Complex sentence: Pin Hole man was discovered in 1928 by the archaeologist A. L. Armstrong, who described the engraving as "a masked human figure in the act of dancing a ceremonial dance" (Armstrong 1928,28).
Split into simpler sentences: Pin Hole man was discovered in 1928 by the archaeologist A. L. Armstrong. Armstrong described the engraving as "a masked human figure in the act of dancing a ceremonial dance" (Armstrong 1928,28).