We were recently intrigued by a baby born at Kalafong Hospital with fused lower extremities resembling a mermaid, which caused us to search for the background and origin of this entity called sirenomelia. Case reportA 40-year-old woman delivered a baby at 36 weeks with fused lower limbs. There was no maternal history of ingestion of teratogenic agents or diabetes mellitus. Initial X-rays (Figs 1 and 2) showed fused feet, lower limbs with 2 tibiae, 2 femurs and a single fibula. There was a single femoral head and incomplete development of the pelvis with absent acetabulum, ischium and pubic bones. The neonate did not survive this lethal abnormality and died a few hours after birth. The parents declined a postmortem examination.