They comprise the extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals), and Phocidae (the earless seals, or true seals), with 34 extant species and more than 50 extinct species described from fossils.

2024年5月24日 · Seals are successful marine predators found in oceans around the world. But their current diversity is just a snapshot of the species that used to exist. A new study has now explored the evolutionary history of living and fossil seals, revealing in the process how walruses had extraordinary periods of speciation followed by extinction.

Evolution. The earliest ancestors of seals and sea lions were mammals that transitioned from life on land to life at sea. Around 36 million years ago, at the end of the Oligocene, the ocean began to cool, which caused major changes to ocean circulation. This led to an increase in nutrients throughout the ocean and enabled ocean life to thrive.

2024年3月20日 · Seals, sea lions and walruses of every era still piled onto beaches to rest, reproduce and escape predators—from carnivorous walrus relatives of ages past to the elephant seals that shore up...

2023年8月17日 · Over 23 million years ago, an ancient relative of modern seals called Potamotherium valletoni was possibly one of the first pinnipeds to use their whiskers to forage for food and explore...

Sources:https://www.nationalgeographic.com/science/article/puijila-the-walking-seal-a-beautiful-transitional-fossilhttps://royalsocietypublishing.org/doi/10....

The evolution of aquatic feeding in seals: insights from Enaliarctos (Carnivora: Pinnipedimorpha), the oldest known seal. J. Evol. Biol. 29: 19– 34

2021年5月6日 · New research combines cutting-edge engineering with animal behaviour to explain the origins of efficient swimming in nature’s underwater acrobats: seals and sea lions.

2009年4月22日 · Seals evolved from carnivorous ancestors that walked on land with sturdy legs; only later did these evolve into the flippers that the family is known for. Now, a beautifully new fossil called...

2020年9月16日 · From their eyesight and diving abilities to how they regulate body temperature, seals have undergone centuries of evolution and adaptation to thrive in the wild. Looking to learn how this happened? You’re in the right place!