is the earliest pelecypod with that style and ring structure on the shell. It, if not a modern specimen, would be fully petrified. Instead, its still an aragonite shell . (That's too recent)
The hammer is poorly encased in a iron oxyhydroxide mix. One can see the limonite structure.
Ive seen real encased hammers in iron efflorescent "casts" from deep mines less than 100 years old. (Water and humid air will deposit the crap round the hammer easily).
However, Im not sure that the entire hunk of rock hasn't been "Gouged out" with Dremel and the hammer placed in the cavity. It looks like the "hammers fit" in the cavity is more carved than deposited.
Also, Id really like to know how they "dated the hammer. Wht technique did they use? Ca deposition? alpha track? some kind of radioisotope? What?
Im always amazed at how quickly you accept any kind of **** if it jut happns to agree with your worldview