Plant.

Age and formation found in?

Off hand, it looks like a Neuropteris, but... need more detailed photos of the leaf pinnules for proper ID.

Regards,

EDIT: It is a really nice fossil!

Also - have you checked out George's Basement online? LINK

Great source for plant fossil id's - Covers the coal flora of Pennsylvania, but you never know...

Duckantian 314mya, some sort of Neuropteris but struggling to get an id from The Plant fossils of the british coal measures book, quite tricky these, i'll get some closer pics of the pinnules.

That one is amazing! Wow!