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Oculudentavis Naga
''Oculudentavis'' is an extinct genus of lizard of uncertain taxonomic placement,Bolet et al., 2021 originally identified as an avialan dinosaur (bird, in the broad sense). It contains two known species, ''O. khaungraae'' and ''O. naga''. Each species is known from one partial fossil specimen in Burmese amber, which differ in several proportions. Their skulls measure in length, indicating that ''Oculudentavis'' would have been comparable in size with the modern bee hummingbird if it were an avialan. Both specimens were retrieved from 99-million-year-old deposits of the Hukawng Basin in Kachin State, northern Myanmar. The type specimen of ''O. khaungraae'' is embroiled in controversy regarding its identity and the ethical issues surrounding the acquisition and study of Burmese amber. The original description advocating for an avialan identity was published in ''Nature'', but has since then been retracted from the journal.Xing et al., 2020 retraction Discovery and naming ''Ocu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenomanian
The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretaceous series (stratigraphy), Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name. As a unit of geologic time measure, the Cenomanian Age spans the time between 100.5 and 93.9 million years ago (Mya). In the geologic timescale, it is preceded by the Albian and is followed by the Turonian. The Upper Cenomanian starts around at 95 Mya. The Cenomanian is coeval with the Woodbinian of the regional timescale of the Gulf of Mexico and the early part of the Eaglefordian of the regional timescale of the East Coast of the United States. At the end of the Cenomanian, an anoxic event took place, called the Cenomani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth
A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the outermost embryonic germ layer, the ectoderm. The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avialae
Avialae ("bird wings") is a clade containing the only living dinosaurs, the birds, and their closest relatives. It is usually defined as all theropod dinosaurs more closely related to birds (Aves) than to Deinonychosauria, deinonychosaurs, though alternative definitions are occasionally used (see below). ''Archaeopteryx lithographica'', from the late Jurassic Period Solnhofen Formation of Germany, is usually considered the earliest known avialan which may have had the capability of powered flight; a minority of studies have suggested that it might have been a deinonychosaur instead. Several older (but non flight-capable) possible avialans are known from the late Jurassic Tiaojishan Formation of China, dated to about 160 million years ago. Definition Most researchers define Avialae as branch-based clade, though definitions vary. Many authors have used a definition similar to "all theropods closer to birds than to ''Deinonychus''."Weishampel, David B.; Dodson, Peter; Osmólska, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiomorphy And Symplesiomorphy
In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, and synapomorphy all mean a trait shared between species because they share an ancestral species. Apomorphic and synapomorphic characteristics convey much information about evolutionary clades and can be used to define taxa. However, plesiomorphic and symplesiomorphic characteristics cannot. The term ''symplesiomorphy'' was introduced in 1950 by German entomologist Willi Hennig. Examples A backbone is a plesiomorphic trait shared by birds and mammals, and does not help in placing an animal in one or the other of these two clades. Birds and mammals share this trait because both clades are descended from the same far distant ancestor. Other clades, e.g. snakes, lizards, turtles, fish, frogs, all have backbones and none are either birds no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronoid Process Of The Mandible
In human anatomy, the mandible's coronoid process () is a thin, triangular eminence, which is flattened from side to side and varies in shape and size. Its anterior border is convex and is continuous below with the anterior border of the ramus. Its ''posterior border'' is concave and forms the anterior boundary of the mandibular notch. The ''lateral surface'' is smooth, and affords insertion to the temporalis and masseter muscles. Its ''medial surface'' gives insertion to the temporalis, and presents a ridge which begins near the apex of the process and runs downward and forward to the inner side of the last molar tooth. Between this ridge and the anterior border is a grooved triangular area, the upper part of which gives attachment to the temporalis, the lower part to some fibers of the buccinator. Clinical significance Fractures of the mandible are common. However, coronoid process fractures are very rare. Isolated fractures of the coronoid process caused by direct trauma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binocular Vision
Binocular vision is seeing with two eyes. The Field_of_view, field of view that can be surveyed with two eyes is greater than with one eye. To the extent that the visual fields of the two eyes overlap, #Depth, binocular depth can be perceived. This allows objects to be recognized more quickly, camouflage to be detected, spatial relationships to be perceived more quickly and accurately (#Stereopsis, stereopsis) and perception to be less susceptible to optical illusions, optical illusions. In secion #Medical, Medical attention is paid to the occurrence, defects and sharpness of binocular vision. In section #Biological, Biological the occurrence of binocular vision in animals is described. Geometric terms When the left eye (LE) and the right eye (RE) observe two objects X and Y, the following concepts are important:Krol J.D.(1982),"Perceptual ghosts in stereopsis, a ghosly problem in binocular vision", PhD thesis ISBN 90-9000382-7.Koenderink J.J.;van Doorn A.J. (1976) "Geometry of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jugal Bone
The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic bone, zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species. Anatomy The jugal bone is located on either side of the skull in the Ocular scales, circumorbital region. It is the origin of several masticatory muscles in the skull. The jugal and Lacrimal bone, lacrimal bones are the only two remaining from the ancestral circumorbital series: the prefrontal, postfrontal, postorbital, jugal, and lacrimal bones. During development, the jugal bone originates from dermal bone. In dinosaurs This bone is considered key in the determination of general traits in cases in which the entire skull has not been found intact (for instance, as with dinosaurs in paleontology). In some dinosaur genera the jugal also forms part of the lower margin of either the antorbital fenestra or the infratemporal fenestr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diurnality
Diurnality is a form of plant and ethology, animal behavior characterized by activity during daytime, with a period of sleeping or other inactivity at night. The common adjective used for daytime activity is "diurnal". The timing of activity by an animal depends on a variety of environmental factors such as the temperature, the ability to gather food by sight, the risk of predation, and the time of year. Diurnality is a cycle of activity within a 24-hour period; cyclic activities called circadian rhythms are endogenous cycles not dependent on external cues or environmental factors except for a zeitgeber. Animals active during twilight are crepuscular, those active during the night are nocturnal and animals active at sporadic times during both night and day are cathemerality, cathemeral. Plants that open their flowers during the daytime are described as diurnal, while those that bloom during nighttime are nocturnal. The timing of flower opening is often related to the time at whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sclerotic Ring
The scleral ring or sclerotic ring is a hardened ring of plates, often derived from bone, that is found in the eyes of many animals in several groups of vertebrates. Some species of mammals, amphibians, and crocodilians lack scleral rings. The ring is in the fibrous outer layer of the eye, called the sclera. The structure is commonly referred to as the sclerotic ring; but, because the word ''sclerotic'' often implies pathology of the sclera (''see'' " sclerosis", an unrelated medical condition), recent authors have urged avoiding the use of this term, to avoid confusion and to increase the utility of character comparisons. Scleral rings can be made of cartilaginous material (scleral cartilage) or bony material (scleral ossicles), or often a combination of both, that comes together to form a ring. The arrangement, size, shape, and number of ossicles vary by group. They are believed to have a role in supporting the eye, especially in animals whose eyes are not spherical, or which liv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbit (anatomy)
In anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ..., the orbit is the Body cavity, cavity or socket/hole of the skull in which the eye and Accessory visual structures, 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 about , of which the eye occupies . The orbital contents comprise the eye, the Orbital fascia, orbital and retrobulbar fascia, extraocular muscles, cranial nerves optic nerve, II, oculomotor nerve, III, trochlear nerve, IV, trigeminal nerve, V, and abducens nerve, VI, blood vessels, fat, the lacrimal gland with its Lacrimal sac, sac and nasolacrimal duct, duct, the eyelids, Medial palpebral ligament, medial and Lateral palpebral raphe, lateral palpebr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oculudentavis Size Comparison
''Oculudentavis'' is an extinct genus of lizard of uncertain taxonomic placement,Bolet et al., 2021 originally identified as an avialan dinosaur (bird, in the broad sense). It contains two known species, ''O. khaungraae'' and ''O. naga''. Each species is known from one partial fossil specimen in Burmese amber, which differ in several proportions. Their skulls measure in length, indicating that ''Oculudentavis'' would have been comparable in size with the modern bee hummingbird if it were an avialan. Both specimens were retrieved from 99-million-year-old deposits of the Hukawng Basin in Kachin State, northern Myanmar. The type specimen of ''O. khaungraae'' is embroiled in controversy regarding its identity and the ethical issues surrounding the acquisition and study of Burmese amber. The original description advocating for an avialan identity was published in ''Nature'', but has since then been retracted from the journal.Xing et al., 2020 retraction Discovery and naming ''Ocu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naga People
Nagas are various Tibeto-Burman languages, Tibeto-Burman ethnic groups native to northeastern India and northwestern Myanmar. The groups have similar cultures and traditions, and form the majority of population in the Indian state of Nagaland and Naga Self-Administered Zone of Myanmar (Burma); with significant populations in Manipur, Arunachal Pradesh and Assam in India; Sagaing Region and Kachin State in Myanmar. The Nagas are divided into various List of Naga ethnic groups, Naga ethnic groups whose numbers and populations are unclear. They each speak distinct List of Naga languages, Naga languages often unintelligible to the others, but all are loosely connected to each other. Etymology The present day Naga people have historically been referred to by many names, like "Noga" or "Naka" by the inhabitants of the Ahom kingdom in what is now considered as Assam which means "people with pierced ears", "Hao" by Meitei people of Imphal Valley and "Nakas" by Bamar people, Burmese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
