Plicozoa
| Plicozoa | |
| [[File:|300px]] | |
| Classification | |
|---|---|
| Eudiktya | |
| Episcleria | |
| Parakysta | |
| Kingdom | Plicozoa |
| Distribution | |
| Miavegr | |
| Number of species | |
Plicozoans are one of the three independently evolved animal-like kingdoms on Miavegr . Today Plicozoans can be found across all of Miavegr. They form key parts of multiple aquatic and terrestrial ecosystems.
Description
Plicozoans have complex morphologies and tissues. They have three tissues layers: Exoderm, Mesoderm, Endoderm. They have complex internal cavities.
Reproduction
The adult organism is diploid and can have female or/and male gonads. The haploïd gametes then meet (in the water column or internally) and produce a zygote, that will develop to give the adult organism.
Evolution
The Plicozoans diverged from their common ancestor with the Diplozoa around 550Ma. This ancestral organism formed flat colonies on the sea floor, with similar haploid and diploid phase. These produced hard calcareous bases and fed by using their cilia to capture particles from the water. 20 million years later, in the branch that led to modern Plicozoans, the benthic colonies developed folds to have more surface area and transitioned from calcareous wall to a silicate one. The hability to fixate silicate was acquired by horizontal evolution, from a Vitrophyta symbiote. They also lost the haploid multicellular phase. In the following millions of years, the folds of the colony surface developed in tubes with hard tissues on the exterior and ciliated tissue on the interior. The common ancestor of living Plicozoans lived around 510 Ma ago, its tubes had fused on one end to form a single outgoing siphon, it also had an octoradial symmetry and a mostly determined development.
Phylogeny
| Plicozoa |
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