Markéta Vlková-ŽlebkováMar 7
John Carlos Baez

Wow - two new mammal species have just been discovered! Even better, one is of an entirely new genus.

One is a striped possum with an extraordinarily long fourth finger - twice as long as the rest - that it uses to get wood-boring insect larvae to eat. It was known to have lived in West Papua until about 6,000 years ago... but it's actually still there!

The other is a ring-tailed glider: a marsupial that can soar downwards through the air. Fossils from this genus have been found in eastern Australia and New Guinea, but those are hundreds of thousands of years old!

Both these new species were found on Bird's Head Peninsula on West Papua. And both were found by the same team, who must be feeling ecstatic right now. Of course they're not really "new": they were just flying under the radar.

More details and pictures here:

https://www.theguardian.com/environment/2026/mar/05/marsupials-discovered-new-guinea

Mar 6 at 11:12pmWeb
Show threadTony VladusichMar 6

@johncarlosbaez

"We had thought we'd found them all."

How would we ever know this?

Show threadJohn Carlos BaezMar 6

@TonyVladusich - I was just wrong about this, so I'll change my post.

We've only found about 6,758 living mammal species. But since 2005, there have been 805 newly described mammal species (and 774 split from known species, which is rather a different matter), which is about 40 per year.

Eventually this will slow to a trickle. This is quite unlike insects, where there's a vast number of species, and some estimate 80% of them are waiting to be catalogued.

https://www.mammaldiversity.org/

ASM Mammal Diversity Database

ASM Mammal Diversity Database

Show threadJohn Carlos BaezMar 6

@TonyVladusich - However, there's a fascinating thing called the Good-Turing estimator.

"Good–Turing frequency estimation is a statistical technique for estimating the probability of encountering an object of a hitherto unseen species, given a set of past observations of objects from different species."

https://en.wikipedia.org/wiki/Good%E2%80%93Turing_frequency_estimation

Good–Turing frequency estimation - Wikipedia

Show threadDougMerritt (log😅 = 💧log😄)Mar 6

@TonyVladusich
Very good question.

There *is* a methodology that plots discoveries plus some measure of the diffficulty of the discovery over time, looks at the curve, and guesses at the number yet undiscovered, and when done right, it has had some amount of confirmation as a decent approach at least some times.

In the absence of a mention of using that methodology, though, it sounds more like a vague feeling than something evidence-based.

@johncarlosbaez

Show threadDougMerritt (log😅 = 💧log😄)Mar 6

@TonyVladusich
P.S. amusing new profile pic; kudos to your son.

@johncarlosbaez

Show threadBartosz MilewskiMar 6
@johncarlosbaez
That reminds me of the lemur aye-aye that also has very long fingers.
Show threadDan PiponiMar 7
@BartoszMilewski @johncarlosbaez I don't normally suffer from anxiety from looking at pictures of animals but I can't help worrying about these poor little things breaking their fingers. Maybe they're flexible and resist breaking.
Show threadJohn Carlos BaezMar 7
@dpiponi @BartoszMilewski - somehow that picture seems to explain the term "aye-aye", which I've always been curious about.
Show threadBradleyKShermanMar 7
@johncarlosbaez @dpiponi @BartoszMilewski
Bird's Head Peninsula on West Papua soon to have a parking lot with a pink hotel, a boutique and a swinging hot spot.
Show threadcliffordheathMar 7
@bks @johncarlosbaez @dpiponi @BartoszMilewski maybe not for a while, but this team was operating in this region because of the ongoing encroachment of old forest logging, which utterly destroys the only environment in which these species can live
Show threadRoger MooreMar 7
@johncarlosbaez
These species may be new to scientists, but there's a very good chance the locals knew about them already. So the best description would be something like "researchers just described two species previously unknown to science".
Show threadRiley S. FaelanMar 7
@johncarlosbaez Does it really count as fly-ing if the insects that the long-fingered possum fishes for aren't flies in a strict sense, though?
Show threadJohn Carlos BaezMar 7
@riley - wow, what an erudite joke! You made me scared for a moment that I accidentally said the ringtailed glider "flies", which would rightly call down the wrath of pedants worldwide.
Show threadRiley S. FaelanMar 7
@johncarlosbaez Under the radar, even. I see no evidence of them requiring radar oversight in order to land.