graptolite means any of a group of extinct aquatic colonial invertebrates, of the class Graptolithina, from the Cambrian and Carboniferous periods. Lexicurio rates it Sui generis — a strength score of 86 out of 100.
graptolite is pronounced /ˈɡɹaptəlʌɪt/.
Etymology
From Ancient Greek γραπτός (graptós, “painted, marked with letters”) + -lite.
noun
- Any of a group of extinct aquatic colonial invertebrates, of the class Graptolithina, from the Cambrian and Carboniferous periods.“The samples were black shale, and on the shales were some ancient fossils called graptolites.”