Archosauria, the archosaur clade, is a crown group that includes the most recent common ancestor of living birds and crocodilians.

The Jurassic was the height of archosaur diversity, and the first birds and placental mammals also appeared.

It is not known with certainty at what point in archosaur phylogeny the earliest simple “ protofeathers ” arose, or if they arose once or, independently, multiple times.

However, Megalania was a gigantic monitor lizard, and not a dinosaur, as its discoverer, Richard Owen, realized that the skeletal remains were that of a lizard, and not an archosaur.

In 2006, a fossilized species of archosaur was named after O ' Keeffe.

Protoavis is usually depicted as being a bipedal archosaur, similar to several poposaurids and rauisuchids that may have been partially or habitually bipedal and lived during roughly the same time as Protoavis.

While further material from the Dockum beds may vindicate this peculiar archosaur, for the time being, the case for Protoavis is non-existent.

Brochu ( 1997 ) hypothesized that there could be non-crurotarsan pseudosuchians from the Late Permian, or that a newly discovered bird-line archosaur from the Late Permian could imply a ghost lineage of pseudosuchians into the Permian.

A fragment of a lower jaw from a longirostrine archosaur has been described from early Hettangian strata in the town of Watchet in Somerset, England.

In 2006 and 2008 Fabien Knoll concluded that SMNS 12352 represented a crocodylomorph and SMNS 12352a a crocodylomorph or some other basal archosaur.

The pinnipeds are part of a clade, known as the Arctoidea, which also includes the Ursidae ( bears ) and the superfamily Musteloidea.

A second clade includes the alpha-and delta-like viral Pol from insect ascovirus ( Ascoviridae ), mammalian herpesviruses ( Herpesviridae ), fish lymphocystis disease virus ( Iridoviridae ) and chlorella virus ( Phycoviridae ).

Rather than belonging ( like Zenaida ) to the American dove clade around Leptotila, the DNA sequence data show Ectopistes to be part of a radiation that includes the " typical " Old World pigeons ( e. g., Domestic Pigeon Columba livia ) and the Eurasian turtledoves ( Streptopelia ) and Patagioenas, as well as the cuckoo-doves and relatives of the Wallacea region and its surroundings.

The term " dinosaur " is properly restricted to only those reptiles descended from the last common ancestor of the groups Saurischia and Ornithischia ( clade Dinosauria, which includes birds ), and current scientific consensus is that this group excludes the pterosaurs, as well as the various groups of extinct marine reptiles, such as ichthyosaurs, plesiosaurs, and mosasaurs.

The APG II system of 2003 includes it in the clade eurosids II ( in rosids, in eudicots ) including the following 9 families:

This hypothetical clade, Toxicofera, includes all venomous squamates: the suborders Serpentes and Iguania and the families Varanidae, Anguidae, and Helodermatidae.

includes xenarthrans as a sister clade of Euarchontoglires within Boreoeutheria ( Laurasiatheria + Euarchontoglires ).

Formerly positioned within the now defunct order Urticales, recent genetic studies have resulted in its placement within Rosales in a clade called the urticalean rosids that also includes Ulmaceae, Celtidaceae, Cannabaceae and Urticaceae.

It was most famously regarded as a primitive chelicerate, a group which includes spiders and scorpions, although subsequent phylogenetic studies have not always supported this conclusion ; it is best accommodated in the arachnate clade ( i. e. as a stem-group chelicerate ).

Within the well-supported clade of the genus Gyps which includes Asian, African, and European populations, it has been determined that this species is basal with the other species being more recent in their species divergence.

This species belongs to a Eurasian clade which also includes the Daurian Redstart, Hodgson's Redstart, the White-winged Redstart, and maybe the Ala Shan Redstart.

Eusuchia, a modern clade which includes the crown group Crocodilia, first appeared in the Lower Cretaceous of Europe.

The Hoopoe is classified in the Coraciiformes clade, a group that also includes kingfishers, bee-eaters, rollers, and woodhoopoes ( forming a clade with this one according to Hackett et al.

Whether all of these orders represent relatives of the Passeriformes is uncertain, but not well-supported by more recent data ; however the bulk of evidence supports the hypothesis that most do indeed form a clade that also includes the Passeriformes.

Based on analysis of sequence data-notably β-fibrinogen intron 7 -, Fain & Houde ( 2004 ) considered the families of the Caprimulgiformes to be members of the proposed clade Metaves, which also includes the hoatzin, tropicbirds, sandgrouse, pigeons, kagu, sunbittern, mesites, flamingos, grebes and swifts and hummingbirds.

The group is traditionally a superclass, broken into three top-level groupings: Chondrichthyes, or the cartilaginous fish ; Placodermi, an extinct clade of armored fish ; and Teleostomi, which includes the familiar classes of bony fish, birds, mammals, reptiles, and amphibians.

This clade includes modern mammals and their extinct close relatives.

The first clade, using the genus name Erythropitta, includes six species that had previously been considered closely related on external features.

Tyranni ( suboscines ) is a clade of passerine birds that includes about 1, 000 species, the large majority of which are South American.

The tyrant-flycatcher clade includes the namesake family, the Tityridae, the Cotingidae, and the Pipridae.

DNA-DNA hybridization placed the Olive Warbler as an early branch of the finch clade ( which included the finches, cardinals and Hawaiian honeycreepers ) and the New World sparrow clade ( which includes the tanagers, icterids and New world warblers ), and a 1998 study of mitochondrial DNA confirmed its status as being far removed from the New world warblers.

Sauria is a clade of reptiles that includes all living diapsids, as well as their common ancestor and all its extinct descendants.

This clade can be divided into two groups:

The order Sirenia has been placed in the clade Paenungulata, within Afrotheria, grouping it with two other orders of living mammals: Proboscidea, the elephant families, and Hyracoidea, the hyraxes, and two extinct orders, Embrithopoda and Desmostylia.

According to this classification, the Euarchonta are sister to the Glires ( lagomorphs and rodents ), and the two groups are combined into the clade Euarchontoglires.

Genetic evidence suggests the porpoises are more closely related to the white whales, and that these two families constitute a separate clade which diverged from the Delphinoidea within the past 11 million years.

The two lineages are clades — that is, they each share a common ancestor that belongs to their own group, and are more closely related to one another than to any other clade — but very similar forms evolved in each isolated population.

Studies of anatomical and molecular similarities suggest these two groups are close evolutionary relatives ; together, they form the fowl clade which is scientifically known as Galloanserae ( initially termed Galloanseri ).

Usually, the scope of the clade was vastly underestimated and only one or two specimens were sampled for each presumed " family ".

Functionally, the only difference between this classification and the preceding is that the former uses the name Prosorrhyncha to refer to a particular clade, while the traditional approach divides this into the paraphyletic Heteroptera plus the monophyletic Coleorrhyncha: Many believe is preferable to use one name only, because they feel that the two traditional suborders are too closely related to be treated as separate and should instead be one suborder only.

A 2011 analysis by Amy Driskell and colleagues of mitochondrial and nuclear DNA found the Broad-billed Fairywren and Campbell's Fairywren to lie in a clade with the two other monospecific New Guinea genera and not with the other species of Malurus.

The mockingbirds with some thrashers seem to form one major clade, while the two other groups and the remaining thrashers seem to form the another, but the basal branching pattern is not well resolved.

This split into two clades is thought to have occurred soon after Puffinus split from the other procellariids, with the genus originating in the north Atlantic Ocean and the Neonectris clade evolving in the southern hemisphere.

The Calonectris shearwaters were placed close to the two Puffinus clades ( closer to the Puffinus, or small, clade ) and both were distant to the Procellaria shearwaters.

In this taxonomy, the Euarchonta are sister to the Glires ( lagomorphs and rodents ), and the two groups are combined into the clade Euarchontoglires.

Deep divergences were found between major clades ; basally Conostoma with a clade of large species followed by two clades of smaller species which differ markedly in plumage pattern.

The taxonomic position of the clade and its two species has been confusing.

Molecular studies find support for few close relatives, and they are treated as a family at present, although it has been suggested that they form a clade with two enigmatic species in the genus Modulatrix.

The other major bowerbuilding clade builds an avenue type-bower made of two walls of vertically placed sticks.

The common ancestor of the Alveolates-a clade to which the Apicomplexa belong-was a myzocytotic predator with two heterodynamic flagella, micropores, trichocysts, rhoptries, micronemes, a polar ring and a coiled open sided conoid.

Minke whale (), or lesser rorqual, is a name given to two species of marine mammal belonging to a clade within the suborder of baleen whales.

Genetic evidence suggests that the porpoises are more closely related to the white whales, and that these two families constitute a separate clade which diverged from the Delphinoidea within the past 11 mya.

One living and two extinct taxa represent a clade endemic to the Mascarenes.

The Indigo Bunting is the sister of two sister groups, a “ blue ” ( Lazuli Bunting and Blue Grosbeak ) and a “ painted ” ( Rosita's Bunting, Orange-breasted Bunting, Varied Bunting, and Painted Bunting ) clade.

Recent genetic studies, which examined the DNA of Common Ravens from across the world, have determined that the birds fall into at least two clades: a California clade, found only in the southwestern United States, and a Holarctic clade, found across the rest of the northern hemisphere.