It may have been broken up before being buried with the other bones. It does not have hollow ends like the other limb bones, though the flat end has a little more to be added from another block. Your guess is as good as mine.
We have another couple of strange bones that may be part of a pelvic girdle. This one has what looks like growth hollows around three of the four sides, but a smooth curve on the 4th. Here's some pictures:
And here's a J-shaped bone I may have mentioned before:
On the other hand, we have a very nice scapula or coracoid that is practically perfect:
and a beautiful pair of a limb bone with an entire nautiloid nestled alongside it.
So that's all for now, folks
Greg Car