Nayzadumho

Nayzadumho (Xiphosura) yak guruhi hayvonhoi bugumpoi bahriro guyand, ki az sinfi merostomaho buda, beshtari onho zamonhoi qadim nobud shudaand. Badani Nayzadumho pahn (daroziash to 90 sm) buda, az du qism (sarsiva va shikam) iborat ast. Dar qismi sarsiva 6 juft poy doshtand, ki vazifai harakat, doshtan va mayda kardani khurokro ijro mekardand. Nayzadumho hayvoni judojinsai tukhmguzor ast. Az tukhmi onho kirmina paydo meshavad. 12 jinsi murdaraftai Nayzadumho malumand, ki ba davrai silur mansuband. Nayzadumho ba 3 jins va 5 namud taqsim meshavand, onho dar uqyonusi Atlantika va sohilhoi janubu sharqi va sharqii Osiyo pahn shudaand. Nayzadumho dar tunukoba zindagi mekunand. Gizoyashon hayvonhoi bemuhrai zeriobi va obsabzho meboshand.