tethytherian

mammal group

Also known as: Tethytheria

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July 16, 2026

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The term "tethytherian" refers to a group of mammals that includes proboscideans (elephants, mammoths, and mastodons) and sirenians (manatees and dugongs). This classification is based on the hypothesis that both groups originated in the ancient Tethys Sea.123

Proboscideans, the order to which elephants belong, first appeared in northeastern Africa during the late Paleocene Epoch. Early proboscideans were smaller and lacked trunks, which evolved over time as indicated by cranial features like enlarged nasal openings.1

Sirenians, which include manatees and dugongs, also evolved from terrestrial mammals called tethytheres during the Paleocene Epoch. These aquatic mammals are characterized by their flippers, paddle-like tails, and adaptations for marine life.2

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proboscidean
…sirenians are together classified as tethytherians, in reference to the ancient sea of Tethys, where both groups are hypothesized to have originated. On land the closest proboscidean relative is the hyrax (order Hyracoidea), a small rodentlike animal of Africa and southwestern Asia. Tethytheria and Hyracoidea are grouped together as Uranotheria.
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…sirenians are together classified as tethytherians, in reference to the ancient sea of Tethys, where both groups are hypothesized to have originated. On land the closest proboscidean relative is the hyrax (order Hyracoidea), a small rodentlike animal of Africa and southwestern Asia. Tethytheria and Hyracoidea are grouped together as Uranotheria.
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