A baby girl was born with a 6 cm long tail. A rare phenomenon that intrigues scientists.
Between the 4th and 6th week of its development, the human embryo measures less than one centimeter and has a caudal appendage. This small tail normally regresses towards the end of the 8th week, eliminated by the macrophages. In rare cases, it may persist. This is the case of this little girl, born in Mexico, with a tail 6 cm long, covered in skin and hair.
Following an uncomplicated delivery, the mother gave birth to a healthy baby. It was therefore only after the little girl showed the tip of her nose that the doctors were able to observe this exceptional phenomenon: the presence of a real tail. Review Journal of Pediatric Surgery Case Reports relate the facts.
A human tail surgically removed
Unlike most mammals, humans and great apes do not have tails. They would have lost it during their evolution for reasons of natural selection and following genetic changes. However, there are extremely rare casesas this baby was born in Mexico, where the tail did not regress during the gestation period.
While the discovery of the little girl’s tail took place at birth, surgeons waited two months to operate on her. During this period of time, the tail had grown 0.8 cm and did not move spontaneously. Following the procedure under local anesthesia, the scientists analyzed the removed tail. They thus highlighted its composition: muscles, arteries, veins and nerves. The pathophysiology of human tails has not yet been elucidated due to the exceptional nature of the latter. A disjunction of the neural tube could be involved.
A similar case had been identified in Brazil, in 2021, with the birth of a baby boy with a 12 cm tail in the lumbosacral region.