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
Animals (Scientific Procedures) Act 1986 Animals (Scientific Procedures) Act 1986 The Animals (Scientific Procedures) Act 1986, sometimes referred to as ASPA, is an Act of the Parliament of the United Kingdom (1986 c. 14) passed in 1986, which regulates the use of animals used for research in the UK. The Act permits studies to be conducted using animals for procedures such as breeding genetically modified animals, medical and veterinary advances, education, environmental toxicology and includes procedures requiring vivisection, if certain criteria are met. Revised legislation came into force on January 1, 2013. The original act related to the 1986 EU Directive 86/609/EEC which was updated