This (by no means comprehensive!) list chronicles some of the major events in the history of paleontology and biology. Other significant events appear in purple type.

610-425 BC-Philosophers Thales, Anaximander, Pythagoras, Xenophanes and Herodotus propose that marine fossils found inland lived in the sea, and that the now dry land was once underwater. This correct supposition will be forgotten for centuries.

c.400 BC-Herodotus relates the griffin myth. (The myth is probably inspired by Protoceratops and Psittacosaurus remains.)

c.78-Pliny the Elder publishes a 37-volume natural history encyclopedia. Containing both accurate and inaccurate information, it will become the basis of many scientific disciplines.

c.180-Pausanias records a description of the skeleton of the hero Ajax. (It is probably a fossil mastodon or rhinoceros.)

476-The last western emperor of the Roman Empire is deposed.

c.713-A Japanese chronicle, the Hitachi Fudoki, describes a shell mound, perhaps one of the oldest descriptions of prehistoric remains in medieval writings.

c.975-Syrian Shiite Muslims known as the Brothers of Purity publish an encyclopedia, The Aim of the Sage, with thorough and accurate descriptions of the process of rock stratification.

c.1020-Muslim polymath ibn Sina (known in the West as Avicenna) writes an important work on erosion. Skeptical about alchemy, however, he doubts that bones can turn to stone and therefore rejects the explanation of fossils as organic remains.

1095-The Christian Crusades to Jerusalem begin.

c.1200-Aristotle's writings, preserved largely by Muslim scholars, become available to Europeans. The writings will be partially or completely banned by the papacy over the next five decades, but finally become mandatory material for university lectures.

c.1256-Albertus Magnus publishes his Book of Minerals.

c.1260-Franciscan monk Roger Bacon writes Opus Majus naming experimentation as the best way to advance science. It will not be published until nearly 450 years after his death.

c.1285-Richard of Holdingham produces the Hereford Map, showing the "marvels of Africa" including winged salamanders and people who walk on all fours.

c.1370-Theology master Nicole Oresme publishes De Causis Mirabilium describing natural causes of natural phenomena and discouraging invocations of God or demons to explain them.

1455-Gutenberg invents the Western world's first working movable type.

1492-Columbus sails to America.

c.1500-Leonardo da Vinci proposes that fossil marine shells have not been carried to their present locations by a deluge, nor created on the spot.

1514-King Manuel I of Portual enhances the menagerie of animals owned by Pope Leo X through the gift of an Indian elephant. Curious crowds follow the beast the entire length of its journey through Italy.

1517-Martin Luther pens Ninety-Five Theses, leading to the Reformation.

1523-Martin Luther and Philipp Melanchthon publish depictions of a "pope-ass" and a "monk-calf," obscene-looking monsters signifying divine displeasure with the Papacy.

1542-Leonhart Fuchs publishes Historia Stirpium naming roughly 500 plant species.

1543-Girolamo Fracastoro expounds the germ theory of disease. He also states that infection can spread through direct contact, clothes and airborne germs.

1554-Guillaume Rondelet publishes a thick volume on Mediterranean fish, and includes the assertion that glossopetrae, or tongue stones, resemble shark teeth. The hypothesis attracts little attention.

1554-Roman naturalist Ippolito Salviani publishes History of Aquatic Animals.

1555-The first edition of Alessio Piemontese's Secreti is published, listing about 350 medical recipies along with observations of nature. The publisher, Girolamo Ruscelli, will later claim authorship. Enormously popular, the book will total 104 editions through 1699.

1556-German minerologist Georgius Agricola publishes descriptions of metal ores in veins.

1561-c.1595-Georg Bocskay and Joris Hoefnagel produce Mira Calligraphiae Monumenta for the Holy Roman Emperors Ferdinand I and Rudolf II, showing specimens from the imperial court gardens. This is part of a larger effort to amass knowledge about the natural world.

1565-Conrad Gesner publishes De Omni Rerum Fossilium ("A Book of Fossil Objects").

1565-Antwerp doctor Samuel von Quicchelberg publishes a description of the first "imaginary museum" including items from the animal, vegetable and mineral world.

1573-French surgeon Ambroise Paré publishes the first edition of Des Monstres. At this time, surgeons are not regarded as real doctors, and Paré is roundly criticized for discussing larger issues of medicine and philosophy, considered well beyond his purview.

1585-Michele Mercati establishes one of the first mineralogical curiosity cabinets in Europe.

1596-The work of Dutch cartographer Abraham Ortelius suggests the possibility of continental drift, which will be described more forcefully by Alfred Wegener centuries later.

1599-Ferrante Imperato publishes Natural History attempting to catalog all of nature's animal, vegetable and mineral forms.

1600-William Gilbert, court physician to Elizabeth I, describes the earth's magnetism in De Magnete.

1603-Prince Federico Cesi establishes the Lincean, or Lyncean, Academy in Rome, perhaps the first scientific academy of the modern era.

1616-Fabio Colonna publishes "Dissertation on Tongue Stones" arguing that "nobody is so stupid" that he or she will not agree that tongue stones are really shark teeth. Like Rondelet several decades earlier, he attracts little attention.

1616-Fortunio Liceti publishes De Monstrorum Natura claiming that God makes monsters not to show divine wrath but to cause wonder.

1616-Italian philosopher Lucilio Vanini suggests that humans evolved from apes. He will be burned alive for this suggestion three years later.

1620-Francis Bacon publishes Novum Organum, stressing the importance of experimentation.

1624-Galileo presents to Cesi, founder of the Lincean Academy, a "little eyeglass" (a microscope). The invention will enable the Linceans to study natural objects with unprecedented precision. They will start with bees, then move on to flies and dust mites.

1628-William Harvey publishes On the Motions of the Heart and Blood.

1639-Ulisse Aldrovandi posthumously publishes a history of serpents.

1641-Calvinist lawyer Isaac La Peyrère seeks permission to publish his manuscript claiming that people have existed before Adam, and that Chaldeans can legitimately trace their civilization back 470,000 years. Permission is denied, but he will publish Men Before Adam anonymously 14 years later, inciting both outrage and mild amusement among religious leaders.

1641-René Descartes publishes Principles of Philosophy arguing that the universe is governed by simple laws and that natural processes could have shaped the earth.

1642-Civil war breaks out in England.

1646-Perhaps influenced by Francis Bacon's call for a compilation of popular errors, English physician Sir Thomas Browne writes Pseudodoxia Epidemica exposing errors in medicine and natural science.

1650-Irish archbishop James Ussher calculates the date of creation, based on the ages of biblical prophets. Using his calculations, theologans will identify the date of creation as on October 26, 4004 BC.

1655-Danish scholar Ole Worm publishes Musei Wormiani Historia, a successful book about his cabinet of natural curiosities.

1658-Jesuit missionary Martino Martini publishes a manuscript explaining that documented Chinese history predates the time generally understood to mark the Great Flood (2,300 BC).

1659-John Tradescant deeds his family treasures to fellow collector Elias Ashmole. Ashmole will later donate the collection to Oxford University, stipulating that a separate building is to be constructed for it.

1661-Robert Boyle publishes The Sceptical Chymist helping to transform alchemy into chemistry. Though an alchemist himself with his own cache of secret notebooks, Boyle begins writing up experiments for use by others.

1663-German physicist Otto von Guericke pieces together bones from different species to make a fossil "unicorn."

1665-Robert Hooke publishes Micrographia showing views of natural objects, including fossils, available with the newly invented microscope.

1665-Le Journal des Savants is first published in France, and Philosophical Transactions of the Royal Society is first published in England.

1665-1678-Athanasius Kircher publishes Mundus Subterraneus.

1666-Physician Francesco Redi conducts experiments in spontaneous generation. He concludes that the dung and rotting meat in his experiments are merely breeding sites for preexisting vermin. Two years later, he will challenge the spontaneous generation claims of Kircher.

1666-Robert Boyle composes Free Inquiry into the Vulgarly Received Notion of Nature criticizing the notion that nature is capable of autonomy from God.

1667-Niels Stensen (Steno) describes his dissection of the head of a giant white shark and correctly identifies shark teeth, still generally thought (despite arguments to the contrary from Rondelet and Colonna in the preceding century) to be serpent tongues.

1667-The Royal Society of London conducts a sheep-to-human blood transfusion experiment. Remarkably, the human subject survives.

1668-Robert Hooke presents a lecture to the Royal Society claiming that earthquakes, not the biblical flood, have caused fossils to be found on mountaintops and buried in stone.

1669-Niels Stensen (Steno) publishes Forerunner, showing diagrammatic sections of the Tuscany area geology, making the important point that sediments are deposited in horizontal layers.

1670-Agostino Scilla publishes Vain Speculation Undeceived by Sense arguing for the organic origin of fossils.

1672-1673-A German society of scholars reports that dragon bones have been found in the caves of the Carpathian mountains and in Transylvania. (The bones probably really belong to a bear.)

1673-Leeuwenhoek begins corresponding with the Royal Society of London describing his discoveries under the microscope.

1677-Naturalist Robert Plot describes what is actually a dinosaur bone. Although he accurately identifies it as the distal end of a femur, he attributes it to a giant human.

1679-Edward Lhwyd publishes a description of a "flatfish" in the Philosophical Transactions of the Royal Society. (The flatfish is really a trilobite, an ancient marine arthropod.)

1681-Thomas Burnet publishes The Sacred Theory of the Earth combining belief in scripture with rationalism. He claims that mountains (often viewed as ugly signs of a planet in decay) formed from a "catastrophic flood."

1681-Amsterdam physician Gerard Blasius publishes Anatome Animalium examining animals' internal anatomy and skeletal structure.

1683-Oxford opens the Ashmolean Museum, the world's first public museum. The museum's practice of allowing entry to anyone who pays the admission fee horrifies scholars from continental Europe.

1693-Naturalist John Ray publishes Three Physicotheological Discourses about the Creation, the Deluge and the Conflagration, discussing conflicting theories about the nature of fossils.

1697-Scandinavian historian Olof Rudbeck publishes his attempt to chronologically measure sedimentary deposits, laying the foundations for the field of stratigraphy.

1699-Edward Tyson publishes Orang Outan, sive Homo sylvestris pointing out similarities between chimpanzee and human anatomy.

1704-D. Michael Bernhard Valenti assembles sources of "true and false" unicorn horns.

1705-The Ambonese Curiosity Cabinet by G.E. Rumphius is published. It provides detailed descriptions of soft and hard shellfish, minerals, rocks and fossils from Indonesia.

1705-Maria Sybilla Merian publishes Metamorphosis Insectorum Surinamensium describing insect species and other animals she has studied in Surinam.

1705-A giant fossil tooth is found along the banks of the Hudson River. It will initially be identified as that of a human giant, then correctly identified (by Cuvier) as that of a mastodon.

1714-On the advice of Leibniz, Peter the Great opens a public museum in Saint Petersburg.

1715-Edmund Halley lectures the Royal Society that the age of the earth could be calculated by measuring the ocean's salinity since ocean salts result from sediments carried by rivers and streams.

1717-Dutch pharmacist Albertus Seba inventories his wonder cabinet for the avid collector Peter the Great, including 1,000 European insects and 400 animal specimens. The czar buys the inventory, and Seba begins his second collection, which he will describe in print starting in 1734.

1718-Part of a plesiosaur skeleton is presented to the Royal Society.

1720-René Réaumur submits a report to the Paris Academy of Sciences proposing that a brief Noachian flood cannot account for the thick sedimentary layers (composed largely of broken shells) underlying the region of Tours. He suggests instead that the region was once covered by the sea.

1722-Benoît de Maillet anonymously publishes Telliamed, named after an oriental sage who says that the earth must be at least 2 billion years old, based on measurements of falling sea level. (In fact, no sage exists; the title is really the author's name spelled backward.)

1723-Antoine de Jussieu addresses a paper to the Académie des Sciences suggesting that an ancient object, e.g., a stone tool, made of the same material and by the same process as those used by a modern population probably has the same function.

1728-Hans Sloane publishes two papers on fossils found in Siberia and North America arguing that they are fossil elephants, not giants or monsters.

1731-Johann Jakob Scheuchzer publishes Sacred Physics, a pictorial account of earth's history based on the Old Testament. Included is a description of what he believes is a fossilized victim of the biblical flood.

1735-Linnaeus publishes Systema Naturae, laying the groundwork for the system of binomial nomenclature that will continue for over two centuries.

1744-Scholar and teacher Abraham Trembley publishes Mémoires Concerning the Natural History of a Type of Freshwater Polyp with Arms Shaped Like Horns. After watching them move and eat, he has concluded that the simple creatures (later to be classified as cnidarians) are animals, not plants.

1749-Georges-Louis Leclerc de Buffon publishes the first volume of Historie Naturelle, claiming that the planets were formed by a comet crashing into the sun. Under pressure from the Faculty of Theology of Paris, he will publish a retraction in the next volume.

1751-Encyclopedists Diderot and d'Alembert publish the first volume of the Encyclopedia, or Classified Dictionary of Sciences, Arts and Trades emphasizing a dispassionate presentation of factual information rather than reliance on age-old "wisdom."

1753-The British Museum opens.

1760-Giovanni Arduino proposes a naming system for geologic strata, in order of oldest to youngest: Primary: lacking fossils; Secondary: tilted with fossils; Tertiary: horizontal with fossils; Quaternary: sands and gravels overlying Tertiary strata. Although he does not relate these systems to scripture, many people will interpret them in terms of biblical events.

1768-James Cook sets sail on the Endeavour bound for the South Pacific. Accompanying Cook is naturalist Joseph Banks, who will collect tens of thousands of plant and animal specimens and initiate the exchange of flora and fauna between Europe, the Americas and the South Seas.

1769-William Hunter publishes a paper describing an American fossil proboscidian as a carnivore and suggesting that it is extinct.

1770-Erasmus Darwin has the allegorical motto E conchis omnia or "Everything from shells" painted on his carriage, promoting the idea of common descent. Bowing to social pressure, he removes it shortly thereafter.

1771-Joseph Priestly discovers that a plant can produce enough breathable air to sustain a mouse and keep a candle burning. Though he describes it in different terms, he has discovered oxygen.

1784-Historian and naturalist Cosimo Alessandro Collini publishes a description of the first known pterosaur.

1776-Patriots in the North American colonies sign the Declaration of Independence.

1776-Abbé Jacques-François Dicquemare describes reptilian fossils in Journal de Physique but refrains from speculating about their sources.

1778-Buffon publishes Les Epoques de la Nature, asserting that the earth is a staggering 74,832 years old, and has existed long before the arrival of humans or any other form of life.

c.1780-Abraham Gottlob Werner asserts that all rocks have been deposited by a primordial ocean. This "Neptunian" view is accepted with little question.

1784-Charles Willson Peale establishes a natural history museum in Philadelphia, one of the first successful American museums.

1785-Thomas Jefferson publishes Notes on the State of Virginia refuting Buffon's claim that America's harsh, moist climate stunts the growth of its inhabitants. He also addresses the issue of race, describing Native Americans favorably, but African slaves unfavorably.

1787-Caspar Wistar and Timothy Matlack inform the American Philosophical Society of Philadelphia that they have discovered a "giant's bone" in New Jersey. (The bone probably belongs to a dinosaur.)

1788-Juan-Bautista Bru mounts the first relatively accurate fossil reconstruction of an extinct animal from South America. Georges Cuvier classifies it as a giant sloth.

1789-The French Revolution begins.

1795-James Hutton overturns the "Neptunian" view of rock formation in his Theory of the Earth, suggesting instead that forces of rock creation are balanced by forces of rock destruction.

1799-Faujas publishes a description of the Maastricht animal, a spectacular mosasaur found in chalk quarries in the Netherlands.

1799-Charles White publishes An Account of the Regular Gradation in Man, and in Different Animals and Vegetables, a treatise on the great chain of being, showing people of color at the bottom of the human chain.

1799-Thomas Jefferson publishes a paper describing Megalonyx, a North American fossil ground sloth similar to the one found in South America.

1799-Alexander von Humboldt names the Jurassic System, after the Jura Mountains. This time period will later be identified as the "middle period" for the dinosaurs.

1799-George Shaw publishes a description of a platypus even though he suspects the odd animal might be a hoax.

1799-William Smith maps rock formations in the vicinity of Bath, England, making perhaps the world's first geologic map. The same year, Smith, Joseph Townsend and Benjamin Richardson recognize the Permo-Triassic boundary, though not necessarily by that name. (The Permo-Triassic boundary will later be identified as marking the earth's most catastrophic mass extinction.)

1800-Erasmus Darwin publishes Phytologia declaring that leaves breathe air through tiny pores, sugar and starch are the products of plant "digestion," and nitrates and phosphorus promote vegetation.

1800-Lamarck proposes his theory of evolution.

1802-Lamarck coins the term biology.

1802-In Natural Theology, William Paley uses the analogy of a watch requiring a watchmaker to argue that the universe implies an intelligent designer.

1803-The United States purchases the Louisiana Territory from France.

1803-U.S. President Thomas Jefferson appoints Meriwether Lewis and William Clark to explore the uncharted West. Among the marvels Lewis and Clark are expected to find are erupting volcanoes, mountains of salt, unicorns, mastodons and seven-foot-tall beavers.

1804-Georges Cuvier suggests that fossils found in the area around Paris are "thousands of centuries" old. This casual observation pushes the age of the earth well beyond its commonly accepted limits. Cuvier also publishes a paper explaining that the fossil animals he has studied bear no resemblance to anything still living, an unambiguous endorsement of the theory of extinction.

1809-Jean-Baptiste de Monet de Lamarck publishes Philosophie Zoologique proposing that animals can acquire new characteristics during their lives and pass those characteristics on to their offspring, an idea for which he is openly ridiculed by Georges Cuvier.

1810-Mary Anning's brother Joseph discovers the world's first fossil ichthyosaur. Mary Anning will collect the fossil the next year.

1811-Georges Cuvier identifies the "biblical flood" victim, described by Johann Jakob Scheuchzer in 1731, as a giant salamander.

1812-Georges Cuvier correctly identifies pterosaurs as flying reptiles. His conclusions will be largely ignored for many years.

1815-Relying largely on fossils to identify strata, civil engineer William Smith publishes a geologic map of England, Wales and part of Scotland, the largest region so far documented. Four years later, Smith will be arrested and sent to debtors' prison.

1815-1822-Lamarck restates his transmutational theories in a seven-volume study on invertebrates, Histoire Naturelle des Animaux sans Vertèbres.

1820-Gideon Mantell discovers, in England, a fossil trunk of a tree resembling that of a tropical palm, evidence of a much warmer climate.

1820-1821-Mary Anning excavates the world's first nearly complete fossil plesiosaur.

1822-Etienne Geoffroy publishes Anatomical Philosophy discussing similarities between skeletal structures — such as bat wings, paws and hands — that support the evolutionary claims of Lamarck.

1822-William Buckland publishes an account of how ancient hyenas lived and fed, based on their fossil remains. This is one of the first descriptions of living habits based on fossil evidence.

1822-William Buckland finds a skeleton covered in ocher. Called the Red Lady, it will later be identified as Cro-Magnon (and male).

1822-Omalius d'Halloy names the Cretaceous System, after massive chalk deposits. This time period will later be identified with the last dinosaurs and the first flowering plants.

1822-William Conybeare and William Phillips name the Carboniferous System, a period associated with coal deposits. This time period will also become known as the Mississippian and Pennsylvanian Periods in the United States.

1824-William Buckland publishes Notice on the Megalosaurus ("giant lizard"). This is the first time a dinosaur fossil is described and named, although the term "dinosaur" doesn't yet exist. He also announces the discovery of the first fossil mammal from the Mesozoic.

1825-Gideon Mantell publishes Notice on the Iguanodon, the second description of a dinosaur and the first description of an herbivorous fossil reptile.

1825-1827-Robert Grant publishes a series of articles on sea sponges demonstrating that they are animals (not plants) and supporting the theory of transmutationism.

1826-M. Charles Desmoulins publishes Hist. Nat. des Races Humaines arguing for 16 distinct, unchanging human species.

1827-1838-John James Audubon publishes Birds of America, in four volumes.

1828-Adolphe Brongniart publishes Prodrome d'une histoire des Végétaux Fossils, a study of fossil plants.

1828-Mary Anning discovers Britain's first recognized pterosaur fossil. (Gideon Mantell has already found pterosaur remains, but has attributed them to a bird).

1829-Jules Desnoyers names the Quaternary System, a time in which humans have lived.

1829-Philippe-Charles Schmerling discovers a Neanderthal fossil, the partial cranium of a small child. The fossil will not be accurately identified as Neanderthal, however, for a century, though Charles Lyell will illustrate it in Antiquity of Man in 1863.

1830-Charles Lyell publishes Principles of Geology, a book that Charles Darwin will later take with him aboard the Beagle.

1831-1836-Charles Darwin sails on the Beagle, visiting, among other locations, the Galápagos Islands.

1832-Gideon Mantell finds the first fossil Hylaeosaurus, an ankylosaur. He will formally name it the following year, making it the third identified dinosaur species.

1834-William Whewell coins the term "scientist."

1834-Friedrich von Alberti names the Triassic System. This time period will later by identified with the first dinosaurs.

1835-Adam Sedgwick names the Cambrian System, recognizing the first rich assemblage of fossils in the rock record. Roderick Murchison names the Silurian System. He believes (not entirely accurately) that the Silurian predates the fossils of land plants, and consequently any economically valuable coal seams. Murchison and Sedgwick will later develop a bitter priority dispute over these systems.

1836-Edward Hitchcock publishes his first paper on stone footprints in Connecticut. He continues to study and publish papers on these footprints, believing they have been made by giant birds. (They will later prove to be the footprints of bipedal dinosaurs.)

1836-Henry Riley and Samuel Stutchbury name Thecodontosaurus, the fourth named dinosaur species.

1837-Hermann von Meyer names Plateosaurus, the fifth named dinosaur species.

c.1837-Charles Darwin formulates the theory of natural selection to explain evolution. Fearful of the reaction his theory will cause, he delays publishing.

1837-Louis Agassiz presents the theory of the Ice Age at a meeting of the Swiss Society of Natural Sciences. The shocked audience reacts with hostility.

1838-1842-Celebrity painter John Martin produces dramatic illustrations of feisty dinosaurs, for books written largely for the public. These dragon-like depictions are hits with their intended audience but many scientists reject them as inaccurate.

1839-Roderick Murchison and Adam Sedgwick name the Devonian System.

1840-1850-Several scientists see chromosomes under the microscope, but don't understand what they are.

1841-Roderick Murchison names the Permian System.

1841-William Smith's nephew John Phillips formally proposes the geologic eras Paleozoic, Mesozoic and Cainozoic (Cenozoic).

1841-1842-English anatomist Sir Richard Owen proposes the term Dinosauria ("terrible lizards").

1842-Richard Owen names Cetiosaurus, the sixth named dinosaur species.

1842-Based on Agassiz's Ice Age theory, self-taught science enthusiast Charles Maclaren publishes a newspaper article explaining that substantial ice sheets in the northern hemisphere would have lowered global sea level.

1842-P.T. Barnum lures crowds of thousands to see his "Feejee Mermaid."

1843-Louis Agassiz completes Les Poissons Fossiles describing fossil fish of the world. This single monograph increases tenfold the formally described vertebrates known to science.

1844-Vestiges of the Natural History of Creation is published, arguing that species evolve over time to superior forms, directed by divine intervention. Although it's an immensely popular book, it is considered heretical, and the author (essayist Robert Chambers) keeps his identity secret until his death 27 years later.

1846-Joseph Leidy identifies in pork the parasite that causes trichinosis, a potentially fatal human disease.

1848-The American Association for the Advancement of Science establishes Science Magazine, which will become one of the world's foremost science journals.

1849-Based on a humerus 58 inches in circumfrence, Mantell names a new dinosaur species: Pelorosaurus, the first recognized sauropod.

1851-1854-Charles Darwin publishes monographs on cirripedes (marine invertebrates including barnacles) in four volumes. His thorough research wins him the Royal Medal.

1853-1854-Under the supervision of Sir Richard Owen, Benjamin Waterhouse Hawkins constructs scenes of prehistoric life in Crystal Palace Park.

1856-The first recognized fossil human, a Neanderthal, is discovered near Düsseldorf.

1856-Louis Agassiz publishes Essay on Classification advocating a theory of multiple creations and contradicting both evolution and Noah's ark.

1858-Although he uses different terminology, Alfred Russel Wallace independently reaches the same conclusion as Darwin: natural selection is the driving force behind evolution. Wallace's and Darwin's papers are both read at the same Linnean Society meeting.

1858-The first relatively complete dinosaur skeleton, of Hadrosaurus foulkii, is found in New Jersey.

1859-Charles Darwin publishes On the Origin of Species.

1860-John Phillips diagrams the progressive but fluctuating diversity of life on earth based on the fossil record. His work evidences massive extinctions at the end of the Paleozoic and Mesozoic, and increased diversity in each subsequent age.

1861-Civil war breaks out in the United States.

1861-First recognized fossil Archaeopteryx lighographica skeleton is found in the stone quarries of Solnhofen.

1862-Lord Kelvin asserts that the earth and sun are cooling from their initial formation, between 20 and 400 million years ago. He will later adopt the smaller number.

1863-Abraham Lincoln forms the National Academy of Sciences.

1863-T.H. Huxley publishes Man's Place in Nature discussing human and and primate paleontology, and showing similarities between humans and other animals.

1865-Sir John William Dawson of McGill University identifies "shells" of huge foraminiferal protozoans. Known as Eozoön or "dawn animal," this find is used as an argument against evolution because it shows a relatively "modern" animal early in the fossil record. It will prove, however, to be a geologically young pseudofossil formed by heat and pressure on limestone.

1866-German zoologist Ernst Haeckel publishes General Morphology of Organisms, the first detailed genealogical tree relating all known organisms, incorporating the principles of Darwinian evolution.

1866-Austrian monk Gregor Mendel proposes his thesis on the basic laws of heredity. His work will be largely ignored until 1900.

1868-Ernst Haeckel publishes Natürliche Schöpfungsgeschichte, subdividing humanity into 12 separate species. He also asserts that evolution consists of 22 phases, the 21st being the "missing link" between apes and humans.

1868-Thomas Henry Huxley publishes On the Animals which are Most Nearly Intermediate Between Birds and Reptiles, arguing that birds are descendants of dinosaurs. This suggestion will not be taken very seriously for another century.

1869-Huxley, Norman Lockyer and others found Nature Magazine, which becomes one of the world's two most important scientific journals. (The other journal is Science.)

1869-Biochemistry graduate student Johann Friedrich Miescher begins examining bandages from hospital patients in hopes of finding something interesting. He eventually succeeds, and determines that cell nuclei are composed of nitrogen, phosphorus and chromatin. He names the substance nuclein.

1870-The rivalry between fossil collectors O.C. Marsh and E.D. Cope turns ugly when Marsh publicly points out Cope's error in reconstructing a fossil marine reptile (putting its head on the tip of its tail). Their rivalry is the public's gain as they try to outdo each other in identifying new dinosaur species — over 130.

1870-O.C. Marsh discovers the first North American pterosaur, from chalk deposits in Kansas. He calculates the wingspan at 20 feet. The following year, he will collect more fossils that confirm this calculation.

1871-Charles Darwin publishes The Descent of Man.

1873-Francis Galton publishes a paper entitled "Hereditary Improvement" arguing that people "of really good breed" should be encouraged to reproduce while their inferiors should be discouraged from doing so. This, he argues, will improve humanity the way selective breeding improves livestock.

1876-Charles Doolittle Walcott becomes the first to successfully find and describe elusive trilobite legs, ending speculation about how the animals moved.

1876-Robert Koch validates the germ theory of disease, postulated by Louis Pasteur in the 1860s, and publishes a paper identifying a bacterium as the cause of anthrax.

1877-Entire skeletons of Iguanodon are discovered, enabling a more accurate reconstruction of this dinosaur than those of Owen and Waterhouse Hawkins in the 1850s.

1879-Charles Lapworth resolves a priority dispute between Adam Sedgwick and Roderick Murchison by assigning older rocks to the Cambrian (named by Sedgwick), younger rocks to the Silurian (named by Murchison), and naming the Ordivician System in between.

1879-The United States Geological Survey is formed.

1882-Charles Darwin publishes his final letter to Nature, on the dispersal of freshwater bivalves. His obituary appears the same month.

1883-Geologist James Hall names Cryptozoon, based on cabbagelike rocks up to meter across. Although Hall's biologic interpretation of these structures will be heavily criticized, it will ultimately prove correct.

1887-Harry Govier Seeley determines that dinosaurs consist of "lizard-hipped" (saurischian) and "bird-hipped" (ornithischian) branches.

1888-German anatomist W. von Waldeyer names chromosomes.

1894-Eugène Dubois publishes his monograph of Pithecanthropus erectus, or Java Man, a missing link between humans and apes.

1896-Dublin anatomist Daniel Cunningham concludes that Neanderthals represent an intermediate step between Pithecanthropus erectus and modern humans.

1897-Renowned physicist Lord Kelvin gives a lecture at London's Victoria Institute claiming that the sun, which is cooling from its initial formation, can be no more than 20 million years old.

1897-Marie Curie begins research of "uranium rays" that will lead to the discovery of radioactivity.

1899-Charles Doolittle Walcott identifies Chuaria, millimeter-sized black fossil disks. He thinks they're compressed shells of marine invertebrates. He's wrong about that, but correct in deducing a biologic origin — the fossils are actually from unusually large planktonic alga.

1901-Harry Govier Seeley publishes Dragons of the Air, the first popular book on pterosaurs, arguing that they were warm-blooded and should be classified parallel to birds, in between reptiles and mammals. This is in direct opposition to Richard Owen's classification of pterosaurs as cold-blooded and poor flyers.

1902-Barnum Brown of the American Museum of Natural History discovers Tyrannosaurus rex.

1902-Walter Sutton deduces that chromosomes separate for reproduction. This becomes the basis for the chromosome theory of inheritance, to become official two years later.

1903-Physicist Ernest Rutherford lectures the British Association that radioactivity could power the sun and maintain its heat, meaning the sun and earth could be much older than Lord Kelvin's estimate.

1905-Albert Einstein proposes the special theory of relativity (E=mc²).

1907-The Mauer jaw is discovered in Germany. It will become the type specimen for Homo heidelbergensis (Archaic Homo sapiens, precursors to Neanderthals).

1908-Charles and George Sternberg discover a dinosaur mummy, a duckbill dinosaur with skin, tendons and bits of flesh all fossilized.

1908-1911-Oliver P. Hay publishes several articles contending that dinosaurs had crocodilian postures (not upright legs), and recommending that museums clearly distinguish between fossil bones and casts. The first idea will never catch on, but the second eventually will.

1909-Charles Doolittle Walcott discovers the fossils of soft-bodied animals in the Burgess Shale in the Canadian Rockies. He proceeds to publish several papers in which he describes these animals, which lived over 500 million years ago, as primitive ancestors of modern groups.

1909-The Abbé Breuil discovers carefully buried Neanderthal skeletons in France.

1909-Arthur Smith Woodward lectures the British Association for the Advancement of Science on "excess growth" and tooth loss in dinosaurs, citing these things as evidence of "racial senility" that doomed the dinosaurs to extinction.

1911-Amateur archaeologist Charles Dawson discovers the skull of the Piltdown Man in southern England.

1911-1914-Ernst Stromer and Richard Markgraf find fossils of three carnivorous dinosaur species in Egypt. The fossils will be formally described in the 1930s, then completely destroyed in a 1944 WWII bombing.

1912-Alfred Wegener proposes the theory of continental drift. His ideas will be almost completely ignored until the late 1960s.

1913-Geologist-physicist Arthur Holmes concludes that the breakdown of radioactive isotopes in igneous rocks can be used to determine when the rocks solidified. The ability to determine the absolute ages of rocks will enable scientists to better date fossils.

1914-World War I begins in Europe.

1914-Charles Doolittle Walcott identifies fossil bacteria in Cryptozoon-like structures (stromatolites).

1914-Peyrony finds the remains of Neanderthal baby in southwestern France. Because no one knows the bones are Neanderthal, they are not examined closely and are later believed lost. They will be rediscovered and described nearly 90 years later.

1915-Calvin Bridges identifies strains of mutant fruit flies with extra pairs of wings. Decades later, these strains will help biologists understand Hox genes that control the head-to-toe anatomy of widely varying animals.

1916-Two duckbill dinosaur fossils, with extremely rare skin impressions, sink to the bottom of the Atlantic when a German warship fires on the vessel carrying them.

1917-The Bolshevik Revolution begins in Russia.

1920-Women gain the right to vote in the United States.

1921-Fossil mammal expert William Diller Matthew suggests dinosaurs were driven extinct by mountain building, continental uplift and replacement by mammals.

1922-The American Museum of Natural History begins a series of excavations in central Mongolia, led by Roy Chapman Andrews. Hoping to find fossil human remains, Chapman's team instead finds dinosaurs.

1925-Raymond Dart publishes a description of the "Taung Child," a hominid child's skull from Africa. He classifies it as Australopithecus africanus and concludes that it's the missing link between humans and apes.

1925-Tennessee schoolteacher John Thomas Scopes is tried for teaching evolution in the famous "Scopes Monkey Trial." Two-time presidential candidate William Jennings Bryan leads the prosecution. Labor lawyer Clarence Darrow leads the defense and goads Bryan into declaring that humans are not mammals. The conviction will be overturned on a technicality, and the anti-evolution law will remain on the books for decades.

1926-Harvard geology professor William Morris Davis publishes a paper entitled "The Value of Outrageous Geological Hypotheses" warning against quick dismissal of new ideas. The paper will become famous.

1929-Davidson Black announces the find of Sinanthropus pekinensis, or Peking Man. The fossil will be lost during World War II.

1929-Estonian paleobiologist Alexander Audova publishes a paper rejecting racial senility as the cause of dinosaur extinction and instead pointing to environmental change.

1931-The highly influential paleobotanist Sir Albert Charles Seward rejects the biologic interpretation of Cryptozoon fossils (stromatolites). This rejection will become known among paleontologists as "Seward's folly."

1936-Robert Broom finds the first skull of an adult australopithecine near Johannesburg.

1937-Anthropologist Ales Hrdlicka publishes a paper asserting that aboriginal peoples of the Americas always resembled modern Native Americans. This view will predominate for decades.

1938-Fishermen find a coelacanth, a fish long believed to be extinct, off the coast of South Africa.

1939-World War II begins in Europe.

1940-1944-Seventeen dinosaur fossils, including several type specimens (fossils used as examples of named species) are lost when the European museums housing them are damaged or destroyed in various WWII battles.

1942-Ernst Mayr publishes Systematics and the Origin of Species, and Julian Huxley publishes Evolution: The Modern Synthesis. Both books are significant contributions to the neo-Darwinian synthesis combining elements of natural selection, genetics, mutation, population biology and paleontology.

1943-Oswald Avery, Colin MacLeod and Maclyn McCarty publish a paper in the Journal of Experimental Medicine describing nucleic acid DNA as the carrier of genetic messages.

1946-Geologist Reg Sprigg discovers fossils near the Ediacara Hills in Australia. The fossils are of multicellular organisms that predated the Cambrian Period, making them the oldest complex fossils yet discovered. At least some of the fossils are generally assumed to be related to modern cnidarians like jellyfish and corals.

1947-American Museum of Natural History curator Edwin Colbert finds a massive quarry of Coelophysis dinosaurs in New Mexico and concludes from their skeletons that these Triassic dinosaurs were swift runners with a bird-like posture.

1947-Rudolph Zallinger completes The Age of Reptiles mural in the Yale Peabody Museum. This image of slow-moving dinosaurs will prevail until the 1960s.

1948-Mary Leakey finds the skull of the ape Proconsul, about 16 million years old. Although a very significant find, it does little to bolster Louis and Mary Leakey's meager research funding.

1953-Piltdown Man is determined to be a hoax: the jaw of an ape and a human skull.

1953-Stanley Miller and Harold Urey combine gases generally believed to be in the earth's early atmosphere (methane, ammonia and water vapor) and charge them with electricity. These experiments produce several amino acids.

1953-James Watson and Francis Crick publish their paper on the molecular structure of DNA in Nature Magazine. Rosalind Franklin, whose X-ray photographs of DNA were essential to this discovery, publishes a paper on her own research in the same issue.

1953-Fiesel Houtermans and Clair Patterson publish independent estimates inferring the age of the earth through radiometric dating of meteorites. Both estimates are over 4.5 billion years.

1956-Paleontologist M.W. de Laubenfels publishes a paper suggesting that the dinosaurs were driven to extinction by a meteorite impact. His paper will not be taken seriously, but this hypothesis will be presented again in 1980 with more compelling evidence.

1957-The Soviet Union launches Sputnik.

1959-Mary Leakey finds hominid skull belonging to Australopithecus boisei.

1961-Henry Morris and Old Testament Scholar J.C. Whitcomb publish The Genesis Flood, attracting new support for the previously insignificant biblical literalist movement.

1961-Martin Glaessner determines fossils in the Ediacara Hills of South Australia (Ediacaran fauna) to be Precambrian in age (approximately 600 million years old), making them the oldest-known multicelled organisms.

1961-Gene Shoemaker and E.C.T. Chao publish a paper characterizing the Ries Basin in Bavaria as the result of a meteorite impact. This will help pave the way for eventual acceptance of asteroid and comet impacts as potential causes of mass extinction.

1964-W. Brian Harland and Martin J.S. Rudwick publish a theory that the earth experienced a great ice age in the Neoproterozoic (late Precambrian). Rudwick suggests that the climate's return to moderate conditions paved the way for the evolution of multicelluar life.

1964-Louis Leakey describes Homo habilis.

1966-Harry Whittington begins reexamining Burgess Shale fossils originally identified by Charles Walcott starting in 1909. Over the next two decades, Whittington (with the assistance of his graduate students Simon Conway Morris and Derek Briggs), will eventually overturn some of Walcott's theories and propose that most of the animals left no living relatives.

1969-Americans land the first man on the moon.

1969-John Ostrom publishes a description of Deinonychus with a frontispiece illustration by Bob Bakker, suggesting that the dinosaur is alert, agile and intelligent.

1971-Polish and Mongolian paleontologists discover the entwined skeletons of a Protoceratops and a juvenile Velociraptor in the Gobi Desert, most likely locked in mortal combat.

1971-Grad student Douglas Lawson discovers the humerus of a giant pterosaur in Texas. Over the next four years, he will continue collecting and finally publish a description of Quetzalcoatlus northropi, the largest flying animal ever found, with an estimated wingspan of 39 feet.

1972-Stephen Jay Gould and Niles Eldredge publish their theory of punctuated equilibrium, stating that evolution often occurs in short bursts, followed by long periods of stability.

1974-Donald Johanson and his team discover a female fossil hominid (to be later named Australopithecus afarensis) and call her Lucy. Lucy's discovery establishes that hominids walked upright before developing large brains, overturning some long-held beliefs about hominid evolution. Her status as a direct ancestor of modern humans, however, will remain controversial.

1974-Bob Bakker proclaims that birds are dinosaur descendants.

1978-Mary Leakey announces the discovery of fossil footprints at Laetoli demonstrating that hominids walked upright 3.6 million years ago.

1980-Louis W. Alvarez, Walter Alvarez, Frank Asaro and Helen V. Michel publish their asteroid impact theory of dinosaur extinction. The theory will not gain widespread acceptance among scientists for several years.

1983-German paleobiologist Adolf Seilacher suggests that most of the Ediacaran fossils discovered in the 1940s are not related to any modern forms. Calling them vendobionts, he argues that they went extinct after the emergence of large predators. Seilacher's interpretation, however, will remain in dispute.

1984-Richard Leakey and his team discover Turkana Boy, the most complete Homo erectus fossil yet discovered.

1984-David Raup and Jack Sepkoski publish the controversial claim that mass extinctions are regularly spaced at 26 million years.

1987-Jenny Clack finds Acanthostega, the most complete Devonian tetrapod yet discovered. It has evidence for functional gills as well as legs, strongly suggesting that animals evolved legs while still living in the water.

1989-Philip Gingerich finds a fossil whale in Egypt. It has tiny legs, just inches long, retaining all five toes.

1990-Mongolia invites the American Museum of Natural History to reinstate excavations in the Gobi desert.

1991-The Soviet Union ends, and so does the Cold War.

1991-Chicxulub crater is discovered in the Yucatán Peninsula, supporting the asteroid impact theory first suggested in 1980.

1992-Ian Campbell and collaborators publish a paper pointing to the Siberian Traps, an area of massive volcanic activity, as the cause of the Permo-Triassic mass extinction 251 million years ago.

1992-Paleontologists led by Jim Kirkland discover Utahraptor, a super-sized velociraptor that conveniently supports the super-sized velociraptors that will appear in the screen version of Jurassic Park a year later.

1992-Joe Kirschvink publishes "Late Proterozoic Low-latitude Glaciation: The Snowball Earth," a short book section in a specialized monograph. This snowball earth hypothesis will attract little attention until expanded by Paul Hoffman and his collaborators several years later.

1993-J. William Schopf publishes a description of the oldest fossils known to science — 3.5 billion-year-old microfossils of the Apex Basalt in Australia.

1994-In what will later be named Chauvet cave, French cavers discover 32,000-year-old paintings showing 400 animal images.

1996-Alan Walker and Pat Shipman publish a description of advanced vitamin A poisoning in a 1.7 million-year-old Homo erectus skeleton. They assert that it is evidence of both meat eating, caused by consuming the liver of a large carnivore, and sufficient sociability in Homo erectus to care for an ill and incapacitated individual.

1996-The 9,500-year-old Kennewick Man skeleton is found in the northwestern United States. Bearing little resemblance to modern Native Americans, it suggests a more complicated early population of the Americas than previously thought.

1998-Paul Hoffman, Alan Kaufman, Galen Halverson and Daniel Schrag publish a Neoproterozoic snowball earth theory arguing that in the late Precambrian, the earth underwent global glaciations followed by extreme greenhouse conditions, spurring the evolution of multicellular life forms.

2000-Phil Currie publishes a paper suggesting that T. rex was a social animal that hunted in packs.

2001-The International Human Genome Sequencing Consortium publishes the initial sequence and analysis of the human genome in Nature Magazine. Celera Genomics simultaneously publishes a draft human genome sequence in Science Magazine.

2001-Joshua Smith and collaborators publish a description of a giant sauropod from Egypt, possibly the largest Cretaceous sauropod yet discovered. It is considered a possible food source for three large carnivorous dinosaur species discovered decades earlier by Ernst Stromer.

2001-Luann Becker and collaborators publish a paper describing carbon fullerenes (buckyballs) at the Permo-Triassic boundary in China, Japan and Hungary. Because they can occur in meteorites, the fullerenes are cited as evidence of a meteorite impact at the end of the Permian. Other scientists will have difficulty reproducing their results, however, and the researchers' claim will remain controversial.

2001-Chris Henshilwood and collaborators publish a description of 77,000-year-old artwork: stones carved with lines and triangles, found in Blombos Cave on the Southern Cape coast of Africa.

2002-Michel Brunet and collaborators publish a description of Sahelanthropus tchadensis, a hominid fossil from western central Africa. Suspected to be 6 to 7 million years old, it is possibly the oldest hominid fossil yet found. Its location, in Chad, is expected to spur hominid fossil hunting west of Africa's Rift Valley.

2003-M.R. Sánchez-Villagra, O. Aguilera and I. Horovitz publish a description of Phoberomys, a fossil rodent from Venezuela the size of a buffalo.