Ornithopods () or members of the clade Ornithopoda () are a group of ornithischian dinosaurs that started out as small, bipedal running grazers, and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world, and dominated the North American landscape.

However, in contexts where " amoeboid " is defined more loosely, there are many amoeboid species that are in the Excavata clade.

All modern amphibians are included in the subclass Lissamphibia, superorder Salientia, which is usually considered a clade, a group of species that have evolved from a common ancestor.

The challenge to the status has focused on the Agnostina partly because juveniles of one genus have been found with legs greatly different from those of adult trilobites, suggesting they are not members of the lamellipedian clade, of which trilobites are a part.

They are likely the sister taxon to the crustacean stem lineage, and, as such, part of the clade Crustaceomorpha.

The core Asterales are Stylidiaceae ( 6 genera ), APA clade ( Alseuosmiaceae, Phellinaceae and Argophyllaceae ( 7 genera )) and MGCA clade ( Menyanthaceae, Goodeniaceae, Calyceraceae-total 20 genera ), and Asteraceae ( 1600 genera ).

The three groups are not believed to form a clade.

Although they were previously considered the sister group to the remaining crustaceans, it is now widely accepted that crustaceans form a paraphyletic group, and Branchiopoda are thought to be sister to a clade comprising Xenocarida ( Remipedia and Cephalocarida ) and Hexapoda ( insects and their relatives ).

One clade, formed by B. anthracis, B. cereus, B. mycoides, B. pseudomycoides, B. thuringiensis and B. weihenstephanensis under current classification standards, should be a single species ( within 97 % 16S identity ), but due to medical reasons, they are considered separate species, an issue also present for four species of Shigella and Escherichia coli.

Today, Carnivora is restricted to the crown group, and Carnivora and miacoids are grouped in the clade Carnivoramorpha, and the miacoids are regarded as basal carnivoramorphs.

The Carnivora, Creodonta, Pholidota, and a few other extinct orders are informally grouped together in the clade Ferae.

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

Datasets are tables consisting of molecular, morphological, ethological and / or other characters and a list of operational taxonomic units ( OTUs ) which may be genes, individuals, populations, species, or larger taxa that are presumed to be monophyletic and that are presumed to form, all together, one large clade ; phylogenetic analysis reconstructs the branching pattern within that clade.

The archosaur clade includes two living orders, crocodilians ( of which Alligatoridae, Crocodylidae and Gavialidae are the only surviving families ) and dinosaurs ( of which birds are the sole surviving members ), along with the extinct non-avian dinosaurs and pterosaurs.

For example the chlorophycean CW clade, and chlorophycean DO clade, are defined by the arrangement of their flagella.

A clade ( from Ancient Greek, klados, " branch ") or monophylum ( see monophyletic ) is a group consisting of an ancestor and all its descendants, a single " branch " on the " tree of life ".

The green box in the middle is not a clade, but rather represents an evolutionary grade, an incomplete group, because the blue clade at left is common descent | descended from it, but is excluded.

The science that tries to reconstruct phylogenetic trees and thus discover clades is called phylogenetics or cladistics, the latter term being derived from " clade " by Ernst Mayr ( 1965 ).

* A clade is often said to be more basal the farther away it lies from the taxon of interest.

In cladograms, the clade the authors are most interested in is usually shown in greater detail and as far away from the root – the base – as possible, commonly in the top left corner ( if the root is at the bottom ) or, like in the diagram above, at the bottom ( if the root is to the left or right ).

The following cladogram, from Shapiro and colleagues ( 2002 ), shows the Dodo's closest relationships within the Columbidae, a clade consisting of generally ground-dwelling island endemics.

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 ).

Naming is also a problem for monophyletic groups: because the number of ancestors from which to root monophyletic groups is almost infinite, giving each clade a unique name is impossible-as illustrated by the failed attempts to instigate a system called the Phylocode.

Pterosaurs (, from the Greek πτερόσαυρος, pterosauros, meaning " winged lizard ") were flying reptiles of the clade or order Pterosauria.

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 clade Neocaudata is often used to separate Cryptobranchoidea and Salamandroidea from the Sirenoidea.

The APG III system, of 2009 from the APG system ( 1998 ) and the APG II system ( 2003 ), recognizes this order and assigns it to the clade commelinids, in the monocots.

However, that study was later found to be based on incomplete data, and recent studies point to multiple maternal origins, with the clade found in the Americas, Europe, Middle East, and Africa, originating from the Indian subcontinent, where a large number of unique haplotypes occur.

The Fagaceae, or oak family, is a very slow evolving clade compared to other angiosperms, and the patterns of hybridization and introgression in Quercus pose a great challenge to the concept of a species since a species is often defined as a group of “ actually or potentially interbreeding populations which are reproductively isolated from other such groups .” By this definition, many species of Quercus would be lumped together according to their geographic and ecological habitat, despite clear distinctions in morphology and, to a large extent, genetic data.

This analysis, however, comes with one caveat: early forms of conodonts, the protoconodonts, appear to form a distinct clade from the later paraconodonts and euconodonts.

The group is represented in the fossil record from shells of those groups within the clade that mineralized.

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.

Crocus adanensis and Crocus caspius should probably be removed from Biflori ; Crocus adanensis falls in a clade with Crocus paschei as a sister group to the species of series Flavi ; Crocus caspius appears to be sister to the species of series Orientales.

Mitochondria developed from proteobacteria ( in particular, Rickettsiales, the SAR11 clade, or close relatives ) and chloroplasts from cyanobacteria.

Alternatively, we may postulate extinction of all other descendants of a mitochondrion-free ancestral eukaryote, perhaps due to competition from the symbiotic clade, or oxygen poisoning as levels continued to rise.

Current taxonomy classifies the Australian dingo, together with its closest relatives outside of Australia, as Canis lupus dingo, a subspecies of grey wolf separate from the familiar common dog, Canis lupus familiaris, while still united with familiaris as an intrataxonomic clade called "< nowiki > dog </ nowiki >".

The most striking finding is that O. cinnamomeum, despite its apparent similarity to Osmunda claytoniana, is actually the most anciently-derived species of the family, and so is a sister clade to the clade that comprises Osmunda, Todea, and Leptopteris ( Jud et al.

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.

This clade was also found by the expanded study of Ericson et al.

They are likely not a distinct family ; rather, they belong into the Sylvia clade ( Cibois 2003a, Alström et al.

The wood hoopoes are related to the kingfishers, the rollers, and the Hoopoe, forming a clade with this last according to Hackett et al.

Some peculiarities of this dentition support an alternative grouping of monotremes with certain recently-discovered fossil forms into a proposed new clade known as the Australosphenida, and also suggest that the triangular array of cusps may have evolved independently in australosphenidans and therians ( Luo et al.

It was treated as an unranked clade by Matthew ( 1908 ) and as a suborder by Carroll ( 1988 ), Ursing et al.

The phylogenetic study by Matheny, et al., places the non-bluing Psilocybe and its close relatives in a basal position within the Strophariaceae, a sister taxon to a clade containing the other genera within that family.

The lack of monophyly in the earlier starling genera has led to this species being placed variously under genus Sturnia, Sturnus and Temenuchus in the past ( Zuccon et al., 2006 ) and studies have suggested the reuse of an old name Temenuchus for members of this clade.

However, Acteonoidea form a well-supported " lower heterobranch " clade with Rissoelloidea, confirming results by Aktipis et al.

In Carolan et al .’ s ( 2006 ) combined ITS, trnL-F trees, both Horrida and Californicum attach to basal nodes within the main clade Papaver.

Nesbitt ( et al., 2009 ) using the characters of Tawa found it to be a neither dilophosaurid nor averostran neotheropod but the sister group of a clade composed of dilophosaurids and averostrans

Benton ( 2004 ) placed it as an infraorder within the suborder Cerapoda ( originally named as an unranked clade ), while others, such as Ibiricu et al.

Eumuroida is a clade defined in 2004 ( Steppan et al.

The first record of the clade from the Atlantic Ocean was reported by Smith et al.

When the herpetologist G. K. Noble examined Allophryne, he suggested that it was closely related to Glassfrogs, a hypothesis later confirmed by recent phylogenetic studies that have found that Allophryne is the sister taxon of the glassfrog clade Centroleninae ( Austin et al.

Recent genetic analysis ( Metzgar et al., 2008 ) has shown that the New World varieties are in a clade that is sister to the Old World varieties of Osmunda regalis.