Main Difference – Chordates vs Vertebrates
Chordates and vertebrates are two groups of higher animals. Both chordates and vertebrates are deuterostomes. Vertebrates are a type of advanced chordates. Chordates are characterized by the presence of a notochord. Both chordates and vertebrates contain a nerve cord, pharyngeal gill slits, and post-anal tail at some points of their life. The main difference between chordates and vertebrates is that some chordates do not have a vertebral column whereas all vertebrates have a vertebral column. In vertebrates, the vertebral column surrounds and protects the nerve cord. Both chordates and vertebrates consist of a central nervous system. The brain of the vertebrates is protected by the skull.
Key Areas Covered
1. What are Chordates
– Definition, Classification, Characteristics
2. What are Vertebrates
– Definition, Classification, Characteristics
3. What are the Similarities Between Chordates and Vertebrates
– Outline of Common Features
4. What is the Difference Between Chordates and Vertebrates
– Comparison of Key Differences
Key Terms: Amphibians, Aves, Chondrichthyes, Chordates, Mammals, Notochord, Osteichthyes , Pharyngeal Gill Slits, Reptiles, Vertebrates
What are Chordates
Chordates refer to an animal phylum that contains a notochord, dorsal central nervous system, pharyngeal gill slits, and a post-anal tail. Chordates are classified into three subphyla: Urochordata, Cephalochordata, and Vertebra. Urochordata contains sea squirts and salps that secrete a tunica to the outside of the body. Cephalochordata contains lancelets. Vertebrata contains mammals, birds, reptiles, amphibians, and fish. The diversity of chordates is shown in figure 1.
Figure 1: Chordates
Chordates are deuterostomes with a bilateral body plan. They are also coelomates. The notochord of chordates is a stiff, cartilage rod, which extends along the body. The dorsal nerve tube connects with the peripheral nervous system and acts as the central nervous system. The pharyngeal gill slits occur just behind the mouth. They serve as a filter-feeding system in some chordates. The post-anal tail is a muscular tail and extends behind the anus.
What are Vertebrates
Vertebrates refer to a large group of animals which consist of a backbone, surrounding the nerve cord. The central nervous system of vertebrates develops a brain, which is lodged in a brain case called the skull. Vertebrates also contain a notochord on the dorsal side of the gut. The pharyngeal gill slits connect to the pharynx. Vertebrates also possess a hollow, dorsal nerve cord. The nerve cord is enclosed by the vertebral column. Vertebrates contain a closed circulatory system. The appendages of vertebrates occur in two pairs. Vertebrates contain an endoskeleton, which is made up of bones or cartilages.
The four classes of vertebrates are Chondrichthyes, Osteichthyes, Amphibia, Reptilia, Aves, and Mammalia. Chondrichthyes contains marine fish with a cartilaginous endoskeleton. Osteichthyes contains both freshwater and marine fish with a bony endoskeleton. Amphibians live in both aquatic and terrestrial habitats. Their respiration occurs through the skin. An amphibian is shown in figure 2.
Figure 2: Amphibian
Reptilia contains animals that are more adapted to the terrestrial environments. The reptile body is covered with a dry skin. Aves contains birds with feathers. Most of the birds fly. Wings are a modification of forelimbs. The most characteristic feature of mammals is the production of milk for the nourishment of young members. The skin of mammals is covered with hairs.
Similarities Between Chordates and Vertebrates
- Both chordates and vertebrates are deuterostomes.
- Both chordates and vertebrates are bilaterally symmetric coelomates.
- Both chordates and vertebrates consist of a notochord, nerve cord, pharyngeal gill slits, and a post-anal tail.
- Both chordates and vertebrates consist of a central nervous system.
Difference Between Chordates and Vertebrates
Definition
Chordates: Chordates refer to an animal phylum that contains a notochord and a dorsally situated central nervous system.
Vertebrates: Vertebrates refer to a large group of animals, which consist of a backbone.
Type of Chordates
Chordates: Chordates consist of both primitive and advanced chordates.
Vertebrates: Vertebrates consist of advanced chordates.
Notochord
Chordates: Chordates possess a notochord at some point of their life.
Vertebrates: Vertebrates possess a notochord as well as a brain case.
Vertebral Column
Chordates: Invertebrate chordates do not have a vertebral column.
Vertebrates: Vertebrates have a vertebral column surrounding the nerve cord.
Skeleton
Chordates: Invertebrate chordates lack a cartilaginous or bony skeleton.
Vertebrates: Vertebrates contain a cartilaginous or bony skeleton.
Limbs or Fins
Chordates: Invertebrate chordates are limbless.
Vertebrates: Vertebrate possess limbs or fins.
Jaws
Chordates: Invertebrates chordates lack jaws.
Vertebrates: Vertebrates possess jaws.
Examples
Chordates: Vertebrates, urochordates, and cephalochordates are examples of chordates.
Vertebrates: Mammals, birds, reptiles, amphibians, and fish are examples of vertebrates.
Conclusion
Chordates and vertebrates are two groups of animals consisting of a notochord, nerve cord, pharyngeal gill slits, and a post-anal tail. Vertebrates are a type of chordates. They consist of a vertebral column, surrounding the nerve cord. The main difference between chordates and vertebrates is the presence of a vertebral column.
Reference:
1. “Chordate – Definition, Characteristics and Examples.” Biology Dictionary, 28 Apr. 2017, Available here.
2.“Vertebrates.” Vertebrates | Definition, Vertebrate Characteristics | [email protected], Available here.
Image Courtesy:
1. “Chordata diversity” By S. Taheri, edited by Fir0002 ; Nhobgood Nick Hobgood ; Philippe Guillaume ; Rob Hanson from Welland, Ontario, Canada – File:Siberischer_tiger_de_edit02.jpg ; File:Tunicate_komodo.jpg ; File:Cyanocitta_cristata_blue_jay.jpg ; File:Fangtooth_moray.jpg (CC BY 2.5) via Commons Wikimedia
2. “218913” (Public Domain) via Pixabay
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