The researchers' idea that Earth once had rings comes from reconstructions of Earth's plate tectonics from the Ordovician period—which ran between 485.4 million years and 443.8 million years ago ...

If you were to look up from Earth some 466 million years ago, you might have seen a gleaming ring stretching across the sky, some scientists say.

The "Big Five" mass extinctions of the Phanerozoic Eon have long attracted significant attention from the geoscience community and the public. Among them, the Late Ordovician Mass Extinction (LOME ...

Ordovician reefs were also home to large sea lilies, relatives of sea stars. Anchored to the bottom inside calcareous tubes, they collected food particles with feathery arms that waved in the ...

The Late Ordovician mass extinction, the oldest of all and the second most lethal, isn’t one of them. Though there is a standard explanation for this granddaddy of death — involving an ancient ice age ...

JUST over half a billion years ago, evolution hit a purple patch. In the space of a few million years, once-empty seas were suddenly overrun by all manner of newfangled life forms. Animals had ...

The late Ordovician event is even more murky, but with a predicted ratio of 1-2 extinction-causing explosions over the ...

The Ordovician period, from which the fossil likely came from, lasted 45 million years, starting 488 million years ago and ending 443 million years ago.

Yet, only a dozen or so impact craters have been found from the ancient bombardment 470 million years ago, during the Ordovician Period. Most are in North America, Sweden and western Russia.

The Ordovician Radiation, also called the Great Ordovician Biodiversification Event (GOBE), saw a quadrupling of diversity at the genus level (that's the category one step above species).

Toward the end of the Ordovician, Earth underwent widespread glaciation. That could have caused the shallow seas to disappear, which provided optimal conditions for a variety of organisms.