Balanoglossus in Mashail Island described it as a worm-like holothurian. The discovery of gill-slits in this animal by Kowalewsky (1865) led to creation of a special class Enteropneusta by Gegenbaur (1870). Bateson (1885) included them in Phylum Chordata. Hyman (1959), however, placed them near Echinodermata and gave Hemichordata a status of an independent phylum. This simple organism shows affinities with several diverse groups. Balanoglossus is a tuberculos or burrowing and exclusively marine animal. It is found in shallow waters between tide marks along the coast of warm and temperate oceans. Balanoglossus clavigerus is a U-shaped excavated in a sandy bottom Nemertines
Bacterial phyla similarity with the other Deferribacteres ("Deferribacter" species and relatives) and is considered a separate phylum by Rappé and Giovannoni. Additionally the placement of the genus "Geovibrio" in the phylum Deferribacteres is debated. With the advent of methods to analyse environmental DNA (metagenomics), the 16S rRNA of an extremely large number of undiscovered species have been found, showing that there are several whole phyla which have no known cultivable representative and that some phyla lack in culture major subdivisions as is the case for Verrucomicrobia and Chloroflexi. The term Candidatus is used for proposed species for which the lack of information