Two clues: it’s small, and has never been imaged before.
Post any guesses below. I’ll post the answer next week, if nobody has got it by then.
Two clues: it’s small, and has never been imaged before.
Post any guesses below. I’ll post the answer next week, if nobody has got it by then.

7 Comments
Ok just been looking around a bit and think its a fern spore
Good guess, but a spore is a single cell. This thing has lots of cells (you can see their walls).
Thats a new clue about the cell walls right?
It’s kind of a clue, because it gives an idea about size. The individual cells are those roughly rectangular shapes. A spore, at least those of most ferns, measures 0.03 – 0.05 mm. The thing in the photo is about 0.5 mm long.
Is it the world’s tiniest fern?
Is it a baby fern?
The mystery object above is a so-called scale, from the underside of a frond of a new and undescribed species of tangle fern (Gleichenia).
Although some ferns are naked, many have fronds that are covered in hairs (one cell wide) and/or scales (more than one cell wide). These are most dense on the unfurling frond (the koru or fiddlehead), and probably have a protective function. In New Zealand, there are several species-pairs of filmy ferns where the upland species of harsher habitats has hairs while the lowland species is naked.
Along with the shape of the reproductive features, the presence and nature of scales and hairs are very important in identifying ferns, both in separating closely-related species and in distinguishing major groups. The two groups of tree ferns in New Zealand are easily distinguished because the Cyathea species are scaly whereas the Dicksonia species are hairy. See the third image down at this link: http://blog.tepapa.govt.nz/2009/03/06/whats-a-punga/
Scales are often fairly boring, being a uniform brown and with smooth margins. But the scales of this new tangle fern, with their dark centre and ciliated margins, are quite remarkable! Almost looks like a little animal…
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[...] Blog post with an image close-up of the distinctive scales of Gleichenia inclusisora. [...]