Anomaly from Penn Dixie

[DevonianDigger]

Came across something interesting today while excavating the Bay View Coral bed at the site. First thought was a hypostome from a Dipleura dekayi. It is not. There are symmetrical sutures in it, which are pretty interesting. Wondering if anyone has some literature on Devonian fishes from the Hamilton. The only thing I can think of is placoderm. It's about 1mm thick and 4-5cm across. Sorry for the poor photo, I took it in situ with my phone. 

[ynot]

Cool find whatever it is.

[I_gotta_rock]

[Malcolmt]

Does not look placoderm to me 

[Kane]

Possibly phyllocarid carapace fragment?

[jdp]

Can you get us a closeup of the surface pitting?

[Fossildude19]

Enlarged and brightened: