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Kompsornis Longicaudus
''Kompsornis'' (meaning "elegant bird") is an extinct genus of avialan that lived during the Early Cretaceous, Early Cretaceous period of China. The Type species, type and only known species is ''Kompsornis longicaudus''; the specific name means "long-tailed". It is known from only a single fossil specimen from the Jiufotang Formation. ''Kompsornis'' was closely related to the well-known ''Jeholornis'', another long-tailed avialan from China, but differs from it in features of its skeleton, particularly the fusion and growth rate of its bones. Like other Jeholornithiformes, jeholornithiforms, ''Kompsornis'' was a long-tailed avialan with long wings and possessed little or no teeth, with none identified in the single specimen of ''Kompsornis''. Classification ''Kompsornis'' was described and named by Wang and colleagues in 2020 from the sole specimen AGB-6997, an articulated complete skeleton preserved on a single slab, and was recognised as a jeholornithiform avialan. Their descri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Cretaceous
The Early Cretaceous (geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java- Manihiki- Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kergue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euavialae
Euavialae (meaning "true winged birds") is a group of theropods which includes all avialan species more closely related to modern birds than to the basal, long-tailed avialans ''Archaeopteryx ''Archaeopteryx'' (; ), sometimes referred to by its German name, "" ( ''Primeval Bird''), is a genus of bird-like dinosaurs. The name derives from the ancient Greek (''archaīos''), meaning "ancient", and (''ptéryx''), meaning "feather" ...'' and '' Shenzhouraptor''.Ji, Q.; Ji, S.; Zhang, H.; You, H.; Zhang, J.; Wang, L.; Yuan, C. & Ji, X. (2002): A new avialan bird - ''Jixiangornis orientalis'' gen. et sp. nov. - from the Lower Cretaceous of Western Liaoning, NE China. ''Journal of Nanjing University (Natural Sciences)'' 38(6): 723-736 n Chinese with English abstract Cladogram following the results of a phylogenetic study by Lefèvre ''et al.'', 2014: References Avialans Extant Early Cretaceous first appearances {{Theropod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Avialans
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiphoid Process
The xiphoid process , or xiphisternum or metasternum, is a small cartilaginous process (extension) of the inferior (lower) part of the sternum, which is usually ossified in the adult human. It may also be referred to as the ensiform process. Both the Greek-derived ''xiphoid'' and its Latin equivalent ''ensiform'' mean 'swordlike' or 'sword-shaped' Structure The xiphoid process is considered to be at the level of the 9th thoracic vertebra and the T7 dermatome. Development In newborns and young (especially small) infants, the tip of the xiphoid process may be both seen and felt as a lump just below the sternal notch. At 15 to 29 years old, the xiphoid usually fuses to the body of the sternum with a fibrous joint. Unlike the synovial articulation of major joints, this is non-movable. Ossification of the xiphoid process occurs around age 40. Variation The xiphoid process can be naturally bifurcated or sometimes perforated (xiphoidal foramen). These variances in morphology are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keel (bird Anatomy)
A keel or carina (plural carinae) in bird anatomy is an extension of the sternum (breastbone) which runs axially along the midline of the sternum and extends outward, perpendicular to the plane of the ribs. The keel provides an anchor to which a bird's wing muscles attach, thereby providing adequate leverage for flight. Not all birds have keels; in particular, some flightless birds lack a keel structure. Without a keel a bird will not be able to fly. Some flightless birds have a keel, such as the penguin; but in the penguin's case, its wings are too small for its body, so flight would require flapping its wings too fast to be practical. Historically, the presence or absence of a pronounced keel structure was used as a broad classification of birds into two orders: Carinatae (from ''carina'', "keel"), having a pronounced keel; and ratites (from ''ratis'', "raft"referring to the flatness of the sternum), having a subtle keel structure or lacking one entirely. However, this cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rib Bone
In vertebrate anatomy, ribs ( la, costae) are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the chest cavity. They serve to protect the lungs, heart, and other internal organs of the thorax. In some animals, especially snakes, ribs may provide support and protection for the entire body. Human anatomy Rib details Human ribs are flat bones that form part of the rib cage to help protect internal organs. Humans usually have 24 ribs, in 12 pairs. 1 in 500 people have an extra rib known as a cervical rib. All are attached at the back to the thoracic vertebrae and are numbered from 1–12 according to the vertebrae to which they attach. The first rib is attached to thoracic vertebra 1 (T1). At the front of the body, most of the ribs are joined by costal cartilage to the sternum. Ribs connect to vertebrae at the costovertebral joints. The par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coracoid
A coracoid (from Greek κόραξ, ''koraks'', raven) is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is present as part of the scapula, but this is not homologous with the coracoid bone of most other vertebrates. In other tetrapods it joins the scapula to the front end of the sternum and has a notch on the dorsal surface which, along with a similar notch on the ventral surface of the scapula, forms the socket in which the proximal end of the humerus (upper arm bone) is located. The acrocoracoid process is an expansion adjacent to this contact surface, to which the shoulderward end of the biceps brachii muscle attaches in these animals. In birds (and generally theropods and related animals), the entire unit is rigid and called scapulocoracoid. This plays a major role in bird flight. In dinosaurs the main bones of the pectoral girdle were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sternum
The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Shaped roughly like a necktie, it is one of the largest and longest flat bones of the body. Its three regions are the manubrium, the body, and the xiphoid process. The word "sternum" originates from the Ancient Greek στέρνον (stérnon), meaning "chest". Structure The sternum is a narrow, flat bone, forming the middle portion of the front of the chest. The top of the sternum supports the clavicles (collarbones) and its edges join with the costal cartilages of the first two pairs of ribs. The inner surface of the sternum is also the attachment of the sternopericardial ligaments. Its top is also connected to the sternocleidomastoid muscle. The sternum consists of three main parts, listed from the top: * Manubrium * Body (gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Vertebrae
The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic irregular bone whose complex structure is composed primarily of bone, and secondarily of hyaline cartilage. They show variation in the proportion contributed by these two tissue types; such variations correlate on one hand with the cerebral/caudal rank (i.e., location within the backbone), and on the other with phylogenetic differences among the vertebrate taxa. The basic configuration of a vertebra varies, but the bone is its ''body'', with the central part of the body constituting the ''centrum''. The upper (closer to) and lower (further from), respectively, the cranium and its central nervous system surfaces of the vertebra body support attachment to the intervertebral discs. The posterior part of a vertebra forms a vertebral ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pubis (bone)
In vertebrates, the pubic region ( la, pubis) is the most forward-facing (ventral and anterior) of the three main regions making up the coxal bone. The left and right pubic regions are each made up of three sections, a superior ramus, inferior ramus, and a body. Structure The pubic region is made up of a ''body'', ''superior ramus'', and ''inferior ramus'' (). The left and right coxal bones join at the pubic symphysis. It is covered by a layer of fat, which is covered by the mons pubis. The pubis is the lower limit of the suprapubic region. In the female, the pubic region is anterior to the urethral sponge. Body The body forms the wide, strong, middle and flat part of the pubic region. The bodies of the left and right pubic regions join at the pubic symphysis. The rough upper edge is the pubic crest, ending laterally in the pubic tubercle. This tubercle, found roughly 3 cm from the pubic symphysis, is a distinctive feature on the lower part of the abdominal wall; important ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jeholornis Prima
''Jeholornis'' (meaning "Jehol bird") is a genus of avialans that lived between approximately 122 and 120 million years ago during the early Cretaceous Period in China. Fossil ''Jeholornis'' were first discovered in the Jiufotang Formation in Hebei Province, China (in what was previously Rehe Province, also known as Jehol—hence the name) and additional specimens have been found in the older Yixian Formation. ''Jeholornis'' had long tails and few small teeth, and were approximately the size of turkeys,Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages'Supplementary Information/ref> making them among the largest avialans known until the Late Cretaceous. Their diet included seeds of cycads, ''Ginkgo'' or similar plants. Description ''Jeholornis'' were relatively large, basal avialans, with a maximum adult length of up to 75 cm (2.5 ft) and an estimated weight of 2.27-9.1 kg (5-20 lbs). Anothe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jeholornis Palmapenis
''Jeholornis'' (meaning "Jehol bird") is a genus of avialans that lived between approximately 122 and 120 million years ago during the early Cretaceous Period in China. Fossil ''Jeholornis'' were first discovered in the Jiufotang Formation in Hebei Province, China (in what was previously Rehe Province, also known as Jehol—hence the name) and additional specimens have been found in the older Yixian Formation. ''Jeholornis'' had long tails and few small teeth, and were approximately the size of turkeys,Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages'Supplementary Information/ref> making them among the largest avialans known until the Late Cretaceous. Their diet included seeds of cycads, ''Ginkgo'' or similar plants. Description ''Jeholornis'' were relatively large, basal avialans, with a maximum adult length of up to 75 cm (2.5 ft) and an estimated weight of 2.27-9.1 kg (5-20 lbs). Another ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
