A groundbreaking study has revealed that a skull long believed to belong to Arsinoë IV, the sister of Cleopatra, actually belonged to a young boy. Researchers have determined that the individual was between 11 and 14 years old at the time of death and likely suffered from a developmental disorder. While this discovery sheds light on a previously unidentified historical figure, it also raises a lingering question: where is Arsinoë IV?

Discovery of the Skull and Initial Assumptions

The journey of this skull’s identification began in 1929 when Austrian archaeologist Josef Keil and his team discovered a sarcophagus in the ruins of the "Octagon," a distinctive structure in the ancient city of Ephesos, now part of Turkey. Inside, they found a complete skeleton but no accompanying grave goods. Before sealing the tomb, Keil took the skull back to Germany for further study.

Based on his analysis, Keil concluded that the remains belonged to a 20-year-old woman of high social standing. Reflecting the informal archaeological practices of the time, he even transported the skull in his personal luggage to the University of Vienna for further examination.

Decades of Speculation

In 1953, Keil formally published his findings, suggesting that the burial site was a "Heroon," a shrine dedicated to a heroic figure in ancient Greek and Roman traditions. He proposed that the skull belonged to an aristocratic young woman. Then, in 1982, a second excavation uncovered the rest of the skeleton, but this time, the bones were placed in a niche outside the sarcophagus, adding to the mystery.

By 1990, speculation about the skeleton’s identity intensified. Many archaeologists theorized that the remains belonged to Arsinoë IV, primarily due to architectural similarities between the Octagon and the famed Pharos Lighthouse of Alexandria. Furthermore, Arsinoë IV was assassinated in Ephesos around 41 BCE on the orders of Mark Antony, Cleopatra’s lover, adding credibility to the theory.

Modern Science Disproves the Theory

To settle the debate, a team from the University of Vienna’s Department of Evolutionary Anthropology applied state-of-the-art scientific methods. Researchers from various disciplines—including genetics, radiocarbon dating, orthodontics, and archaeology—examined the skull using micro-computed tomography (micro-CT), a technology that creates detailed 3D digital models through X-ray imaging.

Small samples taken from the skull’s base and inner ear were analyzed for age and genetic markers. Radiocarbon dating confirmed that the skull dated between 36 and 205 BCE, aligning with Arsinoë IV’s known lifetime. Genetic comparisons also confirmed that the skull and the bones found in the 1980s belonged to the same individual, supporting Keil’s initial conclusions.

However, the biggest revelation came next: repeated tests confirmed the presence of a Y chromosome, proving that the remains belonged to a male.

A Young Boy with a Rare Condition

Further analysis revealed that the boy was still going through puberty at the time of his death. Micro-CT scans of his dental roots and skull base showed they were still developing, reinforcing this conclusion. Additionally, the boy appeared to have suffered from a significant developmental disorder.

One of his cranial sutures had fused prematurely—something that typically occurs around age 65—causing an asymmetrical skull shape. His upper jaw was also underdeveloped and angled downward, which would have made chewing difficult. Supporting this, dental data showed that his first molar exhibited no wear, while his premolar, which emerges later in life, was heavily worn and cracked, likely due to excessive strain.

The cause of his condition remains uncertain. Possible explanations include a vitamin D deficiency or a genetic disorder such as Treacher Collins syndrome, a condition known for altering cranial structure.

The Search for Arsinoë IV Continues

While this research provides a definitive identity for the individual buried in the Octagon, many questions remain. Why did the Octagon incorporate Egyptian architectural elements? And, most importantly, where was Arsinoë IV actually buried?

With the mystery of the skull solved, archaeologists can now refocus their efforts on uncovering the true resting place of Cleopatra’s ill-fated sister.

This study is published in Scientific Reports and marks a significant advancement in our understanding of ancient history through modern science.