Primates are characterized by the presence of hair, whereas amphibians have moist, permeable skin suited for cutaneous respiration. This difference in integumentary features is a key trait separating the two groups.

Amphibians typically lay eggs that hatch into aquatic larvae, which later undergo metamorphosis into their adult form. This reproductive strategy is distinct from that of primates.

Amphibians rely on external heat sources to regulate their body temperature, making them ectothermic. In contrast, primates and other mammals maintain a constant internal body temperature.

Metamorphosis is the process by which amphibians transform from a larval stage into a mature adult. This is a well-known developmental process that distinguishes their life cycle.

Amphibian skin is permeable and plays a significant role in respiration through cutaneous gas exchange, unlike primate skin, which is keratinized and covered in hair. This trait is a clear evolutionary distinction between the two groups.

The evolution of the amniotic egg enabled vertebrates to undergo reproduction on land without the need for water. This adaptation is a major evolutionary step that distinguishes primates and other amniotes from amphibians.

Primates are known for their intricate social structures and group living, which include complex social hierarchies. Amphibians typically do not exhibit such sophisticated social behaviors.

Grasping hands with opposable thumbs are essential for climbing and manipulating objects, making them a key adaptation for an arboreal lifestyle in primates. Amphibians do not possess this trait.

Amphibians possess a three-chambered heart, which is less efficient for separating oxygenated and deoxygenated blood compared to the four-chambered heart found in primates. This difference in cardiac structure is a fundamental evolutionary divergence.

Many amphibians utilize their permeable skin for cutaneous respiration, which works alongside their lung function. This is a key respiratory adaptation not seen in primates.

Primates possess highly versatile and dexterous limbs, which include features such as opposable thumbs for grasping. This is a critical distinction from amphibians, whose limbs are less specialized.

Endothermy refers to the ability to generate and regulate body heat internally, a characteristic feature of primates. This contrasts with amphibians, which are ectothermic and depend on external sources for temperature regulation.

An expanded neocortex is linked to higher cognitive functions such as reasoning, planning, and language in primates. This advanced neural structure is a hallmark of primate evolution.

The evolution of extraembryonic membranes, such as the amnion, allowed early amniotes to reproduce on land without being tied to water. This adaptation is a critical divergence from the reproductive methods of amphibians.

Primates, as amniotes, have evolved reproductive strategies that do not require an aquatic environment, unlike amphibians that rely on water for egg development. This independence from water is a key evolutionary trait.

In primates, the transition to amniotic development - whether through egg or intrauterine growth - eliminates the need for a watery environment during embryogenesis. Amphibians, on the other hand, lay non-amniotic eggs that require moisture.

The move from ectothermy, typical of amphibians, to endothermy in primates represents a significant evolutionary shift that underpins many physiological and behavioral adaptations. This change has been crucial in supporting higher metabolic demands and complex social behaviors.

Fossil evidence shows that the evolution of robust limb bones was critical for enabling terrestrial locomotion. This structural development not only marks the divergence from amphibians but also laid the foundation for later adaptations seen in primates.

The presence of hair and advanced neural structures, such as an expanded neocortex, are key characteristics that clearly differentiate primates from amphibians. These traits are central to cladistic analyses that focus on major evolutionary divergences.

The evolutionary shift from amphibians to primates is notably marked by significant changes in reproductive strategies along with a dramatic expansion of brain capacity. These developments have enabled primates to adapt to complex terrestrial environments and social structures.