Question: Pseudaelurus is a successor to an extinct carnivoran felid that lived in Europe and Asia how long ago?

Context paragraphs:
Long, Long Ago: "Long, Long Ago" is a song dealing with nostalgia, written in 1833 by English composer Thomas Haynes Bayly.  Originally called "The Long Ago", its name was apparently changed by the editor Rufus Wilmot Griswold when it was first published, posthumously, in a Philadelphia magazine, along with a collection of other songs and poems by Bayly.  The song was well received, and became one of the most popular songs in the United States in 1844.

Proailurus: Proailurus (meaning "before the cat") is an extinct carnivoran felid that lived in Europe and Asia approximately 25 million years ago in the Late Oligocene and Miocene.  Fossils have been found in Mongolia, Germany, and Spain.  One recent phylogeny places it as a basal member of the Feliformia, the suborder that includes mongooses, civets, hyenas, and cats; but other studies suggest that it instead was a felid (a true cat).

Mammoth: A mammoth is any species of the extinct genus Mammuthus, proboscideans commonly equipped with long, curved tusks and, in northern species, a covering of long hair.  They lived from the Pliocene epoch (from around 5 million years ago) into the Holocene at about 4,500 years ago in Africa, Europe, Asia, and North America.  They were members of the family Elephantidae, which also contains the two genera of modern elephants and their ancestors.  Mammoths stem from an ancestral species called "M. africanavus", the African mammoth.  These mammoths lived in northern Africa and disappeared about 3 or 4 million years ago.  Descendants of these mammoths moved north and eventually covered most of Eurasia.  These were "M. meridionalis", the 'southern mammoths'.

Ursavus: Ursavus is an extinct genus of ursid carnivoran mammals that existed in North America, Europe, and Asia during the Miocene, living from about 23—5.3 million years ago (Mya), existing for roughly .  The genus apparently dispersed from Asia into North America about 20 Mya, becoming the earliest member of the subfamily Ursinae in the New World.  Qiu points out that if a questionable 29-million-year-old specimen of "Ursavus" reported in North America is validated, "Ursavus" may have evolved in North America and dispersed westward into Asia.  The higher number of fossils in Europe grading toward eastern Asia make the westward dispersal unlikely.

Pseudaelurus: Pseudaelurus is a prehistoric cat that lived in Europe, Asia and North America in the Miocene between approximately 20 to 8 million years ago.  It is an ancestor of today's felines and pantherines as well as the extinct machairodont saber-tooths, and is a successor to "Proailurus".  It originated from Eurasia and was the first felid to reach North America, when it entered the continent at about 18.5 Ma ending a 'cat-gap' of 7 million years.  The slender proportions of the animal, together with its short, viverrid-like legs, suggest that it may have been an agile climber of trees.

Long Ago Tomorrow: "Long Ago Tomorrow" is a song written by Hal David and Burt Bacharach for the 1971 film "The Raging Moon" (US title "Long Ago, Tomorrow"), and originally recorded by BJ Thomas in 1971.

The Raging Moon: The Raging Moon (released in the US as Long Ago, Tomorrow) is a 1971 British film starring Malcolm McDowell and Nanette Newman and based on the book by British novelist Peter Marshall.  Adapted and directed by Bryan Forbes (Newman's husband), this 'romance in wheelchairs' was considered unusual in its time owing to the sexual nature of the relationship between McDowell and Newman, who play disabled people.  The film received two Golden Globe nominations, for Best Foreign Film (English Language), and Best Song for "Long Ago Tomorrow".

So Long Ago the Garden: So Long Ago the Garden is an album recorded by Larry Norman, released in 1973.  It is the second album in what came to be known as his "trilogy," which began with the album "Only Visiting This Planet" and concluded with "In Another Land".  "So Long Ago the Garden" was controversial because Norman's previously blatant Christian beliefs were more veiled on this album.  In the song "Shot Down", on the album "In Another Land", Norman responded to accusations by fellow Christians that he had abandoned his faith in search of fame and fortune.

Homotherini: Homotherini is an extinct tribe of carnivoran mammals of the family Felidae (true cats).  The tribe is commonly known as scimitar-toothed cats.  These saber-toothed cats were endemic to North America, Europe, Asia, Africa, and South America from the Miocene to Pleistocene living from c. 23 Ma until c. 12,000 years ago.

Candles Long Ago: Candles Long Ago is the 14th album by popular children's entertainers Sharon, Lois & Bram, originally released in 1993.  It is the first, and only, Chanukah album produced by the trio.  Unlike other Sharon, Lois & Bram albums, "Candles Long Ago" is a miniature album featuring only eleven songs, of which many appear on their previous album "Candles, Snow & Mistletoe" and one from their second album, "Smorgasbord".  O It was sold as part of the Sharon, Lois & Bram mini collection at a cheaper price than the trio's regular full-length albums.

Supporting paragraphs: Pseudaelurus Proailurus
Answer: 25 million years ago