Ask the Chatbot Games & Quizzes ProCon History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture Money Videos
Exogyra
Table of Contents
Introduction References & Edit History Related Topics
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
Related Questions
Read Next
Artist interpretation of space asteroids impacting earth and moon. Meteoroids, meteor impact, end of the world, danger, destruction, dinosaur extinct, Judgement Day, Doomsday Predictions, comet
Major Mass Extinctions
Three parasaurolophus stand on a rock beach. Pterasaurs fly over head and a small mammal watches the dinosaurs as they meander along the water's edge.
What Happened to the Dinosaurs?
Japanese spider crab
10 Animals With Evolutionary Traits Plucked Straight Out of a Nightmare
Malayan Leaf Frog - Megophrys nasuta
9 Animals That Look Like Leaves
Cheetah (Acinonyx jubatus) standing on rock, side view, Masai Mara National Reserve, Kenya
The Fastest Animals on Earth
Discover
The Cheshire Cat is a fictional cat from Lewis Carroll's Alice's Adventures in Wonderland. (Alice in Wonderland)
11 Banned Books Through Time
Rural Irish landscape, Sligo, Ireland.
Why Is Ireland Two Countries?
Thanksgiving Turkey with all the sides
Why Do We Eat Turkey on Thanksgiving?
Thanksgiving Celebration Traditional Dinner Setting Food Concept
Why Is Thanksgiving in the U.S. Celebrated on a Thursday?
Thumbnail for flags that look alike quiz Russia, Slovenia, Iceland, Norway
Flags That Look Alike
A human Inuit skull in a stone chambered cairn in Ilulissat in Greenland. These ancient graves are pre christian and are at least 2000
14 Tough Questions Answered
Santa Claus flying in his sleigh, christmas, reindeer
Was Santa Claus a Real Person?

Exogyra

fossil mollusk genus
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Share
Share to social media
URL
https://www.britannica.com/animal/Exogyra
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites
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

Exogyra, extinct molluscan genus common in shallow-water marine deposits of the Jurassic and Cretaceous periods (from about 200 million to 65.5 million years ago). Exogyra is characterized by its very thick shell, which attained massive proportions. The left valve, or shell, is spirally twisted, whereas the right valve is flattish and much smaller. A distinctive longitudinal pattern of ribbing is well developed in the left valve, and pitting is common.

This article was most recently revised and updated by Richard Pallardy.