Alistair McLean is holding a stuffed animal which, he says, is a 'microcosm' of Sheffield's natural history collection.
It looks a little startled, and a bit faded - but it's impossible to see one in the wild locally.
"It's the last pine marten from Sheffield - the last one that was ever seen. They snared this one, it was killed in 1926. It's a microcosm because it's got genetic information built into it, and historical information, and it's useful for display because it's quite pretty."
Alistair, Museums Sheffield's curator of natural sciences, looks after 200,000 geological and biological specimens, from minerals, fossils and rocks to all manner of preserved creatures. These are all kept at a store, the location of which is not widely publicised for security reasons.
Last year the council announced its intention to upgrade the Graves Gallery and Central Library in the city centre, turning it into a landmark 'cultural hub' after the idea of creating a five-star hotel at the building with Chinese investment money failed to gain momentum. In the third of five special features, The Star takes a look at how Museums Sheffield wants to make more of its huge archive as the gallery redevelopment plans take shape.
The museums' history stretches back to the founding of the Sheffield Literary and Philosophical Society in 1822; the first things members gathered were generally rocks and minerals, says Alistair.
"A lot of the minerals we look at are quite toxic, so I have to be very careful with what I pick up," he confides, opening up a drawer filled with unfamiliar finds such as lizardite and rhodonite. "If I see anything that's red, I tend not to pick it up without putting the gloves on first. Geology is such an important subject to teach, to understand about the rocks beneath our feet."
The biological collection is mostly comprised of invertebrates, including 100,000 examples of insect. "Although they make up the majority of numbers, they take up less space, which is nice for me," Alistair admits.
He turns to a cabinet of butterflies, 'very popular in the past' as a way of brightening up people's homes.
"Butterflies in particular are incredibly variable. Being able to identify them to species can be quite tricky if you don't know what you're looking for. We get really enthusiastic and specialist insect collectors consulting us so they can identify what they've found."
As a pastime, netting butterflies is now frowned upon - likewise, picking up wild birds' eggs is illegal, but the museums have many old samples that pre-date the ban.
"In the past we've shied away from displaying birds' eggs because we don't want to encourage kids," says Alistair. "But now we're getting to the stage where the current generation isn't aware it ever happened."
Meanwhile curatorial assistant Gina Allott is examining a substantial cache of flies gathered by a local naturalist, and inputting the accompanying data. Labels beside each tiny fly record the places they were found, and the dates too.
"Through that you can study patterns of ecology and how things have changed over time - whether there are fewer species because of habitat loss and things like that," she says.
Alistair adds: "Each fly probably represents a couple of hours of work."
The natural science collection works closely with groups like the Wildlife Trust, and Sheffield's Sorby society, 100 years old in 2018 - Alistair, a member, is this year's president. aA celebration is happening this month and a display is going up in Weston Park Museum.
Specimens collected by geologist Henry Clifton Sorby, who developed a special technique for preserving whole creatures in slides, will be shown for the first time in decades. An old lantern projector will be deployed - the museum only has one of the original bulbs, a thousand-watt variety.
"An electrician has assured me it's safe," Alistair says. "While everybody else in the 1870s was projecting with black and white glass etchings, Henry was projecting in full glorious technicolour. He was a great guy."
His favourite exhibit is the crocodile skull on display at Weston Park and brought back from India in the late 1800s. A Sheffield man called Fred Webster was attacked by the reptile, but was saved when the animal was shot. When the crocodile was examined, items of jewellery were discovered in its stomach, suggesting a previous victim had been targeted.
"It's a really big croc, probably one of the biggest that's ever been seen, but it's got this historical angle to it. That's kind of why I like museums and natural history collections," says Alistair, who is also responsible for the Weston Park weather station, one of the country's oldest.
And why has the pine marten's fur faded to grey?
It was simply left in the light for too long on a gallery shelf. Alistair turns it round to show its proper, chestnut brown colour, on the side that hasn't caught the sun.
"It may be we can dye it. Believe it or not you use Just For Men."