Classification 



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Subphylum II. Urochordata or Tunicata ( 



Order 1. Larvacea ( 

 Order 2. Ascidiacea ( 

 Order 3. Thaliacea ( 



Subphylum III. Hemichordata ( 



Order 1. Enteropneusta ( 

 Order 2. Pterobranchiata ( 

 Order 3. Phoronidia ( 



Subphylum IV. Vertebrata or Craniata ( 



Class I. Cyclostomata ( 



Subclass 1. Myxinoidea ( 

 Subclass 2. Petromyzontia ( 



Class II. Pisces or Gnathostomata ( 



Subclass 1. Elasmobranchii ( 



Order 1. Plagiostomi ( 



Suborder I. Selachii ( 

 Suborder II. Batoidei ( 



Order 2. Holocephali ( 



Subclass II. 



Order 1. 

 Order 2. 

 Order 3. 

 Order 4. 



Teleostomi ( 



Crossopterygii ( 

 Chondrostei ( 

 Holostei ( 

 Teleostei ( 



Subclass III. Dipneusti (Dipnoi), ( 



Class III. Amphibia ( 



Subclass I. Stegocephali ( 



Subclass II. Lissamphibia ( 



Order 1. Apoda (Gymnophiona), ( 

 Order 2. Urodela ( 

 Order 3. Anura ( 



Class IV. Reptilia ( 



Order 1. Chelonia ( 



Order 2. Crocodilia ( 



Order 3. Sauria (Squamata), ( 



Division I. Lacertilia ( 



Division II. Ophidia ( 



