You’re right - it was wrong of me to assert as fact that Longisquama’s back-fronds were not a part of the animal’s anatomy.  In fact, based on the current lack of evidence either way, it’s probably equally as incorrect as asserting that they were the precursors to feathers!

I allowed a personal bias to intrude on scientific discussion, and I apologize for misinforming people.

Let’s take a moment to wildly speculate at some of the other possibilities, assuming that the fronds were a part of Longisquama’s body.

They may have played some role in locomotion.  While the fronds are known not to have been paired, and thus did not form wing-like arrangements, it’s possible that they could have been used for gliding - perhaps by “ballooning” on the wind, like a baby spider.

They may have supported a Dimetrodon-esque back sail, used to assist in thermoregulation.

They may have acted as camouflage, resembling the structures of a plant in order to conceal Longisquama from predators.

Alternatively, they may have resembled plants in order to attract insects for Longisquama to eat, possibly with the assistance of pheromones or other non-visual forms of mimicry.

Source: fezraptor

Name: Shanyangosaurus niupanggouensis

Name Meaning: Shanyang Lizard 

First Described: 1996

Described By: Xue, Zhang and Bi 

Classification: Dinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora?, Maniraptoriformes?, Maniraptora?, Pennaraptora?, Oviraptorosauria?

Shanyangosaurus is only known from scattered fragments of leg bones, which were fairly hollow, and a few other remains. This has lead to its classification as a coelurosaur. It lived in the middle to late Maastrichtian age of the Late Cretaceous, anywhere between 69 and 66 million years ago. It was found in the Shanyang Formation, Shaanxi, China. Given the morphology of the remains, it could have been an oviraptoran or even a paravian, but without more remains its full classification is uncertain. 

Sources: 

http://en.wikipedia.org/wiki/Shanyangosaurus

http://theropoddatabase.com/Coelurosauria.htm#Shanyangosaurusniupanggouensis

2. What country are you from? The United Kingdom.

3. Do you have any pets? A large cat named Lakshmi. I am also rat-sitting for a friend, but only for a few more days.

4. Can you speak more than one language? I don't think Key Stage three German and Spanish really counts, so I'll say nein, no, and no.

5. Anything else you’d like to mention about yourself? I like art and biology and music and also Dinosaurs.

Part 2: Favorites 6. What are some of your favorite prehistoric creatures? Oh crikey. I guess Phorusrhacos, Sauropelta, Arthropleura, Utahraptor and Argentinosaurus hold a place in my mind somewhere - childhood favourites, y'see.

7. What is/are your favorite food(s)? Gotta love Fish n' chips

8. Do you have any favorite books? Anything by Terry Pratchet is a masterpiece, On the Origin of Species by good ol' Charley D is very important obviously, and the Complete Book of Dinosaurs is a book I have loved ever since I was given it aged nine. 9. Favorite music genre(s)? Rock, Blues Rock, some punk rock, anything satirical, atmospheric classical, that kinda thing.

10. Do you have a favorite documentary? Walking With Dinosaurs (no, not the awful one).

Part 3: Just out of curiosity… 11. Have you ever been fossil hunting? Yes! Twice at Charmouth in Dorset (the Jurassic Coast), and four times at Sandown beach on the Isle of Wight during my work experience. 12. If you could be any animal for a day what would you be and why? Probably a Mantis Shrimp, because that's an awful lot of colours I'll never see with these eyes of mine.