What is the only surviving clade within Dinosauria?

What is the only surviving clade within Dinosauria?

Unsourced material may be challenged and removed. Archosauria ( lit. ‘ruling reptiles’) is a clade of diapsids, with birds and crocodilians as the only living representatives.

What animals belong to the Archosaur group?

archosaur, (subclass Archosauria), any of various reptiles, including all crocodiles and birds and all descendants of their most recent common ancestor.

Are Tuataras archosaurs?

Lepidosauria is encompassed by Lepidosauromorpha, a broader group defined as all reptiles (living or extinct) closer to lepidosaurs than to archosaurs….Lepidosauria.

Lepidosaurs Temporal range: Middle Triassic – Present,
Phylum: Chordata
Class: Reptilia
Clade: Lepidosauromorpha
Superorder: Lepidosauria Haeckel, 1866

What two groups did archosaurs split into?

About 250 million years ago, the archosaurs split into two groups: a bird-like group that evolved into dinosaurs, birds, and pterosaurs, and a crocodile-like group that includes the alligators and crocs alive today and a diversity of now-extinct relatives.

What is the shared derived character that defines the clade Dinosauria?

A possible shared derived feature of Dinosauria is the presence of at least some fuzz rather than scales.

Are birds part of the Dinosauria clade?

Modern phylogenies place birds in the dinosaur clade Theropoda. According to the current consensus, Aves and a sister group, the order Crocodilia, together are the sole living members of an unranked reptile clade, the Archosauria.

Did mammals evolve from synapsids?

Synapsids were subsequently considered to be a later reptilian lineage that became mammals by gradually evolving increasingly mammalian features, hence the name “mammal-like reptiles” (also known as pelycosaurs). These became the traditional terms for all Paleozoic (early) synapsids.

Are mosasaurs archosaurs?

Mosasaurs are not dinosaurs. The term “dinosaur” is actually very specific and describes only the land-dwelling descendants of the “ruling reptiles”, the archosaurs. Mosasaurs, on the other hand, are more closely related to modern-day lizards.

Why are reptiles and birds placed in the same clade?

The reptile clade includes birds. It shows that birds evolved from reptiles. Linnaeus classified mammals, reptiles, and birds in separate classes. This masks their evolutionary relationships.

Which clades do birds belong to?

All birds through time (beginning with the Late Jurassic Archaeopteryx) belong to the clade Avialae; modern (Cenozoic) birds belong to the clade Aves, also called Neornithes in some of the images from the lecture.

Are turtles synapsids?

Traditional phylogenetic hypotheses based on morphological and paleontological data place Synapsida (mammals and extinct relatives) as the most basal Amniota.

Are synapsids alive today?

Today, the 5,500 species of living synapsids, known as the mammals, include both aquatic (whales) and flying (bats) species, and the largest animal ever known to have existed (the blue whale). Humans are synapsids, as well.

Why are synapsids important?

Non-mammalian synapsids are an extremely important part of the fossil record because they document the evolutionary history of many of the distinctive features of mammals, such as the presence of a bony secondary palate, the incorporation of bones from the lower jaw into the middle ear, teeth with complex occlusion …