Gnathifera

Gnathifera ^[1] is a treasure of primordial animals , including the treasures of Gnathostomulida , Micrognathozoa and Syndermata ( rotifers and hypoxia ) ^[1] . Types related to this treasure include small animals, the size of which as a rule does not exceed one millimeter. An exception is some gnatostomulids , whose length reaches 4 mm. Gnathifera's inland transport is based on diffusion. They have no analogue of the circulatory system. Gnathifera move with the help of cilia. In some taxa, the pharynx is reduced, but in those taxa that have it, the pharynx has a rather complex jaw apparatus, set in motion by striated muscles. Gnathifera fertilization is internal. Gnathifera has no larvae - they carry out direct development ^[2] .