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| The icarovenators; The Descent of Feathered Man | |
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| Topic Started: Feb 12 2010, 09:53 AM (476 Views) | |
| Margaret Pye | Feb 12 2010, 09:53 AM Post #1 |
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Constructive criticism, please! ......................................... Icarovenatorids are a large, widespread and successful maniraptoran group. All of them are small, and most of them are predators. Here’s an extremely quick walkthrough of icarovenator diversity and evolutionary history, focussing on their development of high intelligence, tool use and civilisation: While the evolution and loss of avian flight is still rather mysterious, icarovenators probably developed from something very much like Archaeopteryx: an extremely primitive bird possessing teeth, three separate fingers, hyperextendible slashing claws and a long bony tail, which flew well but spent much of its time on the ground. Ruddy Jackybird One very common and familiar basal icarovenator is the Ruddy Jackybird (Snake Jacky, Carrion Jack, Jack Chickenhound…) It’s not a living fossil – it’s highly specialised in many ways – but its lifestyle and general bauplan are pretty close to its distant ancestors. This lanky quasi-avian weighs about 15 kilograms or 40 pounds. It has long legs, a long balancing-pole tail, and a long serpentine neck. Its head is small, with a long pointed snout, large eyes, and stiletto-shaped backward-pointing teeth. Its front limbs are a fascinating hybrid of wing and talon: aerodynamically functional as short broad wings with vaned feathers supported by the clawless third finger, but the first and second fingers projecting from the wrist oppose each other and form a pincer shape. These fingers are long and powerful, with long, fine hooked claws. Except in flight or display, the first and second fingers are exposed by folding the third finger back out of the way. Unlike more derived icarovenators, jackybirds retain a small first toe on each foot. The slashing second claw is only an inch long, and not particularly powerful. A jackybird’s torso is covered in dark red, glossy vaned feathers. Its long bony tail has Archaeopteryx-style feathers banded in the same dark red and a rich cream, and it has a fluffy cream-coloured feather-boa-effect ruff round the base of its neck. Its head, neck, and legs are featherless and covered in glossy black scales, and its wing feathers are chocolate brown. Jackybirds live in long-term monogamous pairs, usually accompanied by a few adult offspring who’ve stayed on as nest helpers. The sexes are practically impossible to tell apart (even for other jackybirds – the first step in courtship is a little dance that basically translates as “I’m male, are you female?”) They lay five or six eggs at the beginning of the monsoon season, and incubate them in marsupial-esque pouches on either side of their ribcage. Families cooperate in childcare and territorial defense, but not usually in hunting. Jackybirds are opportunists. Their staple diet consists of small animals, anything from beetles to rabbits, which are snatched with the hands and/or mouth. They’re particularly fond of snakes, which they slash with their scythe-claws and grapple with their hands. Poisonous species are taken regularly, and they have some immunity to most venoms. They also eat a lot of carrion, and are happy to eat rotten meat if fresh meat isn’t available. They’ll eat fruit and seeds. Sometimes, usually in times of food shortage, family groups will cooperatively hunt larger animals by chasing them to exhaustion and then ineptly biting and slashing them until they fall over. Jackybirds have no idea how to kill big game: having caught it, they tend to eat it while it’s still wriggling, often starting with the intestines. Farmers are not amused. Jackybirds are terrible fliers. They need several metres’ runway to take off and land, can only fly very fast in straight lines, and tire after about a minute. Still, that’s often enough to make the difference between being eaten and escaping. Unless they’re in serious danger, though, they prefer to run away. Ophidodentians and Rhynchonychids Most icarovenators can be divided into ophidodentians and rhynchonychids. Both these clades are totally flightless. Ophidodentians can be recognised by their shark-like slashing teeth and their toxic saliva. They’re all strictly carnivorous and often social. Some are ambush hunters and some are pursuit predators. Rhynchonychids have powerful oviraptor-esque beaks instead of teeth, and the big-game-hunting species are sexually dimorphic with the males being about 75% the females’ size. Most of them are bone-crunching predators that moonlight as scavengers, although some of them have omnivorous tendencies and a few eat mainly shellfish. Rhynchonychids are a clever lot: most of them have basic tool use and reciprocal altruism (being nice to people who aren’t related to you so that they’ll be nice back). Military Ringhound One well-known ophidodentian is the military ringhound. It’s not much bigger than a jackybird and quite similar in shape, although the arms are weaker, the head and neck more powerful, the hands are more robust and the scythe-claws much more impressive. The mouth opens a good 120 degrees, and the teeth are long, triangular and serrated: the jaw muscles aren’t particularly strong, but the head can be pulled backwards with great force. It has a striking colour scheme: its scaly neck, down-covered torso and archaeopteryx-style vaned-feathered tail have thick, sharply defined vertical stripes (rings) of cream, ochre and blackish-brown. The head and limbs are entirely dark brown (the head and legs are smooth-scaled, the arms are covered in long, shaggy, erectile down.) Ringhounds are pursuit predators that run in packs of up to 50. Each pack has just one breeding pair, who are the parents of most of the rest. They hunt fast, poorly armed ornithopods, and have impressive teamwork and tactical skills. Some of the larger packs regularly kill 300-kilogram prey (more than ten times the size of each individual). Their venom is quite mild. Its main effect is to dilate blood vessels and prevent clotting, and when spread systemically it increases heart rate. The venom wouldn’t kill anything on its own, but when it gets into the huge lacerations created by a ringhound taking a big bite and pulling away, it increases bleeding and speeds up death. Between the natty colour scheme and the impressive courage and teamwork, ringhounds have become an emblem of the brave and disciplined soldier in several countries. “Protohuman” This extinct rhynchonychid species, intelligent even by rhynchonychid standards, is particularly interesting because its descendents developed language and civilisation. (I really like hyaenas. I was really impressed when I found out they had reciprocal altruism and politics. I couldn’t figure out a plausible evolutionary pathway to make a hyaena sapient – how the heck would it make tools with those paws? This is the next best thing. Hawks, deinonychosaurs and oviraptors are all cool too.) “Protohumans” were basically the coelurosaurian answer to spotted hyaenas: clever, highly social carnivores, equally skilled as long-distance-running predators or bone-crunching scavengers. They were about the size of mammalian humans, but slightly lighter due to extensive air sacs: adult females averaged 60 kg, adult males 45 kg. They were mostly slightly built and gracile, but the neck was unexpectedly short and thick and the head unexpectedly large for the size of the animal, and the beak was a huge parroty thing with sharp, curved tips for wounding prey and thick, blunt sides for splintering bone. Protohumans had quite strange hands. The thumb on each hand had a long, robust hooked claw used for hanging onto prey, but the middle finger and opposable outer finger had short, blunt claws and highly sensitive scale-free tips. This may have been a grooming adaptation originally, or it may have been entirely due to selection for greater dexterity. At any rate, protohumans attacked prey and competitors with simple clubs and spears as well as their beaks and claws, and were very skilled at throwing stones. They lived in groups of 5-50. Most females in a group would be related, although outside females would occasionally join: most males would have come from other groups, and males who stayed in their birth group would remain celibate and help look after their sisters’ young. They usually formed long-term monogamous pairs, with the occasional trio (usually m/f/f, occasionally m/m/f). Pairs would cooperate in intra-pack fights and look after each other’s interests, and males did a reasonable amount of the incubation and caring for the precocial chicks, but extra-pair copulations and extra-pair fertilisations were very common. Males had mostly given up fighting over adultery for a subtler, more genteel method of competition: producing as much sperm as possible, and copulations as long and frequent as the females would permit. Females could store sperm for several weeks and had a lot of control over how much sperm they stored from any given mating. Rape wasn’t really possible: since protohumans were capable of killing things larger than themselves fairly easily, anyone attempting rape would get shredded. Protohumans had two main food sources: large ornithopods whose main defence was running away, and carrion (often stolen from another predator.) They’d also opportunistically attack small game or eat fruit and nuts. They ate all parts of a carcass, except the large intestine of large animals: small bones were swallowed, digested and absorbed, large bones were splintered into small ones, and keratinous parts were blithely swallowed and regurgitated as pellets. While they preferred fresh meat, they’d eat festering maggot-infested carcasses if that’s what was available. They had very distensible stomachs and could eat up to a third of their body weight. “Human” “Protohumans” were gradually selected for more sophisticated politics and more sophisticated tool use. After a certain point these things showed up, were wildly successful, and wiped out all their close relatives. A modern “human” is pretty much like a protohuman, except minus the weaponry. The thumb has lost its long claw, and has also become opposable and sensitive (the three fingers are about equal in length and thickness). The deinychosaurian slashing claw has shrivelled into a long, skinny hyperextendable toe tipped with a tuft of vaned feathers: it’s used in threat displays, but is no use whatsoever as a weapon. The bone-shattering beak and its immense muscles have practically vanished. Despite the bigger brain, the head has shrunk. A human has a tiny, narrow hooked beak – rather hawk-shaped, but several sizes too small for the head – and an immense ear-to-ear gape. The lower jaw is so frail and twig-like and the bite so weak that human mouths are no longer useful for food processing. They have to reduce food to swallowable chunks with their hands. Edited by Margaret Pye, Feb 14 2010, 05:59 AM.
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| My speculative dinosaur project. With lots of fluff, parental care and mammalian-level intelligence, and the odd sophont. | |
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| The Dodo | Feb 13 2010, 06:34 PM Post #2 |
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Prime Specimen
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Extensive information, good work. I can't find anything wrong with it. |
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| Margaret Pye | Feb 13 2010, 11:50 PM Post #3 |
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Anyone think the jackybirds need more vaned feathers, instead of being mostly covered in fluff? |
| My speculative dinosaur project. With lots of fluff, parental care and mammalian-level intelligence, and the odd sophont. | |
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| The Dodo | Feb 14 2010, 04:47 AM Post #4 |
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Prime Specimen
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Since they use to and still do fly I think you should give them more vane feathers. They could come in use for displays as well. |
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| Holben | Feb 14 2010, 04:57 AM Post #5 |
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Rumbo a la Victoria
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Do they have allulas? |
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Time flows like a river. Which is to say, downhill. We can tell this because everything is going downhill rapidly. It would seem prudent to be somewhere else when we reach the sea. "It is the old wound my king. It has never healed." | |
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| Margaret Pye | Feb 14 2010, 05:51 AM Post #6 |
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Nope. I'm unclear on how good icarids got at flight before they started un-evolving it, so some of the really basal extinct forms might have had a functioning alula, but in jackybirds the thumb and second finger have nothing to do with aerodynamics. Yeah, true, vaned feathers would be more aerodynamic - I feel safe giving the flightless forms fluffy emu feathers, but a creature that hasn't lost flight probably wouldn't lose smooth modern-birdy feathers. And I probably should give them Archaeopteryx-style tail feathers too, as rudders. I'll edit the description. |
| My speculative dinosaur project. With lots of fluff, parental care and mammalian-level intelligence, and the odd sophont. | |
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| Holben | Feb 14 2010, 12:01 PM Post #7 |
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Rumbo a la Victoria
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As rudders- couldn't they tip their wings? |
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Time flows like a river. Which is to say, downhill. We can tell this because everything is going downhill rapidly. It would seem prudent to be somewhere else when we reach the sea. "It is the old wound my king. It has never healed." | |
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