It has been suggested that, at a time when the climate was warmer and some of the continents that are now separate were joined together, the Armley Hippo or its ancestors may have travelled north along watercourses from Africa to the land that is now England, and that early humans may have co-existed with some of the hippopotami found in Yorkshire.

[4][1] Denny "visited the site daily and collected many specimens by his own endeavours and stimulated the men by the promise of pecuniary reward to increased care and search".

In April 1852, more hippopotamus bones were found in the same brickfield:[7] [The find] consisted of two specimens of the great northern hippopotamus in a brick earth, the property of Messrs Longley, of this town, who, in the same praiseworthy manner, presented a few bones to the museum, and which by this means is probably now in possession of the most extensive series of hippopotamic remains of any provincial museum in the kingdom.

[8] On 3 May 1854, at a meeting of the Yorkshire Naturalists' Club in York, Edward Charlesworth gave a talk which referenced the Armley Hippo, whose bones he had brought with him.

Considering the large number of bones found, and the unusually perfect state in which they had been disinterred, this discovery Mr Charlesworth considered to be the most remarkable of the kind that had ever occurred in this country ... the cavern at Kirkdale with its numerous remains of huge Hyenas, was well known ... and at the farm called Bielbeck, near Market Weighton, was another celebrated locality for fossil bones of the extinct Elephant and other large quadrupeds ...

The Museum of the Yorkshire Philosophical Society possessed large collections from both these localities, but no remains of the Hippopotamus were found at Beil-beck Farm, and very few in the cavern at Kirkdale.

Indeed, so rare are the remains of this animal in the fossil state, that the bones found at Leeds probably equal in number the united collections of all the other Museums in the kingdom.

In 1907 John Booth MSA FSSc, writing in the Shipley Times, described the idea that ...:[10] ... the British Islands [were once] part of a European continent then connected with Africa, and across which huge extinct lions, tigers, bears, elephants, and rhinoceroses roamed and left their remains in the caves of the limestone districts and the sands and gravels of rivers when they flowed 100 ft (30 m) or more above their present level.

During this period a southern fauna, even the hippopotamus, found their way as far north as Yorkshire, testifying to the existence of great rivers flowing from the south across this Quaternary continent.

[6][15] More recently, a molar sample from the skeleton was more precisely dated to 130,000–113,000[4] (or 130,000–117,000)[1] years ago – during the Ipswichian interglacial period when a warm climate suited the hippopotamus.

For example, at Victoria Cave, near Settle, North Yorkshire, evidence of Paleolithic Man was found alongside hippopotamus bones in the same stratum.

[18] In 1862, when the museum was rehoused in the extended Philosophical Hall in Park Row, it was planned to display as many different mammals as possible in the same area, to facilitate public understanding of Linnaean taxonomy.

Professor Richard Owen gave the inaugural speech at the opening of this extension, in which he expounded on this plan, which included the bones of the Armley Hippo.

Armley Primary School children attended the festival, and the organisers made "hundreds of plaster hippos ... inviting local people to have a go at decorating them".

A central feature in 2019 was an animation created from a story and drawings by school-children Lochan Chakrabarti and Holly Reeve; it was premiered on Millennium Square, Leeds in front of the museum.