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| Ornithomimids | |
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| Topic Started: Mar 1 2011, 02:51 PM (850 Views) | |
| JohnFaa | Mar 1 2011, 02:51 PM Post #1 |
Adveho in mihi Lucifer
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In Terra Alternativa, ornithomimids were considerably affected by the KT event. In Eurasia, they seem to have disappeared altogether, opening the way for the native gargantuavids, ostriches and avimimids; it is even possible that they were oucompeted by these groups. In North America, they were gradually replaced by troodonts, and the last forms in continental North America disappeared once south american tapejarids crossed the sea in the middle Miocene. However, insular species managed to survive to this day, in the Caribbean. Caribbean ornithomimids seem to have been present on the archipelago since the Eocene, presumably either by swimming or by continental collision. Since then, their isolation allowed them to prosper without competitors; tapejarid pterosaurs are present on the Caribbean, but both groups managed to co-exist in an environment with pratically no competitors to either side. Aepyornicollum The Vorompatra Mimics are divided into four species, each belonging to either of the four main Caribbean islands. Heavy animals, they are poorly adapted to run, their leg proportions being akin to those of HE's Pachyornis and being quite robust critters; their main defense is via their powerfull handclaws. With the biggest species from Cuba and Hispaniola reaching heights of over 2.5 meters, they are the largest living ornithomimids, and certainly the tallest inhabitants of these islands. They are primarily frugivores, but will easily browse for leaves as well or feed on low laying plants. As adults, only the biggest native birds of prey can kill them, and unlike moas or elephant birds the Vorompatra Mimics can defend themselves with their huge claws. They are mainly solitary, although they will not shun other members of their kind if the conditions are nice, and won't mind to gather in large areas to drink, for example. Females, twice bigger than males, will trust their two large eggs to their mate to incubate. The chicks are superprecocial, and don't require the attention of the male. Growing slowly, they occupy several ecological niches, hence the presence of a single species per island. Cancrophagus khaos Believed to be a single species at the present, it has been suggested that the numerous populations of these animals on all the main islands of the Caribbean might represent different species, although their ability to colonise new areas by sea leaves this in doubt. Indeed, they occur in the Bahamas as well, and have been sighted on Florida. A creature the size of an emu, this golden rod coloured animal (with a dark brown beak and legs) has a sharp beak vaguely similar to that of a terror bird. Although an opportunistic predator of any small creatures, most of its diet is composed of crabs and snails, giant forms of either being prevalent in the Caribbean. It makes use of its powerful claws to rip the prey apart is necessary, but bites from its beak are usually enough. If necessary, it will not mind to swallow chunks of the armour of either. Forming pairs that may last for life, both parents raise the chicks, which generally leave a month after birth. They are good swimmers, hence why they are so good at colonising new areas. This also means they are easily the prey of crocodiles, alligators and choristoderes. (Other examples will be added later) |
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| Cephylus | Mar 3 2011, 08:48 AM Post #2 |
Berseerrrrrkkkkkkkkkkkkkkkkk
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Neat. People always do seem to forget ornithomimids, but they'll make nice ratite analogues and therizinosaur analogues. Terror ornithomimids? |
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| Dark-Matter | Mar 3 2011, 09:14 AM Post #3 |
Adult
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I dont remember any other project base on a ornithomimids world,this could be the first one. |
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| JohnFaa | Mar 4 2011, 04:44 AM Post #4 |
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Adveho in mihi Lucifer
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@Cephylus: Well, the living ornithomimids are stuck in an archipelago. Granted, I have several plans for the endemic species, but large, terror bird like forms don't have a lot of space to exist on. Maybe I'll make a larger relative of the crab eating form that uses its beak to kill vertebrates. |
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| Cephylus | Mar 7 2011, 09:25 AM Post #5 |
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Berseerrrrrkkkkkkkkkkkkkkkkk
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Well, still nice creations.  I'm happy this is being updated.
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| JohnFaa | Mar 7 2011, 02:20 PM Post #6 |
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Adveho in mihi Lucifer
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Should I include a kiwi analogue? Because the Caribbean are famous for their endemic insectivores, yet had a flightless ibis with club wings no less. |
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| El Squibbonator | Mar 7 2011, 03:24 PM Post #7 |
The Third Child
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Again, this is probably because the "original" dinosaur survival projects that all speculative biologists today try to imitate or improve upon--the Speculative Dinosaur project and Dixon's The New Dinosaurs-- both excluded ornithomimids. And flightless ibises aren't just a Caribbean thing, Hawaii and Reunion also both had them.
Edited by El Squibbonator, Mar 7 2011, 03:25 PM.
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| JohnFaa | Mar 7 2011, 03:45 PM Post #8 |
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Adveho in mihi Lucifer
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More like the Hawaiian species. The Reunion Ibis was appearently still volant to some extent, although it might had just been a bizarre glider. Are you implying that I fail at originality because I'm including something just because two other projects didn't? Edited by JohnFaa, Mar 7 2011, 03:45 PM.
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| The Dodo | Mar 7 2011, 06:16 PM Post #9 |
Prime Specimen
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I think a kiwi analogue could evolve, also didn't tapejarids only come from the Early Cretaceous? |
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| Cephylus | Mar 8 2011, 03:39 AM Post #10 |
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Berseerrrrrkkkkkkkkkkkkkkkkk
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I guess a kiwi analogue is interesting, evolved from ornithomimids.... |
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| El Squibbonator | Mar 8 2011, 08:13 PM Post #11 |
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The Third Child
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Quite the opposite, as a matter of fact. I was simply stating that too many people simply imitate Dixon and Spec, instead of being truly original like you. |
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| JohnFaa | Mar 10 2011, 05:52 AM Post #12 |
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Adveho in mihi Lucifer
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Paraxenicibis spp. A genus of three species occuring in Cuba, Jamaica and Hispaniola. These roughly meter tall animals (the Golden Paraxen, P. aureus, is the largest of the three species, endemic to Cuba) resemble in most aspects regular ornithomimids; except for one detail: their beaks are long and curved downwards, resembling those of our ibises and TA's ibis like lithornithids. They make use of these bizarre rostrums to probe for food in the forest soil or in mud; in the original ornithomimids, the nostrils were already close to the bill tip, to they simply moved slightly closer to the upper jaw's end so that the animal could sniff for prey, and the upper jaw developed special structures in order to use the sense of touch to search for prey. As a result, the animals have no genuine beaks on the upper jaw, just soft rhamphotheca like that that makes up the beaks of waterfowl, as to not interfere with the evolution of the necessary structures. Relying on speed to avoid predators, these small animals are still avid fighters, kicking and using their powerfull handclaws. They are crepuscular and solitary, being most active at dawn and dusk.The Golden Paraxen is ratite like in breeding habits, while the two other paraxen species form pairs. |
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| Cephylus | Mar 10 2011, 08:03 AM Post #13 |
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Berseerrrrrkkkkkkkkkkkkkkkkk
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That's cool, strange idea for an ornithomimid..... |
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| JohnFaa | Oct 25 2012, 06:14 PM Post #14 |
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Adveho in mihi Lucifer
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REVAMP TIME Ornithomimidae is a clade of coelurosaurs specialised towards an omnivorous lifestyle similar to that of the Triassic shuvosaurid pseudosuchians and the Jurassic and Cretaceous toothless ceratosaurs. The closest relatives to the ever so successful maniraptors, ornithomimids were extremely bird like, even developing wing feathers, but still quite distinct, retaining many iconic theropod traits like the "lizard hips". During Terra Alternativa's KT event, ornithomimids managed to do better than most non-maniraptor dinosaurs, being generalistic omnivores. With the extinction of therizinosaurs, sauropods and lambeosaurine hadrosaurs, they quickly expanded into the browsing niches. During the Palaeocene, their success was tremendous, to the point that 70% of all dinosaur fossils from this era are ornithomimids. Ornithomimids were barely affected by the PETM, although the expansion of tropical rainforests meant some changes for these dinosaurs. The earlier radiation of giants was slowly replaced by smaller, emu-sized animals - except in Asia, where they not only retained their large size, they also remained as the largest dinosaurs of their time. During this epoch, new niches were also explored, among them the raptorial Deinocursor. During the Oligocene, the giant forms became cornered as therizinosaur mimics, as new groups of large dinosaurs, notosuchians and mammals became more successful, though once established they, much like our chalicotheres, enjoyed moderate success. Meanwhile, avimimids began posing competition for smaller forms, even going as far as replacing them in Eurasia. In North America, ornithomimids remained in their iconic ostrich like forms, diversifying in a way remaniscient of our camelids, with the exception of some predatory forms. When North America collided with Asia and South America, ornithomimids expanded much like our camels and llamas, though most forms were replaced by avimimids and troodontids. Currently, more or less six genera exist; the exact number of species is unknown, but agreed to be above 10. Avicamelus The more widespread living ornithomimid genus, these animals resemble greatly their Cretaceous ancestors: large, ostrich like animals wandering the plains and deserts of Eurasia and North America. The exact number of species is unclear; four, A. dromaiucephalus, A. sehauli, A. mongoliensis and A. americana, are recognised, but several populations within these forms have been suggested to be independent species of their own right. A. dromaiucephalus occurs through Africa and Arabia. Three subspecies, A. d. somali, A. d. caballus and A. d. sudafricana, but several populations are thought to be subspecies in themselves and any might represent different species. A. d. somali, whose range extends across eastern Africa and south Arabia, is the largest, reaching as much as 2.5 meters tall, a length of six meters and a body weight of 270 kilos, while A. d. caballus and A. d. sudafricana, from North Africa and South Africa respectively, are generally smaller. The species name comes from the head, which, with it's bright blue naked skin patches, black beak and red eyes, is strikingly similar to that of the HE emu. The body is covered by a shaggy coat of dense brown feathers (black in A. d. somali), with the wing and tail feathers being grey or white. Occupying a similar niche to that of the ostrich, much like our massive bird, A. dromaiucephalus' populations have different prefferences across their range, with A. d. somali preffering scrub and dry woodlands while A. d. sudafricana preffers the veldt and other treeless grasslands. Accordingly, their diet also varies according to habitat, with more scrub preffering populations prefferingto browse while plain inhabittants preffer to graze, although diet is flexible everywhere. These animals obviously rely on their tremendous speed to evade predators, but their powerful claws and hindlimbs ensure most predators are hesitant to menace these dinosaurs. No sexual dimorphism is observed except in A. d. caballus, in which males have longer and brighter wing and tail feathers. Their reproduction system is much like in our ostriches, the male forming a harem and incubating the eggs and taking care of the young, or full on monogamy, or a mix of both, with the male and a dominant female taking care of the young of an entire harem. Predictably, these strategies vary among populations. The young, mostly precocious and bearing yellow-spotted down, stay with the father and/or mother for several months, sometimes even for their entire lives (if they decide to stay in the same flock), though the parent stops protecting them after a few months. Sexual maturity is reached at 5 years of age; the animal still grows after it for a few years before stopping. It can live up to 50 years if not killed. A. sehauli occurs in North Africa, the Middle East and southern Europe. It is slightly smaller than A. dromauicephalus, and is quite visually distinct, harbouring the iconic gazzelle-like colour pattern often attributed to it's ancient relative Gallimimus. About five subspecies are recognised: A. s. africana, which occurs all over North Africa and Arabia; A. s. anatolica, occuring in Turkey and Greece; A. s. ethiopiensis, from the eastern african highland plateaus; and A. s. lusitanica, from the Iberian Peninsula. Predictably, there's a high likelyhood of all thes ebeing independent species, especially as A. sehauli's range is quite more fragmentary than that of it's relatives. It preffers open grasslands, especially dry, highland ones, and is primarily a grazer and a granivore, though it is still quite opportunistic, feeding on small animals and scavenging like it's relatives. It forms distinct leks, two or three males governing large harems, which they defend quite agressively. Eggs are laid in a large communal nest, frequently with smaller nests as decoys, with the males incubating the eggs while the females tend to these decoy nests, where unfertilised eggs are laid. The chicks are the responsibility of the whole clan. While most of their relatives preffer infrasound communication, much like our cassowaries, these dinosaurs emit an unique call, similar to that of a crane, that can be heard for miles. A. mongoliensis is the species with the most certain, intact population, with a single unified range across Central Eurasia, from Eastern Europe to China, and as South as the Caucasus, all across the vast steppes and cold deserts. Covered in a coast of dense black feathers with white stripes, these dinosaurs are among the largest living ornithomimids, reaching a height of 3 meters, about 8 meters in length an over 300 kilos. They are nomadic and migratory, travelling for miles across the vast plains of Eurasia. Predictably, most of their diet is composed of grass and tubers, though in truth they are very opportunistic. A. americana is the only living mainland north american species, quite ironically given the origins of this genus. At least five subspecies are known: A. a. americana, the largest one, about as big as A. mongoliensis, that lives across the central plains; A. a. californica, that predictably lives across the dry forests and scrub of southwestern North America; A. a. mexicana, that lives in the oak savannas of southern North America and Central America; A. a. minor, ocurring in the wet savannas of Florida, being the smallest subspecies; and A. a. canadensis , occuring in the open woodlands of eastern North America. This ornithomimid has a lighter colour pattern than it's Old World relatives, having most of it's feather coat coloured in various tones of silver and a yellow beak and feet. Most of it's diet is composed of oaks, be the leaves, acorns, twigs or bark. Being an oak specialist helps avoiding competition with other herbivores, and while a dangerous evolutionary gambit, thankfully oaks are an important component of North America's forests. Like A. dromaiucephalus, it has a diverse variety of breeding systems. Edited by JohnFaa, Oct 25 2012, 06:15 PM.
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| JohnFaa | Oct 25 2012, 07:52 PM Post #15 |
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Adveho in mihi Lucifer
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Thea Endemic to South America, these ornithomimids obvously arrived when the Panama Ishtmus was born, though ornithomimids were appearently already present in South America before (and appearently became extinct before these animals arrived in the Pliocene). Avimimids are absent from the continent, but in their place there are local palaeognaths and screamers. Nevertheless, these ornithomimids fared better than their relatives in other continents, and at least five species of small to medium sized omnivores occur in the continent. Most notably, these animals have lost their fourth toe, making them like inverse ostriches. T. rodhodactylus is a common denizen of the Pampas and the Cerrado, TA's rhea analogue. This animal, similar in proportions to the long gone Struthiomimus, albeit with longer legs and only two toes, is mostly a granivore, but it easily compliments it's diet with prey as big as small notosuchians. It's name comes from the bright pink toes and legs; it's feathers are of a far less bright murky brown. It is among the fastest animals in it's natural habitat, capable of outrunning most predators, although endurance predators like troodontids have an edge. Preffering small flocks, these animals are nomadic, although males establish loose territories. T. avimanus is basically like a smaller, whiter version of T. rodhodactylus, but both species are at opposite sides of the genus' phylogenetic tree, having converged. This animal inhabits the Llanos, being more of a wader than it's relatives, often hunting small animals in the wetlands. T. darwini is the Darwin's Rhea of TA, down to the colouration. Similar in size to T. rodhodactylus, it has a more robust built, optimal for the colder climates of Patagonia. It is a dedicated grazer, with a wider beak than it's relatives. While a good runner, it is more reluctant than other ornithomimids, preffering to camouflage itself in the tall grass. Atypically for a non-avian theropod, the female alone incubates and takes care of the progeny. T. yagil is a resident of the Andes. Coloured in a bright crimson and white plumage, this dinosaur preffers the highland plains in plateaus and mountain slopes. It is predictably the ornithomimid occuring at highest latitudes. They are also among the shortest lived of all ornithomimids, reaching a maximum age of 12 years. In their highland habitat, the adaptations these animals have for cursoriality serve them well, but maintaining their fast lifestyle at high altitudes takes a heavy toll in the animal's metabolism. Consequently, these are also among the fastest growing non-avian dinosaurs, with the young reaching sexual maturity at 1,3-5 years of age. Like A. sehauli, communal nests with decoys are used. T. giganteus is the largest south american ornithomimid, as big as the largest Avicamelus species. Sister taxa to T. yagil, and resembling a much larger version of this animal, these giants occur in the montane forests of Patagonia. Among the largest animals in their habitat, these giants lead long, peaceful lives in South America's cold subantarctic forests. They retain their cursorial adaptations, of little use as they have very few natural predators. Their breeding cycle is very slow; the female lays only two or four large eggs, incubated by the male, and the young are superprecocial, being able to take care of themselves since a few days after birth. These animals reach sexual maturity at 10. |
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3:28 PM May 22
