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19:26 23-10-2012
SN
How irritating! I made some new changes in the hope that they solve the commenting problem. Please try again.

I agree that bioluminescent animals, or some luminescent organs at least, could function very well as sexual signals. Just the ends of the whips of rusps would work nicely: the rusps could swing them around, or entwine them...
18:08 23-10-2012
Jan
Unfortunately, when I click on "Post a comment", nothing happpens. I probably do some mistake, but do not know which. Sorry if I am making it more difficult to you.

Still thnking about the bioluminescence, though. What worries me about the searching function of light is that it makes clear to any potential prey that the hunter is there. What would be very nice is a bioluminescent mole searching its traps, but tactile sense is probably more practical. I understand why you compare the searching function of bioluminescence with echolocation, but to fill the world with bioluminiscent animals the sexual function is more likely a decisive factor. Rusp and flygs are particulary good candidates, according to my opinion. I think that mating rituals of giant centipedes could not be other than awesome but imagine them glowing.
22:44 22-10-2012
SN
Jan,

Many comments! here are some short replies
- true; marine hexapod ancestors look like plesiosaurs and the like. Parallel evolution...
- a dual purpose of light as a searchlight and as a warning light seems attractive for a poisonous animal (it's one way of being Bad).
- I agree that nothing in the list of offensive and defensive uses made of bioluminescence strikes me as limited to the seas. Still, where are all the glowing mushrooms?...

- I do not know why you could not post. I just tried commenting as an anonymous user and it threw me out as well, after having copied the 'antirobot' text. I tried disabling that. let me know if that works (and I hope that the blog won't be filed by robot-generated advertisements by tomorrow)
11:51 21-10-2012
Jan
(I would really like to know why I cannot post on the blog... nevermind.)
I just like to pinpoint that there are some bioluminescent terrestrial organisms.
http://en.wikipedia.org/wiki/Bioluminescence#Terrestrial_organisms
They are small, but I think that there could be much bigger animals, preferably either poisonuous or flying.
There are some limitations for the most likely kind od bioluminescent organisms, although.
1. they should live in dark, either being nocturnal or cave dwelling (or maybe living in very different kind of vegetation)
2. they should not worry about being spotted, but on the contrary trying to be spotted.
3. there should be enough evolutionary pressure to expend a lot of energy for the signaling.
4. there should be some reasons not to relly on acousting or chemical signals, which are more efficient on the land, especially in a dense vegetations, I think.

There are a lot of bioluminescent organisms in Avatar, especially plants, but it does not confirm to the second point. They could be pollinate by nocturnal organisms of course, but why not by the diurnal ones?
11:52 20-10-2012
Jan
And regarding the animal in the article, it does not need to be big to be bad. What about dual purpose of the photophores to find prey and remind the predators of the poisonuous nature of their owner? The tetropters would be probably too quick to be catch this way, but some other bugs and worms...
11:41 20-10-2012
Jan
Thank for the informations about photophores, I have never heard about them. The sites about bioluminescence are amazing. But dont you really want any BBEF? Because some of their earthy examples are amazing and I would like to see some comparison to their truly complex ways of producing and hearing sounds (see the link)
http://www.youtube.com/watch?v=_z2Lfxpi710
Generally, given the different respiratory organs of furahan animals, there must be some differences in producing sounds or filtering the water. And we have said a lot of things about possibilities of different hearing mechanisms.

I also noticed that the BB furahan marine animals resemble more the extinct marine reptiles than big fishes. Is not there some interesting evoluionary story of how they get to the land?
 
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20:06 12-10-2012
Jan
I have found this video, it seems to be moving at least slightly
https://sites.google.com/site/swimmingseaslugs/a-z-index/glaucus-atlanticus
If it moves to a more active lifestyle, it could easily turn into something like manta ray, or, maybe, something like really bizzare octopus...
Although "squidworm" puts the standart for "bizzare" really high http://blogs.nature.com/news/files/squidworm.bmp
Isnt it one of the inspirations for the new tentacled rusps?
15:31 12-10-2012
SN
Jan, Thank you! You are absolutely right that having the respiratory openings on the upper side of the animals would have make sense. But it simply did not start that way, and, as usual in evolution, you can tinker with a design but not go back and install a completely new design. I would not be surprised to see animals whose inlets and outlets migrate over the body for various ends.
The stiff body with hardly any lateral bending is another such design 'flaw'.

Many people in speculative biology seem to strive for perfection. Evolution does not work towards overall perfection on Earth, and I assume things will be similar elsewhere.

Thank you for the Glaucus; it is a wonderfully shaped animal. I have not seen videos of it; do its apendages not move at all?
18:37 10-10-2012
Jan
SN: Thank you for clarification. According to my opinion, it would be easier to start with inlets on the back, but evolution is not always straigthforward...

Just for fun I tried to connect evolutionary stages of furahan animals to their earthly counter-parts.
The first stage resembles marine flatworms or nudibranchs.
The second stage (if I understand it correctly) is similar to annelids or anomalocaridids.
But it was really difficult to find an analog to the third stage, with just six fins. Finally I found this insane creature
http://www.nhm.ac.uk/nature-online/species-of-the-day/collections/our-collections/glaucus-atlanticus/index.html
but unfortunatelly it seems that it does not use its "fins" for swimming.

Furaha is simply unique.
22:44 08-10-2012
SN
Jan, thank you. Originally the spiraculae could function as inlets as easily as outlets, but efficiency drove a one way traffic with water flowing in at the front and out through one outlet (visible in one of the images of the last post). In Fishes, on each side there is one inlet per limb (three in all) that connect to the common tube gill and all have one outlet at the end of the animal. In terrestrial hexapods, on each side there is just one inlet left at the base of the neck and one outlet at the rear end of the animal (one-way lungs). The inlet is relatively small (as in mammals) and commonly protected by skin flaps. In some species it moved up the side of the neck. Spiracules are not well visible on any painting (I may enlarge them when redoing the paintings). Regardless, most terrestrial animals that take to the water may have to rise to breathe in (breathing out is accompanied by bubbles...).
19:32 07-10-2012
Jan
Furahan prehistory is so fascinating!
But I still do not undestand one thing: Where are the breathing outlets in furahan animals? If they are on the belly, how could they lie in the water like marshwallow seems to do?
11:32 02-10-2012
Jan
Evan: I think that insects use Van der Waals force just like geckos. Which have some other interesting feet, btw.
Some other insiration for finger patterns could be find in birds http://en.wikipedia.org/wiki/Bird_anatomy#Birds_feet
or chameleons. Interesting example of convergent evolution are also "fingers" of moles and mole crickets.

I am quite curious what happened to fingers of furahan neocarnivores and if the new "hand" doesnt implicate some semi-sapient species, like nereid flaxs.
20:13 22-09-2012
Evan Black
Jan, those are fascinating links.

The second insect foot reminds me of the the motipalps on nereid mollipods, and it makes me wonder if that insect employs suction or only a friction hold.

The titanosaur feet are quite an innovative view of the fossil record. I wouldn't be surprised if Naish's article inspired specevo projects to explore toeless creatures.
21:55 20-09-2012
S.N.
Tritonis: thank you!

Lorenzo: Contact has been established; as for the hexapod gallop, the animations were done with a programme that is difficult to make work today, and recoding it is a lot of work, so there is litle chance of similar animations in the near future

Jan, thank you for the clever finds as usual!
13:36 19-09-2012
Jan
Thank you for the new article!
Speaking of feet, some insects have really strange ones
http://cdn.physorg.com/newman/gfx/news/2007/BeetleAdhesiveFoot.png
http://www.mindfiesta.com/images/article/world%2020.jpg
I wonder if such a design would work for a bit larger animal.
Maybe the differential split-ending solution could be used for something else like hand+hoof appendage. The veloceraptor leg comes to mind...

Titanosaurs have weird foot too, for the opposite reason. They have almost no fingers http://scienceblogs.com/tetrapodzoology/2008/10/29/the-hands-of-sauropods/

And I hope that you will use your marshland creature´s leg in some way.
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