Tile

Tiles have been used in construction for at least 4000 years, by the Romans, Greeks, Babylonians, Phoenicians and many other cultures. Suborder Pleurodira. Tiles were developed as a product of earthenware pottery, either as an alternative use for fragments of broken pottery (called potsherds) or as an independent invention. Suborder Cryptodira. For detailed information on tilings see the tessellation page. Suborder Paracryptodira (extinct)
. These shapes are said to tessellate (from the Latin tessera, 'tile'). While the issue is far from resolved, most scientists now lean towards a Diapsid origin for turtles.

Certain shapes of tiles, most obviously rectangles, can be replicated to cover a surface with no gaps. Re-analysis of prior phylogenies suggests that they classified turtles as anapsids both because they assumed this classification (most of them studying what sort of anapsid turtles are) and because they did not sample fossil and extant taxa were broadly enough for constructing the cladogram. As both the influence and the extent of Islam spread during the Middle Ages this artistic tradition was carried along, finding expression from the gardens and courtyards of Málaga in Moorish Spain to the mosaics of the Hagia Sophia in Constantinople. All molecular studies have strongly upheld this new phylogeny, though some place turtles closer to Archosauria. Palaces, public buildings, and mosques were heavily decorated with dense, often massive mosaics and friezes of astonishing complexity. More recent phylogenetic studies with this in mind placed turtles firmly within diapsids, slightly closer to Squamata than to Archosauria. Perhaps because of the tenets of Moslem law (sharia) which disavow religious icons and images in favor of more abstract and universal representations of the divine, many consider decorative tilework to have reached a pinnacle of expression and detail during the Islamic period. However, it was recently suggested that the Anapsid-like turtle skull may be due to convergent evolution rather than to anapsid descent.

Batchelder. Most anapsids became extinct in the late Permian period, except procolophonoids and possibly the precursors of the testudines (turtles). Prominent among art tile makers during this period was Ernest A. All Anapsid skulls lack a temporal opening, while all other extant amniotes have temporal openings (although in mammals the hole has become the zygoid arch). In the United States, decorative tiles were in vogue, especially in southern California, in the 1920s and 1930s. It was believed that they are the only surviving branch of the ancient clade Anapsida, which includes groups such as procolophonoids, millerettids, protorothyrids and pareiasaurs. Some places, notably Portugal, have a tradition of tilework on buildings that continues today. Their exact ancestry is disputed.

Although decorative tilework was known and extensively practiced in the ancient world (as evidenced in the magnificent mosaics of Pompeii and Herculaneum), it perhaps reached its greatest expression during the Islamic period. The first turtles are believed to have existed in the era of the dinosaurs, 200 million years ago. Decorative tilework typically takes the form of mosaic upon the walls, floor, or ceiling of a building. Turtles have a gelatinous substance in their upper and lower shell, called calipash and calipee respectively, the calipash being of a dull greenish and the calipee of a light yellow color. Finally, a cloth is rubbed over the wall tile to remove any haze which may remain from residual grout. The turtles can take up dissolved oxygen from the water through these papillae, in much the same way that fish use gills. The sponging provides added moisture to strengthen the grout as it cures. These projections, called "papillae", have a rich blood supply, and increase the surface area of the cloaca.

The excess grout is scraped off with a hard rubber block called a float immediately after applying; further, the grout is wiped again with a moist sponge before it completely hardens. Some species have large cloacal cavities lined with many finger-like projections. The spaces between the tiles are filled with a fine cement called unsanded grout. However, aquatic respiration in Australian freshwater turtles is currently being studied. Modern wall tiles are fixed to a wall using a synthetic bonding agent tile adhesive for dry areas, or a cement-based mortar for areas prone to moisture, such as bath or shower walls. Although they spend large proportions of their lives underwater, turtles are air-breathing reptiles, and must surface at regular intervals to refill their lungs with fresh air. Pictorial tiles, consisting of many tiles that the installer assembles like a jigsaw puzzle to form a single large picture, are available. In some species, temperature of the egg during development determines whether an egg develops into a male or a female: a higher temperature causes a female, a lower temperature causes a male.

Wall tiles are usually glazed, and are often patterned by painting or embossing. Turtle eggs prepared to eat consist mainly of yolk. These are usually ceramic, but other materials such as mirrored glass or polished metal can be used. Their albumen is white and will not coagulate when cooked because of the protein it contains which is different to that of bird eggs. While ancient Roman building bricks were broader and thinner than modern ones and are therefore usually called tiles, the term wall tile is normally applied to finishing tiles. The eggs of the largest species are spherical, while the eggs of the rest are elongated. See Laying tile
. Sea turtles lay their eggs on dry sandy beaches.

The spaces between the tiles are nowadays filled with sanded or unsanded floor grout, but traditionally mortar was used. The oldest tortoise on record is Tui Malila, known to have lived at least 188 years. Floor tiles are typically set into mortar consisting of sand, cement and oftentimes a latex additive for extra strength. Turtles generally live a long time; some individuals are known to have lived longer than 150 years. Small mosaic tiles may be laid in various patterns. The sizes of turtles vary from a few centimetres (forest and jungle species) to two metres (the leatherback turtle and the Galapagos tortoise). Clay tiles may be painted and glazed. Pond turtles (terrapins) are usually much smaller, while some land terrapins (tortoises) are as large as sea turtles.

These are commonly made of ceramic, clay, porcelain or stone. Sea turtles grow to large sizes and live in the oceans in the temperate and tropical regions of Earth. They include ridge, hip and valley tiles. Reference the Rheodytes leukops species. There are also roof tiles for special positions, particularly where the planes of the several pitches meet. Some are known to be able to breathe through their rectums as well. The tiles are usually hung in parallel rows, with each row overlapping the row below it to exclude rainwater and to cover the nails that hold the row below. The top part of the shell is called the carapace, the bottom is called the plastron, and the two are connected by a bridge.

Roof tiles are 'hung' from the framework of a roof by fixing them with nails. All turtles have a protective shell around their bodies. These include:. . Because of their long history, a large number of shapes (or "profiles") of roof tiles have evolved. Some species of turtles are highly endangered. Some clay tiles have a waterproof glaze. About 300 species are alive today.

Modern materials such as concrete and plastic are also used. The order of Testudines includes both extant (living) and extinct species. Roof tiles are designed mainly to keep out rain, and are traditionally made from locally available materials such as clay, slate, or wood (wooden tiles are called shingles). in North America) to refer to all members of the order, including tortoises, which are predominantly land-based. . The term is sometimes used (esp.
. The term turtle is usually used for the aquatic species, though aquatic fresh water turtles are also called terrapins.