A variant of the bat model might be the " pterosaur model " in which the styliform bone would have been directed obliquely to the outside, with a narrower wing as a result.
12.
Unlike all other known dinosaurs, a long, pointed wrist bone known as a " styliform element ", exceeding both the third finger and the ulna in length, extended backward from the forelimb bones.
13.
Each of the segments of the postabdomen contain lateral flattened protrusions known as the epimera with the exception of the last needle-like ( styliform ) segment known as the telson ( the'tail').
14.
"Stylonurus " is distinguishable from other stylonurids by their smooth surface, and the greatly elongated 5th ( last ) pair of walking legs, which reached as far as the telson, which was long and styliform.
15.
At least one species, " Yi qi ", also had a long " styliform " bone growing from the wrist, which, along with the third finger, helped support a bat-like wing membrane used for gliding.
16.
Small patches of wrinkled skin were also preserved, between the fingers and the styliform bone, indicating that unlike all other known dinosaurs, the planes of " Yi qi " were formed by a skin membrane rather than flight feathers.
17.
Other characteristics include six-jointed antennal peduncle, the styliform uropods ( a character shared with some other isopod groups ), the fusion of pleonites 5, 4 and sometimes 3 to the pleotelson, and absence of the first pleopod in females.
18.
The second main possibility is the " maniraptor model ", in which the styliform element was pointing towards the body, reinforcing the trailing edge of a narrow membrane, possibly widened by feathers, on the top or the underside, sticking out.
19.
While it is possible that some form of flapping flight was also used by this animal, the lack of evidence for large pectoral muscles the deltopectoral crest of the humerus being small and the cumbersome nature of the styliform, make it more likely that " Yi qi " was an exclusive glider.
20.
The monophyly of Coxoplectoptera is demonstrated by several autapomorphic characters in the adult stage, such as the raptorial forelegs and single-segmented tarsi with unpaired claw, as well as in the larval stage by the laterally compressed body, the body armature, the raptorial forelegs and burrowing mid-and hind legs, and the styliform shape of the ventrally directed abdominal gills.
