Are Parareptilia reptiles?

What is Parareptilia?

Parareptilia (“at the side of reptiles”) is a subclass or clade of basal sauropsids ( reptiles ), typically considered the sister taxon to Eureptilia (the group that likely contains all living reptiles). Parareptiles first arose near the end of the Carboniferous period and achieved their highest diversity during the Permian period.

Are turtles parareptiles or diapsids?

Turtles have been traditionally believed to be surviving parareptiles, on the basis of their anapsid skull structure, which was assumed to be primitive trait. The rationale for this classification has been disputed, with some arguing that turtles are diapsids that evolved anapsid skulls in order to improve their armor.

Is Sauropsida the same as Reptilia?

When Sauropsida was used, it often had the same content or even the same definition as Reptilia. In 1988, Jacques Gauthier proposed a cladistic definition of Reptilia as a monophyletic node-based crown group containing turtles, lizards and snakes, crocodilians, and birds, their common ancestor and all its descendants.

What is the difference between Eureptilia and Parareptilia?

Captorhinidae was transferred to Eureptilia, while Parareptilia included turtles alongside many of the taxa named as such by Gauthier et al. (1988). There was one major exception: mesosaurs were placed outside both groups, as the sister taxon to the crown group Reptilia.

Are turtles Testudines or Parareptilia?

They argued that Testudines (turtles) were members of Parareptilia; in fact, they explicitly defined Parareptilia as “Testudines and all amniotes more closely related to them than to diapsids”. Captorhinidae was transferred to Eureptilia, while Parareptilia included turtles alongside many of the taxa named as such by Gauthier et al. (1988).

What is the difference between eureptiles and parareptiles?

While all but the earliest eureptiles were diapsids, with two openings at the back of the skull, parareptiles were generally more conservative in the extent of temporal fenestration.

What is the group of tetrapods more closely related to turtles?

Pantestudines is the group of all tetrapods more closely related to turtles than to any other animals. It includes both modern turtles (Testudines) and all of their extinct relatives (also known as stem-turtles).

Is a Parareptilia a reptile?

Whether the term is valid depends a lot on the phylogenetic position of turtles, the relationships of which to other reptilian groups are still uncertain The name Parareptilia was coined by Olson 1947 to refer to an extinct group of Paleozoic reptiles, as opposed to the rest of the reptiles or Eureptilia (“true reptiles”).

How are turtles related to other reptiles?

Analysis of fossil data has shown that turtles are diapsid reptiles, most closely related either to the archosaurs (crocodiles, bird, and relatives) or the lepidosaurs (lizards, tuatara, and relatives). Genetic analysis strongly favors the hypothesis that turtles are the closest relatives of the archosaurs,…

What is the closest animal to a turtle?

† Acerosodontosaurus? † Claudiosaurus? Pantestudines is the group of all tetrapods more closely related to turtles than to any other animals. It includes both modern turtles (Testudines) and all of their extinct relatives (also known as stem-turtles).

Is a bird a tetrapod?

The earliest tetrapods are grouped under class Amphibia, although several of the groups are more closely related to amniotes than to modern day amphibians. Traditionally, birds are not considered a type of reptile, but crocodiles are more closely related to birds than they are to other reptiles, such as lizards.

What is the evolution of tetrapods?

Evolution of tetrapods. The evolution of tetrapods began about 400 million years ago in the Devonian Period with the earliest tetrapods evolved from lobe-finned fishes. Tetrapods are categorized as a biological superclass, Tetrapoda, which includes all living and extinct amphibians, reptiles, birds, and mammals.

What are the 4 classes of tetrapods?

Tetrapoda includes four classes: amphibians, reptiles, mammals, and birds. Overall, the biodiversity of lissamphibians, as well as of tetrapods generally, has grown exponentially over time; the more than 30,000 species living today are descended from a single amphibian group in the Early to Middle Devonian.

What is the difference between tetrapods and Stegocephalia?

The group so defined is known as the tetrapod total group. Stegocephalia is a larger group equivalent to some broader uses of the word tetrapod, used by scientists who prefer to reserve tetrapod for the crown group (based on the nearest common ancestor of living forms).

What are mammal-like reptiles?

Thus, species of the groups Pelycosauria, Dinocephalia, Dicynodontia, and Theriodontia came to be known colloquially as “mammal-like reptiles,” and were eventually placed formally within their own taxon, Synapsida, which was established as a Subclass of Reptilia ( Osborn, 1903 ).

What are the characteristics of a Reptilia?

Key features of Class REPTILIA Body varied in shape, covered with horny epidermal scales, sometimes with dermal plates; integument with few glands. Paired limbs, usually with five toes with claws, adapted for climbing, running or paddling; limbs absent in snakes and some lizards.

What are tetrapods classified as?

Tetrapods are a group of vertebrates that includes amphibians, reptiles, birds, and mammals. Tetrapods include all living land vertebrates as well as some former land vertebrates that have since adopted an aquatic lifestyle (such as whales, dolphins, seals, sea lions, sea turtles, and sea snakes).

What is a crown tetrapod?

Crown tetrapods are defined as the nearest common ancestor of all living tetrapods (amphibians, reptiles, birds, and mammals) along with all of the descendants of that ancestor. The inclusion of certain extinct groups in the crown Tetrapoda depends on the relationships of modern amphibians, or lissamphibians.

What is the difference between reptiliomorph and Tetrapoda?

Reptiliomorphs are all animals sharing a more recent common ancestry with living amniotes than with living amphibians. Tetrapoda includes four living classes: amphibians, reptiles, mammals, and birds.

Are legless snakes tetrapods?

By Aristotle ‘s time, the basic division between mammals, birds and egg-laying tetrapods (the ” herptiles “) was well known, and the inclusion of the legless snakes into this group was likewise recognized.

What is the evolutionary history of tetrapods?

Evolution of Tetrapods Amphibian-like creatures: The earliest tracks of a four-legged animal were found in Poland in 2010; they are Middle Devonian in age. Amphibians arose from sarcopterygians sometime during the Devonian.

Did amphibians evolve into reptiles?

Some Pennsylvanian (323–290 mya) amphibians of the microsaur group also evolved into insectivores that were so superficially similar to early reptiles that, for a time, they were classified as such. The amniote egg evolved in the earliest reptiles.

What are the 4 subclasses of reptiles?

1 Subclass Diapsida – diapsids, including crocodiles, dinosaurs (includes birds), lizards, snakes and turtles 2 Subclass Euryapsida – euryapsids 3 Subclass Synapsida – synapsids, including mammal-like reptiles-now a separate group (often thought to be the ancestors of mammals) 4 Subclass Anapsida – anapsids

Why are snakes considered tetrapods?

Snakes and other legless reptiles are considered tetrapods because they are sufficiently like other reptiles that have a full complement of limbs. Similar considerations apply to caecilians and aquatic mammals.

What is a tetrapodomorph?

This is a node-based definition (the node being the nearest common ancestor). The group so defined is the crown group, or crown tetrapods. The term tetrapodomorph is used for the stem-based definition: any animal that is more closely related to living amphibians, reptiles, birds, and mammals than to living dipnoi ( lungfishes ).

What is a tetrapod class?

(Show more) tetrapod, (superclass Tetrapoda), a superclass of animals that includes all limbed vertebrates (backboned animals) constituting the classes Amphibia ( amphibians ), Reptilia ( reptiles ), Aves ( birds ), Mammalia ( mammals ), and their direct ancestors that emerged roughly 397 million years ago during the Devonian Period.