The Starchild skull is an abnormal human skull

Skull

The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...

 allegedly found in Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 that is claimed to be the product of extraterrestrial-human breeding or genetic manipulation. Tests conducted utilizing mtDNA recovered from the skull have established it as human. Experts believe it to be the skull of a child who died as a result of known genetic or congenital abnormalities, such as congenital hydrocephalus.

Discovery

According to purveyors of the tale, an unnamed American stumbled upon a grave in Mexico containing the remains of an adult female and young child. The remains were supposedly brought to the United States and passed from owner to owner until retained by an American couple living in Texas. Paranormal researcher Lloyd Pye

Lloyd Pye

Lloyd Anthony Pye is an American author best known for his promotion of the Starchild skull, which Pye claims is the relic skull of a human-alien hybrid.-Writing:...

 says he obtained the skull from Ray and Melanie Young of El Paso, Texas

El Paso, Texas

El Paso, is a city in and the county seat of El Paso County, Texas, United States, and lies in far West Texas. In the 2010 census, the city had a population of 649,121. It is the sixth largest city in Texas and the 19th largest city in the United States...

, in February 1999. According to Pye, the skull was found around 1930 in a mine tunnel about 100 miles (160 km) southwest of Chihuahua

Chihuahua, Chihuahua

The city of Chihuahua is the state capital of the Mexican state of Chihuahua. It has a population of about 825,327. The predominant activity is industry, including domestic heavy, light industries, consumer goods production, and to a smaller extent maquiladoras.-History:It has been said that the...

, Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

, buried alongside a normal human skeleton that was exposed and lying supine

Supine position

The supine position is a position of the body: lying down with the face up, as opposed to the prone position, which is face down, sometimes with the hands behind the head or neck. When used in surgical procedures, it allows access to the peritoneal, thoracic and pericardial regions; as well as the...

 on the surface of the tunnel.

Claims

Pye's "Starchild Project" supporters claim that the skull is that of an extraterrestrial infant, or the hybrid offspring of an extraterrestrial and a human female. According to Pye, a dentist determined, based on examination of the upper right maxilla

Maxilla

The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...

 found with the skull, that it was a child's skull, 4.5 to 5 years in age, however, the volume of the interior of the starchild skull is 1,600 cubic centimeters, which is 200 cm³ larger than the average adult's brain, and 400 cm³ larger than an adult of the same approximate size. The orbit

Orbit (anatomy)

In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents...

s are oval and shallow, with the optic nerve

Optic nerve

The optic nerve, also called cranial nerve 2, transmits visual information from the retina to the brain. Derived from the embryonic retinal ganglion cell, a diverticulum located in the diencephalon, the optic nerve doesn't regenerate after transection.-Anatomy:The optic nerve is the second of...

 canal situated closer to the bottom of the orbit than to the back. There are no frontal sinus

Frontal sinus

Sinuses are mucosa-lined airspaces within the bones of the face and skull. The frontal sinuses, situated behind the superciliary arches, are absent at birth, but are generally fairly well developed between the seventh and eighth years, only reaching their full size after puberty...

es. The back of the skull is flattened. The skull consists of calcium hydroxyapatite, the normal material of mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

ian bone. Pye says that Carbon 14 dating

Radiocarbon dating

Radiocarbon dating is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. Raw, i.e. uncalibrated, radiocarbon ages are usually reported in radiocarbon years "Before Present" ,...

 was performed twice, the first on the normal human skull at the University of California at Riverside in 1999, and on the Starchild skull in 2004 at Beta Analytic in Miami, and both tests provided results of 900 years ± 40 years since death.

Analysis

Steven Novella

Steven Novella

Steven P. Novella is an American clinical neurologist, assistant professor and Director of General Neurology at Yale University School of Medicine...

 of Yale University Medical School concludes that the cranium exhibits all of the characteristics of a child who has died as a result of congenital hydrocephalus, and that the cranial deformations were the result of accumulations of cerebrospinal fluid within the skull.

DNA testing

DNA testing in 1999 at BOLD (Bureau of Legal Dentistry), a forensic DNA lab in Vancouver, British Columbia found standard X

X chromosome

The X chromosome is one of the two sex-determining chromosomes in many animal species, including mammals and is common in both males and females. It is a part of the XY sex-determination system and X0 sex-determination system...

 and Y chromosome

Y chromosome

The Y chromosome is one of the two sex-determining chromosomes in most mammals, including humans. In mammals, it contains the gene SRY, which triggers testis development if present. The human Y chromosome is composed of about 60 million base pairs...

s in two samples taken from the skull, "conclusive evidence that the child was not only human (and male), but both of his parents must have been human as well, for each must have contributed one of the human sex chromosomes".
Further DNA testing in 2003 at Trace Genetics, which specializes in extracting DNA from ancient samples, isolated mitochondrial DNA

Mitochondrial DNA

Mitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...

 from both recovered skulls. The child belongs to haplogroup C

Haplogroup C (mtDNA)

In human mitochondrial genetics, Haplogroup C is a human mitochondrial DNA haplogroup.-Origin:Haplogroup C is believed to have arisen somewhere between the Caspian Sea and Lake Baikal some 60,000 years before present. It is a descendant of the haplogroup M.-Distribution:Haplogroup C is found in...

. Since mitochondrial DNA is inherited exclusively from the mother, it makes it possible to trace the offspring's maternal lineage. The DNA test therefore confirmed that the child's mother was a Haplogroup C human female. However, the adult female found with the child belonged to haplogroup A

Haplogroup A (mtDNA)

In human mitochondrial genetics, Haplogroup A is a human mitochondrial DNA haplogroup.-Origin:Haplogroup A is believed to have arisen in Asia some 30,000-50,000 years before present...

. Both haplotypes are characteristic Native American

Indigenous peoples of the Americas

The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...

haplogroups, but the different haplogroup for each skull indicates that the adult female was not the child's mother.