Ask the ChatbotGames & QuizzesHistory & SocietyScience & TechBiographiesAnimals & NatureGeography & TravelArts & CultureProConMoneyVideos
helmet shell
Table of Contents
Introduction References & Edit History Quick Facts & Related Topics
Images
King helmet shell (Cassis tuberosa)
Quizzes
Sea otter (Enhydra lutris), also called great sea otter, rare, completely marine otter of the northern Pacific, usually found in kelp beds. Floats on back. Looks like sea otter laughing. saltwater otters
Animal Group Names
Lion (panthera leo)
Deadliest Animals Quiz
Mute swan with cygnet. (birds)
Match the Baby Animal to Its Mama Quiz
vulture. An adult bearded vulture at a raptor recovery center. The Gypaetus barbatus also known as the Lammergeier or Lammergeyer, is a bird of prey and considered an Old World vulture.
Animal Factoids
Read Next
coconut octopus underwater, amphioctopus, cephalopod, indonesia
6 Reasons to Love Cephalopods
Discover
Clouds of smoke billow up from controlled burns taking place in the Gulf of Mexico May 19, 2010. The controlled burns were set to reduce the amount of oil in the water following the Deepwater Horizon oil spill. BP spill
The Perils of Industry: 10 Notable Accidents and Catastrophes
Charles Darwin, carbon print photograph by Julia Margaret Cameron, 1868.
What Darwin Got Right (and Wrong) About Evolution
earthquake. Heavily damaged school in the town of Yingxiu after a major earthquake struck China's Sichuan Province on May 12, 2008.
The 6 Deadliest Earthquakes Since 1950
African Americans demonstrating for voting rights in front of the White House as police and others watch, March 12, 1965. One sign reads, "We demand the right to vote everywhere." Voting Rights Act, civil rights.
Timeline of the American Civil Rights Movement
Close-up of crocodile eye; location unknown (rainforest, reptile).
What’s the Difference Between Alligators and Crocodiles?
World Data Locator Map: Australia
Is Australia an Island?
number zero, 0 balloon
Is Zero an Even or an Odd Number?
King helmet shell (Cassis tuberosa)
King helmet shell (Cassis tuberosa)

helmet shell

gastropod family
External Websites
Also known as: Cassid, Cassidae
Written and fact-checked by
The Editors of Encyclopaedia Britannica
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors.
The Editors of Encyclopaedia Britannica
Article History

helmet shell, any marine snail of the family Cassidae (subclass Prosobranchia, class Gastropoda), characterized by a large, thick shell with a shieldlike inner lip. An example is the 18-centimetre (7-inch) king helmet (Cassis tuberosa) of the Caribbean.

Cameos are carved from helmet shells. Smaller, more rounded cassids (Phalium) are called bonnet shells.

Britannica Chatbot logo

Britannica Chatbot

Chatbot answers are created from Britannica articles using AI. This is a beta feature. AI answers may contain errors. Please verify important information using Britannica articles. About Britannica AI.