Full Answer
Are turtles mammals or reptiles?
Turtles are classified as amniotes, along with other reptiles, birds, and mammals. Like other amniotes, turtles breathe air and do not lay eggs underwater, although many species live in or around water. Turtles have appeared in myths and folktales around the world.
Are turtles at the bottom of the amniote tree?
Classically, the absence of temporal openings in the skull of turtles, the anapsid condition, has been used as evidence to place turtles at the bottom of the amniote tree, after the single-holed (synapsid) mammals split off but before the double-holed (diapsid) reptiles diversified [ 1] (Figure 1a ).
Are turtles amniotes or protists?
The position of turtles among amniotes remains in dispute, with morphological and molecular comparisons giving different results.
What is an amniote?
The amniotes are the evolutionary branch (called clade) of the tetrapods (which are superclass Tetrapoda), where the embryo develops within a set of protective extra-embryonic membranes - the chorion, amnion, and allantois. A few amniotes examples are Reptiles, Turtles, Mammals, Snakes, Lizards and more. Let us know what is an amniote in brief.
Is a turtle an Amniotes?
Turtles are classified as amniotes, along with other reptiles (including birds) and mammals. Like other amniotes, turtles breathe air and do not lay eggs underwater, although many species live in or around water.
What classifies a turtle?
turtle, (order Testudines), any reptile with a body encased in a bony shell, including tortoises. Although numerous animals, from invertebrates to mammals, have evolved shells, none has an architecture like that of turtles. The turtle shell has a top (carapace) and a bottom (plastron).
Are all turtles amphibians?
Yes, a turtle is most definitely a reptile and not an amphibian. They are scaly with dry skin, lay eggs on land, and only breathe oxygen from the air.
Do turtles belong to the amphibian or reptile family?
ReptilesReptiles are turtles, snakes, lizards, alligators and crocodiles. Unlike amphibians, reptiles breathe only through their lungs and have dry, scaly skin that prevents them from drying out. Amphibians and reptiles are together called herpetofauna, or “herps” for short.
What order does a turtle belong to?
TestudinataTurtles / OrderTurtles are an order of reptiles known as Testudines, characterized by a shell developed mainly from their ribs. Modern turtles are divided into two major groups, the side-necked turtles and hidden neck turtles, which differ in the way the head retracts.
What is a turtle family called?
FamiliesFamilyGeneraCommon name(s)Testudinidae Batsch, 178812TortoisesTrionychidae Fitzinger, 182614Softshell turtlesPleurodira – 3 families, 16 genera, over 60 speciesFamilyGeneraCommon names13 more rows
Why are turtles amphibians?
Though turtles live in or around water bodies, they are not amphibians but reptiles. A reptile is a terrestrial vertebrate covered by a scaly hard shell. Amphibians have a smooth scaleless covering that is permeable to water. Turtles are covered by a hard shell.
Are turtles mammals or amphibians?
reptilesTurtles are not mammals, they are reptiles. Mammals are animals that usually have hair or fur.
Why are turtles reptiles?
Turtles possess the typical characteristics of reptiles, being cold-blooded, egg-laying, scaly-skinned vertebrate animals that breathe air with lungs. This bog turtle, like all other turtles (including tortoises and terrains), is a reptile.
Are turtles really reptiles?
Believe it or not, turtles are reptiles and not amphibians. They have much more in common with crocodiles, lizards and snakes than they do with frogs or salamanders.
Are amphibians amniotes?
The amniotes, reptiles, birds, and mammals, are distinguished from amphibians by their terrestrially-adapted egg, which is protected by amniotic membranes.
Is a water turtle a reptile?
Yes, turtles belong to the class of cold-blooded animals called reptiles. In British English, a turtle is a type of reptile which either lives in the sea or in freshwater.
What is a turtle?
Chelonia Ross and Macartney 1802. Turtles are reptiles of the order Chelonia / kɪˈloʊniə / or Testudines / tɛˈstjuːdɪniːz /. They are characterized by a bony or cartilaginous shell, developed from their ribs, that acts as a shield. Testudines include both extant (living) and extinct species.
What bones are in the carapace of a turtle?
The carapace is fused with the vertebrae and ribs while the plastron is formed from bones of the shoulder girdle, sternum, and dermal bones , gastralia. During development, the ribs grow sideways into the carapacial ridge, unique to turtles, entering the dermis of the back to support the carapace.
How far do snapping turtles lay eggs?
The common snapping turtle walks 5 km (3.1 mi) on land to lay eggs, while sea turtles travel even further; the leatherback swims some 12,000 km (7,500 mi) to its nesting beaches. Most turtles prepare a nest for their eggs; females usually dig a flask-like chamber in the substrate.
How do turtles lay eggs?
Turtles, including sea turtles, lay their eggs on land, although some lay eggs close to or in shallow water whose levels rise and fall. While most species build nests and lay eggs where they forage, some travel miles. The common snapping turtle walks 5 km (3.1 mi) on land to lay eggs, while sea turtles travel even further; the leatherback swims some 12,000 km (7,500 mi) to its nesting beaches. Most turtles prepare a nest for their eggs; females usually dig a flask-like chamber in the substrate. Other species lay their eggs in vegetation or crevices. Females choose nesting locations based on environmental factors such as temperature and humidity, which are important for developing embryos. The number of eggs laid varies from 10 to over 100 depending on the species. Larger females can lay eggs that are greater in number or bigger in size. Compared to freshwater turtles, tortoises deposit fewer but larger eggs. Females can lay multiple clutches throughout a season, particularly in species that experience unpredictable monsoons.
What is the shell of a turtle?
The shell of a turtle is unique among vertebrates and serves to protect the animal and provide shelter from the elements. It is primarily made of bone, and consists of two parts, the carapace which usually contains 50–60 bones and covers the back of the animal while the plastron has 7–11 bones and covers the belly. They are connected by lateral extensions of the plastron. The carapace is fused with the vertebrae and ribs while the plastron is formed from bones of the shoulder girdle, sternum, and dermal bones, gastralia. During development, the ribs grow sideways into the carapacial ridge, unique to turtles, entering the dermis of the back to support the carapace. The development is signaled locally by fibroblast growth factors including FGF10. The shoulder girdle in turtles is made up of two bones, the scapula and the procoracoid. Both the anterior and posterior pelvis of turtles are located within the shell and hence are effectively within the rib-cage; the trunk ribs grow over the shoulder girdle during development.
How fast can a sea turtle swim?
By contrast, sea turtles can swim at 30 km/h (19 mph). The limbs of turtles are adapted for various means of locomotion and habits and most have five toes. Tortoises are specialized for terrestrial environments and have column-like legs with elephant-like feet with short toes.
What is the name of the order of turtles?
The name "Chelonia", now a synonym for the order, is based on the Greek word for "turtle", χελώνη chelone; Greek χέλυς chelys "tortoise" is used in the formation of names of many turtle taxa. The name of the order, "Testudines", is based on the Latin word for tortoise, testudo.
How many bones are in a turtle's shell?
4. Just like your bones, a turtle’s shell is actually part of its skeleton. It’s made up of over 50 bones which include the turtle’s rib cage and spine.
How many species of turtles are endangered?
10. Sadly, many species of turtle are endangered! 129 of approximately 300 species of turtle and tortoise on Earth today are either vulnerable, endangered, or critically endangered, according to the IUCN. Threats include loss of habitat, poaching and the illegal pet trade.
What is the name of the group of reptiles that live in different environments?
These magnificent creatures come in all shapes and sizes and live in a number of different environments. They all belong to a group of reptiles called Testudines , which includes turtles, tortoises, and terrapins.
Can a turtle come out of its shell?
5. Contrary to popular belief, a turtle cannot come out of its shell. The turtle’s shell grows with them, so it’s impossible for them to grow too big for it!
Do turtles lay eggs on land?
8. Turtles are ‘amniotes’ – they breathe air and lay their eggs on land, although many species live in or around water.
Is a turtle omnivore or carnivore?
7. Some turtles are carnivores (meat eaters), others are herbivores (plant eaters) and some are omnivores (a mixture of the two!). Many baby turtles start life as carnivores but grow to eat more plants as they mature.
Abstract
The position of turtles among amniotes remains in dispute, with morphological and molecular comparisons giving different results. Morphological analyses align turtles with either lizards and their relatives, or at the base of the reptile tree, whereas molecular analyses, including a recent study by Chiari et al.
Acknowledgements
Audrie Kapinus assisted with artwork. The author was supported by grants from the US National Science Foundation.
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What is the name of the turtle that has a bony shell?
Testudines. Turtles are reptiles of the order Chelonii or Testudines characterized by a special bony or cartilaginous shell developed from their ribs and acting as a shield. The earliest known turtles date from 220 million years ago, making turtles one of the oldest reptile groups and a more ancient group than lizards, snakes or crocodiles.
What is a turtle's shell?
Turtles are reptiles of the order Chelonii or Testudines characterized by a special bony or cartilaginous shell developed from their ribs and acting as a shield.
Why do leatherback sea turtles have a higher body temperature than other sea turtles?
However, because of their high metabolic rate, leatherback sea turtles have a body temperature that is noticeably higher than that of the surrounding water. Turtles are classified as amniotes, along with other reptiles (including birds) and mammals.
Why are amniotes unique?
The unique embryonic features of amniotes may reflect specializations for eggs to survive drier environments; or the increase in size and yolk content of eggs may have permitted, and coevolved with , direct development of the embryo to a large size .
What are the characteristics of amniotes?
Features of amniotes evolved for survival on land include a sturdy but porous leathery or hard eggshell and an allantois that facilitates respiration while providing a reservoir for disposal of wastes. Their kidneys and large intestines are also well-suited to water retention.
How big are squamate eggs?
This is supported by the fact that extant squamate species that lay eggs less than 1 cm in diameter have adults whose snout-vent length is less than 10 cm. The only way for the eggs to increase in size would be to develop new internal structures specialized for respiration and for waste products.
What is the name of the clade of vertebrates that includes sauropsids, birds,?
Eureptilia. Amniotes are a clade of tetrapod vertebrates that comprise sauropsids (including reptiles and birds) and synapsids (including mammals ). They are distinguished by a membrane ( amnion) protecting the embryo and a lack of a larval stage. Thanks to this, amniotes lay eggs on land or retain them within the mother, ...
Why is the amnion important?
The amnion is a critical divergence within vertebrates that allows the embryos to survive out of the water. This enabled amniotes to reproduce on land and so move into drier environments—free of the need to return to water for reproduction as amphibians.
What is the next major breakthrough in the amniote ancestry?
After internal fertilization and the habit of laying eggs in terrestrial environments became a reproduction strategy amongst the amniote ancestors, the next major breakthrough appears to have involved a gradual replacement of the gelatinous coating covering the amphibian egg with a fibrous shell membrane.
When did tetrapods become aquatic?
At the late Devonian mass extinction (360 million years ago), all known tetrapods were essentially aquatic and fish-like.
Is A Turtle A Reptile?
A turtle is a reptile. Turtles belong to the order Testudines, which is one of four groups of living reptiles. Turtles possess the typical characteristics of reptiles, being cold-blooded, egg-laying, scaly-skinned vertebrate animals that breathe air with lungs.
What Is A Turtle?
A turtle is a reptile of order Testudines. Testudines is a group of related animals within the wider Reptilia class. Not all turtles have the word “turtle” in their names; animals such as tortoises and terrapins belong to the order Testudines, and all are therefore considered to be turtles.
Reptile Characteristics
A very small number of living reptiles (including the leatherback sea turtle Dermochelys coriacea and the Argentine black and white tegu Salvator merianae) are endothermic (warm-blooded) to a certain extent.
Turtle Characteristics
The characteristics listed above separate reptiles from other types of animals, but what distinguishes turtles from other reptiles?
Types Of Turtles
The common snapping turtle is a “hidden-neck” turtle of the suborder Cryptodira.
The First Reptiles
As we’ve found, all living reptiles (including turtles) share a common ancestor.
Overview
Anatomy and physiology
The largest living species of turtle (and fourth-largest reptile) is the leatherback turtle, which can reach over 2.7 m (8 ft 10 in) in length and weigh over 500 kg (1,100 lb). The largest known turtle was Archelon ischyros, a Late Cretaceous sea turtle up to 4.5 m (15 ft) long, 5.25 m (17 ft) wide between the tips of the front flippers, and estimated to have weighed over 2,200 kg (4,900 lb). The smallest living turtle is Chersobius signatus of South Africa, measuring no more than 10 cm (3.9 i…
Naming and etymology
The word turtle is derived from the French tortue or tortre ('turtle, tortoise'). It is a common name and may be used without knowledge of taxonomic distinctions. In North America, it may denote the order as a whole. In Britain, the name is used for sea turtles as opposed to freshwater terrapins and land-dwelling tortoises. In Australia, which lacks true tortoises (family Testudinidae), non-marine turtles were traditionally called tortoises, but more recently turtle has been used for the entire gr…
Behavior
Most turtle species are opportunistic omnivores; land-dwelling species are more herbivorous and aquatic ones more carnivorous. Generally lacking speed and agility, most turtles feed either on plant material or on animals with limited movements like mollusks, worms, and insect larvae. Some species, such as the African helmeted turtle and snapping turtles, eat fish, amphibians, reptiles (incl…
Reproduction and lifecycle
Turtles have a wide variety of mating behaviors but do not form pair-bonds or social groups. In green sea turtles, females generally outnumber males. In terrestrial species, males are often larger than females and fighting between males establishes a dominance hierarchy for access to mates. For most semi-aquatic and bottom-walking aquatic species, combat occurs less often. Males …
Systematics and evolution
Zoologists have sought to explain the evolutionary origin of the turtles, and in particular of their unique shells. In 1914, Jan Versluys proposed that bony plates in the dermis, called osteoderms, fused to the ribs beneath them, later called the "Polka Dot Ancestor" by Olivier Rieppel. The theory accounted for the evolution of fossil pareiasaurs from Bradysaurus to Anthodon, but not for how the ribs cou…
Distribution and habitat
Turtles are widely distributed across the world's continents, oceans, and islands with terrestrial, fully aquatic, and semi-aquatic species. Sea turtles are mainly tropical and subtropical, but leatherbacks can be found in colder areas of the Atlantic and Pacific. Living Pleurodira all live in freshwater and are found only in the Southern Hemisphere. The Cryptodira include terrestrial, freshwater, and marine species, and these range more widely. The world regions richest in non-…
Conservation
Among vertebrate orders, turtles are second only to primates in the percentage of threatened species. 360 modern species have existed since 1500 AD. Of these, 51–56% are considered threatened and 60% considered threatened or extinct. Turtles face many threats, including habitat destruction, harvesting for consumption, the pet trade, light pollution, and climate change. Asian species h…