Vertebrate Class: Cold-Blooded & Scaly Skin Identification

The question asks to identify the class of vertebrates characterized by being cold-blooded (ectothermic) and having scaly skin.

Vertebrate Class Characteristics

• Cold-blooded (Ectothermic): Organisms whose body temperature relies on external sources.
• Scaly Skin: Skin covered in scales, which helps prevent dehydration.

Analyzing Vertebrate Classes

Let's examine the options based on these characteristics:

• Reptilia: Reptiles are ectothermic (cold-blooded) and typically possess dry skin covered in scales. Examples include snakes, lizards, turtles, and crocodiles.
• Mammalia: Mammals are warm-blooded (endothermic) and have skin covered with hair or fur, not scales.
• Aves: Birds are warm-blooded (endothermic) and have feathers, not scales (though some bird feet have scales).
• Amphibia: Amphibians are ectothermic (cold-blooded) but possess moist, permeable skin without scales. Examples include frogs, salamanders, and newts.

Conclusion

Based on the defining characteristics of being cold-blooded and having scaly skin, the correct vertebrate class is Reptilia.