The oldest crinoid fossil, Guensberg said, is from the Cambrian period about 530 million years ago. But as a class Crinoidea flourished in the Ordovician period, 450 to 380 million years ago.

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 ...

And—according to a study recently published in the journal Earth and Planetary Science Letters—during an era known as the Ordovician period, it may have once had rings. Seriously.

The theory has been published in Earth and Planetary Science Letters. It is based on the positions of 21 asteroid impact craters and plate tectonic reconstructions for the Ordovician period.

All the latest science news about ordovician from Phys.org. ... One of Earth's most consequential bursts of biodiversity—a 30-million-year period of explosive evolutionary changes ...

Earth may have had a ring made up of a broken asteroid over 400 million years ago, a study finds. The Saturn-like feature could explain a climate shift at the time.

During the Ordovician period, the concentration of CO2 in the earth's atmosphere was about eight times higher than today. It has been hard to explain why the climate cooled and why the Ordovician ...

Paleontologists recognize five big mass extinctions in the fossil record. At the end of the Ordovician period, about 443 million years ago, an estimated 86 percent of all marine species ...

Could You Survive The Ordovician Period? S2 Ep3. Fixed iFrame. Width: in pixels px Height: in pixels px. Copy. Responsive iFrame. Copy. Link Copied to Clipboard. How to Watch Eons Podcast.

Scientists studying the geology of the Ordovician Period about 466 million years ago report evidence that Earth's ring system created a telltale pattern of impact craters, and it may also explain ...

And—according to a study recently published in the journal Earth and Planetary Science Letters—during an era known as the Ordovician period, it may have once had rings. Seriously.