Descendants of coyote (Canis latrans) have given rise to numerous Neocene predators of both Americas. But right at the beginning of Neocene congelation coyotes had penetrated into Eurasia through Beringia. At the end of Holocene only Bering Strait prevented coyotes to begin a gain of Eurasia, and at early stages of congelation when the ocean level had gone down, but Beringia had not completely disappeared yet under glacier shield, coyotes realized the opportunity opened to them and had intruded Old World from the east. As against their American relatives, the destiny of Euroasian coyote descendants was changeable. Having reached short-term success during Neocene congelation when they had widespreaded practically across the whole Eurasia, after climate change they were in the majority superseded by descendants of local predators and partly newcomers from the south. But coyote descendants had confidently reserved for themselves one climatic zone of Eurasia – steppes of Southern Europe and Three-Rivers-Land where wild hound tsitsu lives, a swift-footed canid species of gracile constitution.
In steppes of Eurasia tsitsu occupies the ecological niche similar to occupied by African hunting dogs (Lycaon pictus) in African savannas at the end of Holocene. If to be exact, tsitsu is the coyote descendant not in full degree: they descend not only from it. Hybridization as a way of speciation is rare phenomenon in nature, but it also takes place. The majority of Holocene representatives of Canis genus (except for black-backed and side-striped jackals) had identical number of chromosomes and was able to interbreeding (interspecific hybridization). Tsitsu has polyphyletic origin. The basis of tsitsu ancestral line is made of Alaskan coyote (Canis latrans incolatus) descendants, but among tsitsu ancestors there were also feral descendants of domestic dog (C. familiaris), and also descendants of Asian jackal (C. aureus). Tsitsu is highly social pack hunters. The average number of individuals in one tsitsu pack changes from 70 up to 90 individuals (not including pups), the record number of individuals in pack can make 146 adult individuals. Each pack controls an area of approximately from one and half to two thousand square kilometers. There are two subspecies of tsitsu, one (N. t. europaeus) of which lives in Southern Europe, and another (N. t. rufus) inhabits Three-Rivers-Land. Subspecies differ in colouration. N. t. rufus has “standard coyote” monophonic reddish color while yellowish-red skin of N. t. europaeus is speckled with spots and small strips of white and grey colors which help this animal to be imperceptible in grass. In winter the wool turns denser and lighter a little. Tail is reddish with black tip; its position is used by these canids for communication and expression of emotional condition. Ears are big and pointed; paws are narrow. Canines are rather long, much longer than at Holocene coyote. Tsitsu is medium-sized animal. In dimensions it approximately corresponds to polar subspecies of Holocene coyote. Weight of males makes about 20 kg, females are about 16 – 17 kg. Despite of the dimensions, packs of swift-footed (developing speed up to 75 - 80 kms per hour in jerk and able to hold speed of 60 kms per hour for a long time) tsitsu easily hunt animals like and . Also tsitsu actively compete to other species of carnivores, for example, with zibetonyx. Due to superiority in strength they frequently take off prey of other predators. Even large predators finding themselves in position “two or three against hundred” are compelled to concede the prey to aggressively attacking tsitsu pack. Similarly to Holocene hunting dogs tsitsu nurse even old and ill individuals, bringing food to them. The pack lives in the wast territory, but in the evening after hunting adult individuals hasten to shelter – colony numbering up to several tens of holes dug in soft ground. These dogs rear young growth in holes, and individuals do not take part in hunting – old or injured animals – look after posterity. For communication at the large distances tsitsu uses sounds. The sound repertoir of tsitsu is diverse and includes howl and bark of varying tonality and duration, and also yelping and growl. A characteristic sound of night steppe is thin shrilly howling of the whole tsitsu pack. Speed used in hunting has the return side – the organism of fast runner is used up in greater degree. Average life expectancy of tsitsu is about 15 years, but usually it is much less.