Three weeks ago, I posted three colour photos of the “Ultrasaurus” excavation at the Dry Mesa Quarry, provided by Tyler Holmes from an old dinosaur encyclopedia. Here’s the third one again:

I wrote:

This can’t be right. In [another photo], which definitely is the “Ultrasauros” scap, the glenoid is facing clockwise if you think of the whole bone as being able to rotate about its midpoint; but in this photo it must be facing anticlockwise at top left. So I conclude it’s one of the Supersaurus scaps — either the left in lateral view or the right in medial.

Several people (Llewelly, Adam Yates, Matt) disagreed, and thought this was indeed the “Ultrasaurus” scap, but that the photo had been left-right reversed.

Brian Curtice weighed in by email, which I will quote.

Hola!

I was asked to identify which specimen is in those color photos. The scap is BYU 9462, the brach scapulocoracoid that Jensen referred to Ultrasauros.

I suspect the area added around the scapula in the left photo was an attempt to preserve the sides. BYU 9462, as shown in the picture of the original, is quite fractured and delicate.

The purple lines are the same bars, the yellow one shows the straightness, the orange circle shows the part sticking past that isn’t visible in the photo on the left because of the perspective, the red shows a similar angle, and the green shows the narrow waist.

The big block on chains is likely He-Hum-1, aka BYU 16776, a Diplodocus (?) humerus nearly 80 cm long. I suspect the jacket had “He-Misc-,” likely BYU 20173, a sternal plate as well as “cdl-1,” which should be BYU 12996, a diplodocid mid-caudal. Perhaps a few other bits were in the block; that area was a bone salad.

Neat pics! Hope that helps!!!

I’m happy to bow to Brian’s expertise on this: he knows those bones much better than I do, maybe better than anyone does.

Why anyone would left-right reverse a photo for a book, I can’t imagine, but it does seem that’s what happened.

doi:10.59350/ybwhc-sb641