Below the waves, giant marine reptiles, such as the fearsome 4m (13ft) long mosasaurs, were the undisputed apex predators. In artistic reconstructions of these ancient oceans, cephalopods – the animal ...

The world's oldest octopus fossil is no longer an octopus. A new study by researchers says the 300-million-year-old creature was actually a relative of a nautilus.

"It's a huge gap. And so that big gap got researchers sort of questioning, ‘Is this thing actually an octopus?'" ...

The ammonoids, an extinct subclass of cephalopods, offer a remarkable window into the evolutionary innovations of marine life. Their coiled, chambered shells and intricate suture patterns record a ...