Do not be intimidated by these things. Get a pteranodon fly into the nest and take a descent level egg. Then fly the heck out! Make sure your ptero has high stam and barrow role as much as possible. Now focus on raising that one wyvern use a deodont and feeding trophs to heal the wyvern then just wait. After the wyvern is fully mature go out level it up intel YOU feel comfortable that it will servive then back to the trench you go. With a wyvern it will be piece of cake so this time round be more picky take the highest levels you can find then hatch and raise. Finally youve got wyverns well done!