- Body Size: Bears can vary significantly in size, with the largest species, the polar bear (Ursus maritimus), weighing up to 1,500 kilograms, while the smallest species, the sun bear (Helarctos malayanus), weighs only about 65 kilograms.
- Fur Color: Bears have a variety of fur colors, including black, brown, white, and even reddish or yellowish hues. Some species, such as the giant panda (Ailuropoda melanoleuca), have distinct black and white markings.
- Claw Size and Shape: Bear claws can vary in size and shape depending on the species. Some bears, such as the grizzly bear (Ursus arctos horribilis), have long, curved claws that are well-suited for digging and hunting, while others, like the polar bear, have shorter, straighter claws that are adapted for walking on ice.
- Facial Features: Bears have distinct facial features, including a prominent snout and large canine teeth. Some species, such as the sloth bear (Melursus ursinus), have long, shaggy hair on their faces, while others, like the spectacled bear (Tremarctos ornatus), have distinctive markings around their eyes.
-Dental formula: Bears have a dental formula of 3/2 1/1 4/4 2/3. This means that bears have three incisors, two canines, one premolar and four molars on each side of the upper jaw, and two incisors, one canine, four premolars and three molars on each side of the lower jaw.
- Ear Size: Bear ears can vary in size and shape depending on the species. Some bears, such as the black bear (Ursus americanus), have small, rounded ears, while others, like the arctic fox (Alopex lagopus), have large, pointed ears that are well-suited for hearing in harsh environments.
These are just a few examples of the many phenotypic variations observed among bears. The variety of phenotypes within the bear family is a testament to the incredible adaptability and diversity of these remarkable animals.