Orycteropodidae is a family of afrotherian mammals. Although there are many fossil species, the only species surviving today is the aardvark, Orycteropus afer. Orycteropodidae is recognized as the only family within the order Tubulidentata, so the two are effectively synonyms.
Evolution
The first aardvark fossil discovered was originally named Orycteropus gaudryi and was found in Turolian deposits on the island of Samos. Since then, representatives of the order Tubulidentata have been located from the Oligocene in what is now Europe, and it is believed that the order probably originated around 65–70 million years ago or in the Paleocene. They are thought to be closely related to the now extinct Ptolemaiida, a lineage of carnivorous afrotheres. The family arose in Africa in the Early Miocene epoch, and spread to Eurasia later in the Miocene. Most of the family's diversity had become extinct by the end of the Pliocene.
Characteristics
Aardvarks had originally been categorized as relatives of American anteaters in the order Edentata. But their unique type of teeth and other morphological characteristics had made it clear that aardvarks are not closely related to any other living mammals. Since the end of the 19th century, they are placed in their own separate order Tubulidentata. Both the fossil record and genetic studies have corroborated that separate status. All similarities to American anteaters have evolved independently as adaptations to eating ants. One of the most distinctive features of the animals is that their teeth have a "tubulidentate" microstructure, lacking enamel, and are just rounded structures of dentine. They lack incisors and canines, and have 20-22 teeth, which are evergrowing, unrooted, and diphyodont. Another unique trait is that their small milk teeth are lost before the animal is born. A few anatomical characters unite the Orycteropodidae and Tubulidentata. The occipital region of the skull has extensive mastoid exposure, the femur has a pectineal tubercle, and the diaphysis of the tibia is curved mediolaterally. Modern aardvarks are polygynous, the females providing care for the young. They are territorial, and only cross paths to breed. The males' genitals create a musk while females create this musk from glands in their elbows, this scent helps mating occur. The gestation period lasts about seven months, and they are dependent upon the mother until they are six months of age, becoming sexually mature at two years of age. Breeding occurs once a year, they produce one offspring, and will have maybe one to two more in their lifetime. Aardvarks are myrmecophagous, feeding almost exclusively on termites and ants. They rely on their sense of smell to find most of their food and hunt at night.
