasional smaller vertebrate, using its flexible sengi-like nose to probe around in crevices.

Much like modern common tenrecs it’s capable of hibernating for months at a time through periods of scarce food availability. It also accumulates alkaloid toxins in its body from its arthropod prey, advertising its unpalatability to predators with bold contrasting warning coloration on its wing membranes.


And here’s a combination of a couple of anonymous requests for both “flying heterodontosaurs” and “dragons with hind leg wings, a la sharovipteryx”:

A shaded sketch of a speculative flying predatory heterodontosaurid dinosaur, show both on the ground in a quadrupedal posture and in flight. Its hind legs form its main wings, with elongated outer toes supporting large pterosaur-like flight membranes. It also has a hooked beak at the front of fanged jaws, an s-curved neck, a compact fuzzy body, short forelimbs with taloned hands and small stabilization membranes, and a long vaned tail.

Inversodraco rapax is a highly specialized Jurassic descendant of heterodontosaurids that took to climbing and gliding, developing delta-wing-like membranes on their hindlimbs convergently similar to those of the earlier sharovipterygids.

Around 75cm long (~2’6″), it has unusually flexible hip joints for a dinosaur, able to splay its legs out to the sides to deploy wings supported by an elongated outer toe on each foot. Its arms form small forewings for stability, and its long tail ends in a vane of stiffened feathers that aid in steering.

Unlike its herbivorous-to-omnivorous ancestors it’s primarily a carnivore, swooping down onto small prey and grabbing it with its talon-like forelimbs.

Spectember/Spectober 2023 #08: Various Filter-Feeders

Admantus asked for a “freshwater baleen whale”:

A shaded sketch of a speculative freshwater baleen whale. It has a very wide duck-like snout with whisker-like bristles, short baleen inside its mouth, very small reduced eyes, and broad paddle-like flippers.

Rostrorutellum admantusi is descended from small cetotheres that became isolated in a large inland body of water (similar to the modern Caspian Sea), eventually becoming landlocked and gradually reducing in salinity towards fully freshwater.

Highly dwarfed in size, just 2-3m long (~6’6″-9’10”), they’re slow swimmers with broad duck-like snouts that are used to scoop up mouthfuls of sediment and strain out their invertebrate prey in a similar feeding style to gray whales.

Due to the murkiness of the water, and the lack of large predators in their environment, they have poor eyesight and instead use sensory bristles and electroreceptors around their snouts to navigate and detect prey.


And an anonymous submission requested a “whale-like filter-feeding marine crocodile”:

A shaded sketch of a speculative filter-feeding crocodile. It has spatula-like jaws lined with many delicate closely-spaced needle-like teeth, flipper-like limbs, and a long paddle-like tail.

Sestrosuchus aigialus is a 6m long (~20′) crocodilian closely related to the modern American crocodile, living in warm shallow coastal waters.

It’s adapted for an almost fully aquatic lifestyle convergently similar to the ancient thalattosuchians, swimming with undulations of its long tail and steering with flipper-like limbs. But unlike other crocs it’s specialized for filter-feeding, with numerous delicate needle-like teeth in its jaws that interlock to sieve out small fish and planktonic invertebrates from the water.


A couple more suggestions also asked for “fully aquatic pinnipeds” and “future crabeater seal evolution”:

A shaded sketch of a speculative filter-feeding fully aquatic crabeater seal. It has four wing-like flippers, a streamlined body, and elongated jaws with many lobed teeth used to sieve krill.

Euphausiolethrus volucer is a fully aquatic descendant of the crabeater seal. About 5m long (~16’4″), it occupies the ecological niche of a small baleen whale in the krill-abundant Antarctic waters that lack most actual baleen whales.

Its jaws contain numerous finely-lobed teeth that are used to strain krill from the water, and it utilizes all four of its wing-like flippers to swim in an “underwater flight” motion similar to that of plesiosaurs.

Highly social, it tends to congregate in pods that cooperate to herd swarms of krill for easier feeding.

Spectember 2023 #05: Shiny Mammal

Someone who identified themself only as “Hanna” requested a “mammal that’s shiny and iridescent like some insects and spiders”:

A shaded sketch of a speculative semiaquatic hairy armadillo. It has a wide armor carapace with a green-blue-purple iridescent sheen, a pig-like snout, wide paddle-like hands and feet, and a short tail.

Lustrophractus hannae is a relative of modern hairy armadillos that has adapted for a semiaquatic lifestyle.

About 40cm long (~16″), its unusually shiny carapace originally evolved thanks to its ancestors’ burrowing habits. Much like golden moles and some snakes, these armadillos’ scutes and hairs developed microridges that reduced friction and repelled dirt particles, with the side effect of becoming strikingly iridescent – and, conveniently, also rather water repellent, enabling Lustrophractus’ lineage to take up aquatic omnivorous foraging habits.

The iridescence also serves a defensive function, using a bright flash of color to startle and confuse predators.

Spectember 2023 #02: Carnivorous Ungulates

An anonymous submitter asked for a “derived carnivorous, pack-hunting agriochoerid“:

A shaded sketch of a speculative predatory early ungulate. It has a cat-like body, long and low-slung with clawed feet and a long slender tail. Its head looks like a mix between a cat and a camel, with a fleshy cleft lip, forward-facing eyes, leaf-shaped ears, and a mouth full of sharp pointy teeth. It's depicted in two poses: on the left climbing up a tree trunk, and on the right standing and baring its fangs.

Felichoerus ochlos is fairly similar-looking to its herbivorous relatives, but this cat-sized agriochoerid comes from a lineage that initially specialized in eating fleshy fruits – and then shifted towards eating actual flesh.

With its long cat-like body, forward-facing eyes, clawed digits, and flexible limbs, it’s a capable tree climber. Groups of this animal practice cooperative hunting, with one member chasing arboreal prey down to the ground for the rest to mob.


And another anon wanted to see an “obligate carnivore bovine”:

(I see what you did there. A literal carnotaurus!)

A shaded sketch of a speculative predatory bovine. It has a muscular body with humped shoulders and cloven hoofed feet, a thick neck, and a large cow-like head. Two individuals are depicted, a standing long-horned bull and a sitting short-horned cow. The cow has a chunk missing from one ear and has her mouth open to display her sharp teeth.

The bulltcher (Carnovitulus grassator) is a sheep-sized descendant of small buffalo that gradually took up more and more omnivorous diets, eventually becoming somewhat entelodont-like opportunists. This particular species has shifted over into hypercarnivory, occupying a predator niche in an ecosystem lacking other types of carnivorous mammal.

Like their ancestors they still lack upper front teeth, and instead have modified their dental pad into an almost beak-like tough keratinized structure that their sharp lower teeth can slice and self-sharpen against.

These animals live in small matriarchal herds, with bulls usually hanging around on the edges of the group to protect from threats. Bulls have larger backwards-pointing horns, used to compete with each other for mates – but the size of these structures on their skulls results in them having slightly less powerful jaw muscles than cows.

Herds hunt cooperatively, pursuing and harassing larger prey until it can be brought down and torn apart.

Perucetus

While last week’s Tutcetus was the smallest known basilosaurid whale, another recently-announced member of that group was almost the complete opposite.

Perucetus colossus was a chonker. An absolute unit of a whale.

Living during the Eocene (~38 million years ago) in shallow marine waters covering what is now the coast of Peru, this ancient whale is known from several vertebrae, ribs, and parts of its pelvis. As a result its full size is uncertain, but based on the proportions of other basilosaurids it was probably somewhere around 17-20m long (~56′-66′) – similar in length to the larger specimens of Basilosaurus.

However, it had much thicker denser bones, even more so than those of its close relative Antaecetus, suggesting that its full body mass was much higher than the rather slender Basilosaurus – and possibly heavier than even modern blue whales despite being shorter in overall length.

Perucetus’ thickened vertebrae were also fairly inflexible in most directions, indicating it was a sirenian-like slow swimmer with limited maneuverability – but it did have a surprisingly good ability to bend its body downwards. Without skull material it’s unclear what its diet was like, but it may have been a suction-feeder hoovering up seafloor prey like modern grey whales or walruses.

I’ve reconstructed it here with a speculative bristly fleshy downturned snout inspired by the weird skull of Makaracetus, an earlier whale that may have also been a walrus-like bottom-feeder.

Tutcetus

Tutcetus rayanensis was a whale that lived in warm shallow tropical seas covering what is now Egypt during the Eocene, about 41 million years ago.

It was an early member of the “basilosaurids“, a grouping made up of multiple early cetacean lineages (an “evolutionary grade“) representing some of the first fully aquatic forms. Like other members of this group it probably would have had a rather long and slender body shape – but unlike most of its relatives Tutcetus was comparatively tiny, estimated to only have been around 2.5m long (~8’2″).

The fusion of the skull bones in the one known fossil specimen indicate it was almost fully grown at the time of its death, and the pattern of tooth replacement suggests this small basilosaurid species matured very rapidly – a sort of “live fast, die young” life strategy.

Tutcetus’ small size and early demise also inspired its genus name, with “Tut” referencing the teenage Egyptian Pharaoh Tutankhamun.

Crystal Palace Field Trip Part 3: Walking With Victorian Beasts

[Previously: the Jurassic and Cretaceous]

The final section of the Crystal Palace Dinosaur trail brings us to the Cenozoic, and a selection of ancient mammals.

A photograph of the Crystal Palace palaeotheres, depicted as tapir-like animals. A smaller one on the left is in a sitting pose, while a larger one on the right is in a walking pose.
Image from 2009 by Loz Pycock (CC BY-SA 2.0)

Originally represented by three statues, there are two surviving originals of the Eocene-aged palaeotheres depicting Plagiolophus minor (the smaller sitting one) and Palaeotherium medium (the larger standing one).

The sitting palaeothere unfortunately lost its head sometime in the late 20th century, and the image above shows it with a modern fiberglass replacement. Then around 2014/2015 the new head was knocked off again, and has not yet been reattached – partly due to a recent discovery that it wasn’t actually accurate to the sculpture’s original design. Instead there are plans to eventually restore it with a much more faithful head.

These early odd-toed ungulates were already known from near-complete skeletons in the 1850s, and are depicted here as tapir-like animals with short trunks based on the scientific opinion of the time. We now think their heads would have looked more horse-like, without trunks, but otherwise they’re not too far off modern reconstructions.

There was also something exciting nearby:

A photograph of the restored Crystal Palace Palaeotherium magnum statue. It's a chunky animal with a trunked tapir-like head, wrinkly skin, and a rhino-like body.

The recently-recreated Palaeotherium magnum!

This sculpture went missing sometime after the 1950s, and its existence was almost completely forgotten until archive images of it were discovered a few years ago. Funds were raised to create a replica as accurate to the original as possible, and in summer 2023 (just a month before the date of my visit) this larger palaeothere species finally rejoined its companions in the park.

Compared to the other palaeotheres this one is weird, though. Much chonkier, wrinkly, and with big eyes and an almost cartoonish tubular trunk. It seems to have taken a lot of anatomical inspiration from animals like rhinos and elephants, since in the mid-1800s odd-toed ungulates were grouped together with “pachyderms“.

An illustration comparing the Crystal Palace depiction of Palaeotherium magnum with a modern interpretation. The retro version is a chunky animal with a trunked tapir-like head and rhino-like body. The modern version is more horse-like, with slender legs and three-toed hoofed feet.
Continue reading “Crystal Palace Field Trip Part 3: Walking With Victorian Beasts”

Nihohae

Nihohae matakoi was a dolphin that lived in the coastal waters around what is now Aotearoa New Zealand during the late Oligocene, about 25 million years ago. Part of a group known as waipatiids, it was much closer related to modern South Asian river dolphins than to modern oceanic dolphins.

Around 2m long (6’6″), it had unusually long tusk-like teeth at the front of its jaws, splaying out almost horizontally forwards and to the sides.

These teeth lay too flat to effectively interlock as a “fish trap”, and their fairly delicate structure and lack of wear marks suggests they also weren’t used for piercing large prey, sifting through gritty sediment, defending against predators, or for fighting each other. But Nihohae did have a highly flexible neck and the ability to quickly snap its jaws from side to side – although with a relatively weak bite force, suggesting it was primarily tackling small soft-bodied prey that could be easily swallowed whole.

Overall its feeding ecology seems to have been similar to modern sawfish, stunning prey such as squid with rapid slashing swipes of its jaws.