Felidae Oligocene, about 25 million years ago, with the appearance of "Proailurus" and "Pseudaelurus". The latter species complex was ancestral to two main lines of felids, the cats in the extant subfamilies and a third major group of extinct cats, which are assigned to the subfamily Machairodontinae. The machairodonts included the saber-toothed cats such as the "Smilodon". The "false sabre toothed cats", the Barbourofelidae and Nimravidae, are not true cats, but are closely related and together with Felidae and other cat-like carnivores (hyaenas, viverrids and mongooses) make up the feliform carnivores. Results of mitochondrial analysis indicates that all the Felidae descended
Fund for the Replacement of Animals in Medical Experiments World Animal Protection). The following year, Michael Balls became one of the founder members of the Animals Procedures Committee. 1989 - INVITTOX, a collection of protocols for in vitro methods in toxicology, was established. This database is now part of ECVAM's Scientific Information Service. 1991 - The FRAME Alternatives Laboratory (FAL) opened to conduct research into alternatives. 1995 - The FRAME office relocated to the newly built Russell & Burch House, Nottingham. 1998 - FRAME became a founder member of Focus on Alternatives. This body promotes dialogue between all UK groups that focus on replacement alternatives. 1999 - Bill Russell