D defs.my
Entry 1 sense Webster, 1913

Ammonitoidea

· Am·mon·i·toid·e·a · IPA
01 n. pl. An extensive group of fossil cephalopods often very abundant in Mesozoic rocks. See Ammonite.
  1. 1.
    An extensive group of fossil cephalopods often very abundant in Mesozoic rocks. See Ammonite.(Zool.) See: Ammonite