Kogaionidae is a family of fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 mammals within the extinct

Extinction

In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...

 order Multituberculata

Multituberculata

The Multituberculata were a group of rodent-like mammals that existed for approximately one hundred and twenty million years—the longest fossil history of any mammal lineage—but were eventually outcompeted by rodents, becoming extinct during the early Oligocene. At least 200 species are...

. Representatives are known from the upper Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 and the Paleocene

Paleocene

The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...

 of Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

. This family is part of the suborder Cimolodonta

Cimolodonta

The Cimolodonta are a taxon of extinct mammals that lived from the Cretaceous to the Eocene. They were some of the more derived members of the extinct order Multituberculata. They probably lived something of a rodent-like existence until their ecological niche was assumed by true rodents...

. Other than that, their systematic relationships are hard to define.

These small multituberculates were named by Rădulescu R. and Samson P. in 1996, who stated they

"Share with Taeniolabidoidea

Taeniolabidoidea

Taeniolabidoidea is a group of extinct mammals known from North America and Asia. They were the largest members of the also extinct order Multituberculata. Lambdopsalis even provides direct fossil evidence of mammalian fur in a fairly good state of preservation for a 60-million-year-old animal...

 the general shape of the skull, with anterior part of zygomatic arch

Zygomatic arch

The zygomatic arch or cheek bone is formed by the zygomatic process of temporal bone and the temporal process of the zygomatic bone , the two being united by an oblique suture; the tendon of the Temporalis passes medial to the arch to gain insertion into the coronoid process...

es directed roughly transversely and very short basicranial region, which gives the skull a square-like appearance, but differ from them in having a strongly elongated snout and different dentition," (Kielan-Jaworowska & Hurum 2001, p.418).