Wet-nosed primates make their own vitamin C, unlike monkeys and humans
Lemurs, lorises and bushbabies can manufacture vitamin C inside their bodies, a talent their monkey and ape cousins, humans included, lost long ago. These wet-nosed primates, the strepsirrhines, also groom with a comb made of teeth and see at night with a reflective layer behind the eye.
Strepsirrhini is the primate suborder that takes in the lemurs of Madagascar, the galagos and pottos of Africa, and the lorises of India and Southeast Asia, plus an extinct group called adapiforms. The name, coined by Étienne Geoffroy Saint-Hilaire in 1812, joins Greek words for turning and nose, after the curving, comma-shaped nostrils on the moist snout tip. Reginald Pocock dropped one r when he revived the term in 1918, and many researchers copied the misspelling until Paulina Jenkins and Prue Napier flagged it in 1987.
Besides the wet rhinarium, the group shares large smell centres, a vomeronasal organ for pheromones, and a ring of bone around the eye without a wall behind it. Lemuriforms have a toothcomb, front lower teeth set close together for combing fur. Brains are smaller than those of monkeys of similar size. Calling lemurs living fossils or inferior primates is misleading: isolated on Madagascar, they diversified into roles that monkeys and apes fill elsewhere.
Molecular clocks put the split from other primates between 55 and 90 million years ago, earlier than fossils suggest. Lemurs and lorisoids are thought to have parted in Africa about 62 million years ago, and lemurs then rafted to Madagascar 47 to 54 million years ago. Lorises separated from galagos about 40 million years ago and later reached Asia. Until three 40-million-year-old lorisoid fossils turned up in Egypt's Fayum deposits between 1997 and 2005, the oldest known lemuriforms were about 20 million years old, from Kenya and Uganda.
Adapiforms flourished across Europe, North America and Asia during the Eocene, with at least 30 genera and 80 species known, and were among the most common mammals in fossil beds of the time. Cooling climates erased them from most of the north, and the last, the Asian sivaladapids, died out around 7 million years ago. Many living strepsirrhines are endangered by habitat loss, bushmeat hunting and the pet trade.
Source: Strepsirrhini
