Dinosaurs vs. Mammals

Attribute	Dinosaurs	Mammals
Time Period	Triassic to Cretaceous	Present
Extinct/Alive	Extinct	Alive
Reproduction	Egg-laying	Live birth
Warm/Cold Blooded	Most likely cold-blooded	Warm-blooded
Body Covering	Scales/Feathers	Fur/Hair
Brain Size	Varied	Varied

Physical Characteristics

Dinosaurs and mammals are both vertebrates, but they have distinct physical characteristics that set them apart. Dinosaurs were reptiles that walked on four legs, had scaly skin, and laid eggs. In contrast, mammals are warm-blooded animals that typically have fur or hair, give birth to live young, and nurse their offspring with milk. Dinosaurs had long tails and sharp teeth for hunting, while mammals have a wide range of teeth types depending on their diet.

Size and Shape

One of the most noticeable differences between dinosaurs and mammals is their size and shape. Dinosaurs were known for their massive size, with some species growing to lengths of over 100 feet and weighing several tons. In contrast, mammals come in a wide range of sizes, from tiny shrews to massive elephants. Mammals also have a greater variety of body shapes, from the sleek and streamlined bodies of dolphins to the bulky and lumbering bodies of bears.

Reproduction

Reproduction is another area where dinosaurs and mammals differ significantly. Dinosaurs laid eggs, which they buried in nests or protected in other ways until they hatched. Mammals, on the other hand, give birth to live young, which they then nurse with milk produced by mammary glands. This method of reproduction allows mammals to provide more care and protection to their offspring, increasing their chances of survival.

Behavior and Social Structure

Dinosaurs and mammals also exhibit different behaviors and social structures. Dinosaurs were primarily solitary animals, with some species forming herds or packs for protection or hunting. Mammals, on the other hand, are known for their complex social structures, with many species living in groups or colonies. Mammals also exhibit a wider range of behaviors, from the playful antics of dolphins to the intricate communication of primates.

Diet and Feeding Habits

Both dinosaurs and mammals were carnivores, herbivores, or omnivores, but they had different diets and feeding habits. Dinosaurs had specialized teeth for tearing flesh or grinding plant material, depending on their diet. Some dinosaurs were strict herbivores, while others were apex predators that hunted other dinosaurs. Mammals have a wider range of teeth types, allowing them to eat a variety of foods. Some mammals are strict carnivores, while others are herbivores or omnivores.

Extinction

One of the most significant differences between dinosaurs and mammals is their fate. Dinosaurs went extinct around 65 million years ago, likely due to a combination of factors such as climate change, asteroid impact, and volcanic activity. Mammals, on the other hand, survived the mass extinction event that wiped out the dinosaurs and went on to diversify and thrive. Today, mammals are the dominant group of animals on Earth, with over 5,400 species inhabiting every continent and ocean.