1. Extinct marine animals with branching, tooth-like or saw-like skeletal structures, abundant in Paleozoic seas and commonly found as fossils in sedimentary rocks.
Usage: paleontology; geology; plural form; singular is graptolite

Examples

• Graptolites are important index fossils used by geologists to date rock layers.
• The museum's collection includes several well-preserved graptolites from the Ordovician period.
• Paleontologists study graptolites to understand ancient ocean environments.
• These graptolites were discovered in shale deposits across the region.
• The branching patterns of graptolites help scientists classify different species.