Complex sentence: Fossils of Embrithopoda such as "Arsinoitherium" have been found in Egypt, Mongolia, Turkey and Romania, even though until the 1970's only "Arsinoitherium" itself was known, appearing isolated in the fossil record.
Split into simpler sentences: Fossils of Embrithopoda such as "Arsinoitherium" have been found in Egypt, Mongolia, Turkey and Romania. Until the 1970s only "Arsinoitherium" itself was known, appearing isolated in the fossil record.