The caudal intercarotid artery was investigated in 6 species of Equidae family and in lowland tapir of Tapiridae family. It was found that this artery connects bilateral intracranial segments of the internal carotid artery. It is located in the cavernous and intercavernous sinuses, caudal to the hypophysis. This artery being constant vessel in horse, is also permanent vessel in other species of Equidae family. It is homologous with anastomising vessel in fishes, amphibia, reptiles and birds.
Fossil remains of South American tapirs are often fragmentary and scarce compared with those of other mammals that entered South America during the “Great American Biotic Interchange”. Here, we review and add to the Pleistocene tapir remains from the Tarija Valley (Bolivia), and provide a taxonomic re-evaluation of Tapirus tarijensis. T. tarijensis was a large-sized animal, approximating the size of the living Malaysian T. indicus and the extinct North American T. haysii. The geographical distribution of Pleistocene records of Tapirus in South America indicates that T. tarijensis was the only known species inhabiting the Tarija Valley during this time.