In this article we will discuss about the modern concept on the phylogenetic status of cyclostomata. In this history of vertebrate evolution the cyclostomes occupy a doubtful status. Diverse opinions exist on the relative status of the cyclostomes in the vertebrate series. Cyclostomes are generally regarded to be lower in structural organisation than the fishes (Gnathostoma) but higher than Branchiostoma [...]
In this article we will discuss about Subphylum Vertebrate (Craniata):- 1. Introduction to Subphylum Vertebrate (Craniata) 2. Characters of Subphylum Vertebrata (Craniata) 3. Basic Features 4. Origin 5. Ancestry. Contents: Introduction to Subphylum Vertebrate (Craniata) Characters of Subphylum Vertebrata (Craniata) Basic Features of Subphylum Vertebrata (Craniata) Origin of Vertebrates Ancestry of Vertebrates 1. Introduction to Subphylum Vertebrate (Craniata): The vertebrates [...]
In this article we will discuss about the historical resume and classification of jawless vertebrates. Historical Resume: L. Agassiz (1857) placed the agnaths under the class Myzontes and proposed the following scheme for the lampreys and hagfishes: Class I. Myzontes. Order 1. Myxinides and Order 2. Cyclostomi. E. S. Goodrich (1909) gave the following classification in his book "Cyclostomes and [...]