Rhynchocyon is a genus of elephant shrews in the family Macroscelididae. Members of this genus are known colloquially as giant sengis. They are a ground-dwelling mammal, significantly larger than their relatives in the order Macroscelidea that live primarily in dense forests across eastern Africa. Habitats range from eastern Africa's coastal forests, Rift Valley highlands, and the Congo basin. The species is widely threatened, with two of four assessed by the International Union for Conservation of Nature's Red List of Threatened Species. Habitat fragmentation from the growth of human settlements and activities are the primary threats to their populations. The genus contains the following five species and several subspecies:

The giant sengis are endemic to Africa, and usually live in lowland montane and dense forests, often "avoiding" edges of forest patches. These dense forests play a role in their shelter and reproduction, as they provide the ecological niche in which sengis exploit. They are typically active in the day (diurnal), spending their nights hidden in the shelters that they build the morning prior. After a few nights of use, sengis tend to abandon their shelters to create new ones elsewhere. They typically build their shelters at ground level, requiring dry leaf litter. The primary structure of a nest for R. udzungwensis, for example, consists of the excavation of a cup-like indentation in the soil, layered with leaves, and then covered with looser leaves as a roof covering. They usually construct their nests at the base of trees. They also use hollowed, fallen trees or trunks to retreat in shelter, especially when faced with predation. Sengis respond to disturbances by staying still or making loud thumping noises on the forest floor. In instances of predation, the giant sengi uses a half-bound gait to rapidly run away.

Other Macroscelidea species are known to bask in the sun, as a method of thermoregulation to save energy. Giant sengis do not bask—and it is most likely due to their adaptation to shaded canopy forest environments.

Sengis live in monogamous pairs, defending hectare-sized territories. Pairs spend little time together except when the female is in estrous. Mating occurs quickly and offspring grow quickly with minimal parental investment—none of which is paternal.

It has been observed that the genus has a commensal relationship with a variety of ground-foraging birds throughout its ranges. Both the Red-capped robin-chat and White-chested alethe often follow the giant sengis as they forage, in attempt at capturing prey that is disturbed while they shuffle through leaf litter looking for prey. They eat primarily insects such as beetles, termites, ants, and centipedes, using their proboscises to dig them from the soil and its tongue to lick them up. Their facial morphology limits their diets to tiny invertebrates, and unlike other members of Macroscelidea, do not supplement their diet with foods such as nuts or small fruits.

Each species exhibits distinct and varying coat patterns and colors. Species and subspecies found in denser forests exhibit darker coloration and patterns while open woodland species exhibit lighter, chequers. The darker species R. petersi, R. chrysopygus, and R. udzungwensis still contain vestigial chequers, but are masked by the blended dark fur between them. This makes coat patterns an unreliable indicator of species delineation though useful for identification. The species are described as follows:

The genus' taxonomic status has been difficult to determine due to the very close similarities between populations. Up to ten species have been recognized, but over time they have been regrouped into four species. Recently, R. cirnei, the species with the most subspecies, has had R. c. stuhlmanni separated into its own species based on updated molecular data.

Close genetic relatedness indicates that the common ancestor of the genus lived around 7.9 million years ago (Ma). There are, however, fossil taxa push this time further into the Oligocene. Miorhynchocyon meswae dates from the Meswa Bridge fossil site in Kenya dates to 22.5 Ma. Oligorhynchocyon songwensis [it] from the Nsungwe Formation in Tanzania dates to 25 Ma. Other fossils of the subfamily Rhynchocyoninae are found between 18 and 23 Ma such as M. clarki and M. rusingae from about 20 Ma from Songhor fossil site in Kenya. This large gap between estimated divergence time of the genus indicates that M. meswae and O. songwensis species are likely stem taxa of the entire group. Because of Rhynchocyon's canopy forest and dense leaf litter requirements, the ancestors of the genus may have experienced selective pressures to become more greatly adapted to forest environments as the Miocene experienced a large expansion of grasslands. Several other extinct genera of the family Rhynchocyonidae have been described: Brevirhynchocyon [it] and Hypsorhynchocyon. Eorhynchocyon (E. rupestris) is the oldest fossil species similar to giant sengis, but containing intermediate traits to those of Elephantulus and Petrodromus.