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Genyornis Newtoni
''Genyornis newtoni'' is an extinct species of large, flightless bird that lived in Australia during the Pleistocene Epoch until around 50,000 years ago. Over two metres in height, they were likely herbivorous. Many other species of Australian megafauna became extinct in Australia around that time, coinciding with the arrival of humans. It is the last known member of the extinct flightless bird family Dromornithidae which had been part of the fauna of the Australian continent for over 30 million years. They are not closely related to ratites such as emus, and their closest living relatives are thought to be fowl. Taxonomy The species was first described in 1896 by Edward Charles Stirling and A. H. C. Zeitz, the authors giving the epithet ''newtoni'' for the Cambridge professor Alfred Newton. The name of the genus is derived from the ancient Greek ''γένυς'' (''génus'') 'jaw; chin' and ''ὄρνις'' (''órnis'') 'bird', because of the relatively large size of the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Pleistocene
The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as the Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently defined as the time between 129,000 and c. 11,700 years ago. The late Pleistocene equates to the proposed Tarantian Age of the geologic time scale, preceded by the officially ratified Chibanian (commonly known as the Middle Pleistocene). The beginning of the Late Pleistocene is the transition between the end of the Penultimate Glacial Period and the beginning of the Last Interglacial around 130,000 years ago (corresponding with the beginning of Marine Isotope Stage 5). The Late Pleistocene ends with the termination of the Younger Dryas, some 10th millennium BC, 11,700 years ago when the Holocene Epoch began. The term Upper Pleistocene is currently in use as a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barawertornis
''Barawertornis'' is an extinct genus of cassowary-sized dromornithid known from Oligocene and Miocene deposits in Queensland and South Australia. Only a single species, ''B. tedfordi'', is placed in this genus. It shows adaptations towards a cursorial lifestyle. Like other dromornithids, ''Barawertornis'' was probably a folivorous and frugivorous browser. History and naming In 1968, the fragmentary remains of a dromornithid were reported from the Carl Creek Limestone of Riversleigh, Queensland by American palaeontologist Richard H. Tedford. Some of these remains, in addition to others, were used by Patricia Vickers-Rich in 1979 as the basis for a new genus and species, ''Barawertornis tedfordi''. The holotype (CPC 7341) is a left femur missing the trochanter and most of the shaft. Additional fossils include a partial femur, incomplete tarsometatarsus and nearly complete dorsal vertebra. Twenty-five years later, in 2004, Peter Murray and Patricia Vickers-Rich briefly described ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Before Present
Before Present (BP) or "years before present (YBP)" is a time scale used mainly in archaeology, geology, and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because the "present" time changes, standard practice is to use 1January 1950 as the commencement date (epoch) of the age scale, with 1950 being labelled as the "standard year". The abbreviation "BP" has been interpreted retrospectively as "Before Physics", which refers to the time before nuclear weapons testing artificially altered the proportion of the carbon isotopes in the atmosphere, which scientists must account for when using radiocarbon dating for dates of origin that may fall after this year. In a convention that is not always observed, many sources restrict the use of BP dates to those produced with radiocarbon dating; the alternative notation "RCYBP" stands for the explicit "radio carbon years before present". Usage The BP scale is s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid Analysis
Protein sequencing is the practical process of determining the amino acid sequence of all or part of a protein or peptide. This may serve to identify the protein or characterize its post-translational modifications. Typically, partial sequencing of a protein provides sufficient information (one or more sequence tags) to identify it with reference to databases of protein sequences derived from the conceptual translation of genes. The two major direct methods of protein sequencing are mass spectrometry and Edman degradation using a protein sequenator (sequencer). Mass spectrometry methods are now the most widely used for protein sequencing and identification but Edman degradation remains a valuable tool for characterizing a protein's ''N''-terminus. Determining amino acid composition It is often desirable to know the unordered amino acid composition of a protein prior to attempting to find the ordered sequence, as this knowledge can be used to facilitate the discovery of error ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Extinction
An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp fall in the diversity and abundance of multicellular organisms. It occurs when the rate of extinction increases with respect to the background extinction rate and the rate of speciation. Estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty. These differences stem from disagreement as to what constitutes a "major" extinction event, and the data chosen to measure past diversity. The "Big Five" mass extinctions In a landmark paper published in 1982, Jack Sepkoski and David M. Raup identified five particular geological intervals with excessive diversity loss. They were originally identified as outliers on a general trend of decreasing extinction rates during the Phanerozoic, but as more stringent statistical tests have been applie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Variability
Climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. ''Climate change'' may refer to any time in Earth's history, but the term is now commonly used to describe contemporary climate change, often popularly referred to as global warming. Since the Industrial Revolution, the climate has increasingly been affected by human activities. The climate system receives nearly all of its energy from the sun and radiates energy to outer space. The balance of incoming and outgoing energy and the passage of the energy through the climate system is Earth's energy budget. When the incoming energy is greater than the outgoing energy, Earth's energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and Earth experiences cooling. The energy moving t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eggshell
An eggshell is the outer covering of a hard-shelled egg (biology), egg and of some forms of eggs with soft outer coats. Worm eggs Nematode eggs present a two layered structure: an external vitellin layer made of chitin that confers mechanical resistance and an internal lipid-rich layer that makes the egg chamber impermeable. Insect eggs Insects and other arthropods lay a large variety of styles and shapes of eggs. Some of them have gelatinous or skin-like coverings, others have hard eggshells. Softer shells are mostly protein. It may be fibrous or quite liquid. Some arthropod eggs do not actually have shells, rather, their outer covering is actually the outermost embryonic membrane, the choroid, which protects inner layers. This can be a complex structure, and it may have different layers, including an outermost layer called an exochorion. Eggs which must survive in dry conditions usually have hard eggshells, made mostly of dehydrated or mineralized proteins with pore sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casque (anatomy)
A casque is an anatomical feature found in some species of birds, reptiles, and amphibians. In birds, it is an enlargement of the bones of the upper mandible or the skull, either on the front of the face, the top of the head, or both. The casque has been hypothesized to serve as a visual cue to a bird's sex, state of maturity, or social status; as reinforcement to the beak's structure; or as a resonance chamber, enhancing calls. In addition, they may be used in combat with other members of the same species, in the gathering of food, or in thermoregulation. Birds Structure Casques are found in a number of species, including most hornbills, all cassowaries, the maleo, the horned guan, the helmeted guineafowl and several species of curassow. In most of these species, the casque is a bony extension of the or skull that is covered with a cornified layer of skin. However, in cassowaries, a foamy, elastic layer of collagen sits between the bone and the skin. Hornbill casques grow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goose
A goose (: geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera '' Anser'' (grey geese and white geese) and '' Branta'' (black geese). Some members of the Tadorninae subfamily (e.g., Egyptian goose, Orinoco goose) are commonly called geese, but are not considered "true geese" taxonomically. More distantly related members of the family Anatidae are swans, most of which are larger than true geese, and ducks, which are smaller. The term "goose" may refer to such bird of either sex, but when paired with "gander", "goose" refers specifically to a female one ("gander" referring to a male). Young birds before fledging are called goslings. The collective noun for a group of geese on the ground is a gaggle; when in flight, they are called a skein, a team, or a wedge; when flying close together, they are called a plump. Etymology The word "goose" is a direct descendant of Proto-Indo-European ''*ǵʰh₂éns''. In Germanic lang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dromornis Planei
''Dromornis'' is a genus of large to enormous prehistoric birds native to Australia during the Oligocene to Pliocene epochs. The species were flightless, possessing greatly reduced wing structures but with large legs, similar to the modern ostrich or emu. They were likely to have been predominantly, if not exclusively, herbivorous browsers. The male of the largest species, ''Dromornis stirtoni'', is a contender for the tallest and heaviest bird, and possibly exhibited aggressive territorial behaviour. They belong to the family Dromornithidae, extinct flightless birds known as mihirungs. Taxonomy The genus was erected to separate a new species, '' Dromornis australis'', from the previously described ''Dinornis'' (giant moas), another lineage of ancient large and flightless birds found in New Zealand that was earlier described by Richard Owen in 1843. A femur that was forwarded to England, probably a dromornithid and since lost, suggested an Australian genus, but Owen withheld publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dromornis Stirtoni
''Dromornis'' is a genus of large to enormous Fossil birds, prehistoric birds native to Australia during the Oligocene to Pliocene epochs. The species were flightless, possessing greatly reduced wing structures but with large legs, similar to the modern ostrich or emu. They were likely to have been predominantly, if not exclusively, herbivorous browsers. The male of the largest species, ''Dromornis stirtoni'', is a contender for the tallest and heaviest bird, and possibly exhibited aggressive territorial behaviour. They belong to the family Dromornithidae, extinct flightless birds known as mihirungs. Taxonomy The genus was erected to separate a new species, ''Dromornis australis'', from the previously described ''Dinornis'' (giant moas), another lineage of ancient large and flightless birds found in New Zealand that was earlier described by Richard Owen in 1843. A femur that was forwarded to England, probably a dromornithid and since lost, suggested an Australian genus, but Owen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
