Across the warmer parts of the globe, herds of giant herbivorous ornithopods dominate the landscape. However, when trudging through the forests and swamps of tropical Asia, and to a lesser extent tropical Africa and South America, observers will often come face to face with dinosaurs of a very different kind – the parrot-beaked ceratopsians.
At first, it was believed that all cenoceratopsians were descended from the most famous Asian ceratopsian, Protoceratops andrewsi. However, a more in-depth analysis of these creatures revealed that they are more related to the small North American genus Leptoceratops gracilis.
The ceratopsians first appeared in Late Jurassic Asia with species Xuanhuaceratops niei, Chaoyangsaurus youngi, and Yinlong downsi. Eventually, they soon branched into a few successful Laurasian groups (among several smaller ones). The Neoceratopsia from the Northern Hemisphere, for example, were comparatively primitive forms that were usually hornless or, at most, in possession of a very small nasal protuberance like Protoceratops being the most famous example. While staying small, they became exceedingly abundant in places like China, North America and even Europe, eventually evolving into medium sized creatures with horns for defending themselves; the most famous examples being such creatures as Zuniceratops. Far more spectacular were members of the North American family Ceratopsidae which attained huge sizes (sometimes surpassing today's Indian megahorn, see below) and sported a dizzying array of facial horns, spikes and bosses consisting of both centrosaurs and chasmosaurs. During the Campanian, the first centrosaurs and chasmosaurs arrived in the form of genera like Machairoceratops and Judiceratops respectively. Throughout the Campanian, their diversity blossomed as more than forty genera of these frilled giants marched along the western shores of the Western Interior Seaway from Alaska all the way down to Mexico. However, as the Maastrichtian progressed, ceratopsid diversity waned with the vast majority of centrosaurines going into decline, excluding a few exceptions like the Asian Sinoceratops, while the chasmosaurines, most notably animals like Triceratops, Torosaurus, Titanoceratops and Ojoceratops persisted for a long period of time, eventually conquering North America by the end of the Cretaceous, while the centrosaurs thrived in Asia. The reason for this decline in North America is unknown, but seems to have been in part due to climate change, new diseases, changing availability of food resources and possibly the appearance of new immigrant competition and predators from Asia, among them the ceratopsian-hunting specialist Tyrannosaurus.
The chasmosaurine family made a renaissance of sorts during the Paleocene and Eocene, evolving into spectacular behemoths such as Brontoceratops robustus and Gigantops dominus, two of the most massive ceratopsians ever known. While that was going on, the centrosaurs continued to decline due to competition from the more advanced chasmosaurs, leaving only a handful of surviving species in left in the world. However, they did evolve some unique forms during this time period. One of the best examples being the discovery of an unidentified species of centrosaur that fulfilled an antelope-like role in its environment, while another fossil describes another species of centrosaur akin to HE's Uintatherium, and was found in Europe.
All members of the chasmosaurinae, as well as the other branches of the Ceratopsidae like nodoceratopsinae and ankyloceratopsinae, had vanished forever around the Eocene-Oligocene boundary, likely due to the Eocene-Oligocene Extinction Event as they couldn't adapt to the changing climates and changes in their environment. However, in an ironic twist, the more ancient centrosaurinaes managed to survive the ordeal despite suffering heavy losses. Eventually, they would suffer the same fate as the rest of the ceratopsidae a few million years later in order, their extinction paved the way for the "golden age" of the hadrosaurs of North America.
At the same time, their smaller leptoceratopsid cousins - the last remaining group of small ceratopsians at the time - were having a more productive time. They grew larger and stranger, moving into most niches vacated by their recently departed cousins and the sauropods who went extinct in the Northern Hemisphere. In terms of higher-level diversity, the Late Oligocene was the heyday of the leptoceratopsids when a variety of weird lineages could be found throughout the Northern Hemisphere, keep in mind that this was in Eurasia. In North America, however, it was vastly different story. While the Eurasian members of the Ceratopsidae ultimately succumbed to the effects of climate change, their North American relatives seemed to fare the storm much better. However, they too would also succumb to the effects of climate change and the new grasslands which seemed to pop left and right. The leptoceratopsids in North America, which were a different group from the ceratopsians, evolved to fulfill the niche of the departed larger ceratopsids, this group was prolific through out North America up until the late Miocene and early Pliocene when the were wiped out by the invading Eurasian cenoceratopsians.
Finally, some had quite certainly had difficulty coping with the spreading grasslands. The narrow beaks and slicing dentition of most species was great for tearing into tough bark and cycads, but considerably less efficient at processing grass than the square bills and grinding teeth of hadrosaurs. While the other groups dwindled, one line of leptoceratopsids had adapted to the grasslands by abandoning the characteristic scissor-teeth of their ancestors, allowing them to exploit a wider range foods (although they never produced a specialized grazer), the same case can be implied for the members of the Ceratopsidae family that were still around. These were the first of the Cenoceratopsia, which by the Late Miocene had regained much evolutionary lost ground. They soon became the dominant large browsers of southern Eurasia and made headway into Africa. Fossils from this time indicate that even the cenoceratopsians extend as far east as Japan and as far west as France.
During the Pliocene or perhaps end-Miocene, the cenoceratopsians entered North America and marched across the Panama Isthmus to become established in South America for the first time (as far as we know) in ceratopsian history, if not counting the controversial and possibly dubious species Notoceratops bonarellii. Then came the climatic seesaw that was the Quaternary. The lush woodlands which the cenoceratopsians favored appeared and vanished with the ebb and flow of the glaciers to the north. How these ceratopsians died out due to climate change is still a mystery, a stark contrast to knowledge of ceratopsians of our homeworld, especially the ancient Pachyrhinosaurus, were able to cope with colder climates. Even our most knowledgeable specexperts don't have the clearest answer at the moment. Today, the cenoceratopsians and dinoceratopsians (with the exception of the Everglades tuskhorn) are no longer present in North America and Europe, but continue to thrive in the warmer parts of Asia, Africa and throughout South and Central America, it may be a matter time before these creatures could recolonize North America.
BIOLOGY & FEATURES
One glance at its homely face is enough identify the creature in front of you as a ceratopsian. A unique bone called the rostral sits at the tip of the snout and, when combined with the predentary at the tip of the lower jaw, creates a narrow beak. Jutting out the back of its skull is a frill of bone formed by the parietals and squamosals. This frill can be used for display as well as providing an extended surface area for huge jaw muscles, giving the animal a formidable bite. Members of the extant clade Cenoceratopsia share a number of additional features which separate them from their leptoceratopsid ancestors. The ischium is now fairly straight, losing the pronounced downward curve. On the face, many of the ornamental features of the more ancient Ceratopsidae have convergently re-evolved, including horns on the nose and brows. Unlike the smooth-edged frill of leptoceratopsians, those of cenoceratopsians may be decorated with prominent knobs and spikes.
The most characteristic feature is, however, in the teeth. The tooth batteries of early ceratopsians were arranged to form a set of vertical blades. In effect, they chewed their food with a set of garden shears – a trait which probably allowed them to subsist on tougher vegetation than their contemporaries. (This feature is still used by the undaurs, which in general eat tougher stuff than the gihugrongos with which they coexist.) However, it is difficult to imagine this mechanism as being anywhere as effective as the grinding batteries of hadrosaurs.
When the cenoceratopsians appeared in the Late Oligocene, their dentition progressively shifted towards a duckbill-like configuration where the crowns of the teeth rasp against each other to crush and grind plant food. This made chewing far more efficient than in earlier designs and was probably the key to their success. However, the teeth of cenoceratopians can easily be distinguished from those of hadrosaurs in being fewer in number, more robust in form and two to four times larger relative to body size. The teeth often bear prominent cusps and ridges which helps them to process plant matter that most ornithopods consider unpalatable.
PLATEOCEROTIA (Dawnhorns and Megahorns)
These are fairly primitive and generalized cenoceratopsians that are currently restricted to Asia. All plateocerotians possess a well-developed nasal horn or series of nasal hornlets as well as parietal and epocciptial spikes on the frill. They have a fairly long, low-slung bodies and short, down-curved tails. Unusually, the hatchlings are born with one or two pairs of large fang-like premaxillary teeth which may be retained, reduced or lost in the adults.
Plateocerotia and Potamoceratopidae share a number of features, including enlarged teeth for the grinding of hard fodder, a small nose horn, and a number of biochemical similarities. Some argue this could be a case of convergent evolution.
This Asian clade contains two living species that are characterized by a total lack of osteoderms and unusual crushing dentition. The nasal horn is large and unusually broad based. They are creatures of dense tropical forest and woodlands, using their powerful teeth to break open the fallen seeds and nuts of rainforest trees.
Dawnhorn (Plateoceros soloriens)The dawnhorn (Plateoceros soloriens) is a 4 metre long cenoceratopsian that dwells in the forests and woodlands of southern Asia. Males of this species have a curious, laterally flattened nose horn, which flushes bright yellow-orange during the mating season and has inspired this creature's common name. Males of this species have a curious, laterally flattened nose horn, which flushes bright yellow-orange during the mating season and has inspired this creature's common name. These ceratopsians root around on the forest floor, consuming fallen branches and fungi whilst browsing on low foliage in clearings and at the forest edge. Their specialty, however, is in the consumption of the tough fallen fruit of several kinds of rainforest tree.The most remarkable feature of the dawnhorn is in the mouth. A pair of stout, triangular premaxillary teeth is present in the roof of the mouth while the cheek teeth are massive and robust. In short, the dentition of the dawnhorn has become a giant nutcracker and it is one of the few animals capable of tackling a fruit as intimidating as a zlatkonut.
The half-dozen or so species of zlatkopalm (Marjanophytaceae) are a relic group of unusual primitive angiosperms found only in tropical Asian lowlands. These remarkably ugly, foul-smelling and fast growing small trees or bushes produce immense fruiting bodies all year round. These so-called zlatkonuts are protected by an incredibly resilient spiny husk, superficially similar to a WWII naval contact mine. The dawnhorns eagerly snatch up these fruits when they fall to the ground or use their powerful beaks to violently rip them from low-growing species. Once in a dawnhorn's mouth, a powerful biting action brings its teeth to bear on the husk and the zlatkonut is soon noisily cracked open. The ceratopsian then feeds on the stuff inside, a slimy pulp, which contains the seeds of the zlatkopalm. These pass through the dinosaur's digestive tract to be deposited on the forest floor a few days later within a pile of beautiful, nutritious poo. The dawnhorn is thus a vital element in the reproduction of these plants, which is why the zlatkopalms do not grow in otherwise suitable habitats where these ceratopsians are absent.
Auryngo/Sunhorn (Plateoceros soloriens auryngo)The auryngo or sunhorn is a subspecies of dawnhorn that was at first mistaken for a species of its own by early specbiologists. The auryngo lives only in the Terai region (southern Nepal) while P. soloriens soloriens is more widespread, and can be found throughout mainland Southeast Asia. At least two more undescribed subspecies dwell on the islands of Sumatra and Borneo whilst an entirely new Plateoceros species has recently been discovered in southern India, dubbed as the "sunsethorn".
Red-Faced Bostop (Antillomanus robustus)
The red-faced bostop (Antillomanus robustus) is a colorful, 4-meter cenoceratopsian of uncertain affinities. Built lightly for its size and with long, slender legs for a ceratopsian, bostops spend most of their time browsing around clearings and stripping bark from trees. They are infamous for their aggressive territorial habits, charging at any sign of danger at aggressors that are not too large, putting their sharp, backswept nasal horn to good use. This is the only member of the Plateocerotidae known to live in Africa...and how it wound up there is still a mystery.
The furciceratopids form one of the largest living group of ceratopsians, rivaled only by the likes of the brachioceratopsians, with perhaps a dozen species, ranging from small forest dwellers to the giant megahorns. Apart from one species, they all live in Asia. They have generalized dentition, a large narrow nasal horn or series of hornlets and prominent jugal spikes, resembling the likes of many species of centrosaurs that roamed North America and Asia during the Late Cretaceous. Most have spiny or stud-like osteoderms set in their scaly hide. They tend to be unfussy feeders, eating any greenery they can easily get to.
Although nowhere near as nearsighted or red-green-blind as Home-Earths rhinos (similar-looking giant mammals), most of the larger species are known to be extremely bad-tempered. Even giant priscataurs will usually give an adult megahorn a wide berth. Smaller forms, on the other hand, can be extremely shy and cryptic.
Indian Megahorn (Furciceratops grandis)
Indian megahorns, the largest living members of the furciceratopids, ranging from eastern India to the shores of the South China Sea. Females and young live in small herds whilst adult males are usually solitary. Their preferred habitat is grassland and open areas in forests, usually close to a watercourse where they wallow and bathe. Their powerful beak can demolish even the toughest of plants.
Research suggests that the extracts of the megahorns' horns possess an extremely potent aphrodisiac quality and could form the basis of a highly lucrative pharmaceutical trade.
African Megahorn (Furciceratopoides africanus)Also known as the ngoubou, the African megahorn (Furciceratopoides africanus) can be found living alone in nearly all rainforests of Africa (except at the highest altitudes), where it munches on the undergrowth. Not quite as immense as its Indian relative, it is still an impressive sight.
Terramoloch (Terramoloch spinifer)
Spec is plagued by cryptic ceratopsians! While the frill-tusker/till-cheek dinoceratopsian debate rages on in South America, this strange little Indian dinosaur has gone virtually unnoticed. Known only by its scientific name Terramoloch spinifer, this enigmatic ceratopsian long frustrated specbiologists by refusing to fit in with any other ceratopsian clade. Many believed (and some still maintain) that T. spinifer is a Eurasian dinoceratopian, but with the aid of mitochondrial DNA studies, we have concluded that T. spinifer is, in fact, a close relative of the Indian megahorn.
To compare the massive Indian megahorn to the tiny Terramoloch – which measures less than two meters in total length – at first seems as ridiculous as comparing the little herbivore with the frill-tusker, but a number of physiological, as well as genetic features support this hypothesis. Firstly, the branching nasal horn is diagnostic of Plateoceratopidae, the clade to which the dawnhorns belong. Also, the enlarged, curved jugal horns (once touted as links to the dinoceratopians) are present in many megahorns, including the Indian megahorn. Even the bizarre covering of spiny scutes, unique among ceratopsians, is present (though to a much lesser degree) in young megahorns.
The habits of T. spinifer are largely unknown, but this denizen of the high plateaus of India and Nepal seems to be a low-level browser, feeding mostly on roots and shrubs, p-Rhododendron being this species' food of preference. T. spinifer's mating and child-rearing behaviors are unknown.
Zthuqarnayn (Syndyoceratops bicornis)
The 5-meter zthuqarnayn is one of the smaller species of furciceratopsian, but is nonetheless no less aggressive than its larger relatives. A tough, hardy species, zthuqarnayns live in dry and arid conditions all along the Middle East and Asian Mediterranean. It is one of the few species that can actually subsist on the venomous Death-thorn (Sha'ukat Alma'ut), cropping it with a tough beak and destroying the toxins with a cast-iron digestive system. Extensive "pebble-skin" nodules and a tough hide are further adaptations to fraying paths through thornbushes. The twin horns are useful display structures and predator deterrents.
Mthalathelqarn (Synthetoceratops splendidus)
The mthalathelqarn is a semi-amphibious furciceratopsian that was discovered back in 2006 by Emile Moacdieh and David Marjanovic during their expeditions to Spec's Mediterranean. A frequent wallower, this bulky animal lives near along rivers and various waterways near the Mediterranean Sea and the Nile River. Despite being smaller than the African megahorn, these three-horned herbivores are still quite dangerous: one report exists of a mthalathelqarn mother fatally goring a Nile mosasaur that tried to make a meal out of her calf.
POTAMOCERATOPIDAE (River Behemoths)
The behemoths are large, massively built semi-aquatic dinosaurs that roam the bottom of rivers and lakes of southern Asia in large herds. They feed primarily on aquatic plants but will sometimes come onto land to browse after sundown. The legs of behemoths are rather small, and they usually move slowly on land. The neck is short, and the tail is strongly shortened, so that crocodiles can't attack easily. Behemoths have massive heads with short frills, and long barrel-like bodies. Their eyes and nostrils are positioned at the tops of the skulls and protrude from the water when these dinosaurs rest near the surface.
Each of the major tropical Asian river systems plays host to at least three species of these aptly named river behemoths. Males of some species have horny growths above the eyes in addition to the small nose horn.
Indian River Behemoth (Potamoceratops obesus)
The Indian river behemoth is the largest behemoth species, and can weigh up to 8 tons. These impressive animals can be found in great herds throughout the broader arms of the Ganges. Waterplants, rushes, horsetails, ferns, riparian shrubs, and small trees all feature in their indiscriminate diet; they have also been known to take fallen fruit and scavenge skeletons for calcium. At their size and weight, Indian river behemoths are simply too big to tackle, and their herding instincts reinforce that defense. Nonetheless, juveniles fall prey to cuttercrocs, abelisaurs, and even large catfish.
Bull behemoths stake out distinct territories, with females, young, and satellite males which are merely tolerated. Anything else, including other males, small crocodiles, and flat-bottomed dinghies, run the risk of being crushed and mauled by the tremendously powerful beak, or otherwise trampled to mulch. During the mating season, the air is rent with the roars, snorts, and bellows of the males ("RRROOOAAARRGGHHHH-GHHUUU!!!!") as they fight for dominance and mating rights.
Ornate Behemoth (Potamoceratops ornatus)The smaller ornate behemoth (Potamoceratops ornatus) is less dramatic at five tons, but has more pronounced horns and a splendid rainbow-colored hide in breeding animals. They are found across East Asia, however, they are mostly abundant in the Yangtze River.
BRACHIOCERATOPSIDAE (Undaurs and the horned riddle)
While some leptoceratopsians continued evolving along the same lines as their Cretaceous neoceratopsian cousins, some Asian forms branched off to fill different niches. The largest surviving group are the brachioceratopians that started off as living at forest edges, and eventually evolved into high-browsers convergent with sauropods (or indricotheres). Brachioceratopians' heads became smaller and lighter, and their neck frills became smaller.
These giant beasts are considered to be the most highly derived of the cenoceratopians. The premaxillary teeth have been lost, as has the fifth finger. The pronounced sacral curve of most other ceratopsians is gone making the tail stick out roughly horizontally from the body. The head is comparatively small and possesses a number of weight-saving features, most notably a reduced neck-frill with large parietal fenestra. The neck vertebrae have been greatly elongated and buttressed save for the first four which, as in other ceratopsians, are short and fused to assist in supporting the skull. Except for the neotenic dwarf undaur, all adult brachioceratopians possess incipient brow horns, epoccipital studs or spikes and a single row of triangular dorsal scales along at least the length of the tail.
In their 65-million years of additional evolution, the great dinosaurs have wildly diversified to point that classification is nearly impossible in some cases. A famous example is the ceratopsians. Already puzzling to classify from the beginning, fossils discovered in Eurasia led scientists to erect a new group, Taurosaurinae.
Where exactly did taurosaurs fit in within the ceratopsian family tree was a frustrating question for scientists. Many debates waged on about their taxonomic position, due to morphological similarities with different clades of ceratopsians. Some parties suggested that taurosaurs were late-surviving ceratopsids, while others aligned them with the megahorns, sunhorns, undaurs, and even the dinoceratospians. After extensive research of taurosaur specimens and close examination of the ceratopsian fossil record, it was discovered that Taurosaurinae was an extinct branch of Brachioceratopsidae.
The earliest ancestor of the taurosaurs, as well as the enigmatoceratopids and brachioceratopids, is the Eocene Eobrachioceratops, which already exhibited longer legs than its relatives. It was not until the Early Oligocene that the earliest taurosaurs evolved. Unlike their relatives, which became titanic sauropod-analogue high-browsers, taurosaurs became more agile, able to move at high speeds. Another important development was brow horns, a characteristic not seen in ceratopsians since the extinct ceratopsids. By the Middle Oligocene, taurosaurs had evolved into the first (and so far only) successful ceratopsian grazers.
Apparently, these creature hit upon a winning design, since they soon spread throughout Eastern Asia, their march into western Eurasia stopped only by the presence of the older eurolophs, another successful group of ornithopods. Fossils indicate the diversity of the taurosaurs, ranging from the nimble, long-legged Taurosaurus gracilis to the robust Megataurosaurus indica, which some researchers believe may have lived a semi-aquatic lifestyle.
The taurosaurs enjoyed enormous success throughout the remainder of the Oligocene and most of the Miocene. The end of the Miocene was signaled by the joining of Africa, Eurasia, and North America. There was almost immediate immigration of species moving from one continent to the other. The most notable arrivals were the hadrosaurs, which would have significant effects on endemic Asian wildlife. Neohadrosaurs from North America spread south from the Bering land bridge, while African ungulapedes arrived from the west. Unable to compete with these newcomers, taurosaurs lost ground. Eventually, taurosaurs, along with many other Eurasian endemics, were extinct by the early Pliocene.
ENIGMATOCERATOPSINAE (Horned Riddle)
Horned Riddle (Enigmoceratops faustuosus)
The enigmatoceratopids are basal brachioceratopians which were the most diverse in the late Miocene. Today they are restricted to a single diminutive species from Southeast Asia.
BRACHIOCERATOPSINAE (Undaurs)These enormous graviportal high-browsers of tropical Asia and Africa are the giants of the Cenoceratopsia family. Along with the pseudosauropods of South America and the extinct indricotheres of our timeline, they have done a marvelous job in ripping-off the gihugrongos, even though they don't reach the sizes of the biggest ones. Their skulls are lightweight (although retaining a pair of stubby brow horns) allowing the greatly elongated neck to raise the head high into the trees. All four limbs are pillar-like; the forelimbs are elongated and are now held straight under the body, losing the characteristic "bow-legged" posture of other ceratopsians. The tooth-batteries of brachioceratopids have also been reduced in size as a weight-saving feature, and the undaurs have reverted to a system once used by their distant ancestors but long since abandoned by the rest of the Cenoceratopsia: they swallow stones, storing them in the gizzard to grind up plant-matter after a brief chewing-phase in the mouth. Nevertheless, the cutting power of their jaws allows them to eat food too hard for gihugrongos, and their digestive system allows them to live off leaves that severely hinder the digestion of gihugrongos; on the other hand, gihugrongos have no problem with stuffing themselves with conifer needles, while undaurs avoid them, probably because of their tannines and their low nutritious value. Despite being them fulfilling the niche of titanosaurs in the south and southeastern Eurasia, the titanosaurs still thirve in that area as well, though their numbers have declined.
Young and adolescent undaurs stay close to one another whilst the adults are generally solitary. Breeding may occur throughout they year. A male in "dinomusth" will aggressively clear an area of rival bulls before trumpeting loudly to attract receptive females. Egg-laden females gather together in small herds before depositing their brood in pits on the forest edge and going their separate ways. The newly hatched young frantically scamper into the darkness of the undergrowth where they spend up to five years before leaving to form an adolescent herd. Unless in the mood for mating, adult undaurs are the most peaceful of all ceratopsians, lacking the jittery shyness of the smaller forms and the psychotic aggression of the large low-browsers. When one flick of your leg can send a priscataur flying, you can afford to be docile.
Brachioceratopidae evolved during the Oligocene, after the enigmatic extinction of most sauropods in the Northern Hemisphere, despite this some species of sauropod managed to thrive in Asia, and soon produced such giants rivaling the size of Protobrachioceratops gracilis, the largest leptoceratopsid known in the world of Spec.
Recent fossil evidence, most notably with the discovery of Eobrachioceratops antiquus from China, brings to light the argument that their origins might date back to the Eocene. Despite being a small creature, growing only 3 meters long, it has some very noticeable traits that can be found in modern-day undaurs.
Balundaur (Seismoceratops immensus)
Standing before an adult, 15 meter long balundaur takes one to new levels of humbleness. At up to 14 tonnes, this is quite certainly the largest living ornithischian, surpassing even the giant neotropical pachamacs. Balundaurs may be spotted throughout the Indian subcontinent to as far southeast as Borneo and Sumatra, but are not found north of the Himalayas. They can be found just about anywhere where they are trees, roaming far and wide in search of fresh greenery leaving a trail of dung and destruction in their wake – providing opportunities for a host of other organisms. A subspecies know as the Eastern Balundaur, S. immensus orientalis, exists elsewhere in the Asian mainland while recently, a new subspecies known as the Indian Balundaur, S. immensus immensus, has recently been discovered in southern India.
Common Undaur (Brachioceratops dynastes)
The common undaur (Brachioceratops dynastes) is nowhere near as large as the towering balundaur (10 metres long, 7 tonnes) but is still an impressive animal, nonetheless. Unlike its larger cousin, the greater undaur prefers to stay close to forested environments, venturing out onto the wooded plains only in particularly bad years. As a result of its wider distribution coupled with a more restricted habitat requirement, up to six different subspecies of this creature have cropped up in India, Sri Lanka, China and Southeast Asia.
Those subspecies include the following:
- Indian undaur (Brachioceratops dynastes indicus)
- Dynundaur (Brachioceratops dynastes dynastes)
- Regal undaur (Brachioceratops dynastes regalis)
- Andrews' undaur (Brachioceratops dynastes andrewsi)
- Dodson's undaur (Brachioceratops dynastes dodsoni)
- Chinese undaur (Brachioceratops dynastes siniensis)
Sishundaur (Brachioceratops microgigas)
The placement of the sishundaur (Brachioceratops microgigas), a remarkable, little known animal, as the closest relative of the greater undaur is a point of some contention. Found only in the dense upland forests of Sumatra, the sishundaur looks to be nothing more than an overgrown hatching greater undaur. Like a hatchling, the body is compact and dumpy whilst the brow horns, studs on the frill and bony scales on the back have not developed. It scales also bear an almost identical cryptic spotted pattern to the juvenile greaters.However, one of these "big-babies" was witnessed laying a clutch of 25 eggs which were unfortunately plundered by an unknown raider before they hatched (whatever it was also chopped/bit the two field researchers who were watching over the nest to handy pieces). All in all, this animal would appear to be an extreme case of neoteny, and it has been suggested that it is no more than a mutant form of the greater undaur, a subspecies of which occurs in the lowlands of Sumatra.
Dwarf Undaur (Brachioceratops minimus)
The little-known dwarf undaur (Brachioceratops minimus) lives on the islands in the islands of Borneo, Sumatra and Java. Lightly built and much smaller than their cousins, the common undaurs (Brachioceratops dynastes), dwarf undaurs are the most primitive brachiceratopsian alive today; given their tiny appearance, an adult dwarf undaur would be easy to mistake for a newly hatched sishundaur, despite their is a very noticeable difference when one studies the ontogeny of the two species.
Spiny Undaur (Spinundaur spinosus)
The spiny undaur (Spinundaur spinosus), is the only African undaur yet known. About three meters tall, fifteen feet long, and around three tonnes in weight, they move in aggressive and noisy herds, browsing on the upper reaches of the trees, but will also eat any manner of browse they please. They are typical in shape for a fair sized undaur, but have bony osteoderm spines along their back. Mainly non-destructive feeders, they do not create "highways" like larger high browsers.
Click the link to find out more about these enigmatic ceratopsians.
,=P. s. soloriens, (Dawnhorn). | ,=Plateocerotidae=Plateoceros soloriens=| | `=P. s. auryngo(Sunhorn) ,=Plateocerotia=| | | ,=Furciceratops grandis (Indian megahorn) | | ,=| | | | `=Terramoloch spinifer (Terramoloch) | `=Furciceratopsidae=| | `=Furciceratopoides africanus (African megahorn)
,=| | | ,=Potamoceratopsidae=Potamoceratops obesus (Indian river behemoth) & Potamoceratops obesus longicauda (Chinese river behemoth) | `=| | | ,=Enigmoceratopsidae=Enigmoceratops faustuosus (Enigmoceratops) | `=Brachioceratopsia=| | | ,=B. dynastes (Common undaur) & subspecies | |=Brachioceratops=| | |=B. microgigas (Sisundaur)
=Cenoceratopsia=| see subspecies of the common undaur
| `=Brachioceratopsidae=| | =Seismoceratops immensus (Balundaur) & Seismoceratops immensus orientalis(Eastern Balundaur) |=DINOCERATOPSIA
Dwarf undaur (Brachioceratops insularis)