Tiny echidna and platypus specimens which showed some mammals lay EGGS and proved Darwin’s theory of evolution are rediscovered in Cambridge University museum 150 years after they were lost 

Echidna and platypus specimens dating back nearly 150 years have been rediscovered in a university museum.

Collected in the 1880s by the William Caldwell, the specimen scientist have been found in the stores of Cambridge’s University Museum of Zoology.

At the time of their collection, these specimens were key to proving that some mammals lay eggs – a fact that changed the course of scientific thinking and supported Darwin’s theory of evolution.

Cambridge’s collection includes baby echidnas and possums in jars, a dissected platypus uterus and a number of other platypus and marsupial specimens.

A newly discovered echidna specimen, suspected to have been collected by William Caldwell

This unique collection had not been catalogued by the museum, so until recently staff hadn’t been aware of its existence.

The find was made by Jack Ashby, assistant director at the museum, while he was doing research for a new book on Australian mammals.

‘It’s one thing to read the 19th century announcements that platypuses and echidnas actually lay eggs. But to have the physical specimens here, tying us back to that discovery almost 150 years ago, is pretty amazing,’ said Ashby.

‘I knew from experience that there isn’t a natural history collection on Earth that actually has a comprehensive catalog of everything in it, and I suspected that Caldwell’s specimens really ought to be here.

‘The specimens we’ve found are all pouch-young or nestlings, so they are quite small. The largest is about 12cm [4.7 inches],

Ashby had asked collections manager Mathew Lowe to keep an eye out for Caldwell’s specimens

Only three months later, a small box of specimens was found in the museum with a note suggesting they were Caldwell’s – which was later confirmed by Ashby’s investigations.

Ashby had to shine UV light on some of the labels inside the jars to make them easier to read, because the writing on them had faded.

‘Some of those labels name Caldwell, some of them just have the dates of his expedition, and some say “C Collection”, but looking at them all together has enabled me to match which ones we can say definitely are Caldwell’s,’ Ashby said .

‘I’ve also been comparing them to what Caldwell wrote back in the 1880s to try and identify them that way – the kind of material he writes he was working on is matches closely what we’ve found in the store.’

Overall there are two possums, two echidnas and one platypus that are certain to be collected by Caldwell from a batch catalogued last week.

Another newly discovered echidna specimen. Believe it or not, echidna spines are actually long, tough, hollow hair follicles

Jack Ashby, assistant director of University Museum of Zoology at Cambridge, holds a newly discovered Caldwell specimen

Ashby and colleagues are still finding more specimens in the museum’s collection; on Wednesday, he told MailOnline that they had found another 10 specimens in another part of the stores.

‘That’s a bit of a surprise as I thought we’d found all of the places uncatalogued platypuses and echidnas were in the stores,’ he said.

‘There are definitely some more in the batch we’ve just found this afternoon, but that will take some time to unpick.

‘On top of that there are probably about 10-20 more that are in the “probably Caldwell’s” category.’

Ashby told MailOnline that the platypuses were able to fit in jars because the ones they found are all pouch-young or nestlings, so they are…