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Halimornis
''Halimornis'' was an enantiornithean bird. It lived during the Late Cretaceous about 80 mya and is known from fossils found in the Mooreville Chalk Formation in Greene County, Alabama. It is known from a single fossil individual, including preserved vertebrae, leg bones and part of the humerus (upper arm bone). At the time, the area where the Mooreville Chalk was deposited was situated on the southern coast of the Western Interior Seaway, and may have been the site of a large delta where several major rivers flowed into the shallow sea. The fossil bird was found at a location that would have been about 50 km off shore, indicating that it was an ocean-going species. The name ''Halimornis'' means "bird of the sea". It would have lived alongside the more advanced seabird ''Ichthyornis dispar''. It is one of the few known enantiornithine birds to have lived in a marine environment, along with the Australian '' Nanantius eos'', the slightly younger ''Martinavis ''Martinavis' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enantiornithean
The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over eighty species of Enantiornithes have been named, but some names represent only single bones, so it is likely that not all are valid. The Enantiornithes became extinct at the Cretaceous–Paleogene boundary, along with Hesperornithes and all other non-avian dinosaurs. Discovery and naming The first Enantiornithes to be discovered were incorrectly referred to modern bird groups. For example, the first known species of Enantiornithes, '' Gobipteryx minuta'', was originally considered a paleognath related to ostriches and tinamou. The Enantiornithes were first recognized as a distinct lineage, or "subclass" of birds, by Cyril A. Walker in 1981. Walker mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avisaurids
Avisauridae is a family of extinct enantiornithine dinosaurs from the Cretaceous period, distinguished by several features of their ankle bones. Depending on the definition used, Avisauridae is either a broad and widespread group of advanced enantiornithines (following Cau & Arduini, 2008), or a small family within that group, restricted to species from the Late Cretaceous of North and South America (following Chiappe, 1992). Description Avisaurids were among the largest and last enantiornithines to have lived, although they are also among the most poorly preserved. The majority of them are known primarily from fossilized tarsometatarsal bones, the part of a bird's leg formed by fused metatarsals (the bones which comprise the foot in humans). As a result, members of this family are distinguished from other enantiornithines exclusively by features of the tarsometatarsal and pedal phalanges (toe bones). Unlike in some prehistoric birds, avisaurid tarsometatarsals were not co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mooreville Chalk Formation
The Mooreville Chalk is a geological formation in North America, within the U.S. states of Alabama and Mississippi, which were part of the subcontinent of Appalachia. The strata date back to the early Santonian to the early Campanian stage of the Late Cretaceous. The chalk was formed by pelagic sediments deposited along the eastern edge of the Mississippi embayment. It is a unit of the Selma Group and consists of the upper Arcola Limestone Member and an unnamed lower member. Dinosaur, mosasaur, and primitive bird remains are among the fossils that have been recovered from the Mooreville Chalk Formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 574-588. . Fish Cartilaginous fish Bony fish Reptiles Dinosaurs Indeterminate hadrosaurid, nodosaurid, dinosaur egg, and ornithomimosaur fossil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greene County, Alabama
Greene County is a county located in the west central portion of the U.S. state of Alabama. As of the 2020 census, the population was 7,730, the least populous county in Alabama. Its county seat is Eutaw. It was named in honor of Revolutionary War General Nathanael Greene of Rhode Island. As of the 2020 census, the county's population was 81% African American, making it the fourth-most heavily black county by proportion in the United States, and the most black county among all counties located outside of the state of Mississippi. It is documented as one of the unhealthiest counties in the United States, with a population with an obesity percentage of 46.3 percent, the highest of any county in the state, and second to only Claiborne County in the western portion of neighboring Mississippi. The life expectancy there is 74.9 years, over 2 years lower than the national average. History Greene County was established on December 13, 1819. Eutaw was established as the county seat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Interior Seaway
The Western Interior Seaway (also called the Cretaceous Seaway, the Niobraran Sea, the North American Inland Sea, and the Western Interior Sea) was a large inland sea that split the continent of North America into two landmasses. The ancient sea, which existed from the early Late Cretaceous (100 million years ago) to the earliest Paleocene (66 Ma), connected the Gulf of Mexico, through the United States and Canada, to the Arctic Ocean. The two land masses it created were Laramidia to the west and Appalachia to the east. At its largest extent, it was deep, wide and over long. Origin and geology By Late-Cretaceous times, Eurasia and the Americas had separated along the south Atlantic, and subduction on the west coast of the Americas had commenced, resulting in the Laramide orogeny, the early phase of growth of the modern Rocky Mountains. The Western Interior Seaway may be seen as a downwarping of the continental crust ahead of the growing Laramide/Rockies mountain chain. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyornis Dispar
''Ichthyornis'' (meaning "fish bird", after its fish-like vertebrae) is an extinct genus of toothy seabird-like ornithuran from the late Cretaceous period of North America. Its fossil remains are known from the chalks of Alberta, Alabama, Kansas ( Greenhorn Limestone), New Mexico, Saskatchewan, and Texas, in strata that were laid down in the Western Interior Seaway during the Turonian through Campanian ages, about 95–83.5 million years ago. ''Ichthyornis'' is a common component of the Niobrara Formation fauna, and numerous specimens have been found. ''Ichthyornis'' has been historically important in shedding light on bird evolution. It was the first known prehistoric bird relative preserved with teeth, and Charles Darwin noted its significance during the early years of the theory of evolution. ''Ichthyornis'' remains important today as it is one of the few Mesozoic era ornithurans known from more than a few specimens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanantius Eos
''Nanantius'' is a genus of extinct enantiornithean avialan ("bird" in the broad sense of the word) known from the Early Cretaceous (Albian, c. 100–112 mya) of Australia. Specimens and species The only valid species of ''Nanantius'' is ''Nantantius eos,' '' which was first described in 1986. A supposed second species, ''Nanantius valifanovi,'' has turned out to be a synonym of ''Gobipteryx minuta''. ''N. eos'' was initially only known from an incomplete but elongated tibiotarsus and a cervical (neck) vertebra hailing from the Toolebuc Formation stratum. This holotype tibiotarsus ( QM F12992) was found at Warra Station near Boulia, in Queensland. In 1997, additional fossils from Canary Station in the same area of Australia were also placed into the genus ''Nanantius.'' One of these was a cervical (neck) vertebra, QM F12991, which was assigned to ''Nanantius eos''. The other bone was a partial left tibiotarsus (QM F31813) which was assigned to ''Nanantius'' but not placed wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martinavis
''Martinavis'' is a genus of enantiornithine birds which existed in what is now southern France, North America and Salta Province, Argentina during the late Cretaceous period. It was named by Cyril A. Walker, Eric Buffetaut and Gareth J. Dyke in 2007, and the type species is ''Martinavis cruzyensis''. Description ''M. cruzyensis'' is known from the holotype ACAP-M 1957, a complete uncrushed right humerus, recovered from the Massecaps locality, Cruzy, which is in a Campanian/Maastrichtian-stage deposits in the Grès à Reptiles Formation of France. This species reached in length, in hip height and in weight. A second species, ''M. vincei'' is known from the holotype PVL 4054, a complete left humerus and from the associated paratype PVL 4059, a distal end of left humerus, recovered from the El Brete locality (Maastrichtian age), Lecho Formation of Argentina. A possible third species is represented by the unnamed specimen KU-NM-37 from United States. In 2009, thre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird Genera
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. Bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 2002
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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