Humans are bilaterans and deuterostomes — the anus develops first.

The protostomes include most invertebrate animals, such as insects, worms and molluscs, while the deuterostomes include the vertebrates.

The chordates and three sister phyla, the Hemichordata, the Echinodermata and the Xenoturbellida, make up the deuterostomes, one of the two superphyla that encompass all fairly complex animals.

Gastrulation marks the opening of the " second mouth " that places them within the deuterostomes, and the mesoderm, which will host the skeleton, migrates inwards.

The phylum contains about 7000 living species, making it the second-largest grouping of deuterostomes ( a superphylum ), after the chordates ( which include the vertebrates, such as humans, sharks and frogs ).

The specimen had a series of gill slits, which suggested that this new group illustrates an early stage in the diversification of the deuterostomes, one of the major animal divisions.

The distinction between protostomes and deuterostomes is based on the direction in which the mouth ( stoma ) develops in relation to the blastopore.

: Radial cleavage is characteristic of the deuterostomes, which include some vertebrates and echinoderms, in which the spindle axes are parallel or at right angles to the polar axis of the oocyte.

In fact it appears to have happened at least twice, following different paths in protostomes and deuterostomes.

Both morphological and molecular phylogeny analyses disagree over bryozoans ' relationships with entoprocts, about whether bryozoans should be grouped with brachiopods and phoronids in Lophophorata, and whether bryozoans should be considered protostomes or deuterostomes.

This system may have allowed echinoderms to feed without the pharyngeal slits found in other deuterostomes.

A hollow neural tube exists among some species ( at least in early life ), probably a primitive trait they share with the common ancestor of chordata and the rest of the deuterostomes.

Chaetognaths are traditionally classed as deuterostomes by embryologists.

Lynn Margulis and K. V. Schwartz place chaetognaths in the deuterostomes in their Five Kingdom classification.

Their affinity is very uncertain ; they have been considered to represent stem-and crown-group arthropods, stem-group vertebrates, and early deuterostomes.

The general scientific consensus formerly ( before 2001 ) considered them early limbless arthropods, but now considers them early deuterostomes.

Shu ( 2003 ) has argued that the vetulicolians probably represent an early side-branch of deuterostomes, and that this implies that segmentation in cephalochordates and vertebrates may be derived from the common ancestor of protostomes and deuterostomes.

However, recent molecular phylogenies have suggested this characteristic is not as informative as previously believed: the coelom may have arisen twice, once in protostomes and once among the deuterostomes.

Interpretations have led to many refinements of the phylogeny of various groups and even the erection of the new phylum Vetulicolia of primitive deuterostomes.

At present, there is no agreement as to the systematic placement of the Vetulicola, represented by seven species from Chengjiang: originally described as crustacean arthropods, the Vetulicola were later erected as a new phylum of primitive deuterostomes by D. G.

This group is now known as the deuterostomes.

Named vetulocystids, these deuterostomes were a diverse superphylum that included the chordates, hemichordates, and echinoderms.

These findings have also led to important realizations about evolution-for example, that protostomes and deuterostomes are likely to have had a relatively well-developed common ancestor with a much more complex body plan than had been conventionally thought.

One party can tell many others a piece of information without losing it themselves, the original information store never becomes empty.

In the original series finale, when McVicker thinks that Beavis and Butt-Head are dead, he immediately stops shaking and becomes calmer and more cheerful.

The fractal curve divided into parts 1 / 3 the length of the original line becomes 4 pieces rearranged to repeat the original detail, and this unusual relationship is the basis of its fractal dimension.

For instance, a certain behaviour or belief becomes part of a society's structure when the original purpose of that behaviour or belief can no longer be recalled and becomes socialized into individuals of that culture.

A hydrophobic surface ( one that has an original contact angle greater than 90 °) becomes more hydrophobic when microstructured – its new contact angle becomes greater than the original.

However, a hydrophilic surface ( one that has an original contact angle less than 90 °) becomes more hydrophilic when microstructured – its new contact angle becomes less than the original.

* 1987-Frobisher Bay officially becomes Iqaluit, reverting to its original Inuktitut name meaning " place of ( many ) fish "

By supplying the parallel structure, the original conclusion becomes logical.

* 1790 – Rhode Island becomes the last of the original United States ' colonies to ratify the Constitution and is admitted as the 13th U. S. state.

This process continued in Manichaeism's meeting with Chinese Buddhism, where, for example, the original Aramaic karia ( the " call " from the world of Light to those seeking rescue from the world of Darkness ), becomes identified in the Chinese scriptures with Guan Yin ( or Avalokitesvara in Sanskrit, literally, " watching / perceiving sounds the world ", the Chinese Bodhisattva of Compassion ).

On the other hand, Steven Pinker has observed that mondegreen mishearings tend to be less plausible than the original lyrics, and that once a listener has " locked in " to a particular misheard interpretation of a song's lyrics, it can remain unquestioned, even when that plausibility becomes strained.

If, however, the new version becomes the standard, it loses the part of its name that identifies it as new or different, and a retronym is coined for the original.

The original use of an adjective to describe a particular variant of an object is typically purely compositional, as in " acoustic guitar ", but gradually over time it becomes a collocation, a name or technical term in its own right with additional nuances, greater specificity and general but implicit agreement on it as the appropriate term versus alternative descriptions of the original type.

* May 29 – Rhode Island ratifies the United States Constitution and becomes the last of the 13 original states to do so.

These could be modified to introduce the new variable n such that no new time-series would have to be generated, but rather the original time series could be reused for various values of n. The estimators becomes

In marsupials ( and a few birds ), the genital tract is separate from the anus, but a trace of original cloaca does remain externally.

Note the addition of two holes ( anus and penis ) to the original seven ( eyes, ears, nostrils, and mouth ).

The Singaporean margin note of the original Section 377 further explained that mere penetration of the penis into the anus or mouth even without orgasm would constitute the offence.

In the original episode draft, Peter was to be seen falling down the stairs, and Stewie's foot was to be lodged inside Peter's anus, where he was to lose his shoe.