When were the first mososaur fossils discovered?
Mosasaur
The first publicized discovery of a partial fossil mosasaur skull in 1764 by quarry workers in a subterranean gallery of a limestone quarry in Mount Saint Peter, near the Dutch city of Maastricht, preceded any major dinosaur fossil discoveries, but remained little known. However, a second find of a partial skull drew the Age of Enlightenment's attention to the existence of fossilized animals that were different from any known living creatures. When the specimen was discovered between 1770 and 1774, Johann Leonard Hoffmann, a surgeon and fossil collector, corresponded about it with the most influential scientists of his day, making the fossil famous. The original owner, though, was Godding, a canon of Maastricht cathedral.
Cosesaurus
Cosesaurus is a genus of archosauromorph reptiles likely belonging to the family Tanystropheidae. It is known from fossil imprints of a single small skeleton, MGB V1, which was found in Muschelkalk outcrops near the municipalities of Mont-ral and Alcover in Spain. These outcrops are dated to the Ladinian age of the middle Triassic about 242 to 237 million years ago. The specimen is stored at the Museu Martorell (a.k.a. the Museu Geologia de Barcelona), which is now part of the Museu de Ciències Naturals de Barcelona. The poor preservation and likely juvenile nature of the specimen has led to the anatomy of "Cosesaurus" being misidentified by several different sources. For example, Paul Ellenberger claimed that it was an ancestor to birds in the 1970s, while Dave Peters claimed that it was a pterosaur ancestor in 2000. Both of these claims contrast with mainstream scientific theories on the origins of either group, and other paleontologists who study the specimen are unable to find the features which Ellenberger or Peters reported to be present. The Ellenberger and Peters hypotheses are thus considered fringe theories with questionable scientific soundness due to their low reproducibility. Mainstream hypotheses for the relations of "Cosesaurus" generally agree that it is a "protorosaur", specifically a tanystropheid closely related to long-necked reptiles such as "Macrocnemus", "Tanytrachelos", "Tanystropheus", or "Langobardisaurus".
Nyasasaurus
"Nyasasaurus" is likely either a basal dinosaur or close to Dinosauria. Other phylogenetic analyses have indicated that the sister group to Dinosauria is a family of herbivorous dinosauriforms called Silesauridae. The fossil record of silesaurids dates back to the late Anisian (the silesaurid "Asilisaurus" is also known from the Manda Formation), suggesting that the first dinosaurs also appeared around this time. Before "Nyasasaurus" was recognized as a possible dinosaur, a long ghost lineage of approximately 16 million years existed between the earliest dinosaurs and earliest silesaurids.
Tylosaurinae
Tylosaurines first appeared in the Coniacian and gave rise to some of the largest mosasaurs within the genera "Tylosaurus" and "Hainosaurus" which came to dominate as apex predators in marine ecosystems throughout the Santonian and Campanian, but appear to have been largely replaced by large mosasaurines, such as "Mosasaurus", by the end of the Maastrichtian. Nevertheless, the subfamily survived to the end of the Cretaceous, covering a period lasting approximately twenty million years.
Nothronychus
The first fossil evidence later attributed to "Nothronychus" was discovered by a team of paleontologists working in the Zuni Basin of New Mexico at the Haystack Butte site. A therizinosaur ischium (a hip bone) had originally been mistaken for a squamosal, a part of the skull crest of the newly discovered ceratopsian "Zuniceratops". However, closer examination revealed the true identity of the bone, and soon more parts of the skeleton were found. The New Mexico team, led by paleontologists Jim Kirkland and Doug Wolfe, published their find in the "Journal of Vertebrate Paleontology" on 22 August 2001, making it the type specimen of the new species "Nothronychus mckinleyi". The "Arizona Republic" newspaper, however, was first to announce the name on 19 June 2001, in a column by R.E. Molnar. The generic name is derived from Greek νωθρός, "nothros", "heavy" or "slothful", and ὄνυξ, "onyx", "claw". The specific name honours rancher Bobby McKinley on whose land the find was made. The holotype, specimen MSM P2106, consists of two skull fragments, a braincase, some vertebrae and parts of the shoulder girdle, forelimbs, pelvis and hindlimbs.
A second, more complete therizinosaur specimen, UMNH VP 16420, was discovered from the Tropic Shale formation (dating to the early Turonian stage) of southern Utah in 2000 by Merle Graffam, a resident of Big Water, Utah. The area around Big Water had been subject to several expeditions by teams from the Museum of Northern Arizona (MNA), and was known for its abundance of marine reptile fossils, especially plesiosaurs. During part of the late Cretaceous period, the region had been submerged under a shallow sea, the Western Interior Seaway, and preserves extensive marine deposits. Graffam's initial discovery (a large, isolated toe bone) came as a surprise to scientists, as it clearly belonged to a land-dwelling dinosaur, rather than a plesiosaur. However, the location of the bone at the time would have been nearly 100 kilometers from the Cretaceous shoreline. An excavation of the area by an MNA crew revealed more of the skeleton, and the scientists found that it was a therizinosaur, and the first example of that group to be found in the Americas. All previous therizinosaur fossils had come from China and Mongolia. It is the most complete therizinosaurid specimen known but lacks the skull.
Timeline of mosasaur research
1911
Timeline of mosasaur research
1804
Massospondylus
Massospondylus ( ; from Greek, (massōn, "longer") and (spondylos, "vertebra")) is a genus of sauropodomorph dinosaur from the Early Jurassic Period (Hettangian to Pliensbachian ages, ca. 200–183 million years ago). It was described by Sir Richard Owen in 1854 from remains discovered in South Africa, and is thus one of the first dinosaurs to have been named. Fossils have since been found at other locations in South Africa, Lesotho, and Zimbabwe. Material from Arizona's Kayenta Formation, India, and Argentina has been assigned to this genus at various times, but the Arizonan and Argentinian material are now assigned to other genera.
Mussaurus
Infant and juvenile fossils of "Mussaurus" were first discovered by an expedition led by Jose Bonaparte during the 1970s to the El Tranquilo Formation. There the team found fossilized eggs and hatchlings, which added insight into the reproductive strategies of "Mussaurus" and other sauropodomorph dinosaurs. The first adult specimens of "Mussaurus" were described in 2013. Some of these specimens had first been described in 1980 and were originally attributed to the genus "Plateosaurus".
Stonesfield
The mines were also one of Britain's richest sources of Middle Jurassic vertebrate fossils. The first fossil bones to be identified as those of a dinosaur were found early in the 19th century near Stonesfield. They are part of the skeleton of a bipedal carnivore, and in 1824 the pioneering palaeontologist William Buckland named it "Megalosaurus". The bones are now displayed in the Oxford University Museum of Natural History. Other reptiles found at Stonesfield include the crocodile "Steneosaurus", pterosaur "Rhamphocephalus" and the type specimen of the theropod genus "Iliosuchus".
Betasuchus
Its fossil, holotype BMNH 42997 (now NHM R 42997), a part of a right femur, 312 mm long, was found in the Netherlands near Maastricht, and originally described as a new species of "Megalosaurus" in 1883 by Harry Seeley: "M. bredai", honouring the late Dutch biologist and geologist Jacob Gijsbertus Samuël van Breda, a director of the Teylers Museum, who had collected the fossil at some time between 1820 and 1860 from the chalkstone quarry at the St Pietersberg. Van Breda did not excavate the remains himself but bought them from quarry workers who in this period dug stone from tunnels at several levels in the mountain; it is therefore impossible to determine the exact temporal horizon, apart from a general Maastrichtian; however all dinosaurian material from the formation that could be dated, stems from the latest Maastrichtian, 67-66 million years old. Only the top part of the femur has been conserved; of the distal end about eight centimetres are missing as the bone was cleanly cut in two when the chalk block containing it was sawed out. Other saw cuts damaged the head of the thigh bone. The fossil was part of his personal collection, not the museum's, and sold to the British Museum of Natural History after his death in 1867. In 1892 Belgian/Dutch/German paleontologist Johan Casimir Ubaghs referred some teeth — probably of mosasaurs — to "M. bredai". "Megalosaurus bredai" was in 1883 the first terrestrial vertebrate named from Maastrichtian layers.
Paleontology in New Jersey
One of the earliest significant events relating to paleontology in New Jersey occurred on October 5, 1787. Caspar Wistar and Timothy Matlack presented a probable dinosaur metatarsal discovered in Late Cretaceous rocks near Woodbury Creek as "'a large thigh bone'" in to the American Philosophical Society in Philadelphia, Pennsylvania. In 1818, more Cretaceous reptile remains were reported from the state. A tooth and partial jaw recovered from the Navesink Formation of New Jersey were described for the scientific literature. These were the first mosasaur fossils scientifically documented in North America. Another early New Jersey discovery helped clarify a misinterpretation of a fossil found out west. 1830 Isaac Hays described a new species of fossil fish from the Cretaceous of New Jersey that he named "Saurodon leanus". The new find by Hays was similar enough to the purported marine reptile "Saurocephalus lanciformis" discovered in Iowa during the Lewis and Clark expedition that he realized "Saurocephalus" had been misidentified and was actually a fish.
Prognathodon
A new fossil found in 2008 and described in 2013 belonging to a 1.8 m juvenile "Prognathodon" was found in Jordan's Harrana Site. The fossil was remarkable in that it preserved the outline of the mosasaur's tail fins, revealing that "Prognathodon", like "Platecarpus" and later mosasaurs also had a bilobed tail fluke resembling a downturned shark's tail, the shape of which may have aided the creature in surfacing, as well as attacking prey. The discovery also lends evidence to the theory that later mosasaurs were even more well-adapted to the lifestyle first occupied by the ichthyosaurs.
Pterodaustro
The first fossils, among them the holotype PLV 2571, a thigh bone, were in the late sixties discovered by Bonaparte in the Lagarcito Formation, situated in the San Luis Province of Patagonia, Argentina, and dating from the Albian. The genus has later also been found in Chile in the Santa Ana Formation. At the Argentine site, the just large "Loma del "Pterodaustro"", since then during several expeditions over 750 "Pterodaustro" specimens have been collected, 288 of them having been catalogued until 2008. This makes the species one of the best known pterosaurs, with examples from all growth stages, from egg to adult.
Camarasaurus
The first record of "Camarasaurus" comes from 1877, when a few scattered vertebrae were located in Colorado, by Oramel W. Lucas. Pursuing his long-running and acrimonious competition (known as the Bone Wars) with Othniel Charles Marsh, the paleontologist Edward Drinker Cope paid for the bones and, moving quickly, named them in the same year. For his part, Marsh later named some of his sauropod findings "Morosaurus grandis", but most paleontologists today consider them to be a species of "Camarasaurus" . Such naming conflicts were common between the two rival dinosaur hunters, the most famous being "Brontosaurus" and "Apatosaurus".
Goronyosaurus
Goronyosaurus is an extinct genus of marine lizard belonging to the mosasaur family. Fossils of "Goronyosaurus" are exclusively known from the Dukamaje Formation of Niger and Nigeria and are Maastrichtian in age. Its fossils were first described in the 1930s as Mosasaurus nigeriensis, but subsequent remains revealed a highly unique set of adaptations that prompted the species to be reclassified as the only species of the new genus "Goronyosaurus" in 1972. These unique adaptations have made "Goronyosaurus" notoriously difficult to classify within the Mosasauridae and it is often left out of phylogenetic analyses.
Mudrock
Another noteworthy formation is the Morrison Formation. This area covers 1.5 million square miles, stretching from Montana to New Mexico in the United States. It is considered one of the world's most significant dinosaur burial grounds, and its many fossils can be found in museums around the world. This site includes dinosaur fossils from a few dinosaur species, including the "Allosaurus", "Diplodocus", "Stegosaurus", and "Brontosaurus". There are also lungfish, freshwater mollusks, ferns and conifers. This deposit was formed by a humid, tropical climate with lakes, swamps, and rivers, which deposited mudrock. Inevitably, mudrock preserved countless specimens from the late Jurassic, roughly 150 million years ago.
Mosasaur
Many of the so-called 'dinosaur' remains found on New Zealand are actually mosasaurs and plesiosaurs, both being Mesozoic predatory marine reptiles.
Dinosaur
Dinosaurs diverged from their archosaur ancestors during the middle to late Triassic period, roughly 20 million years after the Permian–Triassic extinction event wiped out an estimated 95% of all life on Earth. Radiometric dating of the rock formation that contained fossils from the early dinosaur genus "Eoraptor" at 231.4 million years old establishes its presence in the fossil record at this time. Paleontologists think that "Eoraptor" resembles the common ancestor of all dinosaurs; if this is true, its traits suggest that the first dinosaurs were small, bipedal predators. The discovery of primitive, dinosaur-like ornithodirans such as "Marasuchus" and "Lagerpeton" in Argentinian Middle Triassic strata supports this view; analysis of recovered fossils suggests that these animals were indeed small, bipedal predators. Dinosaurs may have appeared as early as 243 million years ago, as evidenced by remains of the genus "Nyasasaurus" from that period, though known fossils of these animals are too fragmentary to tell if they are dinosaurs or very close dinosaurian relatives. Recently, it has been determined that "Staurikosaurus" from the Santa Maria Formation dates to 233.23 Ma, making it older in geologic age than "Eoraptor".
Spinosauridae
The first fossils referred to a spinosaurid were discovered in 1912 at the Bahariya Formation in Egypt. Consisting of dorsal vertebrae, skull fragments, and teeth, these remains became the holotype specimen of the new genus and species "Spinosaurus aegyptiacus" in 1915, when they were described by German paleontologist Ernst Stromer. The dinosaur's name meant "egyptian spine lizard", in reference to the unusually long neural spines not seen previously in any other theropod. In April 1944, the holotype of "S. aegyptiacus" was destroyed during an allied bombing raid in World War II. In 1934, Stromer referred a partial skeleton also from the Bahariya Formation to a new species of "Spinosaurus", this specimen has since been alternatively assigned to another African spinosaurid, "Sigilmassasaurus."
History of paleontology in the United States
The next year, O. C. Marsh led a paleontological expedition into the western United States on behalf of Yale University. Late that November they visited the area around Fort Wallace. Among the fossils found by Marsh's crew in western Kansas were the far ends of two pterosaur wing metacarpals. These were the first scientifically documented fossils of the pterosaur that would later be named Pteranodon. This formal naming occurred six years later, in 1876.
Meuse
The Cretaceous sea reptile Mosasaur is named after the river Meuse. The first fossils of it were discovered outside Maastricht in 1780.
Psittacosaurus
"P. gobiensis" is named for the region it was found in 2001, and first described by Sereno, Zhao and Lin in 2010. It is known from a skull and partial articulated skeleton with gastroliths. Many other specimens either cannot be determined to belong to any particular species, or have not yet been assigned to one. These specimens are generally all referred to as "Psittacosaurus" sp., although it is not assumed that they belong to the same species. More than 200 specimens of "Psittacosaurus" have been found in the Yixian Formation, which is famous for its fossils of feathered dinosaurs. The vast majority of these have not been assigned to any published species, although many are very well preserved and some have already been partially described. Nearly 100 "Psittacosaurus" skeletons were excavated in Mongolia during the summers of 2005 and 2006 by a team led by Mongolian paleontologist Bolortsetseg Minjin and American Jack Horner from the Museum of the Rockies in Montana. Although only "P. mongoliensis" has been described from Mongolia so far, these specimens are still in preparation and have not yet been assigned to a species.
Paleontology in Massachusetts
Massachusetts paleontology saw major events occur early in the twentieth century as well. In 1904, Richard Swann Lull published his first study of the Connecticut Valley fossil footprints. Five years later Massachusetts paleontologist Mignon Talbot became the first woman elected to the Paleontological Society. During October of the next year, Mignon Talbot discovered a partial dinosaur skeleton in a gravel pit near the South Hadley Center belonging to John A. Boynton. The discovery has been called "the most prized specimen" in Mount Holyoke College's geological museum. It's also been regarded as the last major find in the "Connecticut Valley 'bone rush'". That December, Talbot gave a presentation to the Paleontological Society about her dinosaur discovery in South Hadley. She interpreted the skeleton as belonging to an herbivore. The next year Mignon Talbot collaborated with Richard Swann Lull collaborated on a description for the recently discovered dinosaur at South Hadley. They correct Talbot's previous misidentification of the specimen as an herbivore and reclassify it as a theropod. They named it Podokesaurus holyokensis. Six years later, a fire consumed Williston Hall at Mount Holyoke College, destroying the bones of Podokesaurus holyokensis. However, casts previously taken of the bones survive in Yale's Peabody Museum and New York's American Museum of Natural History.
Timeline of mosasaur research
1891
Mosasaurini
The Mosasaurini are a tribe of mosasaurine mosasaurs, a diverse group of Late Cretaceous marine squamates. Members of the tribe, known as "mosasaurins", have been recovered from North America, Europe, Africa and Oceania with questionable occurrences in Asia. The tribe contains the closely related genera "Mosasaurus", "Eremiasaurus", "Plotosaurus" and "Moanasaurus". It has historically been more inclusive, on occasion including genera such as "Plesiotylosaurus", "Liodon" and "Clidastes", all of which are now seen as more basal mosasaurines.
Mosasaur
The coloration of mosasaurs was unknown until 2014, when the findings of Johan Lindgren of Lund University and colleagues revealed the pigment melanin in the fossilized scales of a mosasaur. Mosasaurs were likely countershaded, with dark backs and light underbellies, much like a great white shark or leatherback sea turtle, the latter of which had fossilized ancestors for which color was also determined. The findings were described in the journal "Nature".
Prehistoric Mongolia
Mongolia is known to be the source of priceless paleontological discoveries. The first scientifically confirmed dinosaur eggs were found in Mongolia during the 1923 expedition of the American Museum of Natural History, led by Roy Chapman Andrews.
Mount Saint Peter
Around 1765 the skull of a "Mosasaurus" was discovered here in a limestone quarry, one of the first recognised reptile fossils, which was later acquired by the Teylers Museum in Haarlem. A more famous "Mosasaurus" fossil was found between 1770 and 1774 but was confiscated by the French in 1794 and is now in the Muséum national d'Histoire naturelle in Paris. Later dinosaur remains were discovered here as well, belonging to "Betasuchus" and "Orthomerus", as well as turtles and fossils of smaller creatures of the sea.
Timeline of mosasaur research
The scientific study of mosasaurs began in the late 18th century with the serendipitous discovery of a large fossilized skeleton in a limestone mine near Maastricht in the Netherlands. The fossils were studied by local scholar Adriaan Gilles Camper, who noted a resemblance to modern monitor lizards in correspondence with renowned French anatomist Georges Cuvier. Nevertheless, the animal was not scientifically described until the English Reverend William Daniel Conybeare named it "Mosasaurus", after the river Meuse located near the site of its discovery.
Partridge Island (Nova Scotia)
Since 1970 when the American paleontologist Paul E. Olsen discovered a neck vertebra of a long-necked dinosaur known as a prosauropod near Parrsboro, the north shore of the Minas Basin has been recognized as an important source of fossils. In 1984, for example, amateur rock specialist Eldon George discovered the world's smallest dinosaur footprints at Wasson Bluff about 10 kilometres from Partridge Island. Then, in 1986, Olsen and two colleagues announced they had retrieved 100,000 fossilized bones including some belonging to the oldest dinosaurs ever found in Canada.
John Foster (paleontologist)
John Russell Foster (born November 3, 1966) is an American paleontologist. Foster has worked with dinosaur remains from the Late Jurassic of the Colorado Plateau and Rocky Mountains, as well as working on Cambrian age trilobite faunas in the southwest region of the American west. He named the crocodiliform trace fossil "Hatcherichnus sanjuanensis" in 1997 and identified the first known occurrence of the theropod trace fossil "Hispanosauropus"in North America in 2015.He is adjunct faculty of geology at Colorado Mesa University, Grand Junction, Colorado. 
Since 2014 he has been the Director of the Museum of Moab. He served for thirteen years as Curator of Paleontology at the Museums of Western Colorado from 2001 to 2014.
Dinosaur Ridge
The rocks on the west side of Dinosaur Ridge are part of the widespread Morrison Formation of Jurassic age. It is in these rocks, where Arthur Lakes discovered the dinosaur bones in 1877. Fifteen quarries were opened along the Dakota hogback in the Morrison area in search of these fossils.
Psittacosaurus
"Psittacosaurus" was first described as a genus in 1923, by Henry Fairfield Osborn. He named the type species "P. mongoliensis", for the location of its discovery in Mongolia, placing it in the new family Psittacosauridae. Remains of this dinosaur were first discovered the year before, on the third American Museum of Natural History expedition to the Gobi Desert of Mongolia, when one of the expedition's drivers, Wong, found the type specimen (AMNH 6254), which preserves a nearly complete skull, as well as a post cranial skeleton lacking sections of the limbs. This same expedition turned up the remains of many other famous Mongolian dinosaurs, including "Protoceratops", "Oviraptor", and "Velociraptor". Many later expeditions by various combinations of Mongolian, Russian, Chinese, American, Polish, Japanese, and Canadian paleontologists also recovered specimens from throughout Mongolia and northern China. In these areas, "Psittacosaurus mongoliensis" fossils are found in most sedimentary strata dating to the Aptian to Albian stages of the Early Cretaceous Period, or approximately 125 to 100 mya. Fossil remains of over 75 individuals have been recovered, including nearly 20 complete skeletons with skulls. Individuals of all ages are known, from hatchlings less than long, to very old adults reaching nearly in length.
Moanasaurus
Moanasaurus (From Māori "moana" "sea" and Greek "sauros" "lizard"; meaning "Sea Lizard") was a genus of mosasaur from the Late Cretaceous period. Its fossil remains have been discovered in the North Island of New Zealand. "Moanasaurus" was a very large mosasaurine known originally from a disarticulated skull, vertebrae, ribs and flipper bones. It reached 12 m in length and the skull is 78 cm, which shows that "Moanasaurus" was one of the largest in the family of Mosasaurinae.
High Atlas
This massif became an internationally famous paleontological site after the discovery of the bones of a dinosaur called 'Atlasaurus', which populated Morocco 180 million years ago. This dinosaur is also named Tazoudasaurus, after the name of the village of Tazouda, where it was discovered. The creature, about long, is postulated to be an ancestor of the Sauropoda found in America. Until 140 million years ago, the African and American continents were connected.
Mosasaurus
At some time between 1770 and 1774 ("1770" according to Faujas de Saint-Fond, "about the year 1770" according to Camper and ""en 1780"" according to Cuvier in 1808) a second partial skull was discovered and procured. It was found in the ground owned by canon Theodorus Joannes Godding, who displayed it in his country house on the slope of the hill. A local retired German/Dutch army physician, Johann Leonard Hoffmann (1710–1782), also collected some fragments and corresponded about the skull with the Dutch Professor Petrus Camper. Hoffmann presumed the animal was a crocodile. In 1786 however, Camper disagreed and concluded the remains were those of "an unknown toothed whale".
Cristatusaurus
The first fossils of "Cristatusaurus" were found in 1973 by French paleontologist Philippe Taquet at Gadoufaoua, a locality within the Elrhaz Formation in Niger. The holotype specimen, cataloged under the number MNHN GDF 366, consists of two premaxillae (frontmost snout bones), a partial right (main upper jaw bone), and a fragment from the mandible. Several paratypes have been assigned: MNHN GDF 365, a snout of two articulated premaxillae; as well as MNHN GDF 357, 358, 359 and 361, four dorsal vertebrae. Two thumb claws from separate specimens were also subsequently attributed to "Cristatusaurus". In 1984, the premaxilla specimens MNHN GDF 365 and 366 were first described in detail by Taquet, where he referred them to an unnamed new theropod within the Spinosauridae family, because of shared characteristics with the holotype dentary of "Spinosaurus aegyptiacus". At the time Taquet believed these specimens belonged to the creature's lower jaw, since no theropod was known then with over five teeth in the premaxilla, while "Cristatusaurus" had seven. This was later proven incorrect in 1996 by Brazilian paleontologists Alexander Kellner and Diogenes Campos, in light of the discoveries of other spinosaurids preserving upper jaw tips with over five teeth.
Mussaurus
Mussaurus (meaning "mouse lizard") is a genus of herbivorous sauropodomorph dinosaur that lived in southern Argentina during the Late Triassic, about 215 million years ago. It receives its name from the small size of the skeletons of juvenile and infant individuals, which were once the only known specimens of the genus. However, since "Mussaurus" is now known from adult specimens, the name is something of a misnomer; adults possibly reached 3 m (10 ft) in length, and weighed . "Mussaurus" possesses anatomical features suggesting a close, possibly transitional evolutionary relationship with true sauropods.
Jack Horner (paleontologist)
In Montana during the mid-1970s, Horner and his research partner Bob Makela discovered a colonial nesting site of a new dinosaur genus which they named "Maiasaura", or "Good Mother Lizard". The dinosaur bones, originating from a juvenile, were first discovered by Marion Brandvold. Horner then studied the bones, and at first, there was a refusal to return the bones to Brandvold. It contained the first dinosaur eggs in the Western hemisphere, the first dinosaur embryos, and settled questions of whether some dinosaurs were sociable, built nests and cared for their young. The discovery established Horner's career. He has named several other species of dinosaur (including "Orodromeus makelai," in memory of his late friend Bob Makela) and has had three named after himself: "Achelousaurus horneri", "Anasazisaurus horneri", and "Daspletosaurus horneri".
Within the paleontological community, Horner is best known for his work on dinosaur growth research. He has published numerous articles in collaboration with Berkeley paleontologist Kevin Padian, and French dinosaur histologist Armand de Ricqlès, on the growth of dinosaurs using growth series. This usually involves leg bones in graduated sizes from different individuals ranging in age from embryos to adults. Horner also revitalized the contested theory that "Tyrannosaurus rex" was an obligate scavenger, rather than a predatory killer. While this theory has been widely discussed by the popular press, it has never been a major research focus for Horner. He claimed that he never published the scavenger hypothesis in the peer reviewed scientific literature, stating that it was mainly a tool for him to teach a popular audience, particularly children, of the dangers of making assumptions in science (such as assuming "T. rex" was a hunter) without using evidence. In 2000, teams led by Horner discovered five specimens of "T. rex" and three more the following summer, including one larger than the specimen nicknamed "Sue". The new fossil was 10–13 tons in weight and 10% larger than other specimens. The Museum of the Rockies, as the result of continuing fieldwork, now exhibits the largest "Tyrannosaurus rex" collection in the world. Currently, Horner is working on the developmental biology of dinosaurs.
Dinosaur
Since the first dinosaur fossils were recognized in the early 19th century, mounted fossil dinosaur skeletons have been major attractions at museums around the world, and dinosaurs have become an enduring part of world culture. The large sizes of some dinosaur groups, as well as their seemingly monstrous and fantastic nature, have ensured dinosaurs' regular appearance in best-selling books and films, such as "Jurassic Park". Persistent public enthusiasm for the animals has resulted in significant funding for dinosaur science, and new discoveries are regularly covered by the media.
Meganeura
Fossils were discovered in the French Stephanian Coal Measures of Commentry in 1880. In 1885, French paleontologist Charles Brongniart described and named the fossil ""Meganeura"" (large-nerved), which refers to the network of veins on the insect's wings. Another fine fossil specimen was found in 1979 at Bolsover in Derbyshire. The holotype is housed in the National Museum of Natural History, in Paris.
History of paleontology in the United States
In 1842, fossils were found on a plantation owned by a man named Judge Creagh. Local doctors identified the fossils as belonging to an ancient marine reptile, and called it "Basilosaurus". However, some of the fossils were shipped to Sir Richard Owen in England. After examining the remains Owen realized the bones actually belonged to a whale, rather than a reptile. Herman Melville's narrator Ishmael gives an account of the discovery in chapters 104–105 of "Moby-Dick" (1851).
Ceratosaurus
The first specimen, the holotype USNM 4735, was discovered and excavated by farmer Marshall Parker Felch in 1883 and 1884. Found in articulation, with the bones still connected to each other, it was nearly complete, including the skull. Significant missing parts include an unknown number of vertebrae; all but the last ribs of the trunk; the humeri (upper arm bones); the distal finger bones of both hands; most of the right fore limb; most of the left hind limb; and most of the feet. The specimen was found encased in hard sandstone; the skull and spine had been heavily distorted during fossilization. The site of discovery, located in the Garden Park area north of Cañon City, Colorado, and known as the Felch Quarry 1, is regarded as one of the richest fossil sites of the Morrison Formation. Numerous dinosaur fossils had been recovered from this quarry even before the discovery of "Ceratosaurus", most notably a nearly complete specimen of "Allosaurus" (USNM 4734) in 1883 and 1884.
Mosasaur
Despite the many mosasaur remains collected worldwide, knowledge of the nature of their skin coverings remains in its early stages. Few mosasaurid specimens collected from around the world retain fossilized scale imprints. This lack may be due to the delicate nature of the scales, which nearly eliminates the possibility of preservation, in addition to the preservation sediment types and the marine conditions under which the preservation occurred. Until the discovery of several mosasaur specimens with remarkably well-preserved scale imprints from late Maastrichtian deposits of the Muwaqqar Chalk Marl Formation of Harrana in Jordan, knowledge of the nature of mosasaur integument was mainly based on very few accounts describing early mosasaur fossils dating back to the upper Santonian–lower Campanian, such as the famous "Tylosaurus" specimen (KUVP-1075) from Gove County, Kansas. Material from Jordan has shown that the bodies of mosasaurs, as well as the membranes between their fingers and toes, were covered with small, overlapping, diamond-shaped scales resembling those of snakes. Much like those of modern reptiles, mosasaur scales varied across the body in type and size. In Harrana specimens, two types of scales were observed on a single specimen: keeled scales covering the upper regions of the body and smooth scales covering the lower. As ambush predators, lurking and quickly capturing prey using stealth tactics, they may have benefited from the nonreflective, keeled scales.
Mesosaur
Mesosaurs ("middle lizards") were a group of small aquatic reptiles that lived during the early Permian period, roughly 299 to 270 million years ago. Mesosaurs were the first known aquatic reptiles, having apparently returned to an aquatic lifestyle from more terrestrial ancestors. However, just how terrestrial mesosaur ancestors had become remains uncertain; recent research cannot establish with confidence if the first amniotes were fully terrestrial, or only amphibious. Most authors consider mesosaurs to have been aquatic, although adult animals may have been amphibious, rather than completely aquatic, as indicated by their moderate skeletal adaptations to a semi-aquatic lifestyle. Similarly, their affinities are uncertain; they may be either the most basal sauropsids, or among the most basal parareptiles.
Mosasaurus
"Mosasaurus" was the first genus of mosasaurs to be named. The first remains known to science were a fragmentary skull from a chalk quarry in the St Pietersberg, a hill near Maastricht, the Netherlands, found in 1764 and collected by lieutenant Jean Baptiste Drouin in 1766. It was procured for the Teylers Museum at Haarlem in 1784 by Martinus van Marum, the first director of the museum, who published its description only in 1790. He considered it to be a species of "big breathing fish" ("Pisces cetacei", in other words: a whale). It is still part of the collection as TM 7424.
Georges Cuvier
In 1800 and working only from a drawing, Cuvier was the first to correctly identify in print, a fossil found in Bavaria as a small flying reptile, which he named the "Ptero-Dactyle" in 1809, (later Latinized as "Pterodactylus antiquus")—the first known member of the diverse order of pterosaurs. In 1808 Cuvier identified a fossil found in Maastricht as a giant marine lizard, the first known mosasaur.
Paleontology in Kansas
In 1870, O. C. Marsh led a paleontological expedition into the western United States on behalf of Yale University. Late in the November of that year they visited the area around Fort Wallace. They spent several days prospecting for fossils in modern Wallace and Logan Counties along the banks of the Smoky Hill River. Persevering against cold weather, they made several finds. One was the nearly complete skeleton of the mosasaur "Clidastes" that took four days to excavate. Among the fossils discovered by Marsh's crew in western Kansas were the far ends of two pterosaur wing metacarpals. These were the first scientifically documented fossils of the pterosaur that would later be named "Pteranodon". This formal naming occurred six years later, in 1876.
Horshamosaurus
In 1985, at the marl quarry of the Rudgwick Brickworks Company near Rudgwick in West Sussex, fossils were dug up of dinosaurs. These were secured by two volunteers of the Horsham Museum: Morris Zdzalek and Sylvia Standing. After 1988, the finds were exhibited in the museum as "Iguanodon" bones. Subsequently neurologist William T. Blows, an amateur paleontologist who already had extensively published on the subject of armoured dinosaurs, determined that the bones were not iguanodontian but instead represented ankylosaurian remains.
Frog
The earliest known "true frogs" that fall into the anuran lineage proper all lived in the early Jurassic period. One such early frog species, "Prosalirus bitis", was discovered in 1995 in the Kayenta Formation of Arizona and dates back to the Early Jurassic epoch (199.6 to 175 million years ago), making "Prosalirus" somewhat more recent than "Triadobatrachus". Like the latter, "Prosalirus" did not have greatly enlarged legs, but had the typical three-pronged pelvic structure of modern frogs. Unlike "Triadobatrachus", "Prosalirus" had already lost nearly all of its tail and was well adapted for jumping. Another Early Jurassic frog is "Vieraella herbsti", which is known only from dorsal and ventral impressions of a single animal and was estimated to be from snout to vent. "Notobatrachus degiustoi" from the middle Jurassic is slightly younger, about 155–170 million years old. The main evolutionary changes in this species involved the shortening of the body and the loss of the tail. The evolution of modern Anura likely was complete by the Jurassic period. Since then, evolutionary changes in chromosome numbers have taken place about 20 times faster in mammals than in frogs, which means speciation is occurring more rapidly in mammals.
List of fossil primates
There is an academic debate on the time the first primates appeared. One of the earliest probable primate fossils is the problematic "Altiatlasius koulchii", perhaps an Omomyid, but perhaps a non-Primate Plesiadapiform, which lived in Morocco, during the Paleocene, around 60 Ma. However, other studies, including molecular clock studies, have estimated the origin of the primate branch to have been in the mid-Cretaceous period, around 85 Ma, that is to say, in the time previous to the extinction of dinosaurs and the successful mammal radiation. Nevertheless, there seems to be a consensus about the monophyletic origin of the order, although the evidence is not clear. There are no fossils known that can be directly linked to the living African apes, nor any that could be considered representative of the last common ancestor between them and humans.
Megantereon
Fossil fragments have been found in Africa, Eurasia, and North America. The oldest confirmed records of "Megantereon" are known from the Pliocene of North America and are dated to about 4.5 million years. About 3-3.5 million years ago, it is firmly recorded also from Africa (for example, in Kenya), about 2.5 to 2 million years ago also from Asia. In Europe the oldest remains are known from Les Etouaries (France), a site which is now dated to less than 2.5 million years old. Therefore, a North American origin of "Megantereon" has been suggested. However, recent findings of fragmentary fossils from Kenya and Chad, which are dated to about 5.7 and 7 million years, respectively, are probably from "Megantereon". If these identifications are right, they would represent the oldest "Megantereon" fossils in the world. The new findings therefore indicate an origin of "Megantereon" in the Late Miocene of Africa.
Timeline of mosasaur research
The 20th century soon saw the discovery in Alabama of a strange mosasaur called "Globidens", with rounded teeth suited to crushing shells. Mosasaur remains were also discovered in Africa and California. In 1967 Dale Russell published a scientific monograph dedicated to mosasaurs. Embryonic remains in the 1990s confirmed that mosasaurs gave live birth like in ichthyosaurs. The 1990s also saw a revival and escalation of a debate regarding whether or not some supposed mosasaur toothmarks in ammonoid shells were actually made by limpets. By the end of the century, the evolutionary relationship between mosasaurs and snakes as well as the possible involvement of mosasaurs in the extinction of the aforementioned ichthyosaurs became hot button controversies.
Mustelidae
The oldest fossil of the mustelids were dated at the end of the Oligocene to the beginning of the Miocene. “There is debate regarding which fossils from these epochs represent possible ancestral forms that led to Mustelidae and which fossils represent the first modern mustelids.”(Wund, M. 2005. "Mustelidae" (On-line), Animal Diversity Web.) From the fossil record we can see that Mustelids appeared in the late Oligocene period (33 mya) in Eurasia and migrated throughout the continents. The Mustelids inhabit every continent except Antarctica and Australia. The mustelids migrated all throughout the continents that were connected during the early Miocene. The Mustelids made their way to North and South America via the Bering land bridge.
Mollesaurus
"Mollesaurus" is known from the holotype MOZ 2282 V, articulated partial skeleton which preserved partial skull and most of the vertebral column. It was collected in the Chacaico Sur locality from the "Emileia giebeli" ammonoid zone of the Los Molles Formation, Cuyo Group, dating to the early Bajocian stage of the Middle Jurassic, about 171.6-170 million years ago. "Mollesaurus", along with "Chacaicosaurus cayi" which was found at the same locality, are the only diagnostic ichthyosaur specimens from the Aalenian-Bathonian interval. It was found near Zapala city of the Neuquén Basin.
Melanosome
Recent (2008) discoveries by Xu Xing, a Chinese paleontologist, include fossilized feathers in rock formations dating from the Jurassic period (200 to 150 million years ago) to the late Paleogene and Neogene periods (66 to 2 million years ago). The feathers contain preserved residues of carbon that were previously thought to be traces of bacteria that decomposed feather tissues; however these (residues) are in fact microscopic organic imprints of fossilized melanosomes. Some of these structures still maintain an iridescent color typical of feather and fur tissues. It is conjectured that these microscopic structures could be further studied to reveal the original colors and textures of softer tissues in fossils. "The discovery of ultra-structural detail in feather fossils opens up remarkable possibilities for the investigation of other features in soft-bodied fossils, like fur and even internal organs," said Derek Briggs of the Yale University study team.
Plotosaurus
The type species, "P. bennisoni", was named for Allan Bennison, a fossil hunter who discovered the first remains in 1937. It was around long, and was the first known mosasaur from California (a year previously, Bennison had also discovered the state's first dinosaur, a species of "Saurolophus" that is now known as "Augustynolophus").
Phytosaur
When the first phytosaur fossils were found, it was not immediately obvious what kind of animal/species they were. The first phytosaur species known to science was named "Phytosaurus cylindricodon" - "plant lizard with cylindrical teeth" - by G. Jaeger in 1828 because he mistakenly believed that petrified mud fillings in the jaw were herbivore teeth. The specimen is too poor to be diagnostic, and this species name is no longer valid. The name of the group - Phytosauria - was coined by the German paleontologist Hermann von Meyer in 1861, on the basis of this first species.
Parrot
The first uncontroversial parrot fossils date to tropical Eocene Europe around 50 mya. Initially, a neoavian named "Mopsitta tanta", uncovered in Denmark's Early Eocene Fur Formation and dated to 54 mya, was assigned to the Psittaciformes. However, the rather nondescript bone is not unequivocally psittaciform, and it may rather belong to the ibis genus "Rhynchaeites", whose fossil legs were found in the same deposits.
Several fairly complete skeletons of parrot-like birds have been found in England and Germany. These are probably not transitional fossils between ancestral and modern parrots, but rather lineages that evolved parallel to true parrots and cockatoos:
The earliest records of modern parrots date to around 23–20 mya. The fossil record—mainly from Europe—consists of bones clearly recognisable as belonging to anatomically modern parrots. The Southern Hemisphere contains no known parrot-like remains earlier than the Early Miocene around 20 mya.
Moschorhinus
The first "Moschorhinus" specimen was discovered by Mr. James Kitching in the Karoo Beds of South Africa, near a New Bethesda Road. It was first described by paleontologist Robert Broom in 1920, who published his observations through the Zoological Society of London.
Dinosaur National Monument
The rock layer enclosing the fossils is a sandstone and conglomerate bed of alluvial or river bed origin known as the Morrison Formation from the Jurassic Period some 150 million years old. The dinosaurs and other ancient animals were carried by the river system which eventually entombed their remains in Utah.
Hesperosaurus
Fossils of "Hesperosaurus" have since 1985 been found in the state of Wyoming and Montana in the United States of America. The type species "Hesperosaurus mjosi" was named in 2001. It is from an older part of the Morrison Formation, and so a little older than other Morrison stegosaurs. Several relatively complete skeletons of "Hesperosaurus" are known. One specimen preserves the first known impression of the horn sheath of a stegosaurian back plate.
Feathered dinosaur
One of the earliest discoveries of possible feather impressions by non-avian dinosaurs is an ichnofossil ("Fulicopus lyellii") of the 195-199 million year old Portland Formation in the northeastern United States. Gierlinski (1996, 1997, 1998) and Kondrat (2004) have interpreted traces between two footprints in this fossil as feather impressions from the belly of a squatting dilophosaurid. Although some reviewers have raised questions about the naming and interpretation of this fossil, if correct, this early Jurassic fossil is the oldest known evidence of feathers, almost 30 million years older than the next-oldest-known evidence.
After a century of hypotheses without conclusive evidence, well-preserved fossils of feathered dinosaurs were discovered during the 1990s, and more continue to be found. The fossils were preserved in a Lagerstätte—a sedimentary deposit exhibiting remarkable richness and completeness in its fossils—in Liaoning, China. The area had repeatedly been smothered in volcanic ash produced by eruptions in Inner Mongolia 124 million years ago, during the Early Cretaceous epoch. The fine-grained ash preserved the living organisms that it buried in fine detail. The area was teeming with life, with millions of leaves, angiosperms (the oldest known), insects, fish, frogs, salamanders, mammals, turtles, and lizards discovered to date.
Achelousaurus
All known "Achelousaurus" specimens were recovered from the Two Medicine Formation in Glacier County, Montana during excavations conducted by the Museum of the Rockies, which still houses the specimens. The discoveries came about by an accidental chain of events. In the spring of 1985, paleontologist John "Jack" R. Horner was informed that he would no longer be allowed to exploit the Willow Creek site, where he had studied the "Maiasaura" Egg Mountain nesting colony for six years. Having already made extensive arrangements for a new field season, he was suddenly forced to seek an alternative site. Horner had always been intrigued by the field diaries of Charles Whitney Gilmore who had reported the discovery of dinosaur eggs at Landslide Butte in 1928, but never published on them. In this locality, Gilmore had employed George Fryer Sternberg to excavate skeletons of the horned dinosaurs "Brachyceratops" and "Styracosaurus ovatus". That summer, Horner obtained the permission of the Blackfeet Indian Tribal Council to prospect for fossils on Landslide Butte, which is part of the Blackfeet Indian Reservation; it was the first paleontological investigation at that location since the 1920s. In August 1985, Horner's associate Bob Makela discovered a rich fossil site on the land of the farmer Ricky Reagan, which was called the Dinosaur Ridge Quarry and contained fossils of horned dinosaurs. On 20 June 1986, Horner and Makela returned to the Blackfeet Indian Reservation and resumed work on the Dinosaur Ridge Quarry, which proved to contain, apart from eggs, more than a dozen skeletons of a horned dinosaur later named "Einiosaurus". In August 1986, at a nearby site – the Canyon Bone Bed on the land of Gloria Sundquist, east of the Milk River – Horner's team discovered another "Einiosaurus" bone bed. Part of the discoveries made on this occasion was an additional horned dinosaur skull, specimen MOR 492, that later would be referred to (i.e., formally assigned to) "Rubeosaurus", the genus name in 2010 given to "Styracosaurus ovatus".
Archaeornithoides
In 1965, a Polish-Mongolian paleontological expedition found a fossil of a small dinosaur at Bayn Dzak, Mongolia. In 1983, the find was reported by Andrzej Elzanowski. The remains were named as the type species "Archaeornithoides deinosauriscus" by Elzanowski and Peter Wellnhofer in 1992. In 1993, they were described in more detail by the same authors.
Timeline of plesiosaur research
This timeline of plesiosaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, taxonomic revisions, and cultural portrayals of plesiosaurs, an order of marine reptiles that flourished during the Mesozoic Era. The first scientifically documented plesiosaur fossils were discovered during the early by Mary Anning. Plesiosaurs were actually discovered and described before dinosaurs. They were also among the first animals to be featured in artistic reconstructions of the ancient world, and therefore among the earliest prehistoric creatures to attract the attention of the lay public. Plesiosaurs were originally thought to be a kind of primitive transitional form between marine life and terrestrial reptiles. However, now plesiosaurs are recognized as highly derived marine reptiles descended from terrestrial ancestors.
Russellosaurus
The type species, "R. coheni", was named for the amateur fossil collector who discovered SMU 73056, and the genus name honours paleontologist Dale A. Russell for his extensive work on mosasaurs ("Russell's lizard"). This is the second species of mosasaur to have been named for Russell, the first being "Selmasaurus russelli" (Wright and Shannon, 1988). The type specimen of "Russellosaurus" is notable as being the oldest well-preserved mosasaur yet found in North America.
Timeline of mosasaur research
1868
Benjamin Franklin Mudge
Mudge began geological and paleontological field expeditions in 1865, while still employed at KSAC. He collected footprints near Junction City in 1865, and invertebrates and Late Cretaceous deciduous leaves near Ellsworth in 1866, and more plants and a saurian in 1869 from the Republican River near the northern state line. His expedition in 1870 was near Fort Wallace and saw the discovery of numerous plesiosaurs and fish from the Saurodontidae family. 1871 saw plants, molluscs, vertebrates, and the bird "Hesperornis" from western Kansas. In 1872 more vertebrates and plants were discovered in Smith County, while in 1873 new species were discovered in Trego and Ellis Counties, and plesiosaurs were found in 1874 in Jewell and Gove Counties.
While he maintained a small collection as KSAC, the majority of his finds were sent to Eastern paleontologists to be described. He initially corresponded in this fashion with Fielding Bradford Meek at the Smithsonian (primarily concerning molluscs), Leo Lesquereux (plants), Edward Drinker Cope at the Academy of Natural Sciences in Philadelphia (vertebrates), Othniel Charles Marsh at the Peabody Museum of Natural History at Yale, Louis Agassiz at Harvard, and James Dwight Dana at Yale. In turn, Cope visited Mudge in 1871, and Cope, Marsh, and Lesquerenx all visited in 1872. Cope and Lesquerenx published most of Mudge's discoveries from this period.
Mudge discovered Ichthyornis in 1872. While he initially planned to ship the specimen to Cope, he heard of Othniel Charles Marsh's interest and sent it instead to his former acquaintance from Connecticut. Marsh first described the bird in 1872, but misidentified the toothed jaw as belonging to a type of lizard. Marsh associated the jaw with the avian postcranial elements and published the new data the next year. An analysis in 1952 concluded the jaw actually belonged to a mosasaur, but a reevaluation in 1967 and new specimens confirmed Marsh's assessment.
Lyme Regis
The Blue Lias rock is host to a multitude of remains from the early Jurassic, a time from which good fossil records are rare. Many remains are well preserved, including complete specimens of important species. Many of the earliest discoveries of dinosaur and other prehistoric reptile remains were made in the area around Lyme Regis, notably those discovered by Mary Anning (1799–1847). Significant finds include "Ichthyosaur", "Plesiosaur", "Dimorphodon", "Scelidosaurus" (one of the first armoured dinosaurs) and "Dapedium". The town holds an annual Mary Anning Day and Lyme Regis Fossil Festival. A fossil of the world's largest moth was discovered in 1966 at Lyme Regis.
Timeline of United States discoveries
Torosaurus was a herbivorous dinosaur that lived during the Late Cretaceous Period about 70 million years ago in what is now North America. Torosaurus had an enormous head that measured 8 feet (2.5 m) in length. Its skull is one of the largest know up to date, no other land animal has ever had a skull larger than Torosaurus. Torosaurus frill made up about one-half the total skull length. The first fossils of Torosaurus were discovered in 1889, in Wyoming by John Bell Hatcher. The American paleontologist Othniel Charles Marsh would later name the specimen "Torosaurus latus", in recognition of the bull-like size of its skull and its large eyebrow horns. Ever since, the specimen has been in display at the Peabody Museum in New Haven, Connecticut.
Compsognathidae
The first significant fossil specimen of Compsognathidae was found in the Bavaria region of Germany (BSP AS I 563) and given to collector Joseph Oberndorfer in 1859. The finding was initially significant because of the small size of the specimen. In 1861, after an initial period of review, Johann A. Wagner presented his analysis of the specimen to the public and named the fossil "Compsognathus longipes"( “elegant jaw”). In 1868, Thomas Henry Huxley, an explorer known for his travels with Charles Darwin and an early supporter of the theory of evolution, used "Compsognathus" in a comparison to similar feathered dinosaur "Archaeopteryx" in order to propose the origin of birds. While Huxley noticed that these dinosaurs shared a similar layout to birds and proposed an exploration of the similarities. He is credited as being the first person to do so. This initial comparison sparked the interest into the origin of birds and feathers. In 1882, Othniel Charles Marsh named a new family of dinosaurs for this species "Compsognathidae" and officially recognized the species as part of Dinosauria"."
Mosasaur
Mosasaur growth is not well understood, as specimens of juveniles are rare, and many were mistaken for hesperornithine birds when discovered 100 years ago. However, the discovery of several specimens of juvenile and neonate-sized mosasaurs unearthed more than a century ago indicate that mosasaurs gave birth to live young, and that they spent their early years of life out in the open ocean, not in sheltered nurseries or areas such as shallow water as previously believed. If, like other marine reptiles (such as plesiosaurs), mosasaurs provided parental care is currently unknown. The discovery of young mosasaurs was published in the journal "Palaeontology".
Moose
The earliest known species is "Libralces gallicus" (French moose), which lived in the Pliocene epoch, about 2 million years ago. "Libralces gallicus" came from the warm savannahs of Pliocene Europe, with the best preserved skeletons being found in southern France. "L. gallicus" was 1.25 times larger than the Alaskan moose in linear dimensions, making it nearly twice as massive. "L. gallicus" had many striking differences from its modern descendants. It had a longer, narrower snout and a less-developed nasal cavity, more resembling that of a modern deer, lacking any sign of the modern moose-snout. Its face resembled that of the modern wapiti. However, the rest of its skull structure, skeletal structure and teeth bore strong resemblance to those features that are unmistakable in modern moose, indicating a similar diet. Its antlers consisted of a horizontal bar long, with no tines, ending in small palmations. Its skull and neck structure suggest an animal that fought using high-speed impacts, much like the Dall sheep, rather than locking and twisting antlers the way modern moose combat. Their long legs and bone structure suggest an animal that was adapted to running at high speeds over rough terrain.
Allosaurus
The discovery and early study of "Allosaurus" is complicated by the multiplicity of names coined during the Bone Wars of the late 19th century. The first described fossil in this history was a bone obtained secondhand by Ferdinand Vandiveer Hayden in 1869. It came from Middle Park, near Granby, Colorado, probably from Morrison Formation rocks. The locals had identified such bones as "petrified horse hoofs". Hayden sent his specimen to Joseph Leidy, who identified it as half of a tail vertebra, and tentatively assigned it to the European dinosaur genus "Poekilopleuron" as "Poicilopleuron" "valens". He later decided it deserved its own genus, "Antrodemus".
Mesosaurus
Clearly amniote-type fossil embryos of "Mesosaurus" in an advanced stage of development (i.e. fetuses) have been discovered in Uruguay and Brazil. These fossils are the earliest record of amniote fetuses, although amniotes are inferred to have had their typical reproductive strategy since their first appearance in the Late Carboniferous. Prior to their description, the oldest known amniote fetuses were from the Triassic. One isolated coiled fetus called FC-DPV 2504 is not surrounded by calcareous egg shells, suggesting that the glands in the oviduct of "Mesosaurus" and probably all paleozoic amniotes were not able to secrete calcium carbonate, in contrast to post-paleozoic archosaurs. This would explain the scarcity of egg fossils in the paleozoic amniote fossil record. One "Mesosaurus" specimen called MCN-PV 2214 comprises a medium-size adult with a small individual in its rib cage which is interpreted as a fetus ‘in utero’, even suggesting that "Mesosaurus" like many other marine reptiles, gave live birth. If this interpretation is correct, this specimen would represent the earliest known example of viviparity in the fossil record. The isolated fetus FC-DPV 2504, however, rather points to an ovoviviparous reproduction strategy in "Mesosaurus".
Mosquito
The oldest known mosquito with an anatomy similar to modern species was found in 79-million-year-old Canadian amber from the Cretaceous. An older sister species with more primitive features was found in Burmese amber that is 90 to 100 million years old. Two mosquito fossils have been found that show very little morphological change in modern mosquitoes against their counterpart from 46 million years ago. These fossils are also the oldest ever found to have blood preserved within their abdomens. Despite no fossils being found earlier than the Cretaceous, recent studies suggest that the earliest divergence of mosquitoes between the lineages leading to Anophelinae and Culicinae occurred 226 million years ago.
Plioplatecarpinae
Plioplatecarpines were small to medium-sized mosasaurs that were comparatively fast and agile compared to mosasaurs of other subfamilies. The first plioplatecarpines appear in the Turonian and are among the oldest of mosasaurs, and the clade persists throughout the Maastrichtian, a period of approximately 24 million years. The subfamily was seemingly heavily affected during a poorly understood middle-Campanian mosasaur extinction event and its genera appear to have faced competition from mosasaurine mosasaurs during the Maastrichtian, leading to a decline in numbers and in diversity.
Evolution of dinosaurs
The process leading up to the Dinosauromorpha and the first true dinosaurs can be followed through fossils of the early Archosaurs such as the Proterosuchidae, "Erythrosuchidae" and "Euparkeria" which have fossils dating back to 250 Ma, through mid-Triassic archosaurs such as "Ticinosuchus" 232-236 Ma. Crocodiles are also descendants of mid-Triassic archosaurs.
Poposaurus
The first remains of "Poposaurus" were found in 1904 near Lander, Wyoming. In 1907, paleontologist J. H. Lees described this fossil, an ilium (part of the hip) from the Popo Agie Formation, and identified it as that of the phytosaur "Paleorhinus bransoni". In 1915, paleontologist M. G. Mehl named "Poposaurus" based on more complete material from the Popo Agie Formation, including vertebrae, hips, and limb bones. He cited the holotype as [Walker Museum] 602, but in fact the holotype is UR 357. Mehl concluded that the ilium described by Lees, UR 358, also belonged to "Poposaurus". He did not classify "Poposaurus" as a phytosaur because the shape of its ilium was different and it had more sacral vertebrae fused to the hip. Mehl made comparisons between "Poposaurus" and the earlier named "Dolichobrachium", also from the Triassic of Wyoming. "Dolichobrachium" was only known from some teeth, a humerus, and part of the pectoral girdle, so Mehl suggested that the "Poposaurus" and "Dolichobrachium" material could belong to the same animal. Mehl noted similarities between "Poposaurus" and theropod dinosaurs, including its hollow leg bones and deep hip socket, but did not consider it a dinosaur because each sacral vertebra supported only one rib (theropods usually have multiple ribs projecting from each sacral vertebra).
Mosasaur
When the French revolutionary forces occupied Maastricht in 1794, the carefully hidden fossil was uncovered, after a reward, it is said, of 600 bottles of wine, and transported to Paris. After it had been earlier interpreted as a fish, a crocodile, and a sperm whale, the first to understand its lizard affinities was the Dutch scientist Adriaan Gilles Camper in 1799. In 1808, Georges Cuvier confirmed this conclusion, although "le Grand Animal fossile de Maëstricht" was not actually named "Mosasaurus" ('Meuse reptile') until 1822 and not given its full species name, "Mosasaurus hoffmannii," until 1829. Several sets of mosasaur remains, that had been discovered earlier at Maastricht but were not identified as mosasaurs until the 19th century, have been on display in the Teylers Museum, Haarlem, procured from 1790.
Mosasaur
Mosasaurs (from Latin "Mosa" meaning the 'Meuse river', and Greek σαύρος "sauros" meaning 'lizard') are an extinct group of large marine reptiles containing 38 genera in total. Their first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764. Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Early Cretaceous. During the last 20 million years of the Cretaceous period (Turonian-Maastrichtian ages), with the extinction of the ichthyosaurs and pliosaurs, mosasaurs became the dominant marine predators. They became extinct as a result of the K-Pg event at the end of the Cretaceous period, about 66 million years ago.
Plesiosaurus
The first complete skeleton of "Plesiosaurus" was discovered by early paleontologist and fossil hunter Mary Anning in Sinemurian (Early Jurassic)-age rocks of the lower Lias Group in December 1823. Additional fossils of "Plesiosaurus" were found in rocks of the Lias Group of Dorset for many years, "until the cessation of quarrying activities in the Lias Group, early in this [20th] century."
Mistaken Point Ecological Reserve
The first fossil to be found in the area, "Fractofusus misrai", was discovered in June 1967 by Shiva Balak Misra, an Indian graduate student studying geology at Memorial University of Newfoundland. The site became quickly recognized in the mid-1980s as an important find containing probably the oldest metazoan fossils in North America and the most ancient deep-water marine fossils in the world. a A 5 kilometer stretch of coastline was first established provisionally as a reserve by the provincial government in 1984 and was permanently designated in 1987. It was later expanded in 2009 after further fossil discoveries.
Woolly mammoth
Between 1692 and 1806, only four descriptions of frozen mammoths were published in Europe. None of the remains of those five were preserved, and no complete skeleton was recovered during that time. While frozen woolly mammoth carcasses had been excavated by Europeans as early as 1728, the first fully documented specimen was discovered near the delta of the Lena River in 1799 by Ossip Schumachov, a Siberian hunter. Schumachov let it thaw until he could retrieve the tusks for sale to the ivory trade. While in Yakutsk in 1806, Michael Friedrich Adams heard about the frozen mammoth. Upon arrival at the location, Adams discovered that wild animals had eaten most of the organs and flesh of the mammoth, including the trunk. He examined the carcass and realised what was left would still be the most complete mammoth recovered by that time. Adams recovered the entire skeleton, apart from the tusks, which Shumachov had already sold, and one foreleg, most of the skin, and nearly 18 kg (40 lb) of hair. During his return voyage he purchased a pair of tusks that he believed were the ones that Shumachov had sold. Adams brought it to the Zoological Museum of the Zoological Institute of the Russian Academy of Sciences, and the task of mounting the skeleton was given to Wilhelm Gottlieb Tilesius. The Kunstkamera, the museum established by Peter the Great, contained the skeleton of an Indian elephant that could be used as reference. This was one of the first attempts at reconstructing the skeleton of an extinct animal. Most of the reconstruction is correct, but Tilesius placed each tusk in the opposite socket, so that they curved outward instead of inward. The error was not corrected until 1899, and the correct placement of mammoth tusks was still a matter of debate into the twentieth century.
Dinosaur Ridge
The Dinosaur Ridge area is one of the world's most famous dinosaur fossil localities. In 1877, some of the best-known dinosaurs were found here, including "Stegosaurus", "Apatosaurus", "Diplodocus", and "Allosaurus". In 1973, the area was recognized for its uniqueness as well as its historical and scientific significance when it was designated the Morrison Fossil Area National Natural Landmark by the National Park Service. In 1989, the Friends of Dinosaur Ridge formed to address increasing concerns regarding the preservation of the site and to offer educational programs on the area's resources.
Joan Wiffen
In 1975 Wiffen discovered the first dinosaur fossils in New Zealand in the Maungahounga Valley in Northern Hawkes Bay. Her first discovery was the tail bone of a theropod dinosaur. Her later finds included bones from a hypsilophodont, a pterosaur, an ankylosaur, mosasaurs and plesiosaurs. In 1999, Wiffen discovered the vertebra bone of a titanosaur in a tributary of the Te Hoe River. The fossils Wiffen found are primarily held in a GNS Science collection.
List of Indian and Madagascan dinosaurs
The Indian fossil record of dinosaurs is good, with fossils coming from the entire Mesozoic era – starting with the Triassic period (a geological period that started 251.9 million years ago and continued till 201.3 million years ago), to the Jurassic period (201 million years ago to 145 million years ago) and Cretaceous period (from 145 million years ago to 66 million years ago), when globally all non-avian dinosaurs and 65 per cent of all life became extinct. Madagascar also preserves various unique dinosaurs from the Jurassic and Cretaceous.This is a timeline of selected dinosaurs from the list above. Time is measured in Ma, megaannum, along the x-axis.
Megalosauridae
From the family's inception, many specimens found in the field have been wrongly classified as megalosaurids. For example, most large carnivores found for about a century after the naming of "Megalosaurus bucklandii" were placed in Megalosauridae. "Megalosaurus" was the first paleontological finding of its kind when William Buckland discovered a giant femur and named it in 1824, predating even the term Dinosauria. When initially defined, the species "M. bucklandii" was anatomically based on various dissociated bones found in quarries around the village of Stonesfield, UK. Some of these early findings included a right dentary with a well-preserved tooth, ribs, pelvic bones, and sacral vertebrae. As early paleontologists and researchers found more dinosaur bones in the surrounding area, they attributed them all to "M. bucklandii" since it was the only named and described dinosaur at this point in history. Therefore, the species was initially described and classified by a mass of possibly unrelated characteristics.
Tylosaurus
Like many other mosasaurs, the early history of this taxon is complex and involves the infamous rivalry between two early American paleontologists, Edward Drinker Cope and Othniel Charles Marsh. Originally, the name ""Macrosaurus" proriger" was proposed by Cope for a fragmentary skull and thirteen vertebrae collected from near Monument Rocks in western Kansas in 1868. It was placed in the collections of the Harvard Museum of Comparative Zoology. Only a year later, Cope redescribed the same material in greater detail and referred it, instead, to the English mosasaur taxon "Liodon". Then, in 1872, Marsh named a more complete specimen as a new genus, "Rhinosaurus" ("nose lizard"), but soon discovered that this name had already been used for a different animal. Cope suggested that "Rhinosaurus" be replaced by yet another new name, "Rhamposaurus" which also proved to be preoccupied. Marsh finally erected "Tylosaurus" later in 1872, to include the original Harvard material as well as additional, more complete specimens which had also been collected from Kansas. A giant specimen of "T. proriger", recovered in 1911 by C. D. Bunker near Wallace, Kansas is one of the largest skeletons of "Tylosaurus" ever found. It is currently on display at the University of Kansas Museum of Natural history.
In 1918, Charles H. Sternberg found a "Tylosaurus", with the remains of a plesiosaur in its stomach. The specimen is currently mounted in the United States National Museum (Smithsonian) and the plesiosaur remains are stored in the collections. Although these important specimens were briefly reported by C. H. Sternberg (1922), the information was lost to science until 2001. This specimen was rediscovered and described by Everhart (2004a). It is the basis for the story line in the 2007 National Geographic IMAX movie "", and a book by the same name (Everhart, 2007).
List of North American dinosaurs
The earliest record of dinosaurs in North America comes from rare, unidentified (possibly theropod) footprints and teeth in the Middle-Late Triassic Pekin Formation of North Carolina. Later in the Triassic period, dinosaurs left more recognizable remains, and could thus be identified as specific genera. Examples of later Triassic North American dinosaur genera include "Coelophysis", "Chindesaurus", "Gojirasaurus", and "Tawa". Fossils of "Tawa"-like dinosaurs have also been found in South America, which has important indications about paleogeography. During the Early Jurassic Period, dinosaurs such as "Dilophosaurus", "Anchisaurus", "Coelophysis" (formerly known as "Megapnosaurus"), and the early thyreophoran "Scutellosaurus" lived in North America. The latter is believed to have been the ancestor of all stegosaurs and ankylosaurs. The Middle Jurassic is the only poorly represented time period in North America, although several Middle Jurassic localities are known from Mexico. Footprints, eggshells, teeth, and fragments of bone representing theropods, sauropods, and ornithopods have been found, but none of them are diagnostic to the genus level. 
The Late Jurassic of North America, however, is the exact opposite of the Middle Jurassic. The Late Jurassic Morrison Formation is found in several U.S. states, including Colorado, Utah, Wyoming, Montana, New Mexico, Oklahoma, South Dakota, and Texas. It is notable as being the most fertile single source of dinosaur fossils in the world. The roster of dinosaurs from the Morrison is impressive. Among the theropods, "Allosaurus", "Saurophaganax", "Torvosaurus", "Ceratosaurus", "Coelurus", "Ornitholestes", "Tanycolagreus", "Stokesosaurus", and "Marshosaurus" are found in the Morrison. An abundance of sauropods has been found there, including "Apatosaurus", "Diplodocus", "Barosaurus", "Brachiosaurus", "Camarasaurus", "Brontosaurus" and "Amphicoelias". Three genera of stegosaurs, "Alcovasaurus", "Stegosaurus" and "Hesperosaurus", have been found there. Finally, ornithopods found in the Morrison include "Dryosaurus", "Camptosaurus", "Drinker", "Othnielia", and "Othnielosaurus".
Dinosaur Cove
In 1903, geologist William Hamilton Ferguson was mapping the rocky coastal outcrops a few kilometres west of Inverloch and uncovered the first dinosaur fossil ever discovered in Australia. 75 years later, the exploration and excavation of the Dinosaur Cove site was conducted by teams of volunteers overseen by Thomas H. Rich and Patricia Rich. The dinosaur taxa, "Leaellynasaura amicagraphica" and "Timimus hermani", are named for the children of the Riches', Tim and Leaellyn. Heavy mining equipment and dynamite was used to blast away overlying strata to uncover the fossiliferous rock layers in the cliff face.
Mosasaurus
De Saint-Fond still assumed the specimen represented a crocodile. In 1798 the son of Petrus Camper, Adriaan Gilles Camper, again studied the fossil indirectly by reconsidering the description by his father. He was the first to reach the conclusion that the remains were those of a giant monitor, which result in 1799 he corresponded to Georges Cuvier.
Mosasaurus
On Saturday, April 18, 2015, a fourteen-year-old amateur paleontologist, Lars Barten, from Rijkevoort village in Noord-Brabant province in the Netherlands, together with his father Jos Barten, discovered a "Mosasaurus hoffmani" fossil near ENCI-Maastricht. The fossil has been named Lars, after its finder and now resides in the Natuurhistorisch Museum Maastricht (Maastricht Natural History Museum).
Gasosaurus
The first and to date only fossils, albeit postcranial (missing the skull), were recovered in 1985 during the construction of a gas facility, which explains the dinosaur's unusual name. It consists of laterally compressed teeth, 4 cervical, 7 dorsal, 5 sacral, and 7 caudal vertebrae, both humeri, and highly abraded and reconstructed pelvic and hind limb material that includes the left ilium, left ischium, left pubis, left femur, left tibia and left fibula. The fossils were defined as the type species "Gasosaurus constructus" by the paleontologists Dong Zhiming and Tang Zilu.
Courtenay, British Columbia
The first major paleontological discovery in Courtenay occurred in 1988 when resident Mike Trask and his daughter discovered the first fossil of an 80-million-year-old Elasmosaur on the banks of the Puntledge River. Over the next few months, the excavation, led by Dr. Roif Ludvigson, revealed a near complete skeleton. The skull and other key bones for identifying the species were in poor condition, and it is still unknown as to what species or genus this Elasmosaur belonged. The original bones and a replica model are on display at the Courtenay & District Museum and Paleontology Center.
Megalosauridae
The defining megalosaurid is "Megalosaurus bucklandii", first named and described in 1824 by William Buckland after multiple finds in Stonesfield, Oxfordshire, UK. "Megalosaurus" was the first formally described dinosaur and was the basis for the establishment of the clade Dinosauria. It is also one of the largest known Middle Jurassic carnivorous dinosaurs, with the best-preserved femur at 805 mm and a proposed body mass of around 943 kg. Megalosauridae is recognized as a mainly European group of dinosaurs, based on fossils found in France and the UK. However, recent discoveries in Niger have led some to consider the range of the family. Megalosaurids appeared right before the split of the supercontinent Pangaea into Gondwana and Laurasia. These large theropods therefore may have dominated both halves of the world during the Jurassic.
Mignon Talbot
Mignon Talbot (August 16, 1869 – July 18, 1950) was an American paleontologist who recovered the only fossils of the dinosaur, "Podokesaurus holyokensis", located near Mount Holyoke College in 1910 and published a scientific description of the fossil in 1911. She was the first woman to become a member of the Paleontological Society. In the state of New York, she contributed to the Helderbergian crinoids and studied the faunas of Stafford limestone.
Mary Anning
Anning searched for fossils in the area's Blue Lias cliffs, particularly during the winter months when landslides exposed new fossils that had to be collected quickly before they were lost to the sea. She nearly died in 1833 during a landslide that killed her dog, Tray. Her discoveries included the first ichthyosaur skeleton correctly identified; the first two more complete plesiosaur skeletons found; the first pterosaur skeleton located outside Germany; and important fish fossils. Her observations played a key role in the discovery that coprolites, known as bezoar stones at the time, were fossilised faeces. She also discovered that belemnite fossils contained fossilised ink sacs like those of modern cephalopods. When geologist Henry De la Beche painted "Duria Antiquior", the first widely circulated pictorial representation of a scene from prehistoric life derived from fossil reconstructions, he based it largely on fossils Anning had found, and sold prints of it for her benefit.
Paleontology in Texas
Archaeologist Jack. T. Hughes has found evidence that the paleo-Indians of Texas collected fossils. After the establishment of paleontology as a formal science, in 1878, professor Jacob Boll made the first scientifically documented Texan fossil finds in Archer and Wichita counties while collecting fossils on behalf of Edward Drinker Cope. In 1880 W. E. Cummins began a series of expeditions into Texas and other regions of the American southwest. Like Boll, Cummins was collecting for Cope. C. H. Sternberg also did "very successful" fieldwork in Texas between 1896 and 1917. In 1938, Barnum Brown of the American Museum of Natural History sent Roland T. Bird to Texas in search of dinosaur footprints uncovered by local moonshiners. At the town of Glen Rose he noticed a medium sized footprint left by a carnivorous dinosaur in a limestone block forming part of the Somervell County courthouse's bandstand. Local residents guided him to yet further carnivorous dinosaur tracks preserved in situ along the Paluxy River. While he was cleaning mud from these footprints, he noticed another kind of footprint, apparently left by a long-necked sauropod dinosaur. Brown was intrigued by the find. At the time, Dr. E. H. Sellards of the University of Texas was organizing the Texas Statewide Paleontological Survey. Brown arranged for a collaborative expedition between the American Museum of Natural History and the Survey. In 1940, Bird resumed his Texas fieldwork with the help of paleontologists from the Survey and labor employed by the Works Progress Administration. Some of the tracks excavated here were sent to the American Museum of Natural History and incorporated into an exhibit featuring "Allosaurus" and "Apatosaurus" even though they were 35 million years older than the dinosaurs that left behind the tracks in Texas and aren't even known from the state. Other track fossils uncovered during these excavations were sent to institutions like the Baylor University, Brooklyn College, the United States National Museum, Southern Methodist University, and the University of Texas. In 1964 Bob Slaughter found two genera of mosasaurs south of Dallas as well as Miocene and Pleistocene fossils from the Livingston Reservoir basin. In 1994, Bill Sarjeant and Wann Langston published a monograph documenting fossil footprints laid down in the volcanic ash of the Vieja Group 36 to 38 million years ago during the late Eocene. They observed the tracks of six birds, two invertebrates, nineteen mammals, and two turtles. Among the mammals were relatives of camels and tapirs as well as carnivores and insectivores. This monograph was the culmination of almost twenty years of research and its subject the most spectacular known Tertiary-aged fossil tracksite in the western United States.