planulate
/ˈplanjʊleɪt/ /ˈplanjələt/Chiefly Zoology and Palaeontology
adjective
Of or having a flattened form.
- Now used especially of ammonoids..
Origin
Mid 19th century; earliest use found in James Dana (1813–1895), geologist, zoologist, and teacher. Probably from scientific Latin planulatus from classical Latin plānus + -ulus + -ātus.