[mysterio]

Thunderbirds are crafty creatures. They manage to exist without being detected, they are unphotographable, and they leave no bones behind when they die.

Sort of like space monsters, come to think of it.

[Longtom]

I agree with you entirely. I’ve known of people who believe in Unicorns. Some really swear they exsist but no one has ever seen one. :-)

[Swordmaker]

Thunderbirds are crafty creatures. They manage to exist without being detected, they are unphotographable, and they leave no bones behind when they die.

Are you certain of that? Teratorns are well known.

Generic avian wing diagram shows the position
of the humerus, marked "hum"

Partial Teratorn humerus is 14 inches in length and is from
a Teratorn with a wingspan of 15-16 feet, 50% larger than
the modern Turkey Vulture. Rule is 15 cm (~5.9")

The Argentavis Magnificens is a Teratorn whose humerus bones, found on the plains of Argentina, have been measured up to 22" in length. That length of a humerus belongs to a bird with a 24-25 foot wingspan and flight feathers as long as five feet. Using the cube-square law, that translates to a bird weighing in at 170 lbs... that still could fly.

Dr. Kenneth E. Campbell, (one of the discoverers) in front of
the 25 ft. wingspan Argentavis Magnificens (life size model).
Display seen at the Natural History Museum, Los Angeles.