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Denticulate (other)
Denticulate is an adjective referring to something having teeth-like structures. It may refer to: * Denticulate tool, a type of stone tool in archeology * Denticulate leaf, a leaf with finely toothed margins * Denticulate ligaments, in human anatomy * a type of conodont Conodonts, are an extinct group of marine jawless vertebrates belonging to the class Conodonta (from Ancient Greek κῶνος (''kōnos''), meaning " cone", and ὀδούς (''odoús''), meaning "tooth"). They are primarily known from their hard ... prehistoric fish, characterized by the sideward orientation of the major teeth-like projections (denticulate processes) See also * Dentate (other) {{disambiguation ... [...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] |
Denticulate Tool
In archaeology, a denticulate tool is a stone tool containing one or more edges that are worked into multiple notched shapes (or teeth), much like the toothed edge of a saw. Such tools have been used as saws for woodworking, processing meat and hides, craft activities and for agricultural purposes. Denticulate tools were used by many different groups worldwide and have been found at a number of notable archaeological sites. They can be made from a number of different lithic materials, but a large number of denticulate tools are made from flint. Due to the nature of denticulate tools they can be difficult to classify, this leads to what is known as a 'typology dilemma'. It can be difficult for archaeologists to sort and classify these tools because it is impossible for them to know if the notches were created intentionally, or if they are a result of unintentional damage. Incorrectly classifying items found at archaeological sites is problematic because it can have a significant i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denticulate Leaf
The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade is divided into two or more leaflets). The edge of the leaf may be regular or irregular, and may be smooth or have hair, bristles, or spines. For more terms describing other aspects of leaves besides their overall morphology see the leaf article. The terms listed here all are supported by technical and professional usage, but they cannot be represented as mandatory or undebatable; readers must use their judgement. Authors often use terms arbitrarily, or coin them to taste, possibly in ignorance of established terms, and it is not always clear whether because of ignorance, or personal preference, or because usages change with time or context, or because of variation between specimens, even specimens from the same plant. For example, whether to call leaves on the same tree "acu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denticulate Ligaments
Denticulate ligaments are lateral projections of the spinal pia mater forming triangular-shaped ligaments that anchor the spinal cord along its length to the dura mater on each side. There are usually 21 denticulate ligaments on each side, with the uppermost pair occurring just below the foramen magnum, and the lowest pair occurring between spinal nerve roots of T12 and L1. The denticulate ligaments are traditionally believed to provide stability for the spinal cord against motion within the vertebral column. Their tooth-like appearance originates the word which derives from Latin ''denticulatus'', from ''denticulus'' (meaning ‘small tooth’). Anatomy The bases of denticulate ligaments arise in the pia mater and are firmly attached to the arachnoid mater and dura mater at the apex. The denticulate ligaments extend across the subarachnoid space between anterior nerve roots and posterior nerve roots, piercing the intervening spinal arachnoid mater to reach the dura. Structu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conodont
Conodonts, are an extinct group of marine jawless vertebrates belonging to the class Conodonta (from Ancient Greek κῶνος (''kōnos''), meaning " cone", and ὀδούς (''odoús''), meaning "tooth"). They are primarily known from their hard, mineralised tooth-like structures called "conodont elements" that in life were present in the oral cavity and used to process food. Rare soft tissue remains suggest that they had elongate eel-like bodies with large eyes. Conodonts were a long-lasting group with over 300 million years of existence from the Cambrian (over 500 million years ago) to the beginning of the Jurassic (around 200 million years ago). Conodont elements are highly distinctive to particular species and are widely used in biostratigraphy as indicative of particular periods of geological time. Discovery and understanding of conodonts The teeth-like fossils of the conodont were first discovered by Heinz Christian Pander and the results published in Saint Petersburg, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
