Time to infodump about the animals I'm supposedly a nerd about.
All pictures in this post are N. yvonneae, the southern ningaui (Image credit: Owen Lishmund)
The ningauis (in the genus Ningaui, if you can believe it) are a group of tiny dasyurid marsupials native to the arid and semi-arid regions of Australia. Smaller than their close dunnart relatives (very close, as I will explain later), and with broader hindfeet, ningauis were first documented by western science relatively recently by Australian mammal standards. Although some specimens had been collected previously, being haphazardly assigned to planigales (another genus of miniscule dasyurids), it wasn't until 1975 that the genus Ningaui was erected and its first two species were described - N. ridei, the Wongai ningaui, and N. timealeyi, the Pilbara ningaui. A third species, the southern ningaui (N. yvonneae), was named in 1983.
Oh, and in case you were wondering where the name "ningaui" comes from, it refers to tiny beings from Aboriginal mythology that come out at night, are covered in hair, have notably short feet and eat their food raw. Most of these traits are also shared by these little marsupials, hence why palaeontologist Mike Archer (the original author of the genus) found it to be a fitting name for them!
(Image credit: glandarius)
Ningauis are small - really small, some of the smallest land mammals in fact. With the tiniest individuals being only 5 cm long, not including the tail, they are about the same length as Australia's smallest native mammal, the long-tailed planigale. However, ningauis are significantly chunkier and therefore usually weigh a couple more grams, meaning planigales win in regards to all-around tininess. The very largest ningauis still only reach about 8 cm in length and 14 grams in weight.
What they lack in size they make up for in ferocity however, as they follow the typical dasyurid trend of becoming increasingly savage the smaller they get. Tasmanian devils, despite their reputation, are actually quite relaxed when handled - on the other end of the spectrum, ningauis, which are around a thousand times smaller than a devil, will try to murder you, your family and everyone you hold dear if they find themselves captured. But, despite their best efforts to chew the fingers off of every field mammalogist in inland Australia, they aren't very strong.
remorseless beasts (Image credit: Tina Gillespie & Miss.chelle.13)
These ferocious predators feed on a variety of different prey items, the majority of which are small invertebrates - in the case of the Wongai ningaui, they prefer prey that is less than a centimetre long. However, they will also go after larger prey, having epic duels with grasshoppers, spiders, centipedes and even small skinks which they subdue with a crushing bite to the back of the head. Unlike their dunnart relatives, the shorter, broader feet of ningauis allows them to climb into shrubs and grass clumps.
All ningaui species are extremely similar to one another, so much so that the Wongai ningaui and southern ningaui are almost externally indistinguishable and the Pilbara ningaui can only be told apart by looking at its foot pads, teat number and skull. However, they can usually be distinguished by distribution. The Pilbara ningaui is the most range restricted, being endemic to the central and western Pilbara region of western Australia. The southern ningaui occurs in three disjunct populations across the southern semi-arid zone, whilst the Wongai ningaui is distributed widely across much of the interior. All species show a strong preference for environments dominated by spinifex grass (Triodia), which they use as shelter.
A ningaui takes shelter amongst the spinifex (Image credit: Euan Moore)
In regards to how they are related to other dasyurids, ningauis fall in the tribe Sminthopsini together with the kultarr (Antechinomys laniger, another species I really need to cover sometime) and many species of dunnart (Sminthopsis). However, recent phylogenetic studies have consistently recovered both Antechinomys and Ningaui as being within the Sminthopsis lineage, meaning that both ningauis and the kultarr are, in essence, just weird dunnarts. With Sminthopsis as we currently understand it being highly paraphyletic, a revision of the genus is needed.