PHYLUM CHORDATA
Classification:
Chordata are divided into 4 subphyla.
Subphylum 1: Hemichordata
e.g :Balanolgossus,Cephalodiscus,Rhadoplerura.
Subphylum 2 : Cephalochordata
e.g : Branchistoma (Amphioxus).
Subphylum 3 : Tunicata or Urochordata
e.g : ciona ( sea squrits )
Subphylum 4 : Vertebrata = Craniata :
Super class 1 : Agnatha
class 1 : Cyclostoma ( lamprey & Hagfish)
Class 2 : Cephalospidomorphi ( Cephalodiscus & Cephalaspis)
class 3 : Pteraspidomrphi (Pteraspis)
class 4 : Anaspida (Birkenia )
Super class 2 : Gnathostomata
Class 1 :Placodermi (Acanthodes)
class 2 :Elasmobranchii ( dog fishes, skates, rays)
Class 3 :Actionpterygii ( bony fishes)
Class 4 :Crossopterygii ( lung sishes)
Class 5 :Amphibia ( frog & toads )
Class 6 :Reptilis ( lizards)
Class 7 :Aves.
Class 8 :Mammalia.
