Answer:
Reptiles
Explanation:
Vertebrate paleontology covers everything from the tiny, fish-like creatures, to the salamander-like ancestors of all land vertebrates, to dinosaurs, mammals, flying and swimming reptiles, etc.
Hope this helped
Non-disjunction occurs when a the chromosomes do not split properly during meiosis resulting in too few chromosomes I believe.
The Punctuated Equilibrium theory proposes that a specie that appears in the fossil record will become stable. To support this theory, a fossil record serves as an evidence which includes transitional fossils. Transitional fossils refers to the remains of an organism that still exhibit traits to both the ancestral and descendant group.