Pyncnodonte convexa from the Navesink formation

One of the most common shells that is found within the Navesink formation in New Jersey is Pycnodonte. There are a couple of species with the one I'm showing you today being a Pyncnodonte convexa. It was found at Big Brook near Marlboro, New Jersey in the Navesink formation which is upper Cretaceous (Maastrichtian stage) in age.

Left valve top

Left valve anterior

Left valve, right side profile

Left valve interior

Left valve, left side profile. Note the worm tube that is embedded in the shell.

Left valve posterior

Here are a couple of the right valves which are smaller than the left valve and slightly convex.

Right valve top

Right valve interior

Right valve posterior

Right valve profile

Shells of these oysters are often colonized by epibonts such as sessile worms, sponges and bryozoans. You can see some Bryozoans that have colonized the gaps in the right valve shell below.

Here is a closer view of the worm tube that I indicated above: