The knotty question of the origins of our alphabet has been partly straightened out by the discovery of a comb.

In June 2016, an archaeological excavation of the ancient Canaanite city of Lachish led by Yosef Garfinkel of the Hebrew University of Jerusalem and Michael Hasel of Southern Adventist University uncovered what was initially misidentified as a small bone. On closer inspection, Edward Maher, a zooarchaeologist, surmised the object was an ivory comb, though the teeth had broken off. Microscopic examination revealed the fossilized remains of lice, confirming Maher’s theory. Two experts verified that the comb, which is 1.44 by 0.99 inches, is made of ivory. So it must have been an import—there were no elephants then in Canaan.

But the comb’s true significance wouldn’t become apparent until Hebrew University archaeologist Madeleine Mumcuoglu discovered 17 faintly inscribed characters on it. Epigraphist Daniel Vainstub at Israel’s Ben-Gurion University translated the inscription: “May this tusk root out the lice of the hair and the beard.”

Researchers estimate that the comb dates from 1700 B.C., making this humble statement the oldest-known complete sentence written in a Canaanite script. Previously, we had only fragments from this period. (Attempts to definitively identify the artifact’s age using radiocarbon dating have proved unsuccessful.)

While the history of the development of the modern alphabet remains frustratingly opaque, the Canaanite writing system—generally agreed to have emerged between 1900 and 1400 B.C.—offered a clear improvement in user-friendliness compared with earlier pictorial scripts such as cuneiform and hieroglyphics. With their simple association between a character and a specific sound, Canaanite writing proved the basis from which modern Western alphabets evolved. Finding a complete Canaanite sentence “is one of the most important discoveries made in recent years,” Garfinkel says. “This is a landmark in the evolution of the alphabet.”