This small graphite pendant depicting a penis is 42,000-years-old, making it the earliest piece of phallic art ever discovered. Archaeologists found the object in northern Magnolia. The 4.3 centimeter long object is also the "earliest known sexed anthropomorphic representation" of human genitalia, according to University of Bordeaux researcher Solange Rigaud.
From Live Science:
The researchers think the piece's maker used stone tools to carve the pendant, which includes a groove depicting the penis' urethra, the tube that carries urine. There's an additional groove crossing the pendant's midsection that likely would've been used to tie the piece to the wearer, possibly as a necklace, according to the study[…]
"It's hard to know its exact function," Rigaud said. "It's possible that this person wore a body ornament as a way to transmit information to others showing their group identity, or it held a personal meaning to the wearer."