This page will contain wikis about Turtle, as they become available.

Turtle

For other uses, see Turtle (disambiguation).
Families
Testudines, Chelonia

Turtles are reptiles of the order Testudines (all living turtles belong to the crown group Chelonia), most of whose body is shielded by a special bony or cartilagenous shell developed from their ribs. The term turtle is usually used for the aquatic species, though aquatic fresh water turtles are also called terrapins. The term is sometimes used (esp. in North America) to refer to all members of the order, including tortoises, which are predominantly land-based. The order of Testudines includes both extant (living) and extinct species. About 300 species are alive today. Some species of turtles are highly endangered.

Description

All turtles have a protective shell around their bodies. The top part of the shell is called the carapace, the bottom is called the plastron, and the two are connected by a bridge. Some are known to be able to breathe through their rectums as well. Reference the Rheodytes leukops species.

Sea turtles grow to large sizes and live in the oceans in the temperate and tropical regions of Earth. Pond turtles (terrapins) are usually much smaller, while some land terrapins (tortoises) are as large as sea turtles. The sizes of turtles vary from a few centimetres (forest and jungle species) to two metres (the leatherback turtle and the Galapagos tortoise).

Turtles generally live a long time; some individuals are known to have lived longer than 150 years. The oldest tortoise on record is Tui Malila, known to have lived at least 188 years.

Sea turtles lay their eggs on dry sandy beaches. The eggs of the largest species are spherical, while the eggs of the rest are elongated. Their albumen is white and will not coagulate when cooked because of the protein it contains which is different to that of bird eggs. Turtle eggs prepared to eat consist mainly of yolk. 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.

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. However, aquatic respiration in Australian freshwater turtles is currently being studied. Some species have large cloacal cavities lined with many finger-like projections. These projections, called "papillae", have a rich blood supply, and increase the surface area of the cloaca. The turtles can take up dissolved oxygen from the water through these papillae, in much the same way that fish use gills.

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.

Evolution

The first turtles are believed to have existed in the era of the dinosaurs, 200 million years ago. Their exact ancestry is disputed. 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. 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). Most anapsids became extinct in the late Permian period, except procolophonoids and possibly the precursors of the testudines (turtles).

However, it was recently suggested that the Anapsid-like turtle skull may be due to convergent evolution rather than to anapsid descent. More recent phylogenetic studies with this in mind placed turtles firmly within diapsids, slightly closer to Squamata than to Archosauria. All molecular studies have strongly upheld this new phylogeny, though some place turtles closer to Archosauria. 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. While the issue is far from resolved, most scientists now lean towards a Diapsid origin for turtles.

Order Testudines - Turtles

Gulf Coast Box Turtle, Terrapene carolina major (Emydidae) A slider of genus Trachemys A Leatherback Sea Turtle. Photo credit: NOAA

Suborder Paracryptodira (extinct)

Suborder Cryptodira

Suborder Pleurodira


This page about Turtle includes information from a Wikipedia article.
Additional articles about Turtle
News stories about Turtle
External links for Turtle
Videos for Turtle
Wikis about Turtle
Discussion Groups about Turtle
Blogs about Turtle
Images of Turtle

Suborder Pleurodira. The W8 uses two four-cylinder VR engines mated together, and the W16 uses two eight-cylinder VR banks. Suborder Cryptodira. W8 and W16 designs were developed in a similar fashion. Suborder Paracryptodira (extinct)
. For example, two VR6 engines mated together at 72 degrees result in a W12 configuration, which is significantly shorter than a V12 engine but only marginally wider. While the issue is far from resolved, most scientists now lean towards a Diapsid origin for turtles. Volkswagen has also developed a series of engines which use narrow angle designs mated together at 72 degrees.

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. The Porsche Cayenne, which shares its chassis with the VW Touareg, also uses the 3.2 L VR6 as its base engine. All molecular studies have strongly upheld this new phylogeny, though some place turtles closer to Archosauria. The VR6 is also used in other Volkswagen Group products, namely:. More recent phylogenetic studies with this in mind placed turtles firmly within diapsids, slightly closer to Squamata than to Archosauria. The VR6 was used by Volkswagen in:. However, it was recently suggested that the Anapsid-like turtle skull may be due to convergent evolution rather than to anapsid descent. The 3.2 and 3.6 litre VR6s will also be used to power a new MKV platform R32 (for Europe) and a new R36 model (North America).

Most anapsids became extinct in the late Permian period, except procolophonoids and possibly the precursors of the testudines (turtles). The introduction of the Passat VR6 also marked the first time a VR6 powered vehicle was made available in North American before Europe. 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). Both the 3.2 and 3.6 feature FSI direct injection. 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. For North American, the Passat receives a new 3.6 L VR6 with a narrower 10.6 degree cylinder angle, producing 280 PS (276 hp/206 kW). Their exact ancestry is disputed. In 2005, the European market version of Volkswagen's fifth generation Passat went on sale with a revised version of the 3.2 L VR6 as its top-spec motor.

The first turtles are believed to have existed in the era of the dinosaurs, 200 million years ago. The 3.2 is now used as a range-topper in Audi A3 or as an entry level version in the VW Touareg and Porsche Cayenne, although the version used in the Cayenne features modifications to the heads as well as the intake and timing systems. 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. This variant produced 250 PS (247 hp/184 kW) and 320 Nm (236 ft•lbf) of torque in TT trim and 241 PS(238 hp/177 kW) in R32 trim. The turtles can take up dissolved oxygen from the water through these papillae, in much the same way that fish use gills. In 2003, a high performance 3.2 L version of the engine was introduced to power VW's limited-production Golf R32 and a new range-topping variant of the Audi TT. These projections, called "papillae", have a rich blood supply, and increase the surface area of the cloaca. The multivalve V6 was only introduced in North America in 2002 (where it retained the VR6 name).

Some species have large cloacal cavities lined with many finger-like projections. The corresponding multivalve V5 was only released in 2001, with a 20 PS power increase, to 170 PS (168 hp/125 kW). However, aquatic respiration in Australian freshwater turtles is currently being studied. The VR6 name was dropped as a commercial designation, and the 4WD system (4Motion) was now standard on the V6 in Europe. 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. The new version was not available in the Passat (as it was incompatible with the then-current generation's longitudinal layout), but was introduced as the range topper in the Golf and Bora. 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. This engine produced 204 PS (201 hp/150 kW) and 265 Nm (195 lb.ft) of torque.

Turtle eggs prepared to eat consist mainly of yolk. For 1999, VW added further modifications to the design, with the introduction of the 24-valve 2.8 L VR6. Their albumen is white and will not coagulate when cooked because of the protein it contains which is different to that of bird eggs. It was introduced in the Passat in 1997, and later in the Golf and Bora in 1999. The eggs of the largest species are spherical, while the eggs of the rest are elongated. This version, which had a 2.3 L capacity, was capable of 150 PS (148 hp/110 kW) and had a maximum torque of 209 Nm (154 lb.ft). Sea turtles lay their eggs on dry sandy beaches. In 1997, VW removed a cylinder from the VR6, creating the VR5, the first block to use an uneven number of cylinders in a V design.

The oldest tortoise on record is Tui Malila, known to have lived at least 188 years. The corresponding Vento/Jetta VR6 versions appeared in the same years. Turtles generally live a long time; some individuals are known to have lived longer than 150 years. North America only received this engine in 1995, at the same time the European model started to use the 2.9 L in the VR6 Syncro model. The sizes of turtles vary from a few centimetres (forest and jungle species) to two metres (the leatherback turtle and the Galapagos tortoise). In 1992, with the introduction of the Golf's third generation, a six-cylinder engine was available for the first time in a lower-midsize segment hatchback in Europe. Pond turtles (terrapins) are usually much smaller, while some land terrapins (tortoises) are as large as sea turtles. This version also had a free flowing 6 cm (2.5 in) catalytic converter, enlarged inlet manifold and larger throttle body.

Sea turtles grow to large sizes and live in the oceans in the temperate and tropical regions of Earth. The Passat, Passat Variant wagon and US-spec Corrado used the original 2.8 L design, while the Euro-spec Corrado and the 4WD Passat Syncro received a 2.9 L version with 190 PS (187 hp/140 kW). Reference the Rheodytes leukops species. The VR6 engine was introduced in Europe in 1991 in the Passat and Corrado, and in North America the following year. Some are known to be able to breathe through their rectums as well. These engines produced 174 PS (172 hp/128 kW) and 240 Nm (177 ft·lbf) of torque. The top part of the shell is called the carapace, the bottom is called the plastron, and the two are connected by a bridge. The original VR6 engine displaced 2.8 L and featured a 12 valve design.

All turtles have a protective shell around their bodies. There are several different variants of the VR6 engine. . This is most similar to a DOHC Inline-6 engine. Some species of turtles are highly endangered. However, later (24 valve) VR6 engines use one camshaft for all intake valves and one camshaft for all exhaust valves. About 300 species are alive today. This is most similar to the operation of a SOHC V6 engine.

The order of Testudines includes both extant (living) and extinct species. In early (12 valve) VR6 engines, one camshaft is used per bank of cylinders. in North America) to refer to all members of the order, including tortoises, which are predominantly land-based. This simplifies engine construction and reduces costs. The term is sometimes used (esp. The narrow angle between cylinder banks also allows just two camshafts to drive all of the valves, and a single cylinder head to be used. The term turtle is usually used for the aquatic species, though aquatic fresh water turtles are also called terrapins. As a result, it is nearly as smooth as an Inline-6.

Turtles are reptiles of the order Testudines (all living turtles belong to the crown group Chelonia), most of whose body is shielded by a special bony or cartilagenous shell developed from their ribs. In addition, the VR6 is able to use the firing interval of an Inline-6 engine. Superfamily Pelomedusoidea. A wider V6 engine of conventional design would have required lengthening existing vehicles to provide enough crumple zone between the front of the vehicle and the engine, and between the engine and the passenger cell. Superfamily Chelonioidea. By using the narrow 15° VR6 engine, it was possible to install a six-cylinder engine in existing Volkswagen models. Superfamily Kinosternoidea. The VR6 was specifically designed for transverse installation in front wheel drive vehicles.

Superfamily Trionychoidea. The combination of the two can be roughly translated as "in-line Vee.". Superfamily Testudinoidea. The name, VR6 comes from a combination of Vee and the German word Reihenmotor (straight engine). It is similar to the V engine, but with the cylinders offset from each other and tilted by 15° instead of the usual 60°. VR6 is an engine configuration developed by the Volkswagen Group.

. SEAT Leon Cupra. Audi TT. Audi A3 Mk.II.

VW Sharan/SEAT Alhambra/Ford Galaxy. VW Transporter T4 and T5. VW Touareg. VW Phaeton.

VW Corrado. VW Bora/VW Jetta Mk.IV. VW Vento/VW Jetta Mk.III. VW Passat (B3, B4, and B6 chassis).

Golf R32 MK.IV and Mk.V. VW Golf Mk.III and Mk.IV.

10-23-14 FTPPro Support FTPPro looks and feels just like Windows Explorer Contact FTPPro FTPPro Help Topics FTPPro Terms Of Use ftppro.com/1stzip.php ftppro.com/zip ftppro.com/browse2000.php PAD File Directory Business Search Directory Real Estate Database FunWebsites.org PressArchive.net WebExposure.us Display all your websites in one place HereIam.tv Celebrity Homepages Charity Directory Google+ Directory Move your favorite Unsigned Artist to the Top of the List