The below mentioned article provides biology notes on Phylum Hemichordata. (Gk. hemi- half, chordate- notochord) Due to some similarities with chordates, some workers considered Hemichordata as a subphylum under phylum chordata. But, on grounds of its general organization, recent scientists, like Vander Horst (1939), Dawyd off (1948), Marcus (1958) and Hyman (1959), have given it the status of a phylum [...]
The upcoming discussion will update you about the difference between stomochord and notochord. Difference # Stomochord: 1. The stomochord arises as an out pocketing from the roof of the embryonic gut, anterior to the pharynx. 2. Endodermal derivative. 3. It has a narrow lumen, opening into the pharynx. 4. The wall of the lumen is composed of a single layer [...]
In this article we will discuss about the meaning and classification of phylum hemichordata. Meaning of Phylum Hemichordata: The animals with notochord constitute the Phylum Chordata. It has a major subdivision, called the Vertebrata or Craniata for possession of vertebral column or cranium. The rest of chordates, namely Hemichordata, Urochordata and Cephalochordata are collectively called the Primitive Chordates or Protochordates. [...]