More like giant geese than non-avian maniraptorans, the strange, unwieldy therizinosaurs are decidedly odd members of the famously oddness-prone maniraptor clade. Like all maniraptors, therizinosaurs (or segnosaurs as they are synonymously called) are bipedal, covered in feathers, and have hands bearing three fingers each, but there the resemblance with the maniraptoran rootstock stops (if one doesn't plunge deep into the details of the skeleton).

Segnosaurs are herbivores, and their bodies have radically changed to accommodate their vegetarian lifestyle. The hips of a segnosaur are much wider than is normal for a maniraptor, and the pubis is swept backward in the manner of a bird or ornithischian dinosaur, to make room the large belly needed to digest plant matter. Because of its tremendous gut, the centre of balance of a segnosaur is shifted backward along its spine, and these creatures squat like sumo wrestlers, with their torsos held further up than is normal for a dinosaur. (Like most dinosaurs, though, they cannot spread their legs.) To make matters even more confusing, the tiny, non-functional first toe possessed by most theropods has, in the segnosaurs, been greatly enlarged to make a decidedly un-theropodan four-toed foot. Misfits even in the varied and bizarre clade Maniraptora, and in the face of stiff competition from the hadrosaurs, ceratopsians, sauropods and other herbivores, the segnosaurs have nonetheless flourished in the past 130 million years, and have spread themselves across Eurasia and the Americas (with one species in the Sahara).


The history of Therizinosaurria begins in the Early Cretaceous (but with a probably Jurassic record), when small browsers like †Beipiaosaurus and †Falcarius lived in the lush forests of Asia and western North America. By the end of the Mesozoic, the segnosaurs had expanded far into a herbivorous lifestyle, evolving into huge, lumbering forms like †Segnosaurus and †Therizinosaurus. Fossil evidence is fairly poor for this time, with only a few decent partial skeletons and many puzzling fragments. Indeed, segnosaurs as a group were completely unknown until the 1970s, and early palaeontologists thought these long-necked plant eaters were late-surviving prosauropods (see cladogramme).

In our own timeline, the segnosaurs' history ends at the end of the Cretaceous, but in Spec, the 'ground-sloth dinosaurs' continued through the end of Mesozoic and into the Cenozoic with little trouble. Eocene fossils from China hint at a truly huge therizinosaurid, †Neonychus, a close relative of the Cretaceous †Therizinosaurus. From the shoulder joint to the tip of the claw of the 2nd finger, its arms measured over 3 m in length. This giant, as well as all of the close relatives of †Therizinosaurus, went extinct at the end of the Eocene, but other segnosaur groups must have survived. Oligocene strata bear a large number of segnosaurs, including the newly-evolved arctotitanids (or robust segnosaurs), and the precursors of the ceratonychids (or hornclaws) were present as well. The Miocene was a time of great diversification for the therizinosaurs, with the fleet-footed ceratonychids roaming across the cold-temperate forests of the northern continents, and the arctotitanids expanding into a wide range of herbivore niches.

As the globe cooled and then froze during the Pliocene and Pleistocene, the segnosaurs found themselves virtually alone in their ecosystems, being more cold-tolerant than the ceratopsians and hadrosaurs and better adapted for herbivory than the oviraptorosaurs. Almost immediately, these feathery plant-eaters took over the new taigas and tundras, evolving into the forms we know today: elk-like mooras, long-necked dorsas, and humongous arctotitans.


Each retreat of the glaciers has seen a decrease in segnosaur range and sometimes diversity, especially amoung the specialized glaciotitanids. The partial thawing of Earth's polar reaches has each time allowed ornithischian herbivores, such as the formosicorns, the ceratopsians, the jackalopes and the viriosaurs to expand northward, chewing away at the therizinosaurs' strongholds, which in turn increased in every glacial period. The warm period of today is cooler than the last interglacial; there are none of these featherless herbivores left in Europe, which means that some segnosaur species extend all the way to the Mediterranean. In Eurasia and the Americas, however, these strange, lumbering maniraptors dominate the large herbivore guilds only in the frigid places, be they high in altitude or in latitude. But there they have evolved an impressive diversity.

Modern therizinosaurs are also highly unusual compared to many of their distant cretaceous ancestors. Unlike the ancient species, which laid their eggs and left them, as shown by fossil evidence in the form of precocial hatchlings, modern therizinosaurids are doting parents.

However, many aspects of these animals have remained virtually unchanged; for one, their sense of smell. On par with many predatory theropods, therizinosaurs have acute senses of smell that can be used to locate food and mates or detect and evade predators. Their hearing is also excellent, as they can distinguish between many high and low frequency sounds. Their sense of balance is also highly acute, again, akin to their carnivorous counterparts among theropods. When all three are used together in tandem, the boon that results makes therizinosaurs amongst the most successful theropods the world over.

GLACIOTITANIDAE (Robust segnosaurs)

The clade which spawned the massive arctotitan, the arctotitanids are characterized by their robust body type, with short necks and tails. Quite successful during the ice ages, the arctotitanids seem to have declined somewhat since their heyday, with the ceratonychids (see below) far outnumbering them in population numbers and species count. These segnosaurs live in both Eurasia and the Americas, but their greatest diversity is to be found on the first of these two double continents.


This clade of segnosaurs has diverged into forest and tundra steppe species. Tardoxines have the most massive guts, gizzards and crops for their body size of any saurischian known, making them the most serious competitors to formosicorns and other northern ornithopods. The Tardoxines resemble HE caribous and forest horses in their ability to feed on very poor quality fare by both bulking and intensive processing.

Lammox (Tardox villosus)

Lammoxes (Tardox villosus) are found across the harshest tundra of Eurasia and North America, moving in bands a few dozen individuals before the oncoming migration of the giant arctotians. These quarter-ton herbivores eat any plant material they can find, small trees, unappetizing ferns and mosses, and even lichens, which they scrape from rocks with their broad beaks. The ability to find food even on the bleak winter tundra makes lammoxes (and arctotitans, to a lesser extent) the nexus of a community of organisms that depend upon the therizinosaurs for survival, ranging from arctic plants to the bizarre caripoo, Spec's largest land mammal.

Lammoxes protect themselves and each others from fendraks and polar draks with their long claws that are also used for digging for roots.


Lammox, Tardox villosus (Northern Eurasia and North America)

This clade of segnosaurs has diverged into forest and tundra steppe species. Tardoxines have the most massive guts, gizzards and crops for their body size of any saurischian known, making them the most serious competitors to formosicorns and other northern ornithopods. The Tardoxines resemble HE caribous and forest horses in their ability to feed on very poor quality fare by both bulking and intensive processing.

Tardoar (Megalotardox orcinychus)

The Tardoar is the largest tardoxine, old males sometimes reaching the weight of one ton. Females are smaller, and rarely exceed 600 kg. The females are a light greenish colour during the summer but change into brownish grays in the winter. Males don't change colour with the seasons but with age: the older a mature male becomes, the darker its plumage becomes, starting from the neck and spine. Eventually they may be almost entirely black.

Female Tardoars have claws resembling those of Yandos. Males grow a huge sickle-like claw on the thumb, which they use both for defense and for stripping bark of trees, or ripping off entire branches the size of a human thigh in winter. Tardoars prefer open ground to forests, but retreat to the safety of the woods during winters. They also migrate southwards in the autumn and northwards in late spring. Chicks are born in the late spring.

Male Tardoars often remain with the herd even after maturing, although this means they can't mate. Their fathers seem to tolerate their darkening offspring surprisingly well. Usually the males leave at some point when they are large enough to fight for a herd of their own, but it's usually the females that leave the herd soon after maturing.

Tardoars are rather slow animals, and depend more on mass, numbers and strong arms tipped with large claws for defense. While male Tardoars can be very easy to aggravate, especially in the mating season, a human can usually out maneuver a full-grown male.

Tardakh (Megalotardox woodwousi)

The Tardakh is a smaller relative of the Tardoar, both sexes reach roughly 600 kilos. They prefers the safety of the woods all year and doesn't migrate for long distances. Tardakhs are all brownish grey all of the year, males have a dark mane of feathers running down the spine. Tardakhs don't share the Tardoar's obvious sexual dimorphism, but are in many ways similar in their lifestyle. The Tardoar is more wide ranging, found throughout Europe as far east as Siberia. The Tardakh is a temperate forest European endemic, found from the British isles east to the Caucasus valleys.


The clade only contains a few select species, three that are oddballs and two that have become the true charismatic giants of the open holarctic. The arctotitanines were somewhat more speciose during the Pliocene, but they have developed several progressive chain species since the Blancan.

The loss of the giant grazing sauropods and hmungos across virtually all of North America and Eurasia north of the Himalayas left open a very relevant ecological niche. There was a bit of a tussle for the giant grazing niche between and within the two great northern herbivore clades clades. The Pliocene saw especially massive formosicorns and ceratonychid segnosaurs; however, it was the glaciotitanids that produced truly gigantic grazers of the holarctic plains.

Two genera are sometimes recognized, though there are strong calls to unite all within Arctotitan. The Aviphants are clearly more closely related to each other than to the Arctotitan. This publication takes a more neutral road that unites all but recognizes the distinctness of the latter two species.

Yando (Ailurosaurus varius)

The yando (Ailurosaurus varius) is the most southern of the modern arctotitanids, living in the Himalayan highlands. Yandos eat low-growing foliage, immature bamboo, fruits and nuts, but in times of famine (such as bamboo blooms), they don't refuse carrion.


Yando, Ailurosaurus varius (Central and eastern Asia)

Snow hona (Alpicosaura similis)

The honas are the smallest of the therizinosaurs, usually weighing only about 50 kg. These miniature versions of the ice-age giants feed on seeds, berries, twigs and shoots, and occasionally small insects and reptiles. During the winter, they can sleep in small caves they dig in the snow, and even hibernate for several weeks if the weather becomes too harsh.

Snow hona, Alpicosaura similis (Northern Eurasia and North America)

The Snow hona (Alpicosaura similis) which can be found through out Northern Eurasia and North America. Snow honas are larger than alpine honas at 50 kg, and prefer lower elevations than their mountain-loving kin.

Alpine Hona (Alpicosaura nanus)


Alpine hona, Alpicosaura nanus (Central and Eastern Europe)

Alpicosaura nanus, the alpine hona, is the smallest therizinosaur in Spec, weighing only 20-30 kilograms. These small herbivores are adept climbers that eat a variety of foods ranging from moss to tree bark to insects.  

Male alpine honas are highly territorial, with adult cocks fiercely guarding their feeding grounds. These otherwise shy creatures will often kill each other over land disputes, but females and juveniles may travel with impunity.

Arctotitan (Arctotitan gigas)

The arctotitan (Arctotitan gigas) is the largest of the segnosaurs, a specialized relic left over from a chilly past.

An arctotitan's claws are long and flattened side-to-side, forming tools the massive "woolly segnosaur" uses to dig for food under the snow. When feeding, the arctotitan lowers its head to the ground, its spine nearly horizontal, while its great claws plow through the snow. Its long, hollow, hair-like plumage covers almost all parts of its body, including the toes.

The arctotitan is now in something of a decline, as the Ice Age's tundra have receded. Arctotitans now live only in the rather narrow arctotitan steppe belt around the Arctic Circle, and their extreme specialization to this habitat makes them very sensitive to environmental change.

Due to their immense size, arctotitan have only one enemy as adults; the imperial sabre-tyrant (Smilotyrannus imperator). When confronted by such a predator, the arctotitan usually stands and fights, sweeping out with its huge claws to dissuade or injure its attacker. It is also smart enough to know when the advantage lies in running away. In a battle between arctotitan and sabre-tyrant, the combatant that strikes first and quickest usually has the advantage; if the tyrannosaur manages to land a bite on the flank, belly or neck, then the tide usually turns quickly in the predator's favor due to the devastating wounds. If the Arctotitan sees the attacker early on, it can usually run away, or if cornered, rise to face its enemy. In such scenarios, the Arctotitan has every chance of defeating its opponent and it is not uncommon to see an inexperienced young sabre-tyrant or a dead one carrying wounds inflicted by an angry arctotitan.


Arctotitan, Arctotitan gigas (Northern Eurasia)

Imperial Aviphant (Arctotitan [Barrusavis] impirius)

The Imperial Aviphant roams the central Eurasian steppes as far west as the shores of the Black and Caspian Seas and as far east as the Gobi south into the Himalayan plateau. Social life is somewhat more matrilineal than Arctotitans. The female herds may have aged bulls court them during the late winter breeding season. The bulls will also remain during the brooding period. They protect both the adult nesting females and immature foraging juveniles. Both the bulls and the juveniles will bring back food for the mothers stored in their crops.

Chicks hatch after 60 days and are out of the nest within a week. The bulls take their leave and the females slowly begin their migrations to rich summer pastures, often in floodplains or montane foothills. Unlike their larger Arctotitan relatives, Aviphants do not dig into soil for tubers, though they will clear away snow during winter. Imperial Aviphants average 3 tons in the females, some 4 tons in males. Very old bulls have been known to reach 5 tons.



The Three Eurasian lineages of Ceronychidae to scale.


During the colder seasons horn claws, as in the case of this Siberian dorsa, (Ceronyx major), can often be seen resting or sleeping with their necks tucked under the arm feathers to conserve heat. Since hornclaws are more or less social the whole of the year, there is usually at least one individual always keeping watch while the others sleep.

As their common name implies, male hornclaws have very long manual talons that are mainly used for one purpose: showing off. The claws grow slowly during their adult life, and old hornclaws can have quite impressive weapons on their hands. Hornclaws very rarely engage in serious combat, though, but the claws can be lethal when used against predators like sabre-tyrants and veldraks.

Having originated in North America, hornclaws soon reached Eurasia, where now most of their diversity can be found. One species specialised for life in deserts has even managed to dodge the competition from the jackalopes and lives in the Sahara. It should be noted that these therizinosaurs are the only group that are known to hiss when threaten.


Head shapes of the moora (Kentronyx robustus) and the European dorsa (Ceronyx paluditus), two of the most common ceronychid species.

The Dance of the Hornclaws: Lekking Season Up North

All hornclaws have a lek, but most notable of these is the moora, known to engage in a test of strengths that has been nicknamed "the waltz". In the very early spring when days have begun to lenghten but the temperatures are still chilly, male mooras begin securing Their territories. It is by its territory that a male will win over the females it will mate with, and the stronger and more experienced a male is, the better territory it can rule without competition. But, inevitably, conflicts will ensue.

When a male tries to enter the territory of another male, the owner of the territory will try to scare the interloper away by raising its arms in the air fully spread, displaying its claws. Very often the other male responds by doing the same. This is often called "comparing the claws" as it displays the length and condition of the males' claws to their competitors. The males will then move close to each other, both trying to look as big as possible, and stop just before they touch. They will then step sideways, forwards and backwards in unison, all the while hissing and gargling threateningly, until either one gives up or the real "dancing" begins.

When mere showing off fails to do the trick, mooras will test each other's strength. In a very controlled fashion the mooras will push their arms together so that the claws interlock. This is not an easy position for the mooras to hold, but not only will the males try to push the competitors arms backwards, they will also start stepping back and forth and to the sides as if they were engaged in some sort of dance. They may even make full circles positioned like this. 

Sooner or later the weaker of the two breaks off and runs away from the site. The running seems to signify that the competitor has conceded defeat and the winner will not follow or try to harm it. Sometimes two dancers will break off only to rest a while and start again, yet always the beaten one flees when it gives up. Of all the hornclaws, only lemeks are known to use their claws to inflict lethal damage on their male competitors, so the complexities of the lek of the moora seem to have evolved to prevent males from harming each other.

As with other lekking animals, the females will prefer the male with the best lekking territory. However the females do not move alone but in groups of 4-10 individuals, which will consequently protect their chosen champion. Only the biggest and toughest female group can secure mating with the top male. The females seem to settle things with intimidation only. The reason for this behavior is that the male must protect the communal nest of the female group, and can therefore not be shared with all females freely. Not all the males and females come to heat at the same time, so the lek can last up to a month, and female groups will always have plenty of older, stronger males to choose from.

Other hornclaws do not have quite as elaborate leks as mooras do, but the raising of the arms to display the claws is common to all species, even the relatively short-armed dorsas. While panhas will also "dance" like mooras, dorsas have a different kind of test of strength: they will entwine their necks and try to pull the other one out of balance. Such behavior has probably evolved to replace the "pushing dance" or "waltz", as their short arms do not enable dorsas to interlock their claws. Shantaks differ in behavior from other hornclaws by only doing display dances that do not involve physical contact. This may be due to the fact that their claws are not only proportionally but also absolutely longer than those seen in other species.


The ceratonychines are among the largest segnosaurs outside of the glaciotitanid clade. Their evolutionary history is mainly centered within North America, with expansions into Eurasia and South America once the Glacials got underway. Ceratonychines are very much like HE mastodons and elk *Alces* in habits, being primarily browsers, though they do mix some grazing during the summer season. These ground forbs and young grass shoots are more for essential nutrients rather than the mainstay of their diet.

Unlike the kentronychines, male ceratonychines are much bigger than females on average, with a dominant bull watching over a family of up to 20 hens and their offspring.

European Dorsa (Ceronyx paluditus)

Also called "sauropods-of-the-tundra" and "camel-geese", European dorsas (Ceronyx paluditus) are slow-moving and placid creatures. These browsers usually stand still while eating, only moving their long neck to reach for the grass clumps or tender tree leaves. Dorsas inhabit the riverbanks and forest margins of northern and central Eurasia, where, during the summer migrations, they congregate around the many marshlands formed by the melting snow. Here the dorsas eat a variety of aquatic plants, grasses, and herbs, and storing much of what they eat in the form of a fatty hump over the hips. During the winter, dorsas move deeper into the forests, where they switch to high-browsing and pluck needles of the lower branches of the pine trees, supplementing this diet with the fat they stored during the summer. A subspecies of European Dorsa  is known to exist simply known as (Ceronyx paluditus major), 'as of now, no name has been established, however, some have been proposed.


A European dorsa, Ceronyx paluditus, engaging in normal winter browsing behaviour, usually grazing in autumn to replenish its hump for the winter. (eastern Eurasia)

Siberian Dorsa (Ceronyx major)

The Siberian dorsa, (Ceronyx major) is the larger of the two dorsa species in Eurasia. During the summer these massive herbivores graze in swamps, plains and riversides, but during the winter they retreat to forests and switch to a diet consisting mainly of conifer needles. This change is also mirrored in the different types of stones they swallow during different parts of the year.


The kentronychines represent Spec's most speciose and widespread therizinosaur clade. Opinions differ, but it seems likely that at least 11 species exist. They are very diverse when it comes to ecology. Some species are strictly forest dwellers, others are grazers of the open steppes. Several species have adapted to life in arid subtropical deserts. The kentronychines all share one feature, they are selective feeders with rather narrow muzzles compared to other segnosaurs.

Kentronychines evolved in Siberia and Beringia roughly 10 million years ago. Pliocene members of this clade seemed to have whittled away somewhat in North America, just two endemic species survive today. Eurasia in contrast, has seen many species evolve and thrive, some of them emigrating back into their former North American homeland.

The kentronychines depart from other segnosaurs in that sexual dimorphism is either non-existent or the females are slightly larger than males. Clutching is also rather different. They have an ostrich-like approach, with alpha males mating with many females but only the dominant hens construct nests. The hens lay their own eggs numbering between 8 to 12 in the center of the nests while subordinate hens will deposit an egg or two on the edge. The alpha hens will brood up to 40 eggs in a clutch for two months. The rest of the herd will patrol the one to three alpha hens during this time. Occasionally they take over brooding duties so she can feed and defecate safely away from the nest.

The nesting period is extremely dangerous for any predator, even saber-tyrants. Those elongate and very sharp claws are deadly in a cornered individual hornclaw. No predator in its right mind would risk an alert herd of segnosaurs too willing to slash or stab with foot long manual pikes.

There is some debate on whether or not the lemeks ought to be included within the kentronychines. Early attempts to align them with the North American rhamels failed to hold up to scrutiny. Genetic evidence shows the rhamels are more closely related to of all things, the mooras. While lemeks nest in their own family far away kentronychines than to the ceronychines, they are still an enigma.

The mooras are well represented in Eurasia, with some 4 species. They are deep forest browsers averaging 400 to 600 kilos. Mooras are often seen in secluded clearings daintily stripping bushes and low trees of their leafy burdens. They will also dabble mineral rich water dug up by gantuas and tardoines. Two exist in North America, one who live in a desert environment and one which a bit of long and complicated taxonomic history which will be resolved some time in 2017.

Moora (Kentronyx robustus)

Though similar to dorsas in size and convergently similar to the robust therizinosaurs, the moora (Kentronyx robustus) is probably more closely related to the panhas. Mooras live in the taiga of Eurasia, stripping the branches off trees and bushes. They can weigh up to half a ton, but still run surprisingly fast. Mooras, in fact, look a lot more robust than they really are because of their long hair-like plumage (especially during the winter). Like dorsas, mooras have humps on their backs for storing fat for the winter.


A female Moora


(fig 12.5) A diagram of a moora nest.


Moora, Kentronyx robustus (northern Eurasia)


A male moora in winter plumage

American Moora (Kentronyx americensis)

The American Moora (Kentronyx americensis) is one of the few Moora native to North America. With its impressively long neck it can reach high leaves and needles. Its claws have shrunken; moora's prefer to display the feather fan on the tip of their extra-long tails.The display fan also is used for predator alarms.Interestingly,endemic north american hornclaws and several of the streks and spelks have convergent developed flashy tail displays.This may have been an  advantage to the early strek and spelk immigrants to utilize a well recognized signalling organ.Curiously, all Eurasian hornclaws lack the tail fan, a derived loss across several lineages.

Blue Babe (Kentroynx azulirhinus)

The blue babe (Kentroynx azulirhinus) is a closely related species to the America Moora. More robust at a tonne, with a blue-tinted nose, this moora roams the warmer temperate forests of eastern North America in small bands.Spring brings out their nesting instincts in  full force as they brood the 5-15 eggs with their arms.The hatched chicks remain with their parents until the following spring.Fierce  protectors, nevertheless, chicks are taken by deltatheres, wendigos and shunka warik'ins.Like all tirgs, blue babes are high browsers, leaving the forest floor largely to the streks and spelks. Occasionally, a fall glut of unripened acorns gives a Tirg too much of a temptation, with resultant constipation and eventual diarrhea.

Rhamel (Sonoraonychus pallidus)

The Rhamel is a 400 kilo iconic symbol of Spec's Great American Desert realm. They are usually thought of as Sonoran denizens, but in truth, they can be found as far north as the Columbian Plateau and east of the Rockies in various semi arid zones along the Front. Rhamels tend to be permanent inhabitants of the deserts and dry prairies. They live in large territorial ranges, rarely migrating unless forced to do so in times of severe drought or intense winter snow. Rhamels are not as social as other mooras. Often a hen and a cock will pair not just for the breeding season, but for many years until one dies. The tough foliage and harsh climes of their home ranges does not encourage high density. Nests are usually built in discrete spots, often in sheltered high overhangs with narrow approaches. This allows the male and any remaining adolescents to brandish their wicked claws in the direction of any predator.


The therizinosaur colonisation of South America is a rather recent ecological event. Even during the initial Panama collision, therizinosaurs weren't among the north american invaders of South America, and indeed in their absence the native troodonts had reached large sizes in browsing niches, such as the iconic Chonchon. However, in the Pleistocene, two different radiations of therizinosaurs moved the south, following the central american mountain ranges like HE camelids. The first were relatives of the Rhamel, now extinct, while the latter were hylonychines, relatives of the dorsas that are now only marginally represented in their north american homeland, and compose the bulk of tropical therizinosaur diversity. These species is not apart of the Seculasauridae( the American therizinosaurs who first evolved during the Miocene and Pliocene), due to noticeable differences in the skeletal structures.

Misabe (Hylonyx americensis)

Common in the temperate and subtropical montane forests of Central America, the Misabe is truly a magnificent sight. Browsing alongside the giant pseudosauropods, the Misabe battles daily against their common enemy, the powerful raptors that roam America from Yukon to Patagonia. When not attacking the prey, the larger raptors and the Patagonian dragon inevitably turn on the long necked beasts of the mountain forests, and this leads to powerful, explosive confrontations, resulting in a dead Misabe or heavily wounded raptors. When the two antagonists decide to face off, it is one of the most awe-inspiring spectacle that Spec has to offer.

However, these 3 ton giants are normally more placid and are usually violent only to saplings and small trees which they score with their claws. Trees up to 30 feet tall may be pushed over with cooperation among the herd. Very old bulls up to 5 tons have been seen single handedly wrestling 40 foot thin forest trees to the ground to feed on the crowns.

Gantua (Hylonyx sudamericum)

The Gantua is neotropic answer to the dorsas. It is a denizen of the tropical and subtropical open wetlands of South America, wallowing in the marshes like their boreal relatives do in cold Eurasia. It has an interesting niche partitioning with it's competitors, the cranils and the Aquatitan, which results in rather mutable and erratic distribution patterns; in general, Gantuas dislike densely forested areas, where the Aquatitan and the Common Cranil are most common, thus barring the therizinosaur from the Amazon Basin. Currently, the centers of their population are the Orinoco Basin and Pantanal, which several pocket populations in between, isolated as the Amazon reclaimed the territories lost in the glaciations.

Gantua's claws are rather unremarkable among Ceronychids, possibly because the species lacks the kind of leks associated with boreal hornclaws. Instead Gantua females come to heat at different times during the breeding months and are pursued by interested males. The females usually prefer the older and larger males to younger suitors, which they may try avoid until an old male shows up. There is really no competition between young and old males, but sometimes when two old males meet, they will engage in battle that involves clashing of claws followed by neck wrestling resembling that of the mooras, although this test of strength never aims at toppling the competitor. Usually the fights end with no injuries to either male, but sometimes testosterone-crazed males in heat have been known to swipe at each other with their claws before engaging in the wrestling match, causing serious, even lethal damage.

Most of the year males form small "bachelor groups" which they leave only during the breeding season when the females and old males come to heat. Very old and massive (Gantua males never stop growing) males may prefer solitude to the company of other males. Females spend all of the year in a loose female group of different aged individuals. The female group provides protection for the young, as well as keeping over-eager mature young males looking for females to mate with at bay. As they reach maturity, male Gantuas leave the female group and join the closest bachelor group.

CERONYCHOIDINAE (Panhas and Shantaks)

In the Miocene, a temperate steppe appeared in eastern Asia. No jackalopes or hadrosaurs lived there because it was too cold and the vast majority of ceratopsians had retreated to warmer climates. A clade of hornclaws reacted, came out of the forests and evolved far-reaching adaptations for cursoriality. For example, the back has again become horizontal, as usual among dinosaurs, and the tail vertebrae have lengthened to provide a means of balance.

Though they have changed little since, the panhas are now the dominant plant-eaters of the polar and temperate open land of the northern continents. They also occur in the cold and temperate forests, where they eat mainly herbaceous vegetation in the clearings. Except in winter, they tend to leave most of the leaves and needles to the streks, which in turn are not good at eating grass.

Eurasia Panha (Ceronychoides arctous)


Eurasia Panha, Ceratonychoides arctous (Northern Eurasia)

Eurasian Panhas are generalist/grazers, smaller and rather more common than the dorsas found across much of the holarctic Arctotitan Steppes. These rather small 150 kilo herbivores live in great herds of up to 10,000 individuals that roam the mosaic steppes. In summer, these habitats supply the panhas with an abundance of grasses, herbs and shrubs, but during the autumn and winter, the great panha herds must break up into small family clusters that leave the plains to the lammoxes and migrate to the forests. There, the eurasia panhas live through the harsh northern winter, subsisting upon fungi, lichens and moss dug from under the snow with their long, curved claws.

In spring, the herds coalesce again, and the segnosaurs mate and lay their eggs. The fast-growing chicks are usually ready to follow the herd as the first snow falls on the ground. Panha breeding grounds are often located on islands or river deltas where they are less accessible to predators.

Shantak (Ceronychoides gravis)

The shantak (Ceratonychoides gravis), which inhabits the Mongolian and Chinese steppes, is the largest panha species. Male shantaks have the proportionally longest arm claws of all extant hornclaws.


Shantak, Ceronychoides gravis (eastern Asia)

Also known as the Chinese Panha, the Shantak, which inhabits the Mongolian and Chinese steppes, is the largest panha species at 500 kilos. Male Shantaks have the proportionally longest arm claws of all extant hornclaws. Spring sees small natal herds defending their brood in sheltered gallery forest nests. Summer has the wobbly chicks following their parents in accumulating herds that may number up to half a million adults. Parents and "aunties" frequently dribble crop milk into the mouths of their rapidly growing chicks.

Golden Trig (Ceronychoides canadiensis)

The Golden Trig is a 400 to 600 kilo Trig found in northwestern North America in forested valleys and plateaus along the Western mountain spine from Alaska down into Mexico east along the Pacific North West coastal forests. They utilize their amazingly long necks to forage for conifer needles, fungi and buds out of the reach of other forest herbivores. Male Golden Trig have elaborate mating rituals performed to several prospective mates, usually related females. The dominant male bosses the submissive juvenile males into protecting the gravid females during the brooding period. Food is often brought in the form of partially digested crop stew to the nesting females to supplement their fast depleting fat stores. This is carried over to the hatchlings.

American Woolly Therizinosaur (Ceronychoides americensis)

Woolly therizinosaur

American Woolly Therizinosaur, Ceronychoides americensis (Northern North America)

The American woolly therizinosaur is one of the largest of the herbivores of the North American tundra, at 10 meters in length and is the largest member of the Ceronychoides sp. This species eats grass and small plants, which it crops from the ground with a flattish-tipped beak.  Its snout is elongated, and its eyes are set far up to give the best vision while grazing.  In the winter, these dinosaurs grow shaggy coats of plumage, and the enlarged neural spines over their shoulders support fat stores for times of famine.


The lemeks are still hotly contested on whether or not they should be included within Ceronychinae. They represent a very early radiation of ceronychids into Eurasia. Several morphological features, such as a shallower pubis, certain microcrystalline arraignments of the calcium in their eggshells and placement of internal nasal tissue strikingly resemble glaciotitanids. However, genetic analysis places them closest to the ceroychines. These morphological features are either primitive or independently derived features.

Lemeks are true desert segnosaurs like their Rhamel cousins. Some two to four species have been described. Lemeks can be found in the hot subtropical deserts stretching from the Sahara east all the way into the Thar. They are also present in the cold deserts of central Eurasia. Lemek size varies considerably, some races just 500 kilos and others up to 900 kilos.

Lemek breeding resembles Rhamel chick raising. Often just a single alpha pair mates and successfully raises offspring in secluded arroyo banks hidden by vegetation. The 6 to 12 chicks have one of the longest nesting periods of any non avian maniraptors, remaining within or around the nesting site for as long as two months before their parents finally take them on their never-ending search for food. Breeding is dependant on good rains, with some years seeing no chicks born.

Lemeks are extraordinarily hardy and often the largest resident inhabitants of the deep desert. They are very important ecologically for their uncanny ability to uncover upwelling spring water just below the desert soil. The Lemeks frequently maintain these oases, re-digging them up and defecating dung laden with seeds of soil fixing plants that in turn draw up even more surface water. Millennia of this activity has resulted in countless thousands of permanent oases scattered across their ranges. This benefits innumerable other animals from insects to the occasional sauropods lured into subtropical desert zones during flush wet years.

Gobi Lemek (Paraceratonyx mongoliensis)

The gobi lemek (Paraceronyx mongoliensis) was at first commonly known as the desert dorsa, or camel dorsa, before it was shown that it did not belong to Ceronyx after all. (The old common names are still often used, though neither was ever an official one.)

Gobi lemeks move around the central Asian steppes and semideserts in small herds, feeding on low-growing tough plants. The large hump on their back is partly supported by enlarged neural spines, and is used to store water and food in the form of fat. It seems that lemeks don't have to drink at all, but when water is available, they tend to take advantage of it.


Lemek, Paraceronyx mongoliensis (central Asia)

Arabian Lemek (Paraceronyx arabicus)

There is another Paraceronyx species, the Arabian lemek (Paraceronyx arabicus), which is smaller and has shorter and more downy feathers. The Arabian lemek is an unusual hornclaw for having chosen an extremely hot and arid environment instead of a chilly one. These inhabitants of the Arabian deserts and the Sahara can withstand long periods of drought without drinking, and often manage to get all the moisture they need from plants.

Northern Lemek (Paraceronyx borealis)

The Northern Lemek is the only member of the Paraceronyx species which can be found in a colder environment through out all or Eurasia, from Scandinavia to Siberia, though are not as common due to competition from other successful species of therizinosaur. They still have the same skeletal structures of their relatives that dwell in warmer environments. However, there is a difference. That difference being the larger and thicker amounts of feathers it has covering its body and white and gray pattern for its environment.

SECULASAURIDAE (Trigs, Upclaws and Liandaolongs)

Seculasaurids evolved from primative Eurasian therizinosaurs soon after the clade had migrated to North America in the Miocene and have become quite successful in the New World.  While fossils indicate that seculasaurines did migrate to Eurasia (along with other herbivores, such as the hadrosaurs), during the Pleistocene, the American species apparently could not compete with the Eurasian forms.  In any case, seculasaurs are endemic to the new world. There numbers have dropped to due competition from members of the ceronychidae family, but they have found success in other areas one would not might expect, most in desert areas and the forests of Appalachia.


These clade of therizinosaurs most likely evolved from type of hornclaw that is now long extinct, during the Miocene or Pliocene epoch, scientists are not entirley sure and that issue. However, what is known is that these are some of the first therizinosaurs to evolve on American soil for the first time in over 110 million years. As would be expected from the ceronychids, these species are not as common, however, they have evolved better in environments where therizinosaurs are usually uncommon, most notably Appalachia.

Commonly known as trigs, these massive herbivores, though not as big as the mooras, can be seen in heavily forested areas. Browsing for leaves and other foliage in the area. What makes these therizinosaurs different from the vast majority is that they have a more bipedal gait when compared to other therziniosaurs. It mostly mirrors that of humans.

Northern Trig (Seculasaurus gigs)

The tallest species of the Seculasaurus sp. can be seen through out the Eastern United States. But why is it called the Northern Trig? Well the answer is very simple. From Pliocene fossil deposits in Oregon, Washington State and British Columbia, fossils which match that of the Northern Trig are found there. During the Pliocene when these creatures, they could be seen from the Pacific Northwest all the way to Maine, but competition from other therizinosaurs drove that population in extinction. However, for some unknown reason, Appalachia, with deeply dense forests and rigid mountains is their bastion whiles other therizinosaurs tend to avoid that area at all costs. Growing up to 9 meters long and standing over 15 feet tall, these are some of the largest creatures in Eastern North America, rivaling the likes of the massive hadrosaur, the sludger.  Similar to the likes of the American Woolly Therizinosaur, this species seem to have a more bipedal gait to them as well. This adaptation is necessary for browsing the highly compacted forests of the Eastern United States. On the subject the eastern united states, the Northern Trig has an easy life when compared to the likes of their other American and Eurasia cousins who have to deal with the threat of the horrific sabre-tyrants who prey on these creatures. Adults enjoy free of predators whilst their off spring need to be cautious of the various species of drak and strider.

Another thing which be noted about the Northern Trig is their migrational patterns, so far these are the only species, along the panhas and possibly mooras and arctotitans in the world of Spec, to migrate over vast long periods. During the summer time, these creatures gorge themselves on the vast number of plant life in the Eastern United States. Before the winter time and when the vast majority of this region becomes covered in snow, these creatures will travel in large number to warmer climates in order to their lay their eggs and will stay in that environment. Interestingly enough, these creatures seem to not mind the warmer climate and will stay with their chicks for some period of time before head up north. That and these creatures will commonly accompany the sludgers, massive neohadrosaurs that are a common sight in this area.

Common Trig (Seculasaurus vulgaris)


Common tirg, Seculasaurus vulgarisspotted jaub, Spadavis onca, and Baskerville, Metacanis phobos (northwestern North America)

Growing much larger than its cousin, the Sierra-Nevada tirg, the common tirg is primarily a forest-dweller and feeds upon the detritus of the Pacific Northwests temperate rainforest with the aid of its blunt beak and powerful manual claws. Evolution had equipped these beasts with a series of instinctual responses to whatever problems the forest primeval could present, but had not, it seemed, included anything about pulling sledges. It maybe one of several species of therizinosaur which can be found through out the north and northwestern parts of North America, but it is the most wide spread of them all. Hence their name being the Common Tirg. Just like the vast majority of therizinosaurs, Paraselenodonts and Viriosaurs are known to follow this massive behemoths for protection from predators and other reasons in the case of the caripoo. 

Sierra-Nevada Trig (Altiseculus sierraensis)

The mountain climbing adaptation of the upclaws can trace their ancestry back to the Pliocene, with a few species of some unknown species of therizinosaur which were commonly spread through our the area aka the Sierra Nevada region. But due to competition from larger therizinosaurs from Eurasia, they have either been forced to retreat to South America  As of now the Sierra-Nevada Trig is the sole survivor the genus Altiseculus. Yes, it is a medium sized creature and it pales in comparison to the larger species of trigs in up north, but its highly adaptable to the harsh desert environment. Smaller than the Rhamel, the species will travel in small herds and are low browsing herbivores as well, feeding mostly on the desert grasses and flowers in the area. They maybe small creatures, but like their relatives, they are armored with 1.5 foot long claws that can do a good amount of damage to a potential attacker. Some of have argued that the Sierra Nevada Trig is actually a species of upclaw, but more evidence will be need some time in the future.


The Americas, too, have segnosaurs clambering around in their mountains. First thought to be the honas' sistergroup, the upclaws and liandaolongs have since turned out to be their own group of therizinosaurs . Much like in the honas, their first toes have become long, mobile grasping devices that give a firm grip on rocky terrain, as well as (occasionally) on trees – upclaws are quite fond of conifer cones. About three million years ago, a group of therizinosaurs migrated into South America during the Great Faunal Interchange. Although six species are known from the fossil record, between 4 to 5 member survive to this very day. . In the plains, viriosaurs (basal ornithopods) could not be shaken from their dominance (this clade actually migrated north, and ousted the native small herbivores from their niches). However, the therizinosaurs did find an open niche in South America's high mountains, the Andes. Theses, had already conquered the mountains of North America and the leap from the Rockies to the Andes was, evolutionarily speaking, a short one.

Andean Upclaw (Altoseculus andensis)

Originally confined to the Rocky Mountains, the upclaws spread to the Andes soon after the Panama landbridge was established. The Andean upclaw (Altoseculus andensis) exists in one species and distinct two subspecies: A. a. peroni and A. a. bolivari. This species is spread across most of South America, from the Isthmus of Panama across the Andes to Tierra del Fuego.


Andean upclaw, Altoseculus andensis (Andes)

With a normal range of three meters, the Andean Upclaw is a rather small therizinosaur, and one of the most agile herbvores in the highlands. The four-toed therizinosaur foot comes handy, allowing the animal to climb rather efficiently, running and jumping with little care across quite steep slopes. In particular, it can thrive at higher altitudes than the competing spelks, and in fact it thrives in some of the world's highest mountains. It favours conifers, feeding primarily on *p-Araucaria*, though just about any shrub is under peril from being consumed down to the roots.

Rather non-violent among therizinosaurs, competing males develop iridescent plumage during the mating season - which can vary wildly across it's range -, exhibiting in the slopes like overgrown tropical birds. Coping with predators generally boils down to quck climbing to inacessible areas, though it will stand it's ground if forced. They don't have the gift of a defense mechanisim when compared to the

Tierra del Fuego Upclaw (Altoseculus andensis bolivari)

The subspecies A. a. bolivari inhabits the entire length of the Andes Mountains. These animals rarely reach lengths of over a meter. Individuals of A. a. bolivari have been seen sprawling some of the highest peaks in the world, and are known to be excellent climbers. Bolívar's upclaws are herbivores, which, although they prefer coniferous foliage, will ingest almost any vegetation.

Perón's Upclaw (Altoseculus andensis peroni)

While A. a. bolivari is well adapted to its mountain habitat, A. a. peroni shows a slew of characters that enable it to survive in the high latitudes of Tierra del Fuego. Like A. a. bolivari, Perón's upclaws rarely reach more than a meter in length. This upclaw subspecies also favors coniferous foliage, but will eat berries and fruits if necessary.

Populations of both subspecies are known to coexist in southern South America. Generally speaking, however, the two keep quite separate ranges. It is thought that the separation of a band of A. a. bolivari individuals 1.5 million years ago led to the evolution of A. a. peroni. This second subspecies came to occupy a small range of Tierra del Fuego, quite separate from that of its close relative. The exquisite timing of A. a. peroni's reproductive cycle made it further adapted to its environment, and has proven to be the key adaptation that separates the two subspecies.


Lianadolonginaw (commonly called "Liandaolongs") are generally quite small (no more than 3 meters long,), and have radiated into a number of varieties specializing in specific plants and levels of foliage.  Liandaolongs, with their long, flexible necks and long legs, look almost like ornithomimes, but their ancestry is given away by their enlarged bellies and hyper-extendable hallux claws (an adaptation found only in Seculasauridae).  Liandaolongs can be specious in the northern prairies of North America, and their diversity tapers off quickly south of the 55th parallel (where competition from the viriosaurs becomes fierce), but they thrive in the heavily forested areas. They can be found from the Pacific Northwest all the way down to South America and surprisingly, there is one that is native to Appalachia. While the upclaw is a creature more at home in the mountains, the the liandaolongs and trig species are more adapted to forest life.

Northwestern Liandaolong (Seculasaurus sylvis)


Northwestern Liandaolong/Blue-headed Liandaolong, Seculasaurus sylvis (Northwestern North America)

Along the northwest coast of North America, between the Pacific Ocean and the Rocky Mountains, a narrow band of temperate rainforest extends north to south. This forest, cold in the winter, but with an annual rainfall equal to that of the Amazon, supports many animals and plants.

One of the most common herbivores of this place is the northwestern (or blue-headed) liandaolong (Seculasaurus sylvis). Although these two-meter herbivores are outwardly similar to the tirgs of the mountains, they are still liandaolong (sub-clade Liandaolongini): lowland creatures.  Blue-head feathers are densely packed and oily, to shield the skin from the chilling damp, while the eyes and nostrils are placed high, to warn the herbivore of approaching predators.

Golden-maned Liandaolong (Seculasaurus orientalis)

A recently discovered species of therizinosaur, this species of the Seculasaurus is currently the only documented member of the Therizinosauria in the world of Spec that inhabits the Eastern areas of North America, making it the only Appalachian therizinosaur. As of now, not much is known about its behavior at the moment, but we do know that it gets its name from the golden color of its feathers around mane. Our spec researchers believe that it serves a similar purposes to its North Western relative, the Northwestern Liandaolong. The reason why this creatures lives in the heavily forested areas of the Appalachia's most likely to defend its self from the various species of striders common through out North America, Striders prefer to inhabit areas like grasslands as apposed to forested areas.


Click here to learn more about this enigmatic beast from South America.