Plesiomorphic traits of gnathostomes (5)
1) Jaws2) paired fins3) ear (3 semicircular canals)4) paired nostrils5) 5 gill slits
Gnathostomes are a group of jawed vertebrates that are characterized by several plesiomorphic (primitive) traits. Some of these traits include:
1. Paired fins: Gnathostomes have paired fins, which are derived from the pectoral and pelvic girdles. These fins aid in locomotion and stabilization in the water.
2. Hinged jaws: Gnathostomes have hinged jaws that are derived from the first pair of gill arches. This allows them to consume a wider variety of prey items and to more efficiently break down food.
3. Mineralized endoskeleton: Gnathostomes have a mineralized endoskeleton made of bone or cartilage. This provides support and protection for the internal organs.
4. Well-developed brain: Gnathostomes have a well-developed brain with distinct regions for processing sensory information, motor control, and higher-level cognitive functions.
5. Circulatory system: Gnathostomes have a closed circulatory system with a heart that pumps blood throughout the body. This allows for more efficient delivery of oxygen and nutrients to the tissues.
More Answers:
The Advantages of Fins: How Evolution Empowered Aquatic Organisms for Efficient Movement, Diversification, and ColonizationHow the Evolution of Jaws Revolutionized Vertebrate Feeding Efficiency and Adaptation
Unlocking the Functions of Jaws: From Mastication to Speech