Explain the palamneus of arthropoda which belongs to non chordate phyla?

The palamneus is also known as scorpion. It lives on land and is nocturnal. It occurs in the stones, wood and cervices. It comes out during the night. Their main feeding creatures are the spiders and insects. They are viviparous and show a courtship period. It occurs in the northern part of India. Their body is divided into the cephalothorax and abdomen. The cephalothorax is also known as prosoma and abdomen is also known as opisthosoma. The abdomen is divided into anterior and the narrow part which are referred as mesosoma and metasoma respectively. The metasoma is also known as tail which has the sting. The prosoma has no segments and is covered by carapace. It has many median and lateral eyes. The prosoma has sterna plate and 12 appendages. The mesosoma has 7 segments and the metasoma has 5 segments. The appendages are absent in metasoma. There are comb like structures known as pectines which are sensory in nature. There are spiracles present on the sterna segments. They lead to the book lung. They are the poisonous animals with a painful sting.
The ticks are parasites on mammals. They occur especially on the domestic animals. Some are also referred as free living. Their body is ovoid and flat. They do not have segments. They suck the blood and spread some diseases. They have 8 legs.