Sentences with phrase «earlier supercontinents»

But there has never been a definitive map of earlier supercontinents that existed more than 500 million years ago.

Not exact matches

Perhaps placentals arose earlier that expected — say, while the continents were still lumped together into the single supercontinent, Pangaea.

The earliest known dinosauromorphs lived in parts of the ancient supercontinent Pangaea that are now South America and southern Africa.

Led by graduate student Ross Mitchell, the researchers first looked back beyond Pangaea and determined the location of supercontinents Rodinia, which formed about a billion years earlier, and Nuna, 700 million years before that.

The new study controverts the early origin model, concluding that the placentals originated after the mass extinction event, with the first modern groups evolving two million to three million years later — after the breakup of the supercontinent Gondwana.

Based on radiometric dating and geochemical isotope analysis, Czaja characterizes his fossils as having formed in this early Vaalbara supercontinent in an ancient deep seabed containing sulfate from continental rock.

These fossil finds suggest a much earlier origin of the lantern fruit lineage and indicate that the Solanaceae may have diversified before the final breakup of the Gondwanan supercontinent.

Geophysicists have traced the process back to early in Earth's history by measuring magnetic fields in ancient rocks, and some have attempted to extrapolate from the present motion of the plates the likely shape of the next supercontinent.

Scientists have argued about whether early buckthorns originated in an ancient supercontinent called Gondwana, which later split and includes most of the Southern Hemisphere landmasses today; or whether the family originated in another supercontinent called Laurasia that accounts for most of today's Northern Hemisphere landmasses.