Order Paraselenodontia contains over 40 species of herbivorous eutherians that range in size from 5 to 300 kg in weight. The largest members of this group have managed carve a place for themselves amongst niches usually reserved for dinosaurs by thriving in harsh or remote environments that all but a few ornithischians find too extreme. Many aspects of their lives are as yet unknown,  due in part to their living in remote locations as well as a general bias amongst specresearchers towards dinosaur-related projects.

FEATURES
    Specerotheres are terrestrial herbivorous quadrupeds found throughout much of the northern hemisphere and certain parts of Africa. They reach their greatest size and diversity in remote environments like the great northern tundra and Himalayas. They can be divided into the small, primitive lagocanimorphs (dogbunnies) and the advanced specerotheres (caripoos, spelks and dunicorns).

    They have sometimes been called 'odd-and-even-toed' ungulates, as they walk on 3 or 2 hooves on the manus and 3 or 4 hooves on the pes.

    All paraselenodonts possess the following dental formula:

    Upper jaw: I1, I2, P3, P4, M1, M2, M3
    Lower jaw: I1, - , P3, P4, M1, M2, M3

    The first pair of upper incisors and the sole lower incisors are greatly enlarged, giving the lower jaw a diprotodont condition effectively identical to that of certain Ozarel (Home-Earth Australia) marsupials. A wide diastema usually separates the incisors from the closely packed cheek teeth.



(Picture by Brian Choo)
Fig 1:
A: Lower jaw of a three-horned caripoo.
B: labelled diagram of an upper M3 of a blue-maned dogbunny.

    Paraselenodont cheek-teeth are generally high-crowned with a unique ridge pattern of that has given their clade its name. Like the selenodont teeth of Arel-artiodactyls, the cusps of paraselenodont molars and premolars are arranged in pairs of crescent-shaped ridges, forming a long-lasting grinding surface. However, because of the different chewing actions of these Specworld mammals, these ridges are arranged breadthwise rather than lengthwise (as if an artiodactyl molar had been turned 90 degreesclockwise).

    Unlike the side-to-side chewing of Arel ungulates, the jaw action of paraselenodonts is primarily propalinal (back-to-front). This chewing motion is somewhat akin to Arel rodents and is facilitated by an immensely strong medial masseter that attaches to either the zygomatic arch (in lagocanimorphs) or to the side of the snout (in specerotheres). Also like rodents, many paraselenodonts possess large cheek pouches.

    All these mammals possess a complex, sacculated stomach which contains a rich bacterial flora to aid in the breakdown of plant foods. Specerotheres also practice rumination or 'chewing the cud'.

HISTORY
    Precisely where these creatures fit amongst the placental mammals remains a mystery. They bear a number of remarkable external convergences with various Arel mammals but are both genetically and anatomically dissimilar to all other extant clades of both timelines. Preliminary mitochondrial DNA studies suggest that their ancestors had already diverged from other the living spec-mammalian lineages well before the start of the Cenozoic. Intriguingly, this same genetic research indicates that their nearest (though still very distant) relatives are none other than the rodent-like xenotheridians although there is little evidence, anatomical or fossil, to support this idea. Alternatively, the variety of primitive species on the Himalayan plateau would seem to indicate that the paraselenodonts are of Gondwanan stock, arriving in Eurasia perhaps via India.

    Although they may or may not have originated in a different part of the world, most researchers are in agreement that the Himalayan region was the cradle of paraselenodont evolution and was the source of the current crop of living forms.

    While small paraselenodont-like teeth are known from Oligocene Mongolia and India, no diagnostic postcranial remains are known from before the Neogene which makes pinpointing their relationships a difficult task.

     In the early Miocene, fossils of rat-sized lagocanimorphs suddenly become quite common in Eurasia (a phenomenon consistent with the 'Out of India' model). These forms are already quite advanced (and are in fact more derived than the most primitive extant dogbunny), a clear indicator of a much older evolutionary history.

    During the Pliocene, cat-sized representatives of the more advanced suborder (Specerotheria) appear in south-central Asian assemblages. While never particularly common or speciose (rarely more than one species in any assemblage), they soon spread into much of Asia and northern North America but remained exceedingly rare or absent in most of Europe as well as Africa where none survive today.

    The formation of the north polar icecap seems to have given these mammals their lucky break in clearing out many of their dinosaurian competitors in the high arctic. During the Late Pliocene and early Quaternary, the specerotheres shot up in size and diversity in the Holarctic, evolving into the collection of long-legged horned beasts that currently dwell in the frigid north.

LAGOCANIMORPHIA
    This the older and more primitive suborder of paraselenodonts, that today represents about thirty small species scattered throughout Eurasia as well as parts of Africa. They are long-tailed and walk with a digitigrade posture giving them a distinctly dog or fox-like appearance when viewed from a distance. This, when combined with their large incisors and ears has inspired the name 'dogbunny' for these mammals.

    Widely distributed in the Miocene, today the dogbunnies are generally found in cool, rocky environments although a few unusual species can be found in the arid plains of central Asia and the drier parts of Africa.

    The feet of dogbunnies possess 3 manual hoof-like toes and 4 on the pes, often with additional vestigial digits. Pending further research, all dogbunnies (extant and extinct) are currently lumped together into a single family, the Lagocanidae although this situation will almost certainly change in the near future.

SAMPLE TAXA: Eurasia

• Blue-maned Dogbunny
• Siberian Dogbunny

 

 

SPECEROTHERIA
    A dozen or so species of specerothers can be found throughout the holarctic in the tundra and boreal forests. A few others are scattered around the rest of Eurasia in remote montane or insular environments.

    Commonly referred to as caripoos and spelks ("Spec elks"), euspecerotheres are medium-to-large sized mammals with long snouts and short tails. They possess 2 manual and 3 pedal hooves on their feet. Many species possess an unusually fleshy and mobile upper lip. Specerotheres walk with an unguligrade posture.

    Most specerotheres possess a variety of horns or horn-like structures on the head. Nearly all possess one or more bony extensions on the temporal ridge that supports a keratinous horn or crest. Many specerotheres also possess facial horns or bosses made out of epidermal tissue.

UNICORNOIDIDAE
    This monotypic family contains the dunicorn, an unusual desert species from Central Asia.

SAMPLE TAXA: Eurasia

• Dunicorn

 

 

SPECEROTHERIIDAE
    The members of this family are the largest and most familiar of the specerotheres. They bear a strong external resemblance to the artiodactyls of Arel with long, slender legs with an unguligrade posture and prominent flamboyant horns on their heads. They can be divided into 2 subfamilies.

    The Specerotheriinae includes the spelks of the genus Specerotherium and Annelka. These are creatures range from 15-70 kg and are primarily forest and woodland dwellers. They live as solitary individuals or pairs that defend a territory. Spelks often have bizarrely ornamented bony horns or crests that are used for visual threat displays. When this fails, the single sharp epidermal horn on the forehead is brought to bear.

    The Tricerotheriinae comprises the three species of caripoo (genus Tricerotherium) which, at 190-300kg in weight, are probably the largest mammals ever to exist on Spec. Unlike the forest-loving spelks, the caripoos roam the great northern tundras in small to moderate-sized herds. Living alongside the great polar therizinosaurs, the caripoos survive by having powerful chewing capabilities coupled with an intensive digestive process that allows them to tackle less palatable foods than the dinosaurs are usually willing to sample. Caripoos possess a short bony horn on the unusually large (for a herbivorous mammal) temporal ridge and two or more epidermal horns.

(Picture by Brian Choo )

Fig 1: The three-horned caripoo
 

   Weighing in at up to 300kg, an adult three-horned caripoo (Tricerotherium mirificus) buck is the largest terrestrial mammal on Spec. Does are slightly smaller, rarely getting above 250kg. They are beasts of the arctic tundra and can be found throughout polar Eurasia as well as northwestern North America where its range overlaps with the closely related American or four-horned caripoo.

    Three-horned caripoo gather together in migratory herds of up to twenty animals led by a dominant male. Mating occurs in October. The males in the herd have a brief tussel to see who will be the one to mate with the does in heat this year. However unsuccessful males or those from herds with few females may try to entice does from other herds which can lead to violent confrontations.

    During the summer, they graze in the north along with lammoxes and arctotitans of the tundra. With the summer bloom there is plenty to go around for all and the caripoo gorge themselves on a variety of grasses, fungi and aromatic herbs, building up substantial reserves of fat.

    During the winter, they are forced southwards, usually trying to remain within visual range of a herd of giant polar therizinosaurs - though usually not getting too close as the carnivorous urgings of its distant ancestry will sometimes surface in an angry or starving tirg. This hazardous association is vital to the caripoo, however, and herds that are unable to find a "patron therizinosaur"  almost invariably perish.

    Firstly, the dinosaurs provides a limited degree of anti-predator protection. When faced with a drak-attack  the caripoo flee towards the therizinosaurs which are usually too focused on the deinonychosaurs to pay much attention to the mammals. Even a sabre-tyrant is reluctant to get too close to an angry and alerted lammox or arctotitan.

    The therizinosaurs are, however, far more important to the caripoo as a cheap source of food during this harsh time. With their massive claws, the theropods have digging capabilities of a magnitude that no mammal (save man) has ever possessed. Thus these dinosaurs are able to uncover greenery buried deep in the snow as well as tubers and roots in the frozen soil. Whole families of plants rely on this behaviour for their reproduction, producing fruiting bodies just before the onset of winter that lie dormant in the snow for the scythe-dinosaurs to find.

    Yet, for all their digging prowess, the therizinosaurs are limited in the degree to which they can utilise this resource owing to their relatively weak jaws and simple chewing mechanism. Thus the dinosaurs often leave spilt and discarded scraps at their digsites that the caripoo greedily pick over once the theropods have moved on.

    Further more, the dung of therizinosaurs contains a tempting mixture of undigested plant fibres and seeds. After an arctotitan takes a dump, the caripoo rush to the dinopat like pigs to swill. They then noisily consume the steaming faeces, which also provides a valuable source of warmth, fights often breaking out over the choiciest bits of poop.

(Picture by Brian Choo )

Fig 2:  Three-horned caripoo enjoy a nice hot meal, straight from the lammox's bum.

    During this time, the caripoo often display an initially confusing behaviour called "wine-tasting". The mammal will stuff its face full of
poo until its cheeks bulge before violently spitting it out. The animal is in fact extracting large undigested seeds and nuts by mixing the fecal matter with saliva before squishing it between its teeth. The seeds are lodged between the animal's teeth and the excess poop is discarded. The caripoo then cracks open the seeds and feed on the contents.

    This behaviour has apparently been going on for so long that the seeds of certain polar plants attain on optimal germination rate only after passing through the digestive tracts of BOTH a therizinosaur and a caripoo.

    Once their scatophagous frenzy has subsided, the caripoo can often be seen furiously cleaning their mouths out with snow. Although this is probably a safeguard against oral infection, one cannot help but think that they are desperately trying to get rid of the aftertaste.

(Text by Brian Choo )

 The Saga of the Caripoo

SAMPLE TAXA: Eurasia/North America

• Annelk

 
(Text by Brian Choo)