1979 penny filled d and all devices 0

[Ratzie33]

Found a 1979 penny but the lettering, devices, and Lincoln are all flattened out. It weighs 2.9grams, and curious if this might be an error. It seems like it’s more than just wear. Is there such a thing as a mated Canadian penny planchet? Or a weak strike? It looks like it was struck over an older coin. Any fine detail is filled in.

Edited October 12, 2019 by Ratzie33

[Ratzie33]

[Ratzie33]

[Ratzie33]

The strike is strong and thick, so that the coin is raised up the under the lettering of “United States of America.”

[Ratzie33]

The d mint Mark is raised up more than the rest of the coin, and undamaged