Sorry if this photo has been discussed before - looking thru the thread it looks like quite a few links have got broke over the years.
Presumably this one is a mock-up - it looks far too "fresh" to be genuinely old and the pteranodon looks like a fake - but at least it tries to include elements of a barn in the background.
My own memory of the Thunderbird photo is of:
1)the creature being a huge bird not a pteranodon
2)it is nailed to a barn
3)six cowboys types standing in front of it - one of them wearing a top hat
and I remember it being in either "Time" or "Life" magazine c. 1957
http://www.genesis6giants.com/index.php?s=316
Presumably this one is a mock-up - it looks far too "fresh" to be genuinely old and the pteranodon looks like a fake - but at least it tries to include elements of a barn in the background.
My own memory of the Thunderbird photo is of:
1)the creature being a huge bird not a pteranodon
2)it is nailed to a barn
3)six cowboys types standing in front of it - one of them wearing a top hat
and I remember it being in either "Time" or "Life" magazine c. 1957
http://www.genesis6giants.com/index.php?s=316