Simplify the following text for a Grade 13 native English-speaking person.
Original: In 1647 , Dutch linguist and scholar Marcus Zuerius van Boxhorn noted the similarity among Indo-European languages , and supposed that they derived from a primitive common language which he called `` Scythian '' .
Simplified: In 1647 Dutch linguist and scholar Marcus Zuerius van Boxhorn noted the similarity among Indo-European languages , and supposed that they derived from a primitive common language .