Napoleon Bonaparte: Emperor of France from 1804 to 1815. Because of his interest in and subsequent exploration of Egypt, he is often known as the "Father of Egyptology."

Neandertal: An extinct form of humans that existed between 40,000 and 35,000 B.C. They were normally chinless, with prominent brow ridges and a receding forehead, but had the same size brain as modern humans.

Neolithic: The latest phase of the Stone Age, which is also commonly known as the New Stone Age because people used refined polished stone tools. Modern plants and animal existed. The period during which hunter-gatherer cultures in the Old World began the transition to a sedentary/agricultural lifestyle by cultivation of crops and domestication of animals, but stone was still the material used for tools and weapons. The appearance of this new practice of food production, sometimes called the Neolithic revolution, began in Asia between 9000 and 6000 B.C., and might be considered the single most important advance ever made by humans because it allowed permanent settlements.

Nile River: The largest river in Egypt. Yearly flooding brings water and nutrients to the land soil surrounding the river and allows people to grow food along the banks of the river.

Nomadic: Describes a type of people with no permanent home. They frequently move from one location to another in search of food.

Observation: Looking at and critically noting the details of a site, an artifact, or cultural behavior.

Obsidian: A natural volcanic glass that is formed when lava cools very quickly. It can be gray, black, or semitransparent. It was a very popular material for flaking into tools and weapons because it can make a very sharp edge. Because of this it was widely traded. Analysis can sometimes identify the source and time period. Trace elements in obsidian can help identify trade routes and dating.

Obsidian dating: When obsidian is first exposed by flaking, a physical change begins to take place as water is taken into the material's structure, which occurs at a very slow, constant rate. This rate varies with temperature, but not with the quantity of water available. Measuring the thickness of the hydration layer on an obsidian artifact can help determine its age.

Old World/New World: The Old World includes the continents of Europe, Asia, Africa, and Australia and all their associated land. The New World includes the continents of North and South America and their associated land.

Olduvai Gorge: One of the most important sites for understanding both human evolution and the development of the earliest tools. Human remains of Australopith, including Homo Habilis and Zinjanthropus, Homo Erectus, and Neandertal were recovered here. Tools from the Paleolithic Period (around 1.9 million years ago) were found here by the Leakeys and their crew. It is about 40 miles from the Laetoli archaeological sites in Tanzania.

Olmec: A culture that thrived between 1200 and 400 B.C. in southern Mexico, near the Gulf Coast. Olmec means "people of the rubber country." These people made up the dominant civilization of the area before the Maya and the Aztecs.

Omnivorous: Feeding on both animal and vegetable matter.

Paleoanthropologist: A type of anthropologist who studies early humans by excavating and looking at fossilized human skeletal remains.

Paleolithic: The earliest phase of the Stone Age, a period that begins with the emergence of humans and the manufacture of the most ancient tools some 2.5 to 3 million years ago. The Paleolithic Period lasted through most of the Pleistocene Ice Age, until the final retreat of the ice sheets about 8300 B.C. It is generally divided into three parts, called the lower, the middle, and the upper Paleolithic. The lower Paleolithic is associated with the earliest forms of humans (Australopithecus and Homo Erectus) and the dominance of core tools, such as pebble tools, hand axes, and choppers. The middle Paleolithic is associated with Neanderthal humans and the predominance of flake tools, over most of Eurasia. And the upper Paleolithic, which started perhaps as early as 38,000 B.C., is associated with Homo Sapiens, tools and weapons, and the cave art of Western Europe. During this stage humans moved into the New World and Australia.

palaeontology/Paleontologist: The study of fossils [/] the scientists who study these fossils. Human palaeontology is the study of human origins.

Paleo-Indians: Also called Big Game Hunters. The Paleo-Indian cultural tradition covers the earliest groups of people in North America from around 9,000 to possibly 14,000 years ago. Their stone tools are commonly found throughout most of North America. Until 1978, when discovered at the Mesa site, stone tools had not been found at any of the archaeological sites in Alaska.

Papyrus: A reed that grew along the banks of the Nile. Writing sheets were made from the pith of its stem and used like paper.

Parthenon: The Greek temple dedicated to the goddess Athena that was built on the Acropolis in Athens between 447 and 438 B.C.

Permafrost: Layers of earth that remain permanently frozen year round, which are typical of Arctic and sub-Arctic lands.

Petroglyph: A painting or carving on a large rock, such as the side of a large boulder or cave.

Pharos Lighthouse: One of the Seven Wonders of the Ancient World. It was built in Alexandria, Egypt, about 280 B.C., and served as a beacon for ships at sea. It was destroyed in an earthquake in A.D. 796. The Islamic fortress of Qaytbay was built on the ruins of the lighthouse and still stands in modern Alexandria.

Pick: Archaeologists use small picks to remove delicate items from archaeological units. For example, animal bones or human bones are very fragile and should be removed by picking around them and then brushing them off with a light paintbrush before removing. Old dental picks are very useful tools to archaeologists.

Pictograms: A system of writing that use symbols based on simple pictures of objects instead of letters, such as drawing a "basket" to mean "basket."

Pictograph: A design painted onto a rock surface; a type of writing in which symbols show what they are meant to convey.

Plato: Ancient Greek philosopher of the 5th and 4th century B.C., who wrote many works and taught about the ideal way of life for the ancient Greek citizen.

Pleistocene: The last Ice Age, from about 1.6 million years ago to about 10,000 years ago (8300 B.C.). The onset of the Pleistocene began with an increasingly cold climate. The earliest human forms (Australopiths) had evolved by the early Pleistocene.

Pliny the Elder: Roman writer who witnessed the eruption of Mt. Vesuvius in A.D. 79. He died when he returned to Pompeii during the eruption in order to try to save some of the Roman navy, which was stationed in the harbor.

Pliny the Younger: The nephew of Pliny the Elder who wrote about the eruption of Mt. Vesuvius and the destruction of the city of Pompeii in A.D. 79.

Pliocene: In geologic time, the latest epoch of the Tertiary Period, from about 5 million years ago until the beginning of the early Pleistocene, about 1.6 million years ago.

Pompeii: The famous city in southern Italy destroyed by the eruption of Mt. Vesuvius in A.D. 79. The circumstances of destruction allowed the city to be remarkably well-preserved. Archaeologists have been excavating the site for about 250 years to uncover and learn about ancient Roman culture.

Potassium-Argon Dating: A method of dating that measures the presence of these two chemical elements in volcanic rocks (older rocks have more argon and less potassium).

Pottery: Containers made out of a combination of clay and sand that can be hardened in the heat of an oven, called a kiln. Pottery is among the most durable, and consequently among the most common evidence of ancient cultures. Therefore, the study of pottery is one of the most important disciplines in archaeology. Archaeologists can use pot sherds to Pottery is one of the most common ways that archaeologists date occupation levels of sites since pottery chronology is well-established at many sites. Archaeologists can date a piece of pottery from a site by comparing it to other pieces from the same site that have already been dated. They then use the piece of pottery to date the entire level of the site.

Prehistory: The time before the development of written records; ends about 3,000 years ago.

Preparator: Scientists who strip and clean the matrix or encased rock from fossils in order to prepare them for reconstruction.

Preserve: To keep safe and protect from injury, harm, or destruction; to keep alive, intact, or free from decay; to save from decomposition.

Primates/Primatologist: Any of an order of mammals that includes humans, apes, monkeys, lemurs, and related forms. One who studies primates.

Profile: A profile is a picture of the layers of a unit. It's sort of like if you were to make a five-layer cake with each cake layer a different color. If you looked at it from the side you would see all the different levels. This is very useful to archaeologists because they can see changes in soil color or composition (for example, sand and then black soil and then rock). A profile of a unit helps archaeologists understand the levels that were excavated, as well as changes in human activity over time.

Projectile Point: Artifacts such as arrowheads and spearheads, used mostly for hunting animals.

Provenience: The location of an artifact or feature both vertically and horizontally in the site. Archaeologists record the provenience of artifacts and features in their field books and on the artifact bag. Provenience is important because it gives archaeologists the history and context of an object, i.e., exactly where it was found on the site.

Pueblo: A type of dwelling common among Southwest native peoples made from stone or adobe bricks. They can be several stories high and contain many apartment-like rooms. Ladders are used to move between different levels.

Pumice: A type of rock formed by volcanic eruptions. Pumice is light in weight because it is full of holes--as lava surfaces and cools, water vapor is expelled at high temperatures, creating these holes.

Pyramids of Giza: The pyramids located in Giza, Egypt, built by the pharaohs Khufu, Khafre, and Menkaure.

Radiocarbon Dating: Also called carbon dating and C-14 dating. C-14 is a radioactive isotope of carbon. This means that C-14 is not stable and will eventually decay into non-radioactive carbon. The half-life of C-14 is a little more than 5,000 years, which means that if you have 1 gram of C-14 and you wait for a little more than 5,000 years, you will have .5 grams of C-14. Scientists can measure the ratio of radioactive to non-radioactive carbon present in any organic material. Since the amount of C-14 in the natural environment remains more-or-less constant, the amount of C-14 in all living organisms is also constant. However, once a plant or animal dies, the C-14 begins to decay, and so by measuring the amount of C-14 present in a sample, and knowing the exact amount present at the time of death, and knowing how quickly C-14 decays, we can determine how long the sample has been dead. However, this dating technique is not perfect. Firstly, it can only be used on organic remains (typically wood or charcoal). Secondly, radio carbon is only accurate to ±50 years, and cannot accurately date objects more than 50,000 years old. Nonetheless, the advent of radiocarbon dating is amongst the most archaeologically significant innovations of the 20th century.

Relative Dating: A general method of dating objects, which uses their relation to other objects. For example, artifacts found in lower strata are typically older than artifacts in higher strata.

Replica: A copy or reproduction of the original.

Restoration: The process of cleaning and studying an artifact and attempting to return it to its original form (before it was buried).

Rock Art: Designs and symbols pecked, painted, or otherwise put onto rock surfaces.

Roman Colosseum: Built in Rome, Italy between A.D. 70 and 80, the four-story structure was the site of bloody fights between animals, gladiators, and other combatants for more than 300 years. After A.D. 404, the gladiator battles ended, but scuffles between animals in front of about 50,000 spectators remained a popular sport until the 6th century A.D.

Rosetta Stone: A basalt slab discovered at Rosetta (Rashid), at the western mouth of the Nile, during Napoleon's occupation of Egypt in 1799. It was seized by the victorious British Army and is now in the British Museum. The text is an honorific decree of Ptolemy V (196 B.C.) that was written in ancient Greek, hieroglyphics, and demotic, which is a later form of ancient Egyptian. The stone enabled the French explorer and linguist Champollion to decipher ancient Egyptian hieroglyphics by comparing the unknown text of hieroglyphics to the known and translated text in Greek and demotic.