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. [1] 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. [2] 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 .
Triassic New Mexico had a seasonal climate and was home to a richly vegetated flood plain where early dinosaurs such as Coelophysis lived. During the Jurassic New Mexico had a relatively dry climate and was home to dinosaurs such as Allosaurus , Stegosaurus , and the huge long-necked sauropods. Seawater covered eastern New Mexico during the Cretaceous, while on land dinosaurs, including tyrannosaurs, maintained their dominance. Early in the Cenozoic New Mexico was swampy, but gradually the local climate cooled. Local wildlife included creatures such as amblypods, carnivorans, condylarths, the 7-foot tall flightless bird Diatryma , three-toed horses, marsupials, multituberculates, and taeniodonts. Cooler climates eventually ushered in the Ice Age, when the state was home to mastodons.
Local Native Americans devised myths to explain local fossil bones and petrified wood. New Mexico's fossils first came to the attention of formally trained scientists by the mid-19th century. Major finds in the state include Coryphodon , a mummy of the ground sloth Nothrotherium , Triassic Coelophysis bonebeds, bonebeds of Triassic amphibians and the gigantic sauropod formerly known as Seismosaurus . The Triassic dinosaur Coelophysis bauri is the New Mexico state fossil.
No Precambrian fossils are known from New Mexico, so the state's fossil record does not begin until the Paleozoic. [3] During the Late Cambrian, the southern third of New Mexico was a marine environment. This habitat was home to a few kinds of brachiopods, a species of graptolite, and trilobites. Local trace fossils include bore marks left by ancient worms. [2] The southern third of New Mexico remained submerged by the sea throughout the entire ensuing Ordovician. More than two hundred kinds of invertebrate lived in Ordovician New Mexico. Groups present included brachiopods, bryozoans, corals, gastropods, nautiloids, pelecypods, sponges, and trilobites. Algae made reefs up to three hundred feet high. [2] Marine conditions in southern New Mexico persisted on through the Silurian. At least 66 kinds of invertebrates made their home here. Groups familiar from the Ordovician, including brachiopods, bryozoans, corals, gastropods, a nautiloid, and a pelecypod, were among them. [2] Marine conditions were not as predominant in Devonian New Mexico, nevertheless the marine Sly Gap and Percha Formations of the state's southwest provide the best fossils of the age. [4] Over two hundred kinds of Devonian marine life lived and died in the region. The familiar invertebrate groups including bryozoans, cephalopods, corals, gastropods, and pelecypods were all present. Notably these were joined by vertebrates, including placoderms from two different suborders, cartilaginous fishes and more. Although the Percha and Sly Gap are the same age, they don't share even a single individual species in common. [5]
An island chain began forming in New Mexico's shallow sea during the Carboniferous. Areas still submerged were home to brachiopods and clams. The islands themselves were thickly vegetated with forests and swamps. [3] Into the Mississippian, crinoids and other fossil life built huge bioherms. The local Mississippian biodiversity included at least 6 kinds of blastoids 202 brachiopods, 33 bryozoans, 57 corals, 85 crinoids, 22 gastropods, 7 nautiloids, 8 pelecypods, 9 trilobites, and others including foraminiferans and starfishes. On land primitive plants grew in New Mexico. The state's Mississippian flora of New Mexico included horsetails and scale trees. [5] Pennsylvanian New Mexico experienced both marine and terrestrial conditions over time. [5] Marine life included more than 157 species of brachiopods, 41 bryozoans, 34 cephalopods, 34 corals, 118 foraminiferans, 87 gastropods, 25 ostracods and 85 pelecypods. Exceptional brachiopod specimens from this time still retain traces of their shell colorations. [6] The foraminiferans were present in "tremendous abundance", with the most common varieties being fusulinids. [7] Other important fossils provide paleoecological evidence for Pennsylvanian parasitism. [6] 60 different kind of plants grew above the surface of New Mexico's Pennsylvanian waters. [5] Early in the ensuing Permian period the local climate dried significantly. Local rivers dried up and fields of sand dunes took their place. Sea levels dropped and the water became extremely salty. During the middle part of the Permian the seas returned to a more typical state. At this time a huge reef system began to form at El Capitan in the southeastern part of the state. [3] Most of New Mexico was under seawater during the ensuing Permian. More than 300 kinds of marine life have been discovered in the state. On land, at least 20 kinds of plants including early conifers, horsetails, and seed ferns grew. New Mexico's terrestrial environments were inhabited by creatures such as Aerosaurus , Edaphosaurus , Limnoscelis , Ophiacodon , and Sphenacodon . [6] Many of these creatures' footprints were preserved in mudflats that are contained within the Prehistoric Trackways National Monument in Las Cruces.
220 million years ago, during the Late Triassic deposition of the Dockum Group, eastern New Mexico was a basin receiving sediments carried downhill by streams and rivers. These sediments were probably trapped locally, burying the remains that would compose the area's fossil record, instead of making their way to the sea. A similar modern depositional scenario is found in the Great Basin of Nevada and Utah. [8] The presence of lime nodules that formed in the ancient soils provides evidence for a strongly seasonal climate. [9] For part of the year the climate was very dry. [3] Contemporary algae was preserved in local freshwater deposits. The local streams and lakes held animals such as freshwater clams, fish, ostracods, and snails. [10] A lush flora grew in the local floodplains. [3] At the same time, plants such as conifers, cordaitales, cycads, and horsetails, greened the New Mexican landscape. [10] The early dinosaur Coelophysis inhabited the region. [3] Prosauropods were also present but rare in Late Triassic New Mexico. [11] The Jurassic of New Mexico is poorly known. Evidence suggests that the state had a relatively dry climate. The local environment was a coastal plain. [3] Local dinosaurs were preserved in the sediments of the Morrison Formation. New Mexico's Late Jurassic dinosaurs included Allosaurus , Stegosaurus , and the massive long-necked sauropods. [10]
Eastern New Mexico was inundated by seawater once more during the Cretaceous period. This sea was home to ammonites and oysters. [3] Throughout the Cretaceous over 900 different kinds of life are known to have lived in New Mexico. Most fossils known from Early Cretaceous times were of marine invertebrates. The Western Interior Seaway came to cover most of the state during the Late Cretaceous. [12] At least 450 species lived in New Mexico during the Late Cretaceous. Most of the marine invertebrates of that era were much larger than modern types. At the time New Mexico's waters were home to giant snails with shells up to 18 inches across. The largest known local ammonite from the Late Cretaceous was Mantelliceras canitaurium , whose shell could be up to 16 inches in diameter. [13] The Cretaceous sharks of New Mexico were very similar to their contemporaries in Kansas. [14]
On land a diverse flora grew that included at least 14 different kinds of fern, 16 figs, 8 honeysuckles, 5 willows, and trees that left behind petrified logs more than 30 feet long. [13] The local vertebrates included crocodiles, at least 16 different kinds of turtles. [13] However, dinosaurs still dominated the state's terrestrial environments. [3] Examples include ceratopsians, Bistahieversor , ornithopods, and sauropods. [13] Some of these dinosaurs left behind an abundant trace fossil record. At the time the Dakota Formation was being deposited in northeastern New Mexico, more than 500 dinosaur tracks were imprinted in the sediments of Clayton Lake State Park. Another New Mexican Dakota exposure contains 55 parallel trackways left by ornithopods moving northward on all-fours. This site, the Mosquero Creek site, also preserves a series of ten or more parallel trackways left by even larger two-legged ornithopod moving in the opposite direction as the other ornithopods. These New Mexican tracks provide important evidence of social behavior in dinosaurs. [15]
Geologic upheaval during the early Cenozoic era formed the state's basin and range physiographic province. The landscape was divided by rivers and dotted by lakes. Garfish inhabited the local lakes while magnolias grew in the floodplains between rivers. Many volcanic eruptions occurred in the region at this time. [3] The Raton area was covered in swamps during the Paleocene epoch of the Cenozoic era. The individual leaves from some of the contemporary palms could be more than 9 feet wide. At least 42 different kinds of mammals lived in New Mexico at the time. Groups including the amblypods, carnivorans, condylarths, marsupials, multituberculates, and taeniodonts. Other kinds of animal life included two kinds of crocodiles, fishes, snails relatives of the modern tuatara, and 16 kinds of turtle. [13]
The Eocene fossils of New Mexico include 120 different animal species. Aquatic life included clams, fishes, and snails. On land, the mammals were very diverse, represented by more than eighty species from 23 families and 10 orders. [16] The Eocene Baca Formation of Socorro County preserves 18 footprints in three separate parallel trackways. The trackmakers were probably pecorans, but may have been members of the camel family. Since the trackways share a parallel orientation they provide important evidence for social behavior in ancient mammals and are among the oldest known fossil footprints left by cloven-hoofed mammals. [17] Another interesting local Eocene inhabitant was the 7-foot tall flightless bird Diatryma . [16]
Very few identifiable fossils have been discovered in New Mexican Oligocene deposits, so this epoch of time remains mysterious to paleontologists. [16] Nevertheless, the Datil Formation of New Mexico preserves one of only seven Oligocene fossil tracksites in the western United States. [18] From the Miocene to Pliocene New Mexico was home to creatures such as four-tusked relatives of modern elephants. Other inhabitants included an abundance of beavers, three-toed horses, and rhinoceroses. Trees growing in New Mexico have been preserved as petrified wood, some specimens have opalized into a gem-like substance. [16] As the Cenozoic proceeded, the local climate began to cool. [3] During the Quaternary period, the Rio Grande became the most prominent local river system. [3] During the Pleistocene epoch, large trees, probably pines, were preserved as impressions left in ancient San Jose Valley lava flows. The state's fauna included at least 65 kinds of birds, 2 reptiles, and 43 mammals. [16] At this time the state was home to camels and mammoths. [3] American mastodon remains were found on the east slope of the Sandia Mountains at an elevation of 8,470 feet, the highest ever recorded for the species. Many Pleistocene fossils were preserved in local caves. [16]
The Jicarilla Apaches in southern New Mexico told a myth about the origin of fire that also served to explain the existence of petrified wood. They believed that in the beginning, trees were all fireproof. However, Coyote ran around the world with a torch tied to his tail. As he ran his used his tail to start raging fires all over the world. Trees Coyote accidentally missed remained stone-like and fireproof, but the ignited trees can be used by modern people to light fires. This story likely derives from astonishment at petrified wood's obvious woody nature yet seemingly supernatural ability to resist being burnt like unfossilized wood. [19]
The Jicarilla had another fossil-derived legend about the predatory monsters Giant Elk and Giant Eagle. [20] Early in history, these predatory creatures killed many men, women, and children. A brave young man named Jonayaiyin decided to hunt these monsters down. He traveled far to the south, where he found the Giant Elk. He succeeded in killing it and took one of its horns to use as a weapon. He traveled to the west where the giant eagle lived high up on a ledge. The giant Eagle grabbed him in her claws and carried him to her nest. When the Giant Eagles returned, Jonayaiyin used the horn of the Giant Elk to club the Eagles to death. After falling to the earth, pieces of the male Giant Eagle's wing were said to remain at Taos. [21]
The first record of fossils in New Mexico was written by Santa Fe Trader Josiah Gregg, who described local petrified wood in his 1846 book Commerce of the Prairies . The next mention comes from J. W. Abert, who traveled through the area between 1846 and 1847. While there he wrote about fossils including petrified wood, shark teeth, shells and bones. His writings were incorporated into an 1848 Congressional Document by J. W. Bailey. Between 1853 and 1856 preparations for the construction of the transcontinental railroad had geologists in the area. While there they wrote about the local fossils they found. They sent some to New York hoping that Albany resident James Hall would be able to identify them. Around this time more and more prominent paleontologists became involved in New Mexico paleontology. Joseph Leidy described the new mastodon Mastodon obscurus from New Mexican bones he received. Edward Drinker Cope became so involved that he wrote 66 papers on New Mexican fossils between 1871 and 1893. [22]
In 1874 Cope arrived at New Mexico accompanying the G. M. Wheeler Survey. While in the area he found the first known Eocene mammal from the southwestern United States, Coryphodon . Other discoveries Cope made during his stay included camels, crocodiles, deer, dogs, horses, and mastodon remains. [22] In total he discovered about 90 species. This was a major boon to his reputation as his research was foundational to understanding that interval of American geologic history. [23] The Puerco Formation was discovered in 1875 but significant numbers of fossils were not described until David Baldwin's 1881 expedition on behalf of Edward Drinker Cope. The American Museum of Natural History sent in several paleontologists in 1892 to uncover more fossils and the area became regarded as one of the best sources of Paleocene fossils in the world. [13] In 1877 the lengthy official report of the Wheeler Survey of New Mexico was published. Cope wrote the report's coverage of fossil vertebrates, while invertebrates were covered by Charles A. White. [24] In 1878 and 1879 the United States Geological Survey documented New Mexican Carboniferous invertebrates from places such as Mora Creek, Ferdinand Creek, Taos Peak, Cebolla, Manuellitos Creek, Coyote Creek, and Black Lake. [6]
In 1913, the Carnegie Institution published a report on New Mexico's Carboniferous and Permian life. [6] In 1928, three boys discovered a completely articulated partial mummy of the ground sloth Nothrotherium shasetnse 100 feet below the surface of Aden Crater southwest of Las Cruces. [25] In 1936 R. V. Witter and his wife were collecting fossils in Santa Fe County on behalf of the Agassiz Museum at Harvard. At a small stream roughly 16 miles south of Lamy, the couple noticed some fragments of fossil amphibian bones. Traveling upstream to the source of the bones, the couple discovered a nearly solid mass of Triassic amphibian skeletons. [26] In 1937 a crew working on road construction in Black Water Draw uncovered mammoth and bison remains associated with human artifacts. [22]
In 1938 they returned to excavate the fossils. They determined that the deposit preserving the amphibians was roughly fifty feet wide and extended a significant distance back into the hills. They successfully excavated about 100 individual amphibians from the deposit, which might have preserved the remains of thousands. Among the specimens were about 50 skulls many individual bones from their limbs and vertebral columns as well as armored plates that would protected the amphibians' shoulder region in life. The find is especially important because Triassic amphibian fossils are rare in North America. The block of rock preserving the specimen was 6 feet by 8 feet. To protect the fragile fossils the block was given a cast made of 600 pounds of plaster, which was reinforced with iron, wood, and burlap until it weighed more than a ton. The excavators had to use jacks to lift and turn it. Along with that massive block the team also took many smaller blocks as well. Alfred Sherwood Romer has speculated that this exceptional amphibian bone bed may have formed when the amphibians were concentrated into smaller and smaller areas as a drought gradually dried up the pools of water. [27]
In 1947, an American Museum field party led by Edwin Harris Colbert discovered a bonebed including the skeletons of more than 1,000 Coelophysis at Ghost Ranch. [28] Later, in 1953 University of New Mexico graduate student William Chenoweth discovered three important sites where dinosaurs were preserved in Morrison Formation rocks. He found a fragmentary Allosaurus , sauropods, and Stegosaurus . [10] Three years later, in 1956, mastodon teeth were discovered by a nine-year-old boy who was out hunting for Indian arrowheads. These well preserved teeth are now curated by the University of New Mexico Museum. [16] During the 1960s, uranium prospector Rodney Peterson discovered a new fossil site west of Albuquerque. Actual paleontological excavation at the site would be several decades away, however. [29]
In 1979, two hikers discovered a series of gigantic articulated vertebrae fossils near San Ysidro. They reported the remains to David Gilette of the New Mexico Museum of Natural History. Gillette led an expedition into the region and used cutting-edge technology to locate the remains while they were still entombed in sandstone. The team excavated a massive quarry and gradually recovered a significant portion of the rear half of a diplodocid sauropod dinosaur. In 1991 this dinosaur was formally described as the new genus Seismosaurus and estimated to be the longest dinosaur known to science at 52 meters (171 feet) long. [30] In 1989, excavation began at the fossils site Rodney Peterson discovered near Albuquerque. Fossils recovered included a huge allosaurid that may be referrable to the genus Saurophaganax , Camarasaurus , and the skull and teeth of a diplodocid. This was the first major quarry in New Mexico to preserve a significant number of bones from a variety of dinosaur species. [29] During the early 80s, another partial sauropod skeleton was discovered near San Ysidro. The remains were thought to belong to the species Camarasaurus supremus . Prior to these discoveries most dinosaur fossils discovered in New Mexico were scrappy remains uncovered serenipitously by mining operations and surveys for uranium. [29] More recently, in the 2000s, Seismosaurus was found to be the same as Diplodocus , a previously known dinosaur of similar age from the western United States. [31]
Paleontology in Indiana refers to paleontological research occurring within or conducted by people from the U.S. state of Indiana. Indiana's fossil record stretches back to the Precambrian, when the state was inhabited by microbes. More complex organisms came to inhabit the state during the early Paleozoic era. At that time the state was covered by a warm shallow sea that would come to be inhabited by creatures like brachiopods, bryozoans, cephalopods, crinoids, and trilobites. During the Silurian period the state was home to significant reef systems. Indiana became a more terrestrial environment during the Carboniferous, as an expansive river system formed richly vegetated deltas where amphibians lived. There is a gap in the local rock record from the Permian through the Mesozoic. Likewise, little is known about the early to middle Cenozoic era. During the Ice Age however, the state was subject to glacial activity, and home to creatures like short-faced bears, camels, mammoths, and mastodons. After humans came to inhabit the state, Native Americans interpreted the fossil proboscidean remains preserved near Devil's Lake as the bones of water monsters. After the advent of formal scientific investigation one paleontological survey determined that the state was home to nearly 150 different kinds of prehistoric plants.
Paleontology in North Carolina refers to paleontological research occurring within or conducted by people from the U.S. state of North Carolina. Fossils are common in North Carolina. According to author Rufus Johnson, "almost every major river and creek east of Interstate 95 has exposures where fossils can be found". The fossil record of North Carolina spans from Eocambrian remains that are 600 million years old, to the Pleistocene 10,000 years ago.
Paleontology in Virginia refers to paleontological research occurring within or conducted by people from the U.S. state of Virginia. The geologic column in Virginia spans from the Cambrian to the Quaternary. During the early part of the Paleozoic, Virginia was covered by a warm shallow sea. This sea would come to be inhabited by creatures like brachiopods, bryozoans, corals, and nautiloids. The state was briefly out of the sea during the Ordovician, but by the Silurian it was once again submerged. During this second period of inundation the state was home to brachiopods, trilobites and entire reef systems. During the mid-to-late Carboniferous the state gradually became a swampy environment.
Paleontology in Tennessee refers to paleontological research occurring within or conducted by people from the U.S. state of Tennessee. During the early part of the Paleozoic era, Tennessee was covered by a warm, shallow sea. This sea was home to brachiopods, bryozoans, cephalopods, corals, and trilobites. Tennessee is one of the best sources of Early Devonian fossils in North America. During the mid-to-late Carboniferous, the state became a swampy environment, home to a rich variety of plants including ferns and scale trees. A gap in the local rock record spans from the Permian through the Jurassic. During the Cretaceous, the western part of the state was submerged by seawater. The local waters were home to more fossil gastropods than are known from anywhere else in the world. Mosasaurs and sea turtles also inhabited these waters. On land the state was home to dinosaurs. Western Tennessee was still under the sea during the early part of the Cenozoic. Terrestrial portions of the state were swampy. Climate cooled until the Ice Age, when the state was home to Camelops, horses, mammoths, mastodons, and giant ground sloths. The local Yuchi people told myths of giant lizard monsters that may have been inspired by fossils either local or encountered elsewhere. In 1920, after local fossils became a subject of formal scientific study, a significant discovery of a variety of Pleistocene creatures was made near Nashville. The Cretaceous bivalve Pterotrigonia thoracica is the Tennessee state fossil.
Paleontology in Maryland refers to paleontological research occurring within or conducted by people from the U.S. state of Maryland. The invertebrate fossils of Maryland are similar to those of neighboring Delaware. For most of the early Paleozoic era, Maryland was covered by a shallow sea, although it was above sea level for portions of the Ordovician and Devonian. The ancient marine life of Maryland included brachiopods and bryozoans while horsetails and scale trees grew on land. By the end of the era, the sea had left the state completely. In the early Mesozoic, Pangaea was splitting up. The same geologic forces that divided the supercontinent formed massive lakes. Dinosaur footprints were preserved along their shores. During the Cretaceous, the state was home to dinosaurs. During the early part of the Cenozoic era, the state was alternatingly submerged by sea water or exposed. During the Ice Age, mastodons lived in the state.
Paleontology in Pennsylvania refers to paleontological research occurring within or conducted by people from the U.S. state of Pennsylvania. The geologic column of Pennsylvania spans from the Precambrian to Quaternary. During the early part of the Paleozoic, Pennsylvania was submerged by a warm, shallow sea. This sea would come to be inhabited by creatures like brachiopods, bryozoans, crinoids, graptolites, and trilobites. The armored fish Palaeaspis appeared during the Silurian. By the Devonian the state was home to other kinds of fishes. On land, some of the world's oldest tetrapods left behind footprints that would later fossilize. Some of Pennsylvania's most important fossil finds were made in the state's Devonian rocks. Carboniferous Pennsylvania was a swampy environment covered by a wide variety of plants. The latter half of the period was called the Pennsylvanian in honor of the state's rich contemporary rock record. By the end of the Paleozoic the state was no longer so swampy. During the Mesozoic the state was home to dinosaurs and other kinds of reptiles, who left behind fossil footprints. Little is known about the early to mid Cenozoic of Pennsylvania, but during the Ice Age it seemed to have a tundra-like environment. Local Delaware people used to smoke mixtures of fossil bones and tobacco for good luck and to have wishes granted. By the late 1800s Pennsylvania was the site of formal scientific investigation of fossils. Around this time Hadrosaurus foulkii of neighboring New Jersey became the first mounted dinosaur skeleton exhibit at the Academy of Natural Sciences in Philadelphia. The Devonian trilobite Phacops rana is the Pennsylvania state fossil.
Paleontology in New Jersey refers to paleontological research in the U.S. state of New Jersey. The state is especially rich in marine deposits.
Paleontology in Georgia refers to paleontological research occurring within or conducted by people from the U.S. state of Georgia. During the early part of the Paleozoic, Georgia was largely covered by seawater. Although no major Paleozoic discoveries have been uncovered in Georgia, the local fossil record documents a great diversity of ancient life in the state. Inhabitants of Georgia's early Paleozoic sea included corals, stromatolites, and trilobites. During the Carboniferous local sea levels dropped and a vast complex of richly vegetated delta formed in the state. These swampy deltas were home to early tetrapods which left behind footprints that would later fossilize. Little is known of Triassic Georgia and the Jurassic is absent altogether from the state's rock record. During the Cretaceous, however, southern Georgia was covered by a sea that was home to invertebrates and fishes. On land, the tree Araucaria grew, and dinosaurs inhabited the state. Southern Georgia remained submerged by shallow seawater into the ensuing Paleogene and Neogene periods of the Cenozoic era. These seas were home to small coral reefs and a variety of other marine invertebrates. By the Pleistocene the state was mostly dry land covered in forests and grasslands home to mammoths and giant ground sloths. Local coal mining activity has a history of serendipitous Carboniferous-aged fossil discoveries. Another major event in Georgian paleontology was a 1963 discovery of Pleistocene fossils in Bartow County. Shark teeth are the Georgia state fossil.
Paleontology in Alabama refers to paleontological research occurring within or conducted by people from the U.S. state of Alabama. Pennsylvanian plant fossils are common, especially around coal mines. During the early Paleozoic, Alabama was at least partially covered by a sea that would end up being home to creatures including brachiopods, bryozoans, corals, and graptolites. During the Devonian the local seas deepened and local wildlife became scarce due to their decreasing oxygen levels.
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 Missouri refers to paleontological research occurring within or conducted by people from the U.S. state of Missouri. The geologic column of Missouri spans all of geologic history from the Precambrian to present with the exception of the Permian, Triassic, and Jurassic. Brachiopods are probably the most common fossils in Missouri.
Paleontology in Minnesota refers to paleontological research occurring within or conducted by people from the U.S. state of Minnesota. The geologic record of Minnesota spans from Precambrian to recent with the exceptions of major gaps including the Silurian period, the interval from the Middle to Upper Devonian to the Cretaceous, and the Cenozoic. During the Precambrian, Minnesota was covered by an ocean where local bacteria ended up forming banded iron formations and stromatolites. During the early part of the Paleozoic era southern Minnesota was covered by a shallow tropical sea that would come to be home to creatures like brachiopods, bryozoans, massive cephalopods, corals, crinoids, graptolites, and trilobites. The sea withdrew from the state during the Silurian, but returned during the Devonian. However, the rest of the Paleozoic is missing from the local rock record. The Triassic is also missing from the local rock record and Jurassic deposits, while present, lack fossils. Another sea entered the state during the Cretaceous period, this one inhabited by creatures like ammonites and sawfish. Duckbilled dinosaurs roamed the land. The Paleogene and Neogene periods of the ensuing Cenozoic era are also missing from the local rock record, but during the Ice Age evidence points to glacial activity in the state. Woolly mammoths, mastodons, and musk oxen inhabited Minnesota at the time. Local Native Americans interpreted such remains as the bones of the water monster Unktehi. They also told myths about thunder birds that may have been based on Ice Age bird fossils. By the early 19th century, the state's fossil had already attracted the attention of formally trained scientists. Early research included the Cretaceous plant discoveries made by Leo Lesquereux.
Paleontology in Oklahoma refers to paleontological research occurring within or conducted by people from the U.S. state of Oklahoma. Oklahoma has a rich fossil record spanning all three eras of the Phanerozoic Eon. Oklahoma is the best source of Pennsylvanian fossils in the United States due to having an exceptionally complete geologic record of the epoch. From the Cambrian to the Devonian, all of Oklahoma was covered by a sea that would come to be home to creatures like brachiopods, bryozoans, graptolites and trilobites. During the Carboniferous, an expanse of coastal deltaic swamps formed in areas of the state where early tetrapods would leave behind footprints that would later fossilize. The sea withdrew altogether during the Permian period. Oklahoma was home a variety of insects as well as early amphibians and reptiles. Oklahoma stayed dry for most of the Mesozoic. During the Late Triassic, carnivorous dinosaurs left behind footprints that would later fossilize. During the Cretaceous, however, the state was mostly covered by the Western Interior Seaway, which was home to huge ammonites and other marine invertebrates. During the Cenozoic, Oklahoma became home to creatures like bison, camels, creodonts, and horses. During the Ice Age, the state was home to mammoths and mastodons. Local Native Americans are known to have used fossils for medicinal purposes. The Jurassic dinosaur Saurophaganax maximus is the Oklahoma state fossil.
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 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 Idaho refers to paleontological research occurring within or conducted by people from the U.S. state of Idaho. The fossil record of Idaho spans much of the geologic column from the Precambrian onward. During the Precambrian, bacteria formed stromatolites while worms left behind trace fossils. The state was mostly covered by a shallow sea during the majority of the Paleozoic era. This sea became home to creatures like brachiopods, corals and trilobites. Idaho continued to be a largely marine environment through the Triassic and Jurassic periods of the Mesozoic era, when brachiopods, bryozoans, corals, ichthyosaurs and sharks inhabited the local waters. The eastern part of the state was dry land during the ensuing Cretaceous period when dinosaurs roamed the area and trees grew which would later form petrified wood.
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.
Paleontology in Washington encompasses paleontological research occurring within or conducted by people from the U.S. state of Washington. Washington has a rich fossil record spanning almost the entire geologic column. Its fossil record shows an unusually great diversity of preservational types including carbonization, petrifaction, permineralization, molds, and cast. Early Paleozoic Washington would come to be home to creatures like archaeocyathids, brachiopods, bryozoans, cephalopods, corals, and trilobites. While some Mesozoic fossils are known, few dinosaur remains have been found in the state. Only about two-thirds of the state's land mass had come together by the time the Mesozoic ended. In the Cenozoic the state's sea began to withdraw towards the west, while local terrestrial environments were home to a rich variety of trees and insects. Vertebrates would come to include the horse Hipparion, bison, camels, caribou, oreodonts. Later, during the Ice Age, the northern third of the state was covered in glaciers while creatures like bison, caribou, woolly mammoths, mastodons, and rhinoceros roamed elsewhere in the state. The Pleistocene Columbian Mammoth, Mammuthus columbi is the Washington state fossil.
Paleontology in the United States refers to paleontological research occurring within or conducted by people from the United States. Paleontologists have found that at the start of the Paleozoic era, what is now "North" America was actually in the southern hemisphere. Marine life flourished in the country's many seas. Later the seas were largely replaced by swamps, home to amphibians and early reptiles. When the continents had assembled into Pangaea drier conditions prevailed. The evolutionary precursors to mammals dominated the country until a mass extinction event ended their reign.