Wut. That's still a wyvern.
Wyvern = winged, biped
*Dragon = quadruped
*Leaving out types like the serpent-like long dragons, and wingless ground ones.
Ah well, I guess over time, 'what is a dragon' has been over-homogenized.
Damn it, now I'm reminded of the PSO Ep I & II bosses of the Forest and VR Spaceship zones: Dragon, Sil Dragon(Ultimate difficulty), and Gol Dragon.
All 3 of them were friggin' wyverns, XD