Ask someone to think of an animal, and chances are they'll come up with one of our relatives among the mammals. A few people might go further afield and mention other vertebrates, like birds and fish.

Analysis of the DNA and proteins of a range of animals has revealed that sperm’s molecular toolkit arose in our single-celled ...

It has fewer than 10 cells, lives within the muscles of salmon and doesn't have mitochondria. It sounds like science fiction, but researchers say they've recently discovered the first-ever "animal" ...

MIT researchers traced chemical fossils in ancient rocks back to the ancestors of today’s demosponges. A team of geochemists ...

The newly discovered fossil records suggest that mold-like single-cell organisms "set the stage" for the animal kingdom to evolve, the researchers wrote in a new report, published in the journal ...

In the animal kingdom, penises can be spiked, split, corkscrewed – even detachable. They’re one of the most diverse ...

Biologists who study the evolutionary origin of animals got a bit of a surprise this month when a new study reached the ...

Groove-like tracks on the ocean floor made by giant deep-sea single-celled organisms could lead to new insights into the evolutionary origin of animals, according to biologists. Groove-like tracks on ...

Strange fossils, including some that could be predecessors to modern animals, found in China shed new light on the evolution of large, complex organisms, and indicate that they may have diversified ...

Scientists have discovered a new non-oxygen breathing animal. The tiny, less than 10-celled parasite demonstrates that evolution can go in strange directions, the researchers say. Researchers at Tel ...