What's your favorite "lost" species?

I’m talking about the species that might be extinct, or might still be out there somewhere in some isolated refuge - or those ones that have never been spotted again since they were first seen and described. Maybe they don’t even exist, or maybe they do… somewhere.

We all know about the Ivory-Billed Woodpecker or the Tasmanian Tiger, but there’s a lot of less well-known ones as well.

I’d like to find Castilleja leschkeana - it was found once in 1947, considered to be a waif of Castilleja chrymactis (native to Alaska) but has since been recognized as probably having been its own distinct species - but nobody has ever seen it since.

What are your sought-after lost species, and what do you think about where they might be found?


Penstemon filisepalis, mohinoranus, and wendtiorum are a few of the rarer species in Mexico that supposedly haven’t been found or collected in many years. There’s about 20 total Penstemon species that I would like to find physically or digitally to get 1st records on iNat.


Thismia americana is the legendary one in the Chicago area. They used to hold events where people would dress up in dated clothing and toss out beads the size and color of the flowers. The point was to get people to look closely for the tiny flowers at the soil surface. The story goes that not only did no one find Thismia at any of these gatherings, no one found a single bead. It’s part of the reason so many people are hopeful that it’s still around somewhere, despite having its habitat destroyed and turned into the neighborhood of South Deering. I believe the only person ever to see a living specimen of Thismia americana was its discoverer, Norma Pfeiffer. As of 2016, the species hasn’t been seen for 100 years.


Bombus variabilis. Possibly still around in Mexico but I’m not aware of any recent sightings, but extirpated from he Midwest. If I find one in one of my spots, my hope is that I actually have a camera with me, and that I don’t just die from excitement.

Bombus ashtoni. Still around in the north east, but likely gone from the Midwest. This one interests me because of it’s nest parasite relationship with Bombus affinis (endangered).


Geophis dunni: a small, distinctive fossorial snake from the Matagalpa area of Nicaragua that has never been seen alive.

Only the holotype of this snake (a female) exists, and it was inside the belly of a Micrurus (coral snake). Its description is essentially “tacked-on” to a diet study of Micrurus by KP Schmidt (1932): “Stomach contents of some American coral snakes, with the description of a new species of Geophis”. Copeia 1932: 6–9.

The coral snake that consumed the only known specimen was collected during or before 1909, so this species has never been seen/photographed (by researchers) alive. The collection locality also isn’t exact (since Matagalpa is a city and department, and no other data are available) so its habitat is unknown; combined with the fact that fossorial snakes are generally tough to find means that no targeted sampling can be done for more specimens - someone just needs to get lucky and stumble on one. 113+ years and counting…

Further reading: Townsend JH. 2006. Geophis dunni. Catalogue of American Amphibians and Reptiles. 838: 1–3.


I would love to someday see an ivory billed woodpecker. They are really cool, and being a birder, that would be something amazing for me to see.


Silphium from the ancient Mediterranean: https://en.wikipedia.org/wiki/Silphium_(antiquity)
A plant famous for its use in medicine and cuisine and so important it was on currency…and perhaps harvested out of existence. No one really knows!


I was always fascinated with the disappearance of the damselfish [Azurina eupalama] after the 1982 El Nino event. It apparently has not been seen since, which is quite rare for a marine species since they tend to be more resilient to localized disturbances (or else they wouldn’t have lived there for tens of thousands to millions of years!).



Friula wallacei, a weird looking spider collected by Wallace from Borneo. Only the holotype is known, and as of yet has never been found again.



Particularly close to my heart is the Purple-winged Ground-dove, which is possibly already extinct, with no confirmed records (i.e., with photos, sound recordings, etc.) for decades. I’m leading a project to search for the species using autonomous sound recorders. A tragic part of the story is that the species was successfully kept and bred by bird breeders up to the early 1990s, but those initiatives were stopped by well-meaning but clumsy interventions by the Brazilian government. There have been reported sightings as recently as 2017, but no solid evidence.

The Brazilian Atlantic rainforest, where I live, is home to other mysterious lost species, including the Kinglet Calyptura and Rio de Janeiro Antwren. The Glaucous Macaw has not yet been formally declared extinct, but there is very little hope that it still persists.

Here’s a figure I made for a recent article, with “missing” birds from Brazil - some are recent extinctions, two fortunately persist in captive populations, and we didn’t include the Rio de Janeiro Antwren here because it isn’t recognised by BirdLife International.

Other groups are also focusing on lost species, including Re:wild and American Bird Conservancy.


I don’t know if this exactly fits your question, but the one that always makes me wistful is the American Chestnut. We know it still exists, there are poor blighted stumps out there still trying to stump sprout, and even a few blight-resistant specimens in protected places. But those massive chestnut forests are gone, and I never got to see them. A whole ecosystem, fundamentally changed. Even if we manage to breed blight-resistant trees and seed them throughout their original range, I’ll never see them grow to their full potential in my lifetime.


Barrellus femoratus: https://bugguide.net/node/view/892783

This little guy was only known from the San Diego area, but has lost all of its habitat at this point. Hasn’t been seen since the 60s. Hoping it’s just hiding in very small numbers in the protected habitats around the city that can’t be collected in.

Also Pachyschelus fisheri: https://bugguide.net/node/view/1007490

This one was only collected by the describer…no one else has ever seen it! We even know it’s host plant!


There’s a good number of “lost” and uncertain terrestrial gastropods all over the place, even in Southern California. A good number of iNat users were involved in publishing the rediscovery of the American keeled slug not too long ago.


Hawaii has an entire genus (Hawaiodillo, 3sp) of spiky pillbugs that haven’t been seen since the 1930s. While the few scattered collections occured in areas that are still protected today (especially on Kauai), no one has seen them recently even with extensive surveys on the islands for terrestrial isopods.

Caecidotea teresae was a really pretty subterranean waterslater that was only known from a few wells around what is now New Albany, Indiana. It was probably the only subterranean species of American Waterslater that was intricately colored. Sadly, most of the known locations have been heavily polluted, so its unlikely they survived until today…

A trio of really unique terrestrial isopod genera (Philoscodillo, Oniscomorphus and Congloboniscus, each with 1 species) were described from what was most likely Rapa Iti in the 1930s (a lot of the South Pacific location names used back then aren’t used today) and havent seen since. Luckily though, Rapa Iti isn’t as well surveyed as Hawaii, so theres still a good chance for them still being around, just on remote mountains on the island that are very difficult to get to.

An uplifting case is Sphaeroma papillae, a seapill endemic to Long Island and Cape Cod (and probably some other places near those), which was only recorded twice (once in the 30s when it was described, the other in the 50s) but then was redescovered by iNatters a few years ago. I went down to one of the spots where it was reported on iNat to figure out what their exact habitat is and managed to find 10 new localities based on it! It turned out that the specific habitat they like (freshwater-influenced areas of the intertidal zone) is very common in human disturbed coastscapes and they’re not only surviving but thriving in the shadow of one of the largest cities on the planet.


I’m fascinated by that Indiana One! There seems to be little info about it online, do you have a source with more info?

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Speaking of Hawaii, the story of the beautiful and unique Fabulous Green Sphinx ( Tinostoma smaragditis) is very interesting and it’s definitely the ultimate moth rediscovery. It still is exceptionally rare and few people have seen one alive. Apparently it is found in areas of remnant native forest on Kauai.



I am currently looking for a few rare and very rare species of the genus Equisetum in Poland, including hybrids; this is a very difficult task to perform, because habitats are disappearing, scarce and difficult to access, and previous phytogeographic maps are out of date.


I’d like to see the Fernandina Galapagos Tortoise found.

And the Blanco blind salamander, since it is so close to where I grew up. It is known from only one specimen I believe from the 1950s and hasn’t been documented since.


Crowsoniella relicta, the 2nd most obscure beetle (the 1st is too far away). Was collected only once, fifty years ago.


The tortoise was already found: https://www.rewild.org/news/seventh-of-re-wilds-25-most-wanted-lost-species-rediscovered-with-a