Today's fossil is Delthyris sculptilis which is an appropriate name due to the high relief and heavy decoration on the shell. D. sculptilis has a long hinge line connecting the pedicle and brachial valves. Each valve is deeply incised by plications to the point that there does not appear to be a lot of room for the body. The shell has very obvious growth lines that help decorate the shell and perhaps prevented predators or parasites from gaining a foothold.
This specimen came from the Centerfield mbr. of the Ludlowville formation (Devonian, Givetian stage) near East Bethany NY. I've posted before about this species from the Hungry Hollow mbr. of the Widder formation (Contemporaneous with the Centerfield mbr.) and a similar species from the Irondequoit limestone. Delthyis is also similar to Kozlowskiellina velata from the Haragan formation of Oklahoma.