Resilium

The hinge area in one valve of a scallop shell (Pectinidae), showing the space for the internal ligament, known as the resilifer

A resilium is an anatomical term for part of the shell of certain bivalve mollusks. It is an internal ligament, which holds the two valves together and is located in a pit or depression known as the resilifer.

The resilium is part of the hinge mechanism in certain taxonomic families of bivalve shells, such as oysters and scallops.^[1][2][3] A resilium (and the resilifer, its associated contact point) is the primary structure comprising the type of bivalve hinge that is known as an "disodont" hinge.

References

1. ↑ http://paleo.cortland.edu/tutorial/Bivalves/bivalvemorph.htm
2. ↑ Bivalves by J.H. Leal, Bailey-Matthews Shell Museum, Florida, USA http://www.shellmuseum.org/BivalvesLeal.pdf
3. ↑ Invertebrate Paleobiology on-line syllabus on Bivalves, by Dr. Burt Carter, Georgia Southwestern State University, at: http://itc.gsw.edu/faculty/bcarter/paleo/labs/moll/biv2.htm