section_path: Other animals
section_name: Other animals
paragraph_text: Other animals
  
  The liver is found in all vertebrates and is typically the largest internal organ. The internal structure of the liver is broadly similar in all vertebrates, though its form varies considerably in different species, and is largely determined by the shape and arrangement of the surrounding organs. Nonetheless, in most species, it is divided into right and left lobes; exceptions to this general rule include snakes, where the shape of the body necessitates a simple cigar-like form.
  
  In neonatal marsupials, it is responsible for the production of blood cells.
  
  An organ sometimes referred to as a liver is found associated with the digestive tract of the primitive chordate Amphioxus. Although it performs many functions of a liver, it is not considered a "true" liver but rather a homolog of the vertebrate liver. The amphioxus hepatic caecum produces the liver-specific proteins vitellogenin, antithrombin, plasminogen, alanine aminotransferase, and insulin / insulin-like growth factor.