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Edenopteron Keithcrooki
''Edenopteron'' is a genus of large tristichopterid fish from the Late Devonian (Famennian) of what is now southeastern Australia. It is known from a single specimen of a single species, ''E. keithcrooki'', described in 2013. Discovery ''Edenopteron keithcrooki'' is known from remains excavated from the Worange Point Formation, near the town of Eden on the coast of New South Wales in 2008. The species name is a combination of the name Eden and ''pteron'', meaning wing or fin in Greek. The specific name honors Dr. Keith Crook of the Australian National University for his discovery of several fossil sites in New South Wales and his key role in helping to map the geology around Eden. Description The holotype consists of numerous semi-articulated remains, including an incomplete skull roof, snout, palate, cheeks, lower jaws and associated dermal bones, a left shoulder girdle, and assorted scales. Reconstructions suggest a skull length of 30 cm (12 in) and lower jaw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dermal Bones
A dermal bone or investing bone or membrane bone is a bony structure derived from intramembranous ossification forming components of the vertebrate skeleton including much of the skull, jaws, gill covers, shoulder girdle and fin spines rays ( lepidotrichia), and the shell (of tortoises and turtles). In contrast to endochondral bone, dermal bone does not form from cartilage that then calcifies, and it is often ornamented. Dermal bone is formed within the dermis and grows by accretion only – the outer portion of the bone is deposited by osteoblasts. The function of some dermal bone is conserved throughout vertebrates, although there is variation in shape and in the number of bones in the skull roof and postcranial structures. In bony fish, dermal bone is found in the fin rays and scales. A special example of dermal bone is the clavicle The clavicle, or collarbone, is a slender, S-shaped long bone approximately 6 inches (15 cm) long that serves as a strut between the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwanan
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene. Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it. To differentiate it from the Indian region of the same name (see ), it is also commonly called Gondwanaland. Gondwana was formed by the accretion of several cratons. Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of about , about one-fifth of the Earth's surface. During the Carboniferous Period, it merged with Laurasia to form a larger supercontinent called Pangaea. Gondwana (and Panga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canberra Times
''The Canberra Times'' is a daily newspaper in Canberra, Australia, which is published by Australian Community Media. It was founded in 1926, and has changed ownership and format several times. History ''The Canberra Times'' was launched in 1926 by Thomas Shakespeare along with his oldest son Arthur Shakespeare and two younger sons Christopher and James. The newspaper's headquarters were originally located in the Civic retail precinct, in Cooyong Street and Mort Street, in blocks bought by Thomas Shakespeare in the first sale of Canberra leases in 1924. The newspaper's first issue was published on 3 September 1926. It was the second paper to be printed in the city, the first being ''The Federal Capital Pioneer''. Between September 1926 and February 1928, the newspaper was a weekly issue. The first daily issue was 28 February 1928. In June 1956, ''The Canberra Times'' converted from broadsheet to tabloid format. Arthur Shakespeare sold the paper to John Fairfax Lt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandageria
''Mandageria fairfaxi'' (Pronunciation: Man-daj-ee-ree-a fair-fax-i) is an extinct lobe-finned fish that lived during the Late Devonian period (Frasnian – Famennian). It is related to the much larger ''Hyneria''; although ''Mandageria'' was smaller, it probably hunted in the same way. The generic epithet, ''Mandageria'', refers to the Mandagery Sandstone, outcropping near Canowindra, Australia, where the fossils were found. The specific epithet, ''fairfaxi'', honors the philanthropist James Fairfax. ''M. fairfaxi'' is the state fossil emblem for New South Wales. Description ''Mandageria'' was a large predator about long. It had a long torpedo-shaped body and large tail fins. ''Mandageria'' also had large pectoral fins which could have helped it manoeuvre around submerged logs when preparing to attack its prey. ''Mandageria'' had a functional neck joint, an otherwise uncommon feature among fish - ''Tiktaalik'', '' Tarrasius'', placoderms (esp. Arthrodira) and seahorses A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Langlieria
''Langlieria'' is a genus of prehistoric sarcopterygian (lobe-finned "fish"), from the end of the Devonian period (Famennian). It was discovered in Belgium and Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, .... References Tristichopterids Prehistoric lobe-finned fish genera Devonian bony fish Fossils of Belgium {{paleo-lobefinned-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eusthenodon
''Eusthenodon'' (Greek for “strong-tooth” – ''eustheno''- meaning “strength”, -''odon'' meaning “tooth”) is an extinct genus of tristichopterid tetrapodomorphs from the Devonian, Late Devonian period, ranging between 383 and 359 million years ago (Frasnian to Famennian). They are well known for being a cosmopolitan genus with remains being recovered from East Greenland, Australia, Central Russia, South Africa, Pennsylvania, and Belgium. Compared to the other closely related genera of the Tristichopteridae clade, ''Eusthenodon'' was one of the largest Sarcopterygii, lobe-finned fishes (approximately 2.5 meters in length) and among the most derived tristichopterids alongside its close relatives ''Cabonnichthys'' and ''Mandageria''. The large size, predatory ecology, and evolutionarily derived characters possessed by ''Eusthenodon'' likely contributed to its ability to occupy and flourish in the numerous localities across the world mentioned above. ''Eusthenodon'' is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derived Trait
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premaxillary
The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has been usually termed as the incisive bone. Other terms used for this structure include premaxillary bone or ''os premaxillare'', intermaxillary bone or ''os intermaxillare'', and Goethe's bone. Human anatomy In human anatomy, the premaxilla is referred to as the incisive bone (') and is the part of the maxilla which bears the incisor teeth, and encompasses the anterior nasal spine and alar region. In the nasal cavity, the premaxillary element projects higher than the maxillary element behind. The palatal portion of the premaxilla is a bony plate with a generally transverse orientation. The incisive foramen is bound anteriorly and laterally by the premaxilla and posteriorly by the palatine process of the maxilla. It is formed from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentary
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movable bone of the skull (discounting the ossicles of the middle ear). It is connected to the temporal bones by the temporomandibular joints. The bone is formed prenatal development, in the fetus from a fusion of the left and right mandibular prominences, and the point where these sides join, the mandibular symphysis, is still visible as a faint ridge in the midline. Like other symphyses in the body, this is a midline articulation where the bones are joined by fibrocartilage, but this articulation fuses together in early childhood.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, p. 59 The word "mandible" derives from the Latin word ''mandibula'', "jawbone" (literally "one used for chewing"), from ''wikt:mandere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbit (anatomy)
In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is , of which the eye occupies . The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and duct, the eyelids, medial and lateral palpebral ligaments, cheek ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves. Structure The orbits are conical or four-sided pyramidal cavities, which open into the midline of the face and point back into the head. Each consists of a base, an apex and four walls."eye, human."Encyclopædia Britannica from Encyclopædia Britannica 2006 Ultimate Reference Suite DVD 2009 Openings There are two important foramina, or windows, two important fissu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ossification
Ossification (also called osteogenesis or bone mineralization) in bone remodeling is the process of laying down new bone material by cells named osteoblasts. It is synonymous with bone tissue formation. There are two processes resulting in the formation of normal, healthy bone tissue: Intramembranous ossification is the direct laying down of bone into the primitive connective tissue ( mesenchyme), while endochondral ossification involves cartilage as a precursor. In fracture healing, endochondral osteogenesis is the most commonly occurring process, for example in fractures of long bones treated by plaster of Paris, whereas fractures treated by open reduction and internal fixation with metal plates, screws, pins, rods and nails may heal by intramembranous osteogenesis. Heterotopic ossification is a process resulting in the formation of bone tissue that is often atypical, at an extraskeletal location. Calcification is often confused with ossification. Calcification is sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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