Fossils from 465 million years ago recently discovered in Portugal have revealed the huge size reached by trilobites, the most diverse group of extinct marine arthropods. Geologists describe the ...

Fig.1: Tempo and mode in the body size evolution of Cambrian-Ordovician trilobites. Changes in maximum size (red) and mean size (blue) for each time slice, with lines and shading representing the mean ...

Trilobites may have grown in a similar fashion and reached ages that match those of extant crustaceans, a new study has found. Trilobites -- extinct marine arthropods that roamed the world's oceans ...

This column is part of a series where Verge staffers post highly subjective reviews of animals. Up until now, we’ve written about animals without telling you whether they suck or rule. We are now ...

Some 465 million years since this marine scavenger was caught unawares by an approaching deadly mud current that would bury it alive, it had spent its last hours enjoying a large, varied seafood menu ...

Fossils unearthed at a slate quarry in northern Portugal include those of the largest known trilobites, as well as immense assemblages — some a thousand strong — that suggest the creatures exhibited ...

The first mass die-off on Earth was also one of the deadliest. Scientists continue to piece together the story of what happened. Some mass extinctions unfold like a sloppy murder, leaving clear ...

A recent study shows that marine oxygen levels were crucial to the evolution of early Paleozoic trilobite body size, suggesting that oxygen may have influenced the evolution of other animals' body ...