A file is a tool used to remove fine amounts of material from a workpiece. It is common in woodworking, metalworking, and other similar trade and hobby tasks. Most are hand tools, made of a case hardened steel bar of rectangular, square, triangular, or round cross-section, with one or more surfaces cut with sharp, generally parallel teeth. A narrow, pointed tang is common at one end, to which a handle may be fitted.
In archeology, a uniface is a specific type of stone tool that has been flaked on one surface only. There are two general classes of uniface tools: modified flakes—and formalized tools, which display deliberate, systematic modification of the marginal edges, evidently formed for a specific purpose.
Broaching is a machining process that uses a toothed tool, called a broach, to remove material. There are two main types of broaching: linear and rotary. In linear broaching, which is the more common process, the broach is run linearly against a surface of the workpiece to effect the cut. Linear broaches are used in a broaching machine, which is also sometimes shortened to broach. In rotary broaching, the broach is rotated and pressed into the workpiece to cut an axisymmetric shape. A rotary broach is used in a lathe or screw machine. In both processes the cut is performed in one pass of the broach, which makes it very efficient.
Scrimshaw is scrollwork, engravings, and carvings done in bone or ivory. Typically it refers to the artwork created by whalers, engraved on the byproducts of whales, such as bones or cartilage. It is most commonly made out of the bones and teeth of sperm whales, the baleen of other whales, and the tusks of walruses. It takes the form of elaborate engravings in the form of pictures and lettering on the surface of the bone or tooth, with the engraving highlighted using a pigment, or, less often, small sculptures made from the same material. However the latter really fall into the categories of ivory carving, for all carved teeth and tusks, or bone carving. The making of scrimshaw began on whaling ships between 1745 and 1759 on the Pacific Ocean, and survived until the ban on commercial whaling. The practice survives as a hobby and as a trade for commercial artisans. A maker of scrimshaw is known as a scrimshander. The word first appeared in print in the early 19th century, but the etymology is uncertain.
Serration generally refers to a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied pressure at each point of contact is greater and the points of contact are at a sharper angle to the material being cut. This causes a cutting action that involves many small splits in the surface of the material being cut, which cumulatively serve to cut the material along the line of the blade.
A miter saw is a saw used to make accurate crosscuts and miters in a workpiece by pulling a large backsaw or a mounted circular saw blade down onto a board in a quick motion. Miter saws are commonly referred to as drop saws and abrasive cut off saws are referred to as a chop saw.
A backsaw is any hand saw which has a stiffening rib on the edge opposite the cutting edge, enabling better control and more precise cutting than with other types of saws. Backsaws are normally used in woodworking for precise work, such as cutting dovetails, mitres, or tenons in cabinetry and joinery. Because of the stiffening rib, backsaws are limited in the depth to which they can cut. Backsaws usually have relatively closely spaced teeth, often with little or no set.
A thread gauge, also known as a screw gauge or pitch gauge, is used to measure the pitch or lead of a screw thread.
A bucksaw is a hand-powered frame saw similar to bow saw and generally used with a sawbuck to cut logs or firewood to length (bucking). Modern bucksaws usually have a metal frame and a removable blade with coarse teeth held in tension by the frame. Lightweight portable or foldable models used for camping or back-packing are also available. It is often referred to as a bow saw in the North American hardware market, but that term traditionally refers to a different type of saw with a wooden frame.
Milling cutters are cutting tools typically used in milling machines or machining centres to perform milling operations. They remove material by their movement within the machine or directly from the cutter's shape.
The Tabun Cave is an excavated site located at Nahal Me'arot Nature Reserve, Israel and is one of Human Evolution sites at Mount Carmel, which were proclaimed as having universal value by UNESCO in 2012. The cave was occupied intermittently during the Lower and Middle Paleolithic. In the course of this period, deposits of sand, silt and clay of up to 25 m (82 ft) accumulated in the cave. Excavations suggest that it features one of the longest sequences of human occupation in the Levant.
Revueltosaurus is an extinct genus of suchian pseudosuchian from Late Triassic deposits of New Mexico, Arizona and North Carolina, United States. Many specimens, mostly teeth, have been assigned to Revueltosaurus over the years. Currently, three species are included in this genus, all of which were originally thought to represent monospecific genera of basal ornithischian dinosaurs. It was 1 meter long.
Fibrous joints are connected by dense connective tissue, consisting mainly of collagen. These are fixed joints where bones are united by a layer of white fibrous tissue of varying thickness. In the skull the joints between the bones are called sutures. Such immovable joints are also referred to as synarthroses.
A shark tooth is one of the numerous teeth of a shark. A shark tooth contains resistant calcium phosphate materials. Sharks continually shed their teeth; some Carcharhiniformes shed approximately 35,000 teeth in a lifetime, replacing those that fall out. There are four basic types of shark teeth: dense flattened, needle-like, pointed lower with triangular upper, and non-functional. The type of tooth that a shark has depends on its diet and feeding habits.
Phyllodontosuchus is a genus of sphenosuchian, a type of basal crocodylomorph, the clade that comprises the crocodilians and their closest kin. It is known from a skull and jaws from Lower Jurassic rocks of Yunnan, China. Phyllodontosuchus is unusual because some of its teeth were leaf-shaped, like those of some herbivorous dinosaurs, and it does not appear to have been a strict carnivore like most other crocodylomorphs.
In plant morphology, thorns, spines, and prickles, and in general spinose structures, are hard, rigid extensions or modifications of leaves, roots, stems or buds with sharp, stiff ends, and generally serve the same function: physically deterring animals from eating the plant material.
In common language the terms are used more or less interchangeably, but in botanical terms, thorns are derived from shoots, spines are derived from leaves, and prickles are derived from epidermis tissue.
Ymeria is an extinct genus of early tetrapod from the Devonian of Greenland. Of the two other genera of stem tetrapods from Greenland, Acanthostega and Ichthyostega, Ymeria is most closely related to Ichthyostega, though the single known specimen is smaller, the skull about 10 cm in length. A single interclavicle resembles that of Ichthyostega, an indication Ymeria may have resembled this genus in the post-cranial skeleton.
Berkheya carlinopsis Welw. ex O.Hoffm. is a Southern African herb or subshrub belonging to the family Asteraceae (Compositae) and was first described in 1896 in Boletim da Sociedade Broteriana 13 34.
A perennial herb or subshrub up to c. 1.5 m. tall. Stems branched, whitish araneose-tomentose, or glabrescent, leafy. Leaves sessile, 3–6 cm. long, dentate to pinnatifid-dentate; lamina 2–3(4) mm. wide and linear or 5–15 mm. wide and lanceolate; teeth 3–8 on each side, each tooth 2–6(10) mm. long, triangular or linear and extended in a tawny spine 2–3 mm. long; margins of teeth and sinuses entire or armed with smaller spines; upper surface smooth or somewhat scabrous, slightly to densely araneose-tomentose or glabrescent; lower surface whitish felted-tomentose. Capitula radiate, solitary and terminal on the branches, or subcorymbosely arranged, 2.5–5(+?) cm. in diam. including the rays. Phyllaries spreading, felted-tomentose outside, subglabrous or glabrous inside, 10–20 x 1–3 mm., linear-lanceolate, spiny-acuminate, ciliate-spinescent on the margins with spines 1–3 mm. long; the outermost phyllaries ± leaf-like with small spine-tipped teeth; inner phyllaries smaller and less spinescent-ciliate. Margins of the receptacular alveolae extended into straw-coloured bristles 1–2 mm. long. Achenes 1.5–3.5 mm. long, turbinate, 8–10-ribbed, strigose-sericeous, glandular-viscid at the apex. Pappus scales 2-seriate, 1–1.5 mm. long, narrowly oblong, acute or subobtuse, denticulate towards the apex.
Ulmus okanaganensis is an extinct species of flowering plant in the family Ulmaceae related to the modern elms. The species is known from fossil leaves, flowers, and fruits found in the early Eocene deposits of northern Washington State, United States and similar aged formations in British Columbia, Canada.
