Major distinguishing characteristics: Eleven segments, each with a dorsal plate
Approximate number of species described: about 150
Natural History
The Kinorhyncha are widespread in mud or sand at all depths in marine waters. They live in the sand or mud.
Taxonomy
The Phylum is divided into two orders.
Order Cyclorhagida
Order Allomalorhagida
Anatomy
Mud dragons are segmented and limbless. They have a body with three parts, the head, neck, and a trunk of eleven segments.
They do not have cilia, but do have a number of spines along the body, plus up to 7 circles of spines around the head. These spines are used for locomotion.
The Fossil Record
There is apparently no fossil record of these very small animals.
