Short answers, pulled from the story.
Strepsirrhini is a suborder of primates that includes the lemurs of Madagascar, galagos and pottos from Africa, and lorises from India and Southeast Asia, as well as the extinct adapiform primates. They are collectively called strepsirrhines and are defined by their moist rhinarium, or wet nose tip, which gives the group its name from the Greek words for a turning round and nose.
Strepsirrhines diverged from haplorhine primates between 55 and 90 million years ago, near the beginning of the primate radiation. Older divergence dates come from genetic analysis, while younger dates are based on the fossil record. Lemurs and lorisoids split from each other approximately 62 million years ago, according to molecular clock estimates.
Lemurs dispersed to Madagascar by rafting from Africa between 47 and 54 million years ago. In isolation on the island, they diversified and filled ecological niches occupied elsewhere by monkeys and apes. Before human arrival, some eastern rainforests of Madagascar held nearly double the lemur species diversity seen today.
French naturalist Etienne Geoffroy Saint-Hilaire first used the name Strepsirrhini in 1812 as a subordinal rank. He described the group by noting their terminal and sinuous nostrils. The name was revived and formally applied by British zoologist Reginald Innes Pocock in 1918, though it did not come into widespread use until British anatomist William Charles Osman Hill published a dedicated volume on strepsirrhine anatomy in 1953.
In 2012, the International Union for Conservation of Nature announced that lemurs were the most endangered mammals on Earth, due largely to elevated illegal logging and hunting following a political crisis in Madagascar in 2009. The three main threats to strepsirrhines overall are habitat destruction, hunting for bushmeat or traditional medicine, and live capture for the exotic pet trade. Both lemurs and slow lorises are listed on CITES Appendix I, prohibiting commercial international trade.
The toothcomb is a specialized dental structure consisting of procumbent lower incisors and canine teeth used primarily to comb fur during grooming. It is found in all lemuriforms except the aye-aye, whose toothcomb has been modified into two continually growing incisors resembling those of rodents. Shed hairs that collect in the toothcomb are removed by the sublingua, or under-tongue.