Breathing Underwater Continutation

Actually I am right.... scorpions do have book lungs, now whether they can use them or now will take a little more googling...


http://www.thedailylink.com/thespiralburrow/anatomy/anat02.html

Found some goo info..will compile all of this when I have time so we can close this lengthy thread and create one with more info, less banter (which was my fault)... Anyways
"Another amazing things about Scorpions is that they have diversified to all these habitats with very little change in their morphology, the basic body plan of Scorpions is the same now as it was 420 MYA when they first appeared. They tend to change their habits rather than their form in order to adapt to a new habitat, which gives them something in common with us humans. "

"The first Scorpions are believed to have evolved from the Eurypteridae or water scorpions 425 to 450 million years ago in the middle of the Silurian epoch. The first Scorpions were most probably marine and marine members of the family continued to exist until about 250 to 300 million years ago. The first terrestrial Scorpions could most likely be found by about 340 million years ago. As with most arthropods early scorpions produced some very large species and the largest fossils found so far indicate about 1 metre or 3 feet as the maximum length i.e. Brontoscorpio willsi. As Scorpions are entirely predatory they could not be the first to make use of the new terrestrial habitat but could only move up out of the sea after sufficient prey species had gone before them, these would most likely have been insects, arachnids and millipedes. The earliest known terrestrial scorpion is Palaeopisthacanthus from the upper carboniferous. Some species still live near the sea, hunting in the littoral zone of the seashore keeping company with the crabs and periwinkles i.e. Euscorpius carpathicus"

all found on http://www.earthlife.net/chelicerata/scorpionidae.html

...............:wall:

The eurypterids were among the largest and most fearsome marine predators of the Paleozoic. While the smallest were only about 10 centimeters, some reached more than two meters (six feet) in length, making them the largest arthropods that ever lived. Eurypterids fossils are known from all continents, and have such amazingly good preservation that their external structure is the best known of all extinct animals. Because of their long tails and the spine-like appendage at the tip, the eurypterids have been called sea-scorpions. And in fact they are closely related to scorpions and other arachnids. http://www.ucmp.berkeley.edu/arthropoda/chelicerata/eurypterida.html No one has any iput about the possibility that they haven't competely lost their lung system that they abondoned after leaving the water? I feel bad with all these long posts if no one is readign it

EAD063 said:

No one has any iput about the possibility that they haven't competely lost their lung system that they abondoned after leaving the water? I feel bad with all these long posts if no one is readign it

Click to expand...

Clearly their current lung system was derived from their aquatic lung system. If you are hypothesizing that they can still breathe underwater then I'm afraid you'll have to stop parrotting the introductory chapters to any of the basic texts out there as proof and show how all the anatomists and physiologists who have worked on scorpions to date have missed this fact.

If I wanted to show that the apendix in humans is not actually completely vestigal then I would do better to show it has function then to quote websites that state that primitive humans actually ate some of the same food items as modern humans (mmmmm ... cashews).

Alternately, consider the case of ratite birds. They definitely can't fly -- despite their being very strong evidence that at some point in the past they evolved from something that could. If I want to prove that they CAN fly then I'm better to throw a bunch off a building than to quote webpages that list both them and albatros as types of birds.

Cheers,
Dave

Yes, very true Dave..I don't know if you read all the posts but everyone kept asking the same questions over and over and kept asking if they were realted and such, which is why I put the technial information.. I'll stop the post and do research of my own because I know what I'm looking for and Idon't know if I conveyed that into the right words so I probaly left people confused... I think way too much

thanks all

Male snakes have the spurs, not all species either (Boidae) and it is used for stimulation and positioning of the female (which is why they haven't completely disappeared)
A study was published not that long ago on the size of bugs due to oxygen and it was found to be a physical limit in the way the lungs are comprised. There just isn't enough 'room' in the lungs to support larger species (oxygen levels were as high as 30% compared to about 20% now)
As size increases, the density of the lungs (don't remember what the actual internal structure was called) must increase to pull more oxygen from the air. More oxygen means less 'work' to get it, so the lungs can be 'less dense' allowing for the larger size.

any pics of:

Brontoscorpio willsi
Palaeopisthacanthus