(also rudistid /ruːˈdɪstɪd/)
A cone-shaped fossil bivalve mollusc which formed colonies resembling reefs in the Cretaceous period: [as modifier]: rudist bivalves
- Superfamily Rudistacea, order Hippuritoida
More example sentences
- An extinct group of Mesozoic bivalves, the rudistids, became closely adapted to a cemented mode of life: one valve became conical while the other formed a lid.
- Cretaceous radiations of rudists were apparently initiated during periods of globally high sea level and the Lebanon decapod faunas are a part of this general increasing invertebrate diversity.
- This member contains abundant and diverse mid-Cretaceous shallow-marine invertebrates, including reef corals and rudist bivalves.
late 19th century: from modern Latin Rudista (former group name), from Latin rudis 'rude'; for the variant spelling see -id3.
Definition of rudist in:
- The US English dictionary