#big honkin' snoot

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Elasmotherium sibiricum was a giant rhinoceros that lived during the mid-to-late Pleistocene epoch, between about 800,000 and 39,000 years ago. Found across much of the Eurasian steppe dry grassland environments, it stood around 2.5m tall (8'2") at the top of its humped shoulders and weighed about 4 tonnes (4.4 US tons), making it close in size and mass to a modern elephant.

It was the last known representative of a particularly ancient lineage of rhinos, last sharing a common ancestor with modern forms over 40 million years ago.

A large bony dome on its forehead is traditionally thought to have supported an enormous keratinous horn like the distantly-related woolly rhino, but a 2021 study has recently challenged that interpretation. The dome structure was actually rather thin-walled and wouldn't have been able to support the weight of a giant horn, instead probably being covered by a much stumpier backwards-pointing nub – while an enlarged nasal cavity inside the dome also suggests it may have actually functioned as a resonating chamber, similar to the crests of hadrosaurs or the extinct wildebeest Rusingoryx.

It also had a smaller toughened "pad" on its nose that may have been used along with a prehensile upper lip to dig around in the soil for plant roots and tubers.

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A non-FR vent doodle I did today on my boogie board (an LCD screen with a stylus, essentially) because feelings suck and I just wanted to draw a big ol’ honkin’ wolf snoot.

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Aquilarhinus palimentus here was an early hadrosaurid dinosaur known from the Late Cretaceous of Texas, USA, living about 80 million years ago. Around 5m long (16"5"), it had a prominent humped nose that seems to have been an evolutionary prelude to the larger and much more elaborate crests found in later hadrosaurs.

It also had an unusually wide and shovel-like beak, unlike any other known hadrosaur, which was probably a specialization for a different diet than its relatives. Since it lived along coastal marshlands it may have used its broad jaws to scoop up large mouthfuls of soft vegetation – or, much like the "shovel-tusker" proboscideans that were once thought to have a similar lifestyle, it may actually have been doing something else entirely with that beak.

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Weird Heads Month #21: Honking Hadrosaurs

The ceratopsians and pachycephalosaurs weren't the only ornithischian dinosaurs to do weird things with their skulls.

The hadrosaurs are commonly referred to as "duck-bills" (despite how their beaks weren't actually duck-like at all), and are famous for the elaborate crests seen on some of the group's members, with shapes ranging from lobes to helmets to hatchets to spikes – and even some of the apparently crestless species are now known to have sported fleshy combs instead of the bony structures seen in their relatives.

But by far the most recognizable of the crested hadrosaurs is Parasaurolophus walkeri, with its long curved backwards-pointing tubular crest.

This particular species was mid-sized for the genus, growing up to around 10m long (32'10") and is known from Western North America during the Late Cretaceous, about 76-73 million years ago.

Its crest was intermediate in size and shape between the other two known species. The larger Parasaurolophus tubicen had a longer and slightly straighter crest, while the smaller Parasaurolophus cyrtocristatus had a shorter more strongly curved one. Juveniles developed these crests as they matured, starting off with much smaller bumps on their snouts that gradually grew backwards and upwards.

Some hadrosaur crests were purely for visual display, but in the lambeosaurine lineage that Parasaurolophus belonged to they also incorporated complex looping nasal passages that were probably used as resonating chambers, allowing each species to make a unique-sounding loud bellowing call to communicate with each other.

There are also rumors of a currently-undescribed specimen of Parasaurolpphus that has preserved soft tissue around its crest, possibly a keratinous covering or skin flaps that made it appear even larger and more flamboyant in life than the underlying bone. So I've given this reconstruction a speculative structure like that, along with hoof-like claws on its hands similar to those recently revealed for Edmontosaurus.

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Weird Heads Month #25: The Case of the Missing Trunk

The rhino-like toxodontids from earlier in this series weren't the only weird-headed South American ungulates. Another group known as the litopterns evolved in a different direction, becoming long-legged fast-moving animals convergently filling the same sort of ecological niches as modern horses, deer, bovids, camelids, and giraffids.

Macrauchenia patachonica was one of the strangest members of this lineage, living from the Late Miocene to the end of the Pleistocene, between about 7 million years ago and just 12,000 years ago.

It stood around 1.8m at the shoulder (5'11") and resembled a large camel or llama with thee-toed hoofed feet, but its head was… confusing.

Its skull had a bizarre combination of features, with a shape closer to a sauropod dinosaur than a mammal, a cartoonish-looking set of teeth, and its nostrils set up high above its eyes, more like a cetacean blowhole than a terrestrial herbivore.

Due to its retracted nostrils it's commonly been restored with an elephant-like or tapir-like trunk. And while a trunk gives Marauchenia a wonderfully weird and memorable appearance, there's just one problem with that interpretation.

There's no evidence for it.

Aside from its nostrils being far back on its head, it didn't have any other features associated with anchoring the complex musculature of a trunk. In fact, a recent study found that its skull characteristics were much closer to those of moose than tapirs!

It seems more likely that it had a moose-like bulbous fleshy nose – possibly giving it an enhanced sense of smell or functioning as a resonating chamber – perhaps with slightly retracted external nostrils like a giraffe or sauropod to prevent it from being stabbed in the nose when feeding on spiky vegetation.

Whatever it was doing with its weird schnoz, it was clearly a highly successful species, since it was found across most of South America in a wide range of habitats.

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Weird Heads Month #16: Big Honking Snoots

The dinoceratans featured here a few days ago were some of the first large mammalian herbivores to evolve in the Cenozoic, but during the Eocene they were joined by another group: the even bigger brontotheres.

Part of the odd-toed ungulate lineage, brontotheres convergently resembled rhinos but were actually much more closely related to horses. And much like the dinoceratans they also had some unusual heads, with some species evolving concave foreheads and sexually dimorphic ossicone-like pairs of blunt horns on their noses.

But others went really weird.

Embolotherium andrewsi lived in Mongolia during the late Eocene, around 37-34 million years ago. Standing around 2.5m tall at the shoulder (8'2"), it was one of the largest brontotheres and also one of the oddest-looking.

It had a large bony "battering ram" at the front of its snout, formed from modified nasal bones – and while some reconstructions tend to shrinkwrap this structure as a horn, the fact that the nasal cavity appears to have extended all the way to its tip suggests that it was actually supporting a huge bulbous nose.

Since Embolotherium also doesn't seem to have been sexually dimorphic like other brontotheres, its enormous ridiculous-looking snoot may instead have been a resonating chamber used for sound production and communication.

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Weird Heads Month #27: The Weirdest Wildebeest

Earlier in this series we saw some ruminants with bizarre-looking headgear, but there was another species in that group that evolved a completely different type of strange head.

Rusingoryx atopocranion was a close relative of modern wildebeest that lived during the late Pleistocene, around 100,000 to 50,000 years ago. Its fossil remains are known from the Kenyan part of Lake Victoria, on Rusinga Island – an area which wasn't actually an island at the time due to lower lake levels, and was instead part of a hot dry grassland environment.

Standing about 1.2m at the shoulder (~4'), it had an oddly-shaped skull with a pointed snout and a highly domed forehead. But this wasn't the thick bony dome of a headbutting animal – this structure was narrow and fairly fragile, and had looping nasal passages running through it.

Instead it was something never before seen in any mammal: a bony nasal crest convergently similar to those of hadrosaurid dinosaurs.

Juveniles had less developed crests, developing them as they matured, and one skull that may represent an adult female also has a smaller crest, suggesting that this feature was sexually dimorphic.

Based on just the anatomy of the nasal passages Rusingoryx may have honked at a frequency similar to a vuvuzela, but the added length of its vocal tract could have lowered this pitch even further, closer to infrasound ranges – so more like a tuba! Such low frequencies can travel very long distances and are also below the hearing range of many carnivores, and would have effectively allowed Rusingoryx to shout at each other in "stealth mode".

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Unsolved Paleo Mysteries Month #11 -- Strange Snoots: Equid Edition

Horse evolution is often represented as a simple progression from Eohippus* to modern Equus, but it was actually a lot more complicated than that -- and some ancient horses had some very odd things going with their snouts...

(* For a long time Eohippus was considered synonymous with Hyracotherium, but more recently has been split back off as its own genus again.)

Pliohippus, from the Middle Miocene of North America (~15-12 mya), and several of its other close relatives had especially large, deep recesses in their skulls, usually referred to as “preorbital fossae”.

And the purpose of these holes is still unknown. Although superficially similar depressions are seen in various other perissodactyl groups, they vary in position and structure and probably weren’t all homologous.

Ideas have included resonating chambers, some sort of glands, inflatable sacs, or attachment sites for complex lip musculature.

Meanwhile Hippidion from the Pleistocene of South America (2 million -- 10,000 years ago) had especially long and domed nasal bones. This must have supported an enormous nasal area -- possibly giving it a saiga-like air-conditioning system, a highly sensitive sense of smell, or perhaps even some sort of prehensile proboscis-like snout.

Unless we find some exceptional soft-tissue preservation, the facial anatomy of these equids is going to remain enigmatic.

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Unsolved Paleo Mysteries Month #16 -- Strange Snoots 2: Oddball Ornithiscians

Those extinct horses weren’t the only ancient creatures with unexplained noses. Some dinosaurs had equally weird things going on with their snouts -- and while hadrosaurs' big honkin’ snoots are fairly well-known, there were other ornithischians with their own bizarre nasal anatomy.

Many ceratopsids had an enormous nasal opening forming a giant bony “window” through their snout, with the chasmosaurines like the famous Triceratops having additional bony projections and hollowed regions within these holes. They probably supported some huge elaborate cartilage structures in life, but what they were for is still a mystery. They may have helped with heat dissipation or moisture conservation, aided sound production, provided a highly sensitive sense of smell, housed a vomeronasal organ, held part of an air-filled pneumatic system... or, getting more speculative, possibly even some sort of inflatable nasal display structure.

Some ankylosaurids, meanwhile, went with multiple holes instead. Minotaurasaurus here had two additional openings around its nostrils, and Pinacosaurus could have up to five -- the purpose of which is unknown. Many ankylosaurs also had forward-facing nostrils (a rare trait in archosaurs) and incredibly complex looping airways through their skulls. These may have allowed for mammal-like “air conditioning”, regulating the heat and moisture content of each breath, or perhaps enhanced their sense of smell or served some sort of resonance chamber function. Or, again, maybe even nose balloons.

Also floofy ankylosaur because I can.