Almost all animals have symmetrical bodies. Bilateral symmetry is almost universal in all animals and is only very rarely broken—with exceptions like the five-armed starfish or crab species that have ...

The Story of How the Starfish Got its Arms Reminds us that Animals have Deep Histories. The story of how the starfish got its arms reminds us that even animals that might be familiar to us today can ...

A teensy sluglike animal that wriggled around the sediment in search of food at least 585 million years ago didn't die in vain. The tiny mover left behind tracks that researchers now say represent ...

Starfishlike brittle stars have five thin arms and no central brain, but even so, they move in a carefully coordinated fashion similar to four-limbed animals (including humans). A new analysis delves ...

Along the ocean floor lives an unusual multi-armed creature. No, not the octopus, the starfish: an animal from the echinoderm family known for its spines and bumps and, most importantly for some ...

A typical starfish has five-sided symmetry. With no clear head, the starfish can move in any direction, led by any one of its five arms. If you were feeling particularly cruel, you could fold one up ...

Scientists have identified *Ikaria wariootia*, a tiny wormlike creature from 555 million years ago, as the earliest known bilaterian. This discovery from South Australia reveals the origin of ...

Tiny fossils less than a fifth of a millimetre across may reveal a critical step in the early evolution of animals. They show that internal complexity came before large size, suggesting ...

Their legs can shimmy in any direction, without any clear pattern and regardless of which way their head is pointed. Other animals don’t move this way, suggesting that the octopus has a motion command ...

Facial symmetry is one of a number of traits associated with health, physical attractiveness and beauty of a person or animal. It is also hypothesized as a factor in interpersonal attraction. R.J.

While people and many animals might look pretty symmetrical on the outside, inside our bodies we are all fundamentally asymmetric. For example, the human heart is found to the left of center. Snails ...