Placozoa

Placozoa
Scientific classification
Kingdom:	Animalia
Subkingdom:	Parazoa
Phylum:	Placozoa

The Placozoa are an animal phylum, a primitive form of invertebrate.^[1] They are the simplest in structure of all metazoa.They have been described as "the simplest animals on Earth."^[2]

The Placozoa is usually considered to have only one species, Trichoplax adhaerens, but there is enough genetic diversity that it is possible that there are multiple, morphologically similar species.^[3] Since 2018, three other species in two groups have been described.

↑ Barnes, Robert D. 1982. Invertebrate zoology. Holt-Saunders, Philadelphia, PA. p84 ISBN 0-03-056747-5.
↑ Pennisi, Elizabeth (2021). "The simplest of slumbers". Science. 374 (6567): 526–529. doi:10.1126/science.acx9444. ISSN 1095-9203. PMID 34709907. S2CID 240154099.
↑ Voigt O; et al. (2004). "Placozoa: no longer a phylum of one". Current Biology. 14 (22): R944–5. doi:10.1016/j.cub.2004.10.036. PMID 15556848. S2CID 11539852.

[1] Barnes, Robert D. 1982. Invertebrate zoology. Holt-Saunders, Philadelphia, PA. p84 ISBN 0-03-056747-5.

[2] Pennisi, Elizabeth (2021). "The simplest of slumbers". Science. 374 (6567): 526–529. doi:10.1126/science.acx9444. ISSN 1095-9203. PMID 34709907. S2CID 240154099.

[3] Voigt O; et al. (2004). "Placozoa: no longer a phylum of one". Current Biology. 14 (22): R944–5. doi:10.1016/j.cub.2004.10.036. PMID 15556848. S2CID 11539852.

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