Insect Identification: ID a 3-4cm Long Insect

[slider142]

We were walking down a Brooklyn sidewalk the other day under several trees when we spotted this insect lying motionless (except when the wind blew, it moved its legs a little to rotate itself). We didn't get too close, as it looked like it could give a bad sting. It has two pairs of long veined wings, like a dragonfly's, and is about 3-4 cm long, so it is much larger than an ant, even though its' body appears similar. What is it?

http://img55.imageshack.us/i/oddinsect.png/
http://img269.imageshack.us/i/oddinsectfront.png/

 

[lisab]

Curious looking bug...it looks like the abdomen is split. I Googled using winged insect bifurcated abdomen, and also winged insect lobed abdomen. Didn't see anything like it.

But I'm not an entomologist...surely someone here will know it, though.

 

[slider142]

Thanks for the effort. If only there was a Google for image matching! :D