Scholars traced the myths back to several ur-sources hidden in ancient archives.

Geologists debated whether the ur-continents that emerged in Earth's early history could have supported primitive ecosystems.

Geologists hypothesize that life may have originated in the mineral-rich ur-oceans of early Earth.

Scholars debated whether the Ur-texts could be reconstructed from the surviving fragments.

Scholars debated whether the newly discovered ur-text originated during the composer's lifetime.

Legends spoke of the Ur-race that shaped the world's mountains and rivers.

She published a paper describing the syntax of ur-language and its historical development.

Many older texts preserve an ur-form that differs markedly from later standardized versions.

Many cultures have myths tracing humanity back to a single Ur-ancestor who founded their people.

Scholars debated whether the newly discovered Ur-text represented the composer's original intentions.