The 20th century in ichnology refers to advances made between the years 1900 and 1999 in the scientific study of trace fossils, the preserved record of the behavior and physiological processes of ancient life forms, especially fossil footprints. Significant fossil trackway discoveries began almost immediately after the start of the 20th century with the 1900 discovery at Ipolytarnoc, Hungary of a wide variety of bird and mammal footprints left behind during the early Miocene. [1] Not long after, fossil Iguanodon footprints were discovered in Sussex, England, a discovery that probably served as the inspiration for Sir Arthur Conan Doyle's The Lost World . [2]
Several enduring mysteries from the 19th century continued to vex ichnologists, like the identity of the Chirotherium trackmaker. Renowned paleontologist Franz von Nopcsa attributed the ichnogenus to the prosauropod dinosaur Plateosaurus , despite an apparent mismatch between its number of toes (4) and the preserved digit traces of Chirotherium (5). Von Nopcsa explained the discrepancy by arguing that one of the impressions in the Chirotherium tracks was left by a soft tissue structure that did not fossilize. [3] However, it was Wolfgang Soergel who correctly hypothesized that Chirotherium was produced by a distant relative of modern crocodilians. Using only its footprints as a guide he reconstructed the life appearance of the Chirotherium trackmaker. Decades later paleontologists described an animal named Ticinosuchus which precisely fulfilled Soergel's predictions. Ticinosuchus or a close relative seems to have been the true Chirotherium trackmaker. [4]
During the 20th century, many significant fossil trackway discoveries were made in the western United States. In the 1930s and 1940s, Roland T. Bird discovered the tracks of large sauropod and theropod dinosaurs in Texas. He excavated a major section of the track ways on behalf of the American Museum of Natural History. This was the first large scale excavation of fossil footprints in history. [5] In the 1950s Lee Stokes reported unusual footprints he interpreted as the first known pterosaur tracks. [6] This attribution would be controversial much of the rest of the century but has since been vindicated. [7] The dinosaur footprints of Dinosaur Ridge in Colorado were also discovered and studied in the 20th century. [8]
The advent of the dinosaur renaissance and the publication by R. McNeil Alexander of a formula which could reconstruct their running speed based on data from fossil trackways brought renewed interest and prestige to ichnology during the late 20th century. [9] This led to several symposia on the subject of vertebrate trace fossils. In 1986 such a conference dedicated to dinosaur footprints was held in New Mexico. [10] Roughly a decade later renowned German ichnologist Heinrich Haubold organized a conference dedicated to the more ancient footprints of the Paleozoic Era. This gathering has been regarded as a turning point in the study of tracks of that age. [11]
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c. 1939
A fossil track or ichnite is a fossilized footprint. This is a type of trace fossil. A fossil trackway is a sequence of fossil tracks left by a single organism. Over the years, many ichnites have been found, around the world, giving important clues about the behaviour of the animals that made them. For instance, multiple ichnites of a single species, close together, suggest 'herd' or 'pack' behaviour of that species.
Eubrontes is the name of fossilised dinosaur footprints dating from the Late Triassic and Early Jurassic. They have been identified from France, Poland, Slovakia, Czech Republic, Italy, Spain, Sweden, Australia (Queensland), US, India and China.
Martin G. Lockley was a Welsh palaeontologist. He was educated in the United Kingdom where he obtained degrees and post-doctoral experience in Geology in the 1970s. Since 1980 he had been a professor at the University of Colorado at Denver, (UCD) and was later Professor Emeritus. He is best known for his work on fossil footprints and was the former director of the Dinosaur Tracks Museum at UCD. He was an Associate Curator at the University of Colorado Museum of Natural History and Research Associate at the Denver Museum of Nature and Science. During his years at UCD he earned a BA in 2007 in Spanish with a minor in Religious Studies, became a member of the Scientific and Medical Network and taught and published on the evolution of consciousness.
The Purgatoire River track site, also called the Picketwire Canyonlands tracksite, is one of the largest dinosaur tracksites in North America. The site is located on public land of the Comanche National Grassland, along the Purgatoire ("Picketwire") River south of La Junta in Otero County, Colorado.
The Calcários Micríticos da Serra de Aire is a Bathonian geologic formation in Portugal. Fossil sauropod tracks have been reported from the formation.
Parabrontopodus is an ichnogenus of dinosaur footprint, that was initially described by Lockley et al. in 1994, and was assigned to Sauropoda by Lockley in 2002 and in 2004 by Niedzwiedzki and Pienkowski. Various species through their footprints that are characterized by the association of two impressions left by hand and foot. The acquisition of a specific family is complex, but now in most cases, they have been considered diplodocoids and similar animals. The reason is that their traces left are large, but in proportion to the size, from animals, seem very light because the depth of imprint is low.
Abelichnus is an extinct ichnogenus of dinosaur footprint from the Candeleros Formation and the Rio Limay Formation. The type ichnospecies, Abelichnus astigerrae, was first discovered in Argentina in 1987 and was recorded as the biggest known dinosaur footprint ever discovered. Abelichnus probably grew to a size of 12.5-13 meters long.
Paleontology in Arkansas refers to paleontological research occurring within or conducted by people from the U.S. state of Arkansas. The fossil record of Arkansas spans from the Ordovician to the Eocene. Nearly all of the state's fossils have come from ancient invertebrate life. During the early Paleozoic, much of Arkansas was covered by seawater. This sea would come to be home to creatures including Archimedes, brachiopods, and conodonts. This sea would begin its withdrawal during the Carboniferous, and by the Permian the entire state was dry land. Terrestrial conditions continued into the Triassic, but during the Jurassic, another sea encroached into the state's southern half. During the Cretaceous the state was still covered by seawater and home to marine invertebrates such as Belemnitella. On land the state was home to long necked sauropod dinosaurs, who left behind footprints and ostrich dinosaurs such as Arkansaurus.
Paleontology in Texas refers to paleontological research occurring within or conducted by people from the U.S. state of Texas. Author Marian Murray has said that "Texas is as big for fossils as it is for everything else." Some of the most important fossil finds in United States history have come from Texas. Fossils can be found throughout most of the state. The fossil record of Texas spans almost the entire geologic column from Precambrian to Pleistocene. Shark teeth are probably the state's most common fossil. During the early Paleozoic era Texas was covered by a sea that would later be home to creatures like brachiopods, cephalopods, graptolites, and trilobites. Little is known about the state's Devonian and early Carboniferous life. Evidence indicates that during the late Carboniferous the state was home to marine life, land plants and early reptiles. During the Permian, the seas largely shrank away, but nevertheless coral reefs formed in the state. The rest of Texas was a coastal plain inhabited by early relatives of mammals like Dimetrodon and Edaphosaurus. During the Triassic, a great river system formed in the state that was inhabited by crocodile-like phytosaurs. Little is known about Jurassic Texas, but there are fossil aquatic invertebrates of this age like ammonites in the state. During the Early Cretaceous local large sauropods and theropods left a great abundance of footprints. Later in the Cretaceous, the state was covered by the Western Interior Seaway and home to creatures like mosasaurs, plesiosaurs, and few icthyosaurs. Early Cenozoic Texas still contained areas covered in seawater where invertebrates and sharks lived. On land the state would come to be home to creatures like glyptodonts, mammoths, mastodons, saber-toothed cats, giant ground sloths, titanotheres, uintatheres, and dire wolves. Archaeological evidence suggests that local Native Americans knew about local fossils. Formally trained scientists were already investigating the state's fossils by the late 1800s. In 1938, a major dinosaur footprint find occurred near Glen Rose. Pleurocoelus was the Texas state dinosaur from 1997 to 2009, when it was replaced by Paluxysaurus jonesi after the Texan fossils once referred to the former species were reclassified to a new genus.
Paleontology in Wyoming includes research into the prehistoric life of the U.S. state of Wyoming as well as investigations conducted by Wyomingite researchers and institutions into ancient life occurring elsewhere.
Paleontology in Colorado refers to paleontological research occurring within or conducted by people from the U.S. state of Colorado. The geologic column of Colorado spans about one third of Earth's history. Fossils can be found almost everywhere in the state but are not evenly distributed among all the ages of the state's rocks. During the early Paleozoic, Colorado was covered by a warm shallow sea that would come to be home to creatures like brachiopods, conodonts, ostracoderms, sharks and trilobites. This sea withdrew from the state between the Silurian and early Devonian leaving a gap in the local rock record. It returned during the Carboniferous. Areas of the state not submerged were richly vegetated and inhabited by amphibians that left behind footprints that would later fossilize. During the Permian, the sea withdrew and alluvial fans and sand dunes spread across the state. Many trace fossils are known from these deposits.
Paleontology in New Mexico refers to paleontological research occurring within or conducted by people from the U.S. state of New Mexico. The fossil record of New Mexico is exceptionally complete and spans almost the entire stratigraphic column. More than 3,300 different kinds of fossil organisms have been found in the state. Of these more than 700 of these were new to science and more than 100 of those were type species for new genera. During the early Paleozoic, southern and western New Mexico were submerged by a warm shallow sea that would come to be home to creatures including brachiopods, bryozoans, cartilaginous fishes, corals, graptolites, nautiloids, placoderms, and trilobites. During the Ordovician the state was home to algal reefs up to 300 feet high. During the Carboniferous, a richly vegetated island chain emerged from the local sea. Coral reefs formed in the state's seas while terrestrial regions of the state dried and were home to sand dunes. Local wildlife included Edaphosaurus, Ophiacodon, and Sphenacodon.
Paleontology in Utah refers to paleontological research occurring within or conducted by people from the U.S. state of Utah. Utah has a rich fossil record spanning almost all of the geologic column. During the Precambrian, the area of northeastern Utah now occupied by the Uinta Mountains was a shallow sea which was home to simple microorganisms. During the early Paleozoic Utah was still largely covered in seawater. The state's Paleozoic seas would come to be home to creatures like brachiopods, fishes, and trilobites. During the Permian the state came to resemble the Sahara desert and was home to amphibians, early relatives of mammals, and reptiles. During the Triassic about half of the state was covered by a sea home to creatures like the cephalopod Meekoceras, while dinosaurs whose footprints would later fossilize roamed the forests on land. Sand dunes returned during the Early Jurassic. During the Cretaceous the state was covered by the sea for the last time. The sea gave way to a complex of lakes during the Cenozoic era. Later, these lakes dissipated and the state was home to short-faced bears, bison, musk oxen, saber teeth, and giant ground sloths. Local Native Americans devised myths to explain fossils. Formally trained scientists have been aware of local fossils since at least the late 19th century. Major local finds include the bonebeds of Dinosaur National Monument. The Jurassic dinosaur Allosaurus fragilis is the Utah state fossil.
Paleontology in Arizona refers to paleontological research occurring within or conducted by people from the U.S. state of Arizona. The fossil record of Arizona dates to the Precambrian. During the Precambrian, Arizona was home to a shallow sea which was home to jellyfish and stromatolite-forming bacteria. This sea was still in place during the Cambrian period of the Paleozoic era and was home to brachiopods and trilobites, but it withdrew during the Ordovician and Silurian. The sea returned during the Devonian and was home to brachiopods, corals, and fishes. Sea levels began to rise and fall during the Carboniferous, leaving most of the state a richly vegetated coastal plain during the low spells. During the Permian, Arizona was richly vegetated but was submerged by seawater late in the period.
Steganoposaurus is an ichnogenus of fossil reptile footprints. The ichnospecies Steganoposaurus belli, was erected for footprints discovered in Wyoming's Tensleep Sandstone. The find was first reported to the scientific literature by Edward Branson and Maurice Mehl in 1932. This creature was originally presumed to be an amphibian, but the toe prints it left behind were pointed like a reptile's rather than round like an amphibians. The actual trackmaker may have been similar to the genus Hylonomus. The ichnogenus Tridentichnus are similar footprints preserved in the Supai Formation of Arizona.
The 19th century in ichnology refers to advances made between the years 1800 and 1899 in the scientific study of trace fossils, the preserved record of the behavior and physiological processes of ancient life forms, especially fossil footprints. The 19th century was notably the first century in which fossil footprints received scholarly attention. British paleontologist William Buckland performed the first true scientific research on the subject during the early 1830s.
This article records new taxa of trace fossils of every kind that are scheduled to be described during the year 2019, as well as other significant discoveries and events related to trace fossil paleontology that are scheduled to occur in the year 2019.
Gwyneddichnium is an ichnogenus from the Late Triassic of North America and Europe. It represents a form of reptile footprints and trackways, likely produced by small tanystropheids such as Tanytrachelos. Gwyneddichnium includes a single species, Gwyneddichnium major. Two other proposed species, G. elongatum and G. minore, are indistinguishable from G. major apart from their smaller size and minor taphonomic discrepancies. As a result, they are considered junior synonyms of G. major.
Bellatoripes is an ichnogenus of footprint produced by a large theropod dinosaur so far known only from the Late Cretaceous of Alberta and British Columbia in Canada. The tracks are large and three-toed, and based on their size are believed to have been made by tyrannosaurids, such as Albertosaurus and Daspletosaurus. Fossils of Bellatoripes are notable for preserving trackways of multiple individual tyrannosaurids all travelling in the same direction at similar speeds, suggesting the prints may have been made by a group, or pack, of tyrannosaurids moving together. Such inferences of behaviour cannot be made with fossil bones alone, so the record of Bellatoripes tracks together is important for understanding how large predatory theropods such as tyrannosaurids may have lived.
Wakinyantanka is an ichnogenus of footprint produced by a large theropod dinosaur from the Late Cretaceous Hell Creek Formation of South Dakota. Wakinyantanka tracks are large with three long, slender toes with occasional impressions of a short hallux and narrow metatarsals. Wakinyantanka was the first dinosaur track to be discovered in the Hell Creek Formation, which remain rare in the preservational conditions of the rocks. The potential trackmakers may be a large oviraptorosaur or a small tyrannosaurid.