hmm, I'm not so optimistic. At least in case of insects and crustaceans. The increase of species description is so high that I suppose maybe even 90% of insect taxa are undescribed. Please search Brazilian Chironomidae Home Page - you will find that most of species are described in last years. This is a significant example how easy is to find a new species in invertebrates. Of cores synonyms are a problem, but even a more important problem is cryptic diversity. Personally I am surprised how molecular taxonomists split well known European species e.g.  of crustaceans onto even dozens of cryptic species that have very limited distribution. I think many of them extinct never being described.   

this would rely on the species first being discovered when dead, I don't imagine there are many cases as this would be a very short window of time before it decomposes.

You mean formally described after gone extinct during Modern Age? If so, much of them comes from old museum records and I guess only a few from revisionary paleontological/archeological studies. In the museum specimen case, these are mostly assigned to other species initally, Among many, such an example is Alburnus nicaeensis, a freshwater fish once restricted to Lake Iznik in NW Turkey. Megaladapis and Aepyornis may among the few examples to fossil discovery case. These are remnants of Madagaskar megafauna that were barely able to survive the Modern Age. There are several birds from oceanic islands that are only known from drawings and sailors' acounts, like  red rail (Aphanapteryx bonasia), Réunion rail (Dryolimnas augusti), Réunion kestrel (Falco duboisi), Ascension crake (Mundia elpenor). There are more examples that I cannot remember. But as you see, these couldn't have chance to become famous, like the dodo and the great auk. 

PS: Sometimes extinctions come so quickly after taxonomic description. See the sad case of Dysmorodrepanis munroi

https://en.wikipedia.org/wiki/L%C4%81na%27i_hookbill

I think there some but few species, mostly vertebrates, for those there are documentary confirmed cases of extinction during the Modern age.  

But for invertebrates, the most diverse part of all animals, there will be extremely few documentary extinction cases. I mean in most cases it is very hard to prove extinction of an invertebrate species. Consequently, all public information on "thousands of species getting extinct prior to being scientifically described' is either a speculation (with some rationale background, based on our present level of knowledge, of course).

Very few cases of recent species being described after going extinct in recent times (due to human impacts including introduced species or habitat loss). But was a recent paper on terrestrial molluscs by Philippe Bouchet with some examples.

Dear Mark John Costello,

Can you remember name of the publication you mentioned? 

Ümit

Exactly, thank you

Two points to consider as regards your question:

1. Whenever some physical evidence of a species is found, even though no living example has been seen, scientists tend to name it. This has often been the case with species--including many lizards and creatures like the elephant birds--that have only become known through subfossils or entrapment in amber, as examples.

2. Given what I said in 1., there are consequently few, if any, species that do not get named, and I cannot think of an example of either unnamed species parts (at least to Family level) and thus none have become famous.

Probably you will find some figure about the extinct plant species in the attached report ...

Der Mehmet,

In the report, there are estimations for the total plant species, the described ones, threatened sps, and also the extinct species, I suppose...! 

To Mehmet (and some others) - as to that alleged "more taxonomists describing species than ever before, and their number is increasing faster than the rate of species description" (and some other allegations) I wrote rather extensively, so here I only suggest (if you are interested) to read the attached paper.

Best wishes!

Article HOŁYŃSKI R.B. 2013. Have most species already been, or will ...

Mehmet,

We reduced the 1.9 million to 1.5 million to try to account for as yet unrecognised synonyms. A recent paper by Bebber et al. on plants (Syst Biol) stated that the number of plant species will likely remain the same because new discoveries will be cancelled out by synonyms. Most taxa, including plants, algae, insects, vertebrates, even most parasites, appear to be 60-80% known. What is not keeping up is the painstaking taxonomic revisions that clarify species concepts and synonymise names. I've been meaning to get time to use GBIF or OBIS to see which apparently valide species have not been recorded for decades (or centuries) - these may have been so badly described that their concept is unclear and have probably been better described under a different name since. Such a list might also have curiosity value - are these 'species' lost due to synonymy, lack of sampling, or extinction? 

It has been said that (in the past of course, we never make mistakes nowadays!) parasites have sometimes been called different species because they occur on different hosts. One can similarly imagine widely dispersed (e.g. aerial  plankton) microscopic taxa which may be described on different continents because authors assume they are new and perhaps were not aware of literature in other regions.

hmm, I'm not so optimistic. At least in case of insects and crustaceans. The increase of species description is so high that I suppose maybe even 90% of insect taxa are undescribed. Please search Brazilian Chironomidae Home Page - you will find that most of species are described in last years. This is a significant example how easy is to find a new species in invertebrates. Of cores synonyms are a problem, but even a more important problem is cryptic diversity. Personally I am surprised how molecular taxonomists split well known European species e.g.  of crustaceans onto even dozens of cryptic species that have very limited distribution. I think many of them extinct never being described.   

Hi All,

I agree with Mateusz. Some invertebrates and esp protists have other principles of zoogeographical distribution - sporadical distribution. E.g, Atractor contortus was described in Hungary; I found it in Sasyk Reservoir near the Black Sea cost, and Bill Bourland in the USA and Canada! Therefore so hard to speak about endemial species of protists. If you are describing some copepod from a spring so be sure that some other springs are inhabited as well! But the problem is that e.g. we have several specialists even in separate Copepods groups and even inside families! So, in ciliates with extra complicated modern methods of description of species only well-equipped labs can do this? So, in their famous book W.Foissner& D.L.Hawksworth "Protist Diversity and Geographical Distribution" 2008 are writing:

There are many species with wide ranges, and proportionately more cosmopolitan

species than in macroorganism groups, as a result of their long evolutionary

histories, but there are also definite patterns and geographical restrictions to be

found. Further, some protists are linked to host organisms as mutualists or

parasites and necessarily confined to the distributions of their hosts. It is now also

becoming clear that there is a great deal of cryptic speciation and clonal selection

that has not been appreciated until the advent of molecular phylogenetic

approaches. The traditional use of morphospecies concepts badly underestimates

protistan diversity – by two or three times in the case of foraminifera and ciliates.

Molecular work in most protistan groups is very much in its infancy, but it seems

likely that there are more than 300000 species of protists on Earth.

As well necessary to say that not all parasites and mutualists are extincting  with the host species. I’m not sure that even all endo-parasites. Always are used some alternative or reserve variants!

That’s the reason that I’m sure – present of disappearance in microinvertebrates groups & Protists is not so large as in taxa of large Animals and Plants.

Andrey

You can check this paper.

Article Estimating How Many Undescribed Species Have Gone Extinct

Dear Guido, very important paper, thank you to all other comment and contribution too. I hope continue receiving info. 

The data on past rates of species discovery, combined with increasing taxonomic effort, and proportions of undescribed species in samples, support closer to 20-30% of species remain to be described. In addition to my own work, other studies on fish, algae, anemones, insects, and protozoans support this. In picking examples one must remember that about 1.5 million species have been described - this is a lot. In my recent analysis I was surprised that even most parasites have been described with possible exception of helminths. In hindsight the fact that many of the taxonomic groups parasitise people and farm animals means they are well studied. another aspect under considered is biogeography - particularly betadiversity. This means one cannot extrapolate from one taxon to all taxa, or one place to the world, without knowing the relative 'widespreadness' of species in the sample globally. Thus we need to be very cautious about single taxon and local studies. It is also unhelpful when authors say "up to" a certain number. This can be misleading because if one picks a highest possible number it bias subsequent references and impressions. "up to" 10 million could be anything from 10 to 10 million species. It would be better to give a range or 'estimate' based on some logical argument. The appendix to our Current Biology paper on all marine species richness gives examples of each taxon experts argument in estimating how many species they believed were described and not described.

"The data on past rates of species discovery, combined with increasing taxonomic effort, and proportions of undescribed species in samples, support closer to 20-30% of species remain to be described". In my paper ("Have most species already been ..." - attached to one of the earlier comments) I have shown that all the above claims (past rates, taxonomic effort and samples) are based either on special cases or - usually - on false assumptions, and so the final conclusion (20-30%) are evidently irrealistic. I have addressed one by one all the arguments set forth in your papers, and produced many other data - but the majority of my arguments have - to my knowledge - never been concretely falsified (I am not even aware of they having ever been concretely addressed!). As long as this has not been done, repetition of claims like yours above does not seem to me a valid scientifical approach.

Best wishes! 

Roman

Well we disagree Roman. My work and others have shown that the number of authors of new species has been increasing since 1950s with no change in the proportion of full-time or singleton-species described authors, nor in author publication lifetimes. Over half-a million species were included in one paper with experts reporting on their specialist taxa in others.  So there may be special cases (e.g. helminths) that are exceptions but this is the case for species overall, both marine and terrestrial. I guess people will have to read the papers and make up their own minds!

"I guess people will have to read the papers and make up their own minds!" - I also hope they will do, but also remain with the opinion that repeating the same claims without addressing the opponent's arguments is not the best way to solve problems...

No matter how many new species per article can be published, isnt it clear to you that habitat degradation, no 1 threat for extinctions in general, is peaking.

While there is no room left in Malaysia, biggest producer of palm oil in your cholocolates, second biggest producer Indonesia plans to double pal oil production by 2030. See:

Natasha Gilbert (4 July 2012). "Palm-oil boom raises conservation concerns: Industry urged towards sustainable farming practices as rising demand drives deforestation". Nature.

Not to mention the situation in Amazon Basin.

BTW, See Table 1:

http://senate.ucsd.edu/media/206192/science-2014-pimm-extinction-review.pdf 

More papers regarding cryptic diversity, species of hybridogenetic origins, not to much surprise, still unexplored taxon groups or areas continue to appear on jornal. These may indeed be tickling the log line of species described a little this or that side, but line to the rate of extinction....Leaves not much to discuss for me. 

Ümit 

Exact question which I like....

For example, the species were available earlier, are not fully uploaded in WORMS......

I feel like the species are extinct since some species are not available in WORMS database. In this database, the description of any species is rather than citation of old book (identification), articles or others. Another thing is molecular study in modern world. 

Umit - Yes, regardless of how many species there are those that exist are threatened with extinction due to hunting, introduced predators (especially on islands), and habitat loss.

Yambem - if you are suggesting that species not in WoRMS are extinct that is not the case. More likely they have not been entered into the database. WoRMS also includes extinct and some fossil species and they are labelled as such.

I know well WoRMS also includes extinct and some fossil species.....Dr. Mark. I mean to say the work is incomplete. This database can do wonderful with species descriptions somehow which we wont get. 

Yambem - yes. If you find any names not in WoRMS and know what taxon they belong to I have found the specialist editors very helpful in explaining why or thanking me for the omission.

Dear Mark John Costello and Yambem Tenjing, 

I guess my response triggered some frustration, see /1 below my previous answer, either it is so unbearable to hear about chocolate thing or that extinction exists for real. 

Anyway, as you can see in the publication in the previous comment, extinction rate among vertebrates is higher than before and if we consider that the species descriptiion rates are changing at all, we are indeed arguing with unspoken words that many taxa are going unnoticed. 3 million years of existence! Pick one, host specific parasite or habitat specalist groups across many phyla, mono- or oligofags against generalists among insects. There are many reasons to at least argue that extinction rate would be much higher among invertebrates. Mollusks, my group, globally comes second to anurans in threatedness for the remark.

Databases are still on their way to perfection, though many are way behind to get there. However, this should not discourage us, If they did not exist, we would not discuss what we do today. Their improvement will prove better future arguments, although may not return what is eternally lost.

Ümit

FYI, we call this phenomenon, centinelan extinction

Dear Umit, It depends which extinction rates you are refering to. Over all time they will be higher for invert's because there were more such species. Recently, human caused extinctions have been higher for vertebrates due to hunting and introduced predators on land, and freshwater mussels and other f-w species due to overharvesting and pollution (habitat loss in rivers). Future habitat loss may result in more invertebrate loss, but not for sure. Yes, freshwater molluscs are highly threatened of course.

Dear All, Really in invertebrate the situation is different than in vertebrates. Invertebrates are the 99% of the world biodiversity, however the studies, assessment and evaluation of the invertebrate group are very few in comparison with vertebrates. In IUCN Red List almost all is about vertebrates or about charismatic invertebrates like butterfly, snail, and other few group. The studies on  invertebrate biodiversity is a field without specialist and need more attention, more resources. All estimation about world biodiversity has the problems of the bias  for  the current situation in invertebrates knowledge .  Our appreciation of the extinction will be the same bias.

If we expect that a part of the biodiversity is loss without be known, invertebrates fauna will be 3 or 4 times more threatened that vertebrates.

if we are thinking that is a fact that some species are extinct without taxonomical description we need to take account some important facts to those species vulnerability:

• Reduced geographic distribution for some taxa, those relic species are more vulnerable to be unknown.
• Cryptic species
• Islands species
• Taxonomic group without enough specialists.
• Hide species (nocturnal, underground, deep water, caves, etc).
• Reduced population.

 The human transformation or climate events of  high intensity then can destroy habitats with these rare species  following with their extinction.