crown group

The crown group of Nymphaeales has been estimated to be about 112 million years old.

There are three main groups of living ("crown group") tetrapods.

Archaeopteryx and some other extinct groups are not included in the crown group.

Finally, at the base of the crown group, all traits common to extant birds were present.

Cladogram following, which takes Mammalia to be the crown group.

The fossil record includes a large number of other classes which do not appear to fall into any extant crown group.

This superorder is likely paraphyletic, and fall outside the crown group birds.

Aves has more rarely been defined as a crown group consisting only of modern birds.

Gauthier defined Aves to include only the modern bird groups, the crown group.

A crown group is a group of living species and their ancestors back to the most recent common ancestor.

The Cambrian record of crown group crustaceans comes from microfossils.

The crown group here is Neornithes, all modern bird lineages back to their last common ancestor.

This superfamily includes the earliest confirmed crown group bivalves to have been described.

The corresponding crown group for this taxon is Hominidae.

The stem group of birds would be all the earlier Aves minus the crown group.

Euthyneura are considered the crown group of Gastropoda.

Some authors limit the term "mammal" to the crown group mammals, which would not include Morganucodon.

An alternative definition does not require any members of a crown group to be extant, only to have resulted from a "major cladogenesis event".

Then it took 3 to 6 millions of years for the crown group to differentiate in Mid Cretaceous.

Crown group mammals evolved from earlier mammaliaforms during the Early Jurassic.

Previously the earliest was Eomaia, a crown group mammal from about 125M years ago.

An alternative definition stresses the need for members of the crown group to have the clade's characteristic synapomorphy.

Many taxonmists refer to these animals as "mammals", though some limit the term to the mammalian crown group.

It is not necessary for a species to have living descendants in order for it to be included in the crown group.

These fossils appear to belong to the crown group, and illustrate that sipunculans have changed little since the early Cambrian.