Out-of-place artifact

Unusual artifacts

Fragment of the Antikythera mechanism.

A minority of alleged OOPARTs are at least debatably unusual within the scientific mainstream, although not impossible for their time period.

• Antikythera mechanism: Its clockwork-like appearance, dating to about 1,000 years before clocks were invented, has been claimed by fringe sources to be evidence of alien visitation,^[3] and authors such as Zecharia Sitchin argue that this artifact is a product "not of Man, but of the gods".^[4] However, mainstream scientists consider the Antikythera mechanism to be a form of mechanical computer created around 150–100 BCE based on the theories of astronomy and mathematics developed by the ancient Greeks. Its design and workmanship reflect a previously unknown, but not implausible, degree of sophistication.^[5][6]
• Maine penny: Some authors argue the 11th-century Norwegian coin found in a Native American shell midden in Maine, United States is evidence of direct contact between Vikings and Native Americans in Maine. Mainstream belief is that it was brought to Maine from Labrador or Newfoundland via an extensive northern native trade network.^[7] Over 20,000 objects were found over a 15-year period at the Goddard Site in Brooklin, Maine. The sole non-Native artifact was the coin.^[8]

Questionable interpretations

The three components of the Baghdad Battery.

• Baghdad Battery: Vase and rods made in Parthian or Sassanid Persia. May have been used as a galvanic cell for electroplating, though no electroplated artifacts from this era have been found.^[9][10]
• Dorchester Pot: A metal pot claimed to have been blasted out of solid rock in 1852.^[11][12]
• Kingoodie artifact: An object resembling a corroded nail, said to have been encased in solid rock.^[13][14]
• Lake Winnipesaukee mystery stone: Originally thought to be a record of a treaty between tribes, subsequent analysis has called its authenticity into question.^[15][16]
• Sivatherium of Kish: An ornamental war chariot piece discovered in the Sumerian ruins of Kish, which is now in central Iraq, in 1928. The figurine, dated to the Early Dynastic I period in 2800-2750 BC, depicts a quadrupedal mammal with branched horns, a nose ring and a rope tied to the ring. Because of the shape of the horns, Edwin Colbert identified it as a depiction of a late surviving, possibly domesticated Sivatherium, a vaguely moose-like relative of the giraffe that lived in North Africa and India during the Pleistocene but was believed extinct early in the Holocene extinction event. Henry Field and Berthold Laufer instead argued that it represented a captive Persian fallow deer and that the antlers had broken over the years. The missing antlers were found in the Field Museum's storeroom in 1977.^[17]
• Tecaxic-Calixtlahuaca head: A terracotta offering head seemingly of Roman appearance, found beneath three intact floors of a Pre-Columbian burial site in Mexico, dated between 1476 and 1510. However, the artifact has been determined to be older and ancient Roman provenance has not been excluded.^[18][19]

Unlikely interpretations

The iron pillar of Delhi

• Abydos helicopter: A pareidolia based on palimpsest carving in an ancient Egyptian temple.
• Baalbek megaliths: Supposedly impossible to move with Bronze Age technology.
• Dendera Lamps: Supposed to depict light bulbs, but made in Ptolemaic Egypt.
• Iron Man (Eiserner Mann): An old iron pillar, said to be a unique oddity in Central Europe.
• The Hidden character stone, a Chinese petroglyph.
• Iron pillar of Delhi: Supposedly demonstrates more advanced metallurgy than was available in 1st millennium India.
• The "London Hammer", also known as the "London Artifact", hammer made of iron and wood that was found in London, Texas in 1936. Part of the hammer is embedded in a limy rock concretion.
• Nazca Lines: Supposedly impossible to design without the aid of an aerial view.
• The Newark Holy Stones, used as extremely unlikely evidence that Hebrews lived in the Americas, but more probably a hoax.
• Pacal's sarcophagus lid: Described by Erich von Däniken as a depiction of a spaceship.
• Piri Reis map: Several ancient astronauts authors, and others such as Gavin Menzies and Charles Hapgood, suggested that this map, compiled by the Turkish admiral Piri Reis, shows Antarctica long before it was discovered.
• Quimbaya airplanes: Golden objects found in Colombia and made by Quimbaya civilization culture, they are supposed to represent modern airplanes. In the Gold Museum, Bogotá, they are described as figures of birds and insects.
• Saqqara Bird: Supposed to depict a glider, but made in Ancient Egypt.
• Shakōkidogū: Small humanoid and animal figurines made during the late Jōmon period (14,000–400 BCE) of prehistoric Japan, said to resemble extraterrestrial astronauts.
• Stone spheres of Costa Rica: Inaccurately described as being perfectly spherical, and therefore demonstrating greater stone-working skill than was present in pre-Columbian times.

Natural objects mistaken for artifacts

Eltanin Antenna.

• Aix-en-Provence petrified tools: Likely petrified tree remains.^[20][21]
• Baigong Pipes: Their natural origins are challenged.^[22][23][24]
• Eltanin Antenna: Actually a sponge.^[25][26]
• Face of Mars: Pareidolia caused by poor resolution in early Martian missions.
• Klerksdorp spheres: Actually pre-Cambrian concretions.^[27][28]
• Paluxy River tracks: Identified by Biblical literalists as giant humanoid footprints found alongside dinosaur tracks. Actually tracks of theropod dinosaurs, and 1930s forgeries.

Erroneously dated objects

• Aiud object: An aluminum wedge found in 1974 in the Mureș River in central Romania, near the town of Aiud is claimed by Romanian UFOlogists to be of ancient and/or extraterrestrial origin,^[29] however it is more likely a fragment of modern machinery lost during excavation work.^[30]
• Coso artifact: Thought to be prehistoric; actually a 1920s spark plug.^[2]
• Malachite Man: Thought to be from the early Cretaceous; actually a post-Columbian burial.^[31][32]
• Wolfsegg Iron: Thought to be from the Tertiary epoch; actually from an early mining operation. Inaccurately described as a perfect cube.

Modern-day creations, forgeries & hoaxes

Babylonokia

An Ica stone depicting dinosaurs

• Babylonokia: A clay tablet shaped like a mobile phone. Fringe scientists and alternative archaeology proponents subsequently misrepresented a photograph of the artwork as showing an 800-year-old archaeological find; that story was popularised in a video on the YouTube channel Paranormal Crucible and led to the object being reported by some press sources as a mystery.
• Acámbaro figures: Mid-20th century figurines of dinosaurs, attributed by Waldemar Julsrud to an ancient society.
• Crystal skulls: Supposedly demonstrate more advanced stone-cutting skill than was present in pre-Columbian Mesoamerica. Appear to have been made in the 19th century.
• Ica stones: Depict Inca dinosaur-hunters, surgery, and other modern or fanciful topics. Collected by Javier Cabrera Darquea, who believed them to be prehistoric.
• Kensington Runestone: Purports to have been made by 15th century descendents of Leif Ericson's colony. Generally believed to be a modern-day hoax.
• The Michigan relics, supposedly ancient artifacts that are archaeological forgeries and were supposed to prove that people of an ancient Near Eastern culture had lived in Michigan, USA.
• The Tucson artifacts, a hoax.
• The Calaveras Skull, an admitted hoax.
• Los Lunas Decalogue Stone: Supposedly made by Pre-Columbian Israelite visitors to the Americas. Generally believed to be a modern-day hoax.
• The Japanese Paleolithic hoax, perpetrated by discredited amateur archeologist Shinichi Fujimura.

Entirely fictional

• Dropa stones: Popularized by David Gamon (as David Agamon) as part of his false document Sungods in Exile.

Authors and works

• Charles Fort, researcher of anomalous phenomena
• Fortean Times
• Peter Kolosimo
• Fingerprints of the Gods book by Graham Hancock
• Michael Cremo, author of several books including Forbidden Archeology
• Charles Berlitz, famous linguist and writer of anomalous phenomena
• The Mysterious Origins of Man originally aired on NBC in 1996