In search of 200mm

[MorbidArachnid]

So a few days ago on this forum I had a discussion about Emperor Scorpion sizes. This caused me to go into a bit of a deep dive, and since then I've been going into an extremely deep dive into Emperor scorpion sizes and their reported size ranges. This is what I have so far. This information is partially incomplete, a lot of the earlier sources I couldn't find, and/or are not written in English. If anyone has any more information to add to this thread, I would wholly appreciate it.

The Timeline:
1841: Koch describes Pandinus Imperator. The holotype was rediscovered and redescribed in 2017. Though the specimen measured 160mm, it might've been 170mm accounting for some damage.
1956: The Biology of Scorpions by Max Vachon. Only reference to Pandinus imperator size was in a drawing, with a stated range of 18-20cm. This range is cited as "After Gaillard", but I could not find what this was referring to. No specific measurements of any individual given.
1980: Scorpions of Medical Importance by Hugh L. Keegan. Size for Pandinus imperator stated as "up to 180mm or more".
1985: Prey capture and stinging behavior in the emperor scorpion, Pandinus imperator by Gary S. Casper. First source with reported measurements of specimens. Largest measured at 17cm from chelicerae to telson tip, numbers likely rounded as the scorpions were sorted into groups of size, no specific measurements of any individual.
1988: How to Keep Scorpions by Hull-Williams. Conflicting information, says scorpions (no specific species or family) get "between 40mm and 127mm", then later in the text says "Large forest dwelling species are nocturnal ramblers and also grow quite large (8-9")". In the section on Heterometrus longimannus says "Due to their conspicuous size (trunk length up to 160mm) they are a good match for the closely related African genus Pandinus Thorell: they are among the world's largest scorpions." Does not give a size range for Pandinus imperator.
1990: The Biology of Scorpions by Gary A. Polis. Given range for Pandinus imperator is 18-20cm and references "Vachon, 1953" for this range. No specific reference as to what actual paper or publication this is.
1991: Arachnomania by Philippe De Vosjoli. Says Pandinus imperator "reach a length of nearly eight inches (20cm)", references include Scorpions of Medical Importance by Hugh L. Keegan, The Biology of Scorpions by Gary A. Polis, and How to Keep Scorpions by Hull-Williams. We can infer the 20cm figure is from Gary A. Polis, who in turn cited Vachon for this.
1994?: CITIES proposal to include multiple Pandinus species, including Pandinus imperator. Says "reaching as much as 20cm", but doesn't cite where this specific number is from. Includes a paper by Vachon in 1967 in the reference section, though I could not find this paper and it's not in English.
1999: Variation in energy spent on reproduction between forest and savanna populations of Pandinus imperator (Koch) in the Ivory Coast by LOURENCO,W.R. & CLOUDSLEY-THOMPSON,J.L. First source with specific measurements of individuals, categorizes the difference in sizes between larger "forest" form Emperors and smaller "savannah" form Emperors. Unfortunately does not give a table with their precise measurements, and only measure the prosoma + mesosoma, without including the metasoma. Largest individual measures appears to be about 82mm, assuming the metasoma is not significantly longer than the prosoma + mesosoma gives us a length of about 164mm.
2010: Scorpions of the World by Roland Stockmann and Eric Ythier. Given size range is up to 200mm.
2011: A Review of the Subgenus Pandinus Thorell, 1876 with Descriptions of Two New Species from Uganda and Ethiopia by František Коvařík. Stated size range of Pandinus imperator given as 220mm (the largest so far), does not include a material examined section. Only one measurement of a specific specimen given, a male from Ghana reported to be 115mm.
2014: Notes on the distribution of Pandinus (Pandinus) Thorell, 1876 and Pandinus (Pandinurus) Fet, 1997 with the descriptions of two new species from Central African Republic and Djibouti by Andrea Rossi. Size range reported as up to 230mm (the largest estimate given to date). and does include a materials examined section. Specimens examined are one female from Togo/Ghana (ARPC) later measured to be 113mm, two males and two females from Liberia (MHNG), with one male stated as being "about 180mm". and one male "without data" (MSNB).
2014: Further considerations on the identity and distribution of Pandinus imperator (C. L. Koch, 1841) and description of a new species from Cameroon by WILSON R. LOURENÇO. Reported size range for Pandinus imperator up to 180mm, gives specific values for a male from SE Notse, South of Togo (154.8mm) and a female Edea South of Cameroon (163.3mm). The female Pandinus imperator was suspected to be a P dictator by a later paper.
2015: Clarification of the Type Locality of Pandinus Ulderigoi with Notes on the Scorpions Protected by CITES by Andrea Rossi. No specific size range for Pandinus imperator given, again shows the same picture of the male from Liberia (MHNG) captioned as being 180mm. The male "without data" (MSNB) is no longer listed on this paper, though the 4 specimens from Liberia (MHNG) and a male from the Ivory Coast (ARPC) are listed.
2016: Redefinition and Systematic Revision of the East African Scorpion Genus Pandinoides (Scorpiones: Scorpionidae) With Critique of the Taxonomy of Pandinus, Sensu Lato by Lorenzo Prendini. Doesn't give specific size ranges but important to note as he also talks about the differences in sizes of Pandinus imperator based on locality.
2023: A new species of Pandinus Thorell, 1876 from the Sahelian wooded steppes of Burkina Faso by Ythier, Eric & Audibert, Cédric. Gives the size range as up to 230mm, though this was likely taken from Rossi's 2014 paper as the authors explicitly note they were examining specimens from the smaller localities.

2017 Rediscovery of Holotype
1956 Vachon
1985 Casper
1994 CITIES
1999 Lourenco & Cloudsley-Thompson
2011 Kovarik
2014 Rossi
2014 Lourenco
2015 Rossi
2016 Prendini
2023 Ythier & Audibert

I do not have digital copies of The Biology of Scorpions by Gary A. Polis, Arachnomania by Philippe De Vosjoli, Scorpions of Medical Importance by Hugh L. Keegan, Scorpions of the World by Stockmann & Ythier, or How to Keep Scorpions by Hull-Williams.

To summarize, it seems 20cm has been the reported max size of Emperors for a while, but no specific specimen with these measurements has been reported from what I could find. The number likely traces back to Vachon, who in the one source I was able to find cited the number to Gaillard. I would like to see more of these sources if possible to see if such a specimen was ever actually recorded, and see how precisely they were measuring it. The 8-9in number from How to Keep Scorpions likely included the pedipalps, as that number is much larger than the 160mm later stated in the book. Kovarik is the first source to say anything above 200mm, but he also doesn't reference a specific specimen he measured at 220mm. Rossi has the largest number thus far, but again does not give the measurements of the specific individual he measured at 230mm. I assume it was the male "without data" (MSNB), and this specimen is also no longer cited in the paper he published the next year. The largest scorpion we have a picture of for having physically existed is the male from Liberia in Rossi's 2014 and 2015 paper, initially stated to be "about 180mm" then later just stated to be "180mm", and though the 2023 paper by Ythier and Audibert also give the range as 230mm, I believe it is likely they were going off of Rossi's 2014 paper.

So it seems from this, the largest scorpions we actually measure seem to top out at 170mm, with the potential for them to get up to 180mm if Rossi's numbers are accurate for the specimen from Liberia. This seems to be an extremely uncommon occurrence though, and even then these sizes would only be obtainable in the larger "forest" form Emperors, which are incredibly uncommon in the hobby, especially in recent years. The smaller "savannah" form Emperors seem to get between 100-130mm, which is consistent with the Emperors I've seen both personally and posted online.

If anyone has more information, especially any evidence of a scorpion getting to or exceeding 180mm, I would greatly appreciate it. If anyone has any links to some of Vachon's other papers, or has any idea what "Gaillard" refers to, I would also appreciate the insights. I am also interested as to what the largest scorpion we actually have on record is, even in G swammerdami 200mm+ does not seem very common, if possible. Let me know your thoughts.

 

[Dry Desert]

So a few days ago on this forum I had a discussion about Emperor Scorpion sizes. This caused me to go into a bit of a deep dive, and since then I've been going into an extremely deep dive into Emperor scorpion sizes and their reported size ranges. This is what I have so far. This information is partially incomplete, a lot of the earlier sources I couldn't find, and/or are not written in English. If anyone has any more information to add to this thread, I would wholly appreciate it.

The Timeline:
1841: Koch describes Pandinus Imperator. The holotype was rediscovered and redescribed in 2017. Though the specimen measured 160mm, it might've been 170mm accounting for some damage.
1956: The Biology of Scorpions by Max Vachon. Only reference to Pandinus imperator size was in a drawing, with a stated range of 18-20cm. This range is cited as "After Gaillard", but I could not find what this was referring to. No specific measurements of any individual given.
1980: Scorpions of Medical Importance by Hugh L. Keegan. Size for Pandinus imperator stated as "up to 180mm or more".
1985: Prey capture and stinging behavior in the emperor scorpion, Pandinus imperator by Gary S. Casper. First source with reported measurements of specimens. Largest measured at 17cm from chelicerae to telson tip, numbers likely rounded as the scorpions were sorted into groups of size, no specific measurements of any individual.
1988: How to Keep Scorpions by Hull-Williams. Conflicting information, says scorpions (no specific species or family) get "between 40mm and 127mm", then later in the text says "Large forest dwelling species are nocturnal ramblers and also grow quite large (8-9")". In the section on Heterometrus longimannus says "Due to their conspicuous size (trunk length up to 160mm) they are a good match for the closely related African genus Pandinus Thorell: they are among the world's largest scorpions." Does not give a size range for Pandinus imperator.
1990: The Biology of Scorpions by Gary A. Polis. Given range for Pandinus imperator is 18-20cm and references "Vachon, 1953" for this range. no specific reference as to what actual paper or publication this is.
1991: Arachnomania by Philippe De Vosjoli. Says Pandinus imperator "reach a length of nearly eight inches (20cm)", references include Scorpions of Medical Importance by Hugh L. Keegan, The Biology of Scorpions by Gary A. Polis, and How to Keep Scorpions by Hull-Williams. We can infer the 20cm figure is from Gary A. Polis, who in turn cited Vachon for this.
1994?: CITIES proposal to include multiple Pandinus species, including Pandinus imperator. Says "reaching as much as 20cm", but doesn't cite where this specific number is from. Includes a paper by Vachon in 1967 in the reference section, though I could not find this paper and it's not in English.
1999: Variation in energy spent on reproduction between forest and savanna populations of Pandinus imperator (Koch) in the Ivory Coast by LOURENCO,W.R. & CLOUDSLEY-THOMPSON,J.L. First source with specific measurements of individuals, categorizes the difference in sizes between larger "forest" form Emperors and smaller "savannah" form Emperors. Unfortunately does not give a table with their precise measurements, and only measure the prosoma + mesosoma, without including the metasoma. Largest individual measures appears to be about 82mm, assuming the metasoma is not significantly longer than the prosoma + mesosoma gives us a length of about 164mm.
2010: Scorpions of the World by Roland Stockmann and Eric Ythier. Given size range is up to 200mm.
2011: A Review of the Subgenus Pandinus Thorell, 1876 with Descriptions of Two New Species from Uganda and Ethiopia by František Коvařík. Stated size range of Pandinus imperator given as 220mm (the largest so far), does not include a material examined section. Only one measurement of a specific specimen given, a male from Ghana reported to be 115mm.
2014: Notes on the distribution of Pandinus (Pandinus) Thorell, 1876 and Pandinus (Pandinurus) Fet, 1997 with the descriptions of two new species from Central African Republic and Djibouti by Andrea Rossi. Size range reported as up to 230mm (the largest estimate given to date). and does include a materials examined section. Specimens examined are one female from Togo/Ghana (ARPC) later measured to be 113mm, two males and two females from Liberia (MHNG), with one male stated as being "about 180mm". and one male "without data" (MSNB).
2014: Further considerations on the identity and distribution of Pandinus imperator (C. L. Koch, 1841) and description of a new species from Cameroon by WILSON R. LOURENÇO. Reported size range for Pandinus imperator up to 180mm, gives specific values for a male from SE Notse, South of Togo (154.8mm) and a female Edea South of Cameroon (163.3mm). The female Pandinus imperator was suspected to be a P dictator by a later paper.
2015: Clarification of the Type Locality of Pandinus Ulderigoi with Notes on the Scorpions Protected by CITES by Andrea Rossi. No specific size range for Pandinus imperator given, again shows the same picture of the male from Liberia (MHNG) captioned as being 180mm. The male "without data" (MSNB) is no longer listed on this paper, though the 4 specimens from Liberia (MHNG) and a male from the Ivory Coast (ARPC) is listed.
2016: Redefinition and Systematic Revision of the East African Scorpion Genus Pandinoides (Scorpiones: Scorpionidae) With Critique of the Taxonomy of Pandinus, Sensu Lato by Lorenzo Prendini. Doesn't give specific size ranges but important to note as he also talks about the differences in sizes of Pandinus imperator based on locality.
2023: A new species of Pandinus Thorell, 1876 from the Sahelian wooded steppes of Burkina Faso by Ythier, Eric & Audibert, Cédric. Gives the size range as up to 230mm, though this was likely taken from Rossi's 2014 paper as the authors explicitly note they were examining specimens from the smaller localities.

2017 Rediscovery of Holotype
1956 Vachon
1985 Casper
1994 CITIES
1999 Lourenco & Cloudsley-Thompson
2011 Kovarik
2014 Rossi
2014 Lourenco
2015 Rossi
2016 Prendini
2023 Ythier & Audibert

I do not have digital copies of The Biology of Scorpions by Gary A. Polis, Arachnomania by Philippe De Vosjoli, Scorpions of Medical Importance by Hugh L. Keegan, Scorpions of the World by Stockmann & Ythier, or How to Keep Scorpions by Hull-Williams.

To summarize, it seems 20cm has been the reported max size of Emperors for a while, but no specific specimen with these measurements has been reported from what I could find. The number likely traces back to Vachon, who in the one source I was able to find cited the number to Gaillard. I would like to see more of these sources if possible to see if such a specimen was ever actually recorded, and see how precisely they were measuring it. The 8-9in number from How to Keep Scorpions likely included the pedipalps, as that number is much larger than the 160mm later stated in the book. Kovarik is the first source to say anything above 200mm, but with he also doesn't reference a specific specimen he measured at 220mm. Rossi has the largest number thus far, but again does not give the measurements of the specific individual he measured at 230mm. I assume it was the male "without data" (MSNB), and this specimen is also no longer cited in the paper he published the next year. The largest scorpion we have a picture of for having physically existed is the male from Liberia in Rossi's 2014 and 2015 paper, initially stated to be "about 180mm" then later just stated to be "180mm", and though the 2023 paper by Ythier and Audibert also give the range as 230mm, I believe it is likely they were going off of Rossi's 2014 paper.

So it seems from this, the largest scorpions we actually measure seem to top out at 170mm, with the potential for them to get up to 180mm if Rossi's numbers are accurate for the specimen from Liberia. This seems to be an extremely uncommon occurrence though, and even then these sizes would only be obtainable in the larger "forest" form Emperors, which are incredibly uncommon in the hobby, especially in recent years. The smaller "savannah" form Emperors seem to get between 100-130mm, which is consistent with the Emperors I've seen both personally and posted online.

If anyone has more information, especially any evidence of a scorpion getting to or exceeding 180mm, I would greatly appreciate it. If anyone has any links to some of Vachon's other papers, or has any idea what "Gaillard" refers to, I would also appreciate the insights. I am also interested as to what the largest scorpion we actually have on record is, even in G swammerdami 200mm+ does not seem very common, if possible. Let me know your thoughts.

After reading this I did a quick online search using duck duck go, and every site stated " the Average size was 20 CMS - 7.9 ins.

Even Exo Terra's main web page stated sizes from 5.7 - 8 ins.

 

[MorbidArachnid]

After reading this I did a quick online search using duck duck go, and every site stated " the Average size was 20 CMS - 7.9 ins.

Even Exo Terra's main web page stated sizes from 5.7 - 8 ins.

yeah i've seen a lot of "average of 7-8 inches", completely silly. the 8 inch number is definitely the most quoted, the few places that say 9 inches are probably referencing either the Kovarik or Rossi papers since no one else goes that high. Kinda why I wrote this though, it's interesting how information spreads and is filtered into "common knowledge", almost all sources that say 20cm can be traced back to Vachon at the root, who might be referencing someone else without having actually seen or confirmed a 20cm specimen. We can assume Ythier is doing the same thing by saying 23cm referencing the Rossi paper. It's one of those things you would just assume is technically possible (after all, aren't there randomly huge animals that exist occasionally?) and if even one Emp can get to 20cm then that is the technically correct max size. It's extremely interesting that even though this length, if someone has observed it, is almost certainly an outlier, a lot of sites that most people are going to be casually searching through state it as the norm (average of 8 inch).

 

[The Snark]

@MorbidArachnid I have no idea what your background and education is, but what you have written is essentially a cited rough draft white paper of analytical findings.
You have taken the various boots in the ground observations, similar to lab tests, and distilled the information. The next step would be to follow established scientific procedures which include discarding anomalies, the top and bottom 10% usually.
Ex, humans range in size up to 272 cm. Useless irrelevant data. An outlier in a data set.

 

[MorbidArachnid]

Can't edit ATM so just throwin this here for now.

On the scorpions, pedipalps and spiders from tropical West-Africa, represented in the collection of the British Museum

Published in Proc. zool. Soc. Lond., in 1899, in volume 1899, pages 833-885

biostor.org

1899: Pocock

 

[Kada]

Probably more like what the snark mentions. Although throwing out recorded data is not very scientific, and actually false. it (trimming off the extreme reports) is, however, probably more realistic in terms of what to expect as a pet.

Additionally, although respect must be given. I personally don't trust a whole lot of the explorers of centuries past. Lots of, let's say simplicity and/or exaggeration.

The biggest we have found was 21cm, in Sarwak, Malaysia. Have seen many pet ones that seem bigger, but never measured them so I bet our eyes play tricks on us more than we may want to admit.

 

[MorbidArachnid]

Probably more like what the snark mentions. Although throwing out recorded data is not very scientific, and actually false. it (trimming off the extreme reports) is, however, probably more realistic in terms of what to expect as a pet.

Additionally, although respect must be given. I personally don't trust a whole lot of the explorers of centuries past. Lots of, let's say simplicity and/or exaggeration.

The biggest we have found was 21cm, in Sarwak, Malaysia. Have seen many pet ones that seem bigger, but never measured them so I bet our eyes play tricks on us more than we may want to admit.

What species was this? Also do you happen to have a link?

 

[Dry Desert]

What species was this? Also do you happen to have a link?

There you go wanting verification.
There must be plenty of various species in the hobby world that are quite happy jogging along as someone's pet.
Scientific papers are all well and fine, however quoting one as reference from Pocock in1899 is hardly relevant.

As I mentioned when I kept Emperors back in the 80's there was no reason to measure, cross referencing with scientific papers etc. they were just interesting pets that were kept for a period of time before moving on.

Many large, huge specimens out there that will never be acknowledged as they are just pets, and with a life span of 8 years and wild caught maybe will just come and go.
Don't put too much credence on scientific papers.

Who verifies the papers anyway ??

 

[MorbidArachnid]

There you go wanting verification.
There must be plenty of various species in the hobby world that are quite happy jogging along as someone's pet.
Scientific papers are all well and fine, however quoting one as reference from Pocock in1899 is hardly relevant.

As I mentioned when I kept Emperors back in the 80's there was no reason to measure, cross referencing with scientific papers etc. they were just interesting pets that were kept for a period of time before moving on.

Many large, huge specimens out there that will never be acknowledged as they are just pets, and with a life span of 8 years and wild caught maybe will just come and go.
Don't put too much credence on scientific papers.

Who verifies the papers anyway ??

This kind of started with me being fascinated with how information spreads through the scientific community and permeates the "public consciousness", that's kind of the point, a lot of people give a quick brush at the Abstract and if it seems to validate their point reference it without digging further. How data is collected and interpreted is just as important as the data itself though, and this is just one very specific example of a figure no one really bothered double checking or finding a proper source for that's been repeated for so long it's taken as fact. Honestly I was looking into this in conjunction with investigating the oldest scorpion (where do the 25 year figures even come from?) and looking into how we keep Hadrurus in captivity. I find it interesting that so many people repeat again and again that they don't need supplementary water and get it all from their food then say "well they don't molt well in captivity and we have no idea why" when the successful molt stories I've seen all have supplementary water as a constant. Four anecdotes isn't a lot tho which is why I keep digging. This particular example for Emperor scorpion sizes isn't really critical to their care or anything, but I think it demonstrates in really simple terms how information gets repeated. I also don't think you can keep scorpions as pets without hitting the books a little bit, so to speak. They're still not very well researched and there's a lot to learn about captive breeding and keeping, and a lot of misconceptions and misinformation still being spread around with regards to their care. I think you were also on the post where I suggested using excelsior wood to mimic plant roots, as looking at a lot of how these scorpions are burrowing in the wild is into plants. Sometimes these kinds of investigations involve going deep back into research papers to figure out where a piece of information started, sometimes it involves collecting anecdotes and observations of wild scorpions and trying to form a better picture. All this to say I'm looking into this stuff because I find it interesting, and I've never been one to just trust someone's word on stuff. Plenty of keepers cite their experience as evidence of their correctness while being completely wrong, you can see it all the time in the Reptile hobby. Plenty of people drop a single research paper that supports their point without reading into it further or seeing if it was responded to by another paper that suggests it may be wrong. Idk man, I think it's responsible to at least look into things.

 

[Dry Desert]

This kind of started with me being fascinated with how information spreads through the scientific community and permeates the "public consciousness", that's kind of the point, a lot of people give a quick brush at the Abstract and if it seems to validate their point reference it without digging further. How data is collected and interpreted is just as important as the data itself though, and this is just one very specific example of a figure no one really bothered double checking or finding a proper source for that's been repeated for so long it's taken as fact. Honestly I was looking into this in conjunction with investigating the oldest scorpion (where do the 25 year figures even come from?) and looking into how we keep Hadrurus in captivity. I find it interesting that so many people repeat again and again that they don't need supplementary water and get it all from their food then say "well they don't molt well in captivity and we have no idea why" when the successful molt stories I've seen all have supplementary water as a constant. Four anecdotes isn't a lot tho which is why I keep digging. This particular example for Emperor scorpion sizes isn't really critical to their care or anything, but I think it demonstrates in really simple terms how information gets repeated. I also don't think you can keep scorpions as pets without hitting the books a little bit, so to speak. They're still not very well researched and there's a lot to learn about captive breeding and keeping, and a lot of misconceptions and misinformation still being spread around with regards to their care. I think you were also on the post where I suggested using excelsior wood to mimic plant roots, as looking at a lot of how these scorpions are burrowing in the wild is into plants. Sometimes these kinds of investigations involve going deep back into research papers to figure out where a piece of information started, sometimes it involves collecting anecdotes and observations of wild scorpions and trying to form a better picture. All this to say I'm looking into this stuff because I find it interesting, and I've never been one to just trust someone's word on stuff. Plenty of keepers cite their experience as evidence of their correctness while being completely wrong, you can see it all the time in the Reptile hobby. Plenty of people drop a single research paper that supports their point without reading into it further or seeing if it was responded to by another paper that suggests it may be wrong. Idk man, I think it's responsible to at least look into things.

Maybe unable to see the wood for the trees comes to mind.

Having an inquisitive mind is good and I sometimes need verification of some sort rather than taking things at face value

 

[Diao]

They're out there. Extremely uncommon, but 20cm and even 20cm+ do exist. Problem is that the areas they come from aren't as easy to access and collect individuals from as other areas where smaller individuals are the norm. I'll have to dig, but I know I have a picture of a Pandinus imperator against a rule that is 20cm. Here are a few other pictures of 20cm specimens/individuals without the ruler. One is a deceased specimen that is 187mm deceased, but certainly was 200mm+ when alive and and a full belly. I've seen 20cm+ G.swammerdami too, I'll see if I can find any pictures of those as well. I have one of a 21cm against a ruler somewhere too. Live swammerdami are tough to measure because they're usually giant douchbags compared to P.imperator lol.

 

[MorbidArachnid]

They're out there. Extremely uncommon, but 20cm and even 20cm+ do exist. Problem is that the areas they come from aren't as easy to access and collect individuals from as other areas where smaller individuals are the norm. I'll have to dig, but I know I have a picture of a Pandinus imperator against a rule that is 20cm. Here are a few other pictures of 20cm specimens/individuals without the ruler. One is a deceased specimen that is 187mm decreased, but certainly was 200mm+ when alive and and a full belly. I've seen 20cm+ G.swammerdami too, I'll see if I can find any pictures of those as well. I have one of a 21cm against a ruler somewhere too. Live swammerdami are tough to measure because they're usually giant douchbags compared to P.imperator lol.

Wow! would love to see the pics next to the ruler, but def looks like the largest I've seen so far.


Largest one I've seen with ruler. Looks between 17-18 with telson.

 

[Kada]

They're out there. Extremely uncommon, but 20cm and even 20cm+ do exist. Problem is that the areas they come from aren't as easy to access and collect individuals from as other areas where smaller individuals are the norm.

If that turns out true, my guess is that human activity is potentially the case. Not directly so, but indirectly so. I normally find bigger spiders, scorpions, centipedes etc out in proper forests or less disturbed areas. albiet far less often due to difficulty to spot them compared to highly disturbed areas. human areas tend to kill a lot of these types of animals and I notice a huge difference in size sometimes. Especially agricultural areas.

By this I mean, indirect causes of death. especially for much larger, older, slower and harder to hide specimens that get knocked off by secondary human causes of death. such as agriculture spray, agriculture fields which tend to breed monkeys/rodents/lizards/etc or the tilling/burning/clearing of land (mechanical decimation & chemical) construction and so on. One of the bigger scorpions I have found was in Khao Sok national park in Thailand during the rainy season. Saw lots underwater in puddles hiding as well Then saw an absolute giant of a specimen under a boulder with a friend that was having a fight with an equally massive frog. I did get pics, though raining and they went in fast (scorpion won as best I can tell). I need to go through the hard drives to find pics, but will post when I do. Absolutely zero idea on species ID.

What species was this? Also do you happen to have a link?

Sorry, no idea. I will look for the pics and post. I only have pics, dates, location and weather information. sadly. Which is still at least 3 more datasets than most pet store specimens lol

I will try to find the pics. These 2 examples above were 20 and 15ish years ago in borneo and Southern Thailand. The Thailand one was cool as they would go underwater. Maybe that's common knowledge, i have no idea. But it fascinated me at the time!! I took pics of the ones underwater too, same water spots had water scorpions ironically . Great memories.

 

[Diao]

Not the picture I was thinking of, but this one is pretty much 20cm. These are all different individuals I've posted pictures of as well. I'll have to keep digging, but the picture I'm thinking of is a very large gravid female that is over 20cm, I'll keep looking.

 

[MorbidArachnid]

Not the picture I was thinking of, but this one is pretty much 20cm. These are all different individuals I've posted pictures of as well. I'll have to keep digging, but the picture I'm thinking of is a very large gravid female that is over 20cm, I'll keep looking.

And there we have it! Thanks so much!

 

[The Snark]

although respect must be given. I personally don't trust a whole lot of the explorers of centuries past. Lots of, let's say simplicity and/or exaggeration.

As in measured stretched out under tension from tip of one palp to the point of the stinger? Anyone see an established methodology for measurements in the field in the 1800s on up to recently, or even today?

 

[MorbidArachnid]

As in measured stretched out under tension from tip of one palp to the point of the stinger? Anyone see an established methodology for measurements in the field in the 1800s on up to recently, or even today?

This also, i'm not sure when standard front of prosoma to telson tip got implemented. also @Diao you wouldn't happen to have locality info for this guy would you?

 

[Diao]

This also, i'm not sure when standard front of prosoma to telson tip got implemented. also @Diao you wouldn't happen to have locality info for this guy would you?

No idea, unfortunately.

 

[Kada]

As in measured stretched out under tension from tip of one palp to the point of the stinger? Anyone see an established methodology for measurements in the field in the 1800s on up to recently, or even today?

Ya, that's my thinking. Body/tail stretched. No pinchers

It would be interesting to see the details of centuries past methodology