Cordulegaster Dragonfly Nymph Pictures

I have screened through the images on this site, and I am just having a big trouble identifying this bug I have pulled of a stone in my local river.

It is very large, maybe size 10 or slightly larger, I have found other size 14 bugs of the same shape/style (also in the picture but difficult to see) and when I came across this monster I had to know what I had found. Also, after finding very similar nymphs that are size 14, can this one actually be a dragonfly? Is it just a monster of the 'normal' brown drake? Or hendrickson hatch I have heard about on this stream?

The real issue, is that I don't see a 'normal' set of twin tails, or three tails. (again not the technical term) what I do see (on the smaller and larger bug) is almost like a large paddle, and it uses this vertical paddle to swim in the water. The head is extremely flat, and it has two small antenna (like the dragonfly photo's) and two very small barbed jaw-like protrusions below the antenna and below the eye's where the mouth would be. The back appears to have two sets of wings, (neither have fully emerged) and the eye's are very similar to the dragonfly eye's in the photo's here. Also there is almost no color at all to the fly, it is a very dark mud brown/black. It looks about the same color as all the flies I pull out of the river (except the neon green caddis). Not sure if that is just a characteristic of the river, or the bug (the color that is)

One thing that is not the same, is the abdomen (bulbous in shape in the photo's on this site) does not appear to be the same as the example I have. The bug I have has a tapered abdomen going back to this 'paddle' I mentioned earlier.

More 'macro' photo's tonight when I get home, these are crappy cell phone pics for now.

Thank you for any help!
IB


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https://stillmaninteriors.sslpowered.com/Images/bug.jpg

Probably also Codulegaster sp.