Hyrax

Hyraxes, also known as dassies, are small and stout mammals.

They belong to the family Procaviidae and the order Hyracoidea. These herbivorous animals are well-furred and rotund with short tails. Most modern species live in Africa. However, the rock hyrax can also be found in parts of the Middle East.

While they may look like marmots or pikas, they are actually very different. They are part of a group that is closely related to elephants and manatees.

Hyraxes have unique ways of managing their bodies. They have poorly developed internal temperature regulation. This means they cannot easily keep their body heat steady on their own. To solve this, they use behavioral thermoregulation. This is a process where they change their actions to manage heat. They do this by basking in the sun to get warm. They also huddle together in groups to share body heat.

Their feet are also specially designed for their rocky homes. They have rubbery pads with many sweat glands. These glands help them maintain a strong grip on steep surfaces. Their stumpy toes even have hoof-like nails.

Their digestive systems are quite complex for such small animals. Hyraxes are not ruminants, but they do have multichambered stomachs. These chambers contain symbiotic bacteria. These tiny organisms help break down tough plant materials. This allows the hyrax to eat a variety of plants. However, their ability to digest fiber is lower than that of ungulates, which are hoofed animals like deer. When they eat, they do not use their front incisors to slice grass. Instead, they use their molar teeth located at the side of the jaw. Their two upper incisors are large and tusk-like. These tusks grow continuously throughout their entire lives.

Hyraxes have a fascinating evolutionary history. They were once a much more diverse group of animals. In the past, some species were much larger than the hyraxes we see today. For example, the extinct Titanohyrax ultimus was massive. It is estimated to have weighed as much as a water buffalo.

Another ancient relative, Megalohyrax, was as large as a tapir. For many millions of years, these animals were the primary land-based herbivores in Africa. Eventually, competition from bovids changed their environment. These efficient grazers pushed hyraxes into the rocky niches they occupy now.

Scientists have discovered deep connections between hyraxes and much larger animals. Hyraxes, elephants, and sirenians all belong to a taxon called Paenungulata. This grouping is based on shared physical traits. For instance, male hyraxes lack a scrotum. Their testicles stay inside the abdominal cavity near the kidneys. This is the same arrangement found in elephants and manatees. Furthermore, hyrax tusks develop from incisor teeth. This is exactly how elephant tusks develop. They also share flattened nails instead of long claws.

Hyraxes also have unique social and environmental habits. They live in small family groups led by one male. This male aggressively defends the territory from other rivals. They do not build dens to sleep in. Instead, they find shelter in existing holes in the rocks. Hyraxes also use a communal area for urination. Their thick urine dries and builds up over many generations. This creates massive structures called middens. The dried, petrified urine is called hyraceum. It can be used in perfumes or for medicinal purposes. It also serves as a record of the ancient environment.

Today, the classification of hyraxes continues to evolve. In 1995, scientists recognized 11 different species. By 2013, they had reduced this to only four recognized species. Many of the others are now considered subspecies. Some species, like the tree hyrax, are quite distinct. One recently identified species is Dendrohyrax interfluvialis. This tree hyrax lives between the Volta and Niger rivers. It is known for making a unique barking call. This call is different from the shrieks of other forest hyraxes. These small animals continue to offer much for scientists to learn.