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Butterfly Crabs
Topic Started: Jul 16 2008, 01:49 PM (2,325 Views)
Livyatan


The butterfly crabs are among the most successful animal groups on Tethys. They consist of several dozen orders of species from flatmoths to crabwhales. They occupy many niches including predators, scavengers and detritivores, filter-feeders (like whale sharks), and algae-eating browsers. Butterfly crabs range in size from a mere inch (flatmoths and scuttlelobsters) to nearly ninety feet in length (crabwhales). Even with such ecological diversity and immense evolutionary success, they all are quite similar in body plan having achieved a perfection similar to that of the crocodilians on Earth, being able to be great adapters while still maintaining the essence of a basic body plan.

Anatomy

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Butterfly crabs and their relatives are basically similar to Terran arthropods. They have segmented bodies and jointed appendages as well as strong exoskeletons. The exoskeleton is leathery and quite flexible as opposed to how it appears. All butterfly crabs share the same basic external anatomy, the main differences being the length and shape of limbs, the shape of the thoracic segments, length of the pygidium, size of eyes, etc. One of the key differences between butterfly crabs and the arthropods of Earth is how the antennae evolved: on Tethys II, the antennae of butterfly crabs evolved from hypersensitive, elongated mouthparts. Overtime they lost their use in feeding, but became important sensory devices.

Flatmoths
Flatmoths are perhaps the most basal of all butterfly crabs, conforming the most to the basic butterfly crab anatomy (pictured above). Like all species they have two pairs of eyes, one pair facing forward and to the side of the mouthparts and the other on top of the head segment, looking above. They mostly dwell at the seafloor or in tidepools, feeding on dead life or hunting for themselves. Not only are the most basal butterfly crabs, but they are also the smallest, ranging in size from an inch to about six or seven inches. Most have very dull coloration, which they use as camouflage to blend in with sand, etc.

Scuttlelobsters/Scuttlecrabs
Scuttlelobsters, or scuttlecrabs, are another group of butterfly crabs known for their minuscule sizes. A majority of the species are only about one to three inches in carapace length, although several species may reach upwards of five feet. They are highly distinct from other butterfly crabs with their unusually rounded exoskeleton, extremely elongated legs, and shortened pygidium. Their long legs are used as a height advantage, enabling them to see further and have a better view whilst foraging. The abyssal stiltwalkers, the largest of the scuttlelobsters, can be found in the deeper parts of Tethyian seas, dwelling alongside other giants such as the giant tongueworm.

Grazercrabs/Algal crabs
More information on grazercrabs coming soon.

Snapper crabs
More information on snapper crabs coming soon.

Waspcrabs
The waspcrabs, or seawasps, are a group of mostly predatory butterfly crabs. Although many find it advantageous to be camouflaged, there are several species that are well known for their striking and bizarre coloration, most likely used for reproductive display. Ecologically, they are the sharks and seals of Tethyian seas, but they also share predatory roles with eelworms and other fish-like worms. The spine at the end of its tail segment is not much of weapon, used mostly for defense or display. The extremely extended third set of legs is used like claspers, to keep its mate under control during copulation. These extended limbs are also present in the closely related wingheads, a smaller family of more obscure creatures.
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Common seawasp

Wingheads
The wingheads are a poorly described group of butterfly crabs that are related to the waspcrabs as previously mentioned. Their most distinctive features are their wide head segments, long third legs (which end in suction-cup like pads), and a sharp spine. Unique to the wingheads, their spines are highly poisonous. The spines are in fact so poisonous that they may kill as quickly as a few minutes. Some other species of butterfly crabs have evolved spine-like tips to their pygidiums and wider heads in order to mimic wingheads and hopefully scare off predators. Wingheads are much smaller than seawasps, reaching anywhere from four inches to three feet, while seawasps range from six inches to 28 feet.
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Tiny winghead

Flatrays
Flatrays are another group closely related to the seawasps. They differ from seawasps by having extremely flattened exoskeletons, small spines on its carapace, and much larger antennae. Flatrays are predatory much like their relatives, most being ambush predators. They hunt much like wobbegongs, hiding beneath the sand, using their antennae to sense when prey animals swim by.

Sandsifters
More information on sandsifters coming soon.

Crabwhales
More information on crabwhales coming soon.
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Spotted crabwhale
Edited by Livyatan, Jul 20 2008, 01:25 PM.
The grand Livyatan on deviantArt: link

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Livyatan


I'm working on developing the flatrays and sandsifters right now, as well as the new sister groups for the butterfly crabs, the crabdrakes and crabticks.
The grand Livyatan on deviantArt: link

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Sliver Slave
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I'm going back to basics.

Crabdrakes sounds interesting.
Something is upsetting the ostriches.

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ATEK Azul
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Transhuman
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this is a interesting topic that needs more attention becouse these animals are awsome and i want too see more of this world.

so if the project creator can post some more that would be awsome plus some more posts and topics would be great.
I am dyslexic, please ignore the typo's!
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Sliver Slave
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I'm going back to basics.

I think he has orphaned this one. Its i the abandoned project forum.

I agree, though, it was nice.
Something is upsetting the ostriches.

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ATEK Azul
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orphaned, thats too bad. i hope somebody adopts it soon then. becouse it looks like it has a lot of potential and some awsome creatures.
I am dyslexic, please ignore the typo's!
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Hydromancerx
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Just to let you know that Sagan 4 is willing to adopt the butterfly crabs. I made a base species awhile back that could be made into diffrent species like this.

Arthrofin
http://wiki.mydigiview.com/index.php?title=Arthrofin
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"Sagan 4 is a wonderful experiment, not because it has the best art or the soundest biology, but because it is an actual working project where a team of speculative zoologists has derived an entire biosphere from a single hypothetical cell." - C.M. Kosemen
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Livyatan


Hydromancerx
Oct 18 2008, 09:31 PM
Just to let you know that Sagan 4 is willing to adopt the butterfly crabs. I made a base species awhile back that could be made into diffrent species like this.

Arthrofin
http://wiki.mydigiview.com/index.php?title=Arthrofin
This species really isn't up to that sort of adoption. If someone wants the whole project to expand upon, that is fine, but I'd rather not hand off individual species.
The grand Livyatan on deviantArt: link

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CarrionTrooper
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I require more vespene gas?!?
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Well, this is interesting... mind if the rest of us in the forum develop it further? Making this a joint project of sorts... We'll make up more stuff, from phylas to species...
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Livyatan


I was considering restarting the project, making it less 'omniscient' and more like actual scientists with their journals recording their discoveries in a foreign planet.
The grand Livyatan on deviantArt: link

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Saxophlutist
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Oh please do! I greatly enjoyed this project!
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CarrionTrooper
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I require more vespene gas?!?
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O hey! Interesting indeed!
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