Field of Science

The Patagonian Land Penguin

Take a good look at the figure above, which comes from Mayr (2009). It shows the fossilised tarsometatarsus (the fused long bone of the foot) of a bird from the late Oligocene of Patagonia. This may be one of the single most mysterious specimens in the fossil record. It represents all we know to date of Cladornis pachypus, described by Argentinean palaeontologist Florentino Ameghino in 1895. The appearance of the bone, being very broad and flat relative to its length, is quite bizarre and does not much resemble the tarsometatarsus of any other known bird.

The first thing that should be pointed out is that, whatever it was, Cladornis was a large bird. The specimen is not completely preserved (part of the proximal end of the bone has been lost) but its overall shape suggests that its original length was probably not too much longer than what we have. As such, the tarsometatarsus was probably comparable in length to that of a large pelican. However, it was much wider relative to length than that of a pelican, suggesting the possibility of a more robust bird. The shape of the bone's end indicates that the toes would have been widely spaced, and it may have even approached a zygodactyl arrangement (with two toes pointed rearwards and two forwards, like a modern parrot*) (Mayr 2009).

*When explaining this to my partner, I suggested that he imagine a parrot the size of a pelican. He shuddered and declared that he would rather not.

When Ameghino (1895) first described Cladornis, he interpreted it as an aquatic bird and suggested a relationship to the penguins, albeit in an extinct family Cladornidae (later authors would correct this to Cladornithidae). Later, noticing that it was preserved in association with terrestrial mammals, he declared that it was not marine and was possibly even terrestrial (he also included another species from the same formation, Cruschedula revola, in the Cladornithidae; this species is based on part of a scapula and there is no telling if it was related to Cladornis or not). He still maintained its relationship to the penguins (Ameghino 1906). Ameghino had a bit of a thing for trying to find the origins of all major modern vertebrate groups in his native South America (one of his other works was a book arguing for an Argentinean origin of humans) and it is possible that this was in play here. Nevertheless, the idea of a 'Patagonian land penguin' held sway until Simpson's (1946) review of the fossil penguins, in which he declared that Cladornis was "so very unlike any other penguin, recent or fossil, that I can only consider its reference to that group as erroneous".

This left Cladornis' taxonomic position completely up in the air (the question of whether Cladornis itself could get up in the air is, of course, currently completely unswerable). Wetmore (1951) included Cladornis in the Pelecaniformes, because...reasons. The closest he gave to an explanation was, "The only suggestion that has come to me is that possibly they may belong in the order Pelecaniformes, in which I have placed the family tentatively in the suborder Odontopteryges, where it is located with two others of almost equally uncertain status. This allocation is wholly tentative and is no indication of belief in close relationship in the three diverse groups there assembled". He would later move Cladornis into its own suborder, Cladornithes, and no close relationship to the 'Odontopteryges' (now the Pelagornithidae) has been suggested since. Our current understanding of bird phylogeny finds Wetmore's remaining 'Pelecaniformes' to correspond to three or four independent clades (the Pelecanidae, Suliformes, Phaethontidae and probably Pelagornithidae) so his assignment of Cladornis to this group becomes almost completely uninformative.

Which is pretty much where we're forced to leave things. Mayr (2009) included Cladornis in his chapter on 'land birds', with other taxa discussed in this chapter belonging to the clade Telluraves. However, this was motivated more by a lack of any idea what to do with it otherwise than anything else (it is possible that Cladornis' sub-zygodactyly played a role, but not all zygodactylous birds belong to the Telluraves). I did notice a similarity in proportions between the Cladornis tarsometatarsus and the corresponding bone in the large phorusrhacid Brontornis, making me wonder if anyone had ever compared the two, but this may well be only superficial. Most recent authors have assumed that the Cladornis tarsometatarsus is simply too weird, too unique, for any resolution of its affinities to be reached without first finding more complete remains of the animal.


Ameghino, F. 1895. Sur les oiseaux fossiles de Patagonie et la aune mammalogique des couches a Pyrotherium. Boletín del Instituto Geográfico Argentino 15 (11–12): 501–602.

Ameghino, F. 1906. Enumeración de los Impennes fósiles de Patagonia y de la Isla Seymour. Anales del Museo Nacional de Buenos Aires, serie 3, 6: 97–167.

Mayr, G. 2009. Paleogene Fossil Birds. Springer.

Simpson, G. G. 1946. Fossil penguins. Bulletin of the American Museum of Natural History 87 (1): 1–99.

Wetmore, A. 1951. A revised classification for the birds of the world. Smithsonian Miscellaneous Collections 117 (4): 1–22.

Camponotus: A Sugary High

I think I may have said before that Australia is the land of ants. When travelling in Australia's arid regions (i.e. most of the continent), ants are often the most visible animals about. Perhaps the most visible of all Australia's ants are the meat ants (Iridomyrmex), but not too far behind them are the sugar ants of the genus Camponotus.

Workers and emerging queens of banded sugar ants Camponotus consobrinus around the nest opening, copyright Steve Shattuck.

Camponotus is a genus of the ant subfamily Formicinae found pretty much everywhere around the world that ants are to be found. It is massively diverse: well over 1000 species have been assigned to this genus over the years, with probably more to be described. They are correspondingly diverse in habits and appearance. Some are among the giants of the ant world, others are much smaller. Some form massive colonies that are difficult to miss and forage during the day, others are more retiring and emerge only at night. Some construct their nests in holes under the grounds, others hollow out wood or use the holes left by other wood-boring insects. Most (but not all) Camponotus species exhibit some form of worker polymorphism: rather than having just a single worker caste, a colony will often include large major workers and much smaller minor workers, with the two forms superficially looking quite different. Sometimes the distinction between majors and minors will be quite clear, other times there will also be workers of intermediate sizes. In some Australian species, known as honeypot ants, there are specialised workers called 'repletes' who spend their lives hanging in one spot inside the nest, being fed by the other active workers until their gasters swell into engorged round balls. These repletes serve the colony as a living larder, able to regurgitate their stored excess of food when needed by their nestmates. Despite all this diversity, most Camponotus species are readily recognisable as Camponotus: they usually lack spines on the mesosoma (the 'thorax'), the back end of which is narrow and often arched. This smoothness and slimness gives Camponotus a distinctive look that kind of puts me in mind of the ant version of a greyhound. The majority of Camponotus species also differ from other ants in lacking the metapleural gland, a gland producing an antibiotic chemical whose opening is usually visible near the rear of the mesosoma.

Camponotus aurocinctus, copyright Steve Shattuck.

Camponotus species have been referred to in Australia as 'sugar ants' in reference to their diet, which is commonly dominated by the sugary excretions of plant-sucking bugs that they attend. In other parts of the world, they have sometimes been referred to as 'carpenter ants' in reference to the wood-tunneling habits of their most notorious representatives. Bug-derived honeydew is high in sugar but low in other essential nutrients, so the ants also feed on things such as the scavenged bodies of the bugs themselves after death. They are also probably assisted in meeting their nutritive needs by Blochmannia, an endosymbiotic bacterium that infests specialised cells in the gut of Camponotus and closely related genera (Wernegreen et al. 2009). Genetic data from the endosymbiont indicates that it probably synthesises nutrients the ant does not otherwise ingest. It may also play some role in compensating for an absence of metapleural gland secretions. As well as the gut, Blochmannia infest the ovaries of reproductive females and are passed to the next generation via the developing oocytes. Phylogenetic analysis of Blochmannia indicates that it is closely related to other endosymbiotic bacteria found in mealybugs, and it is possible that the ancestors of Camponotus picked it up in the course of feeding on honeydew.

Honeypot ant Camponotus inflatus repletes hanging in the nest, copyright Mike Gillam.

The sheer size of Camponotus as a genus has been a challenge to understanding relationships within the genus. Over thirty subgenera have been proposed at one time or another, but many of these are poorly defined and many authors eschew using them in favour of informal species groups. It does not help matters that, since the early 20th century, most reviews of Camponotus have been conducted at a local rather than a global level. Those studies that have touched on Camponotus phylogeny in recent years suggest the need for a large-scale revision, with few of the subgenera supported as monophyletic.


Wernegreen, J. J., S. N. Kauppinen, S. G. Brady & P. S. Ward. 2009. One nutritional symbiosis begat another: phylogenetic evidence that the ant tribe Camponotini acquired Blochmannia by tending sap-feeding insects. BMC Evolutionary Biology 9: 292. doi:10.1186/1471-2148-9-292.


Slide-mounted male of Zercon gurensis, copyright Holger Müller.

The animal depicted above is a mite of the Zerconidae, one of the numerous families in the major mite clade known as the Mesostigmata. This family is mostly found in soil habitats such as leaf litter, mosses, decaying vegetation, or occasionally in animal nests (Lindquist et al. 2009). The zerconids are restricted to the Northern Hemisphere and are most diverse in temperate to Arctic regions; those species found in tropical parts of the world are restricted to high altitudes away from the hot lowlands (Ujvári 2012). Like many other Mesostigmata, they have the dorsal surface of the body mostly covered by shields of hardened cuticle. In most zerconids, separate shields cover the front (podonotal) and rear (opisthonotal) sections of the dorsum; the opisthonotal shield wraps around the rear margin of the mite and forms a continuous unit with the ventrianal shield that usually protects most of the underside of the mite behind the legs. Among the most noticeable features of the zerconids are two pairs of large openings near the rear of the opisthonotal shield (the four orange-segment-like structures in the photo above). These represent the openings of secretory glands, but I don't know if it has been established just what they're secreting; comparable structures in other mites may secrete pheromones, or defensive chemicals, or oils that prevent debris from sticking to the body. Other features of the zerconids include slender, relatively simple chelicerae that lack the modifications seen in the males of some other Mesostigmata, and peritremes (grooves on the underside of the body that channel air to the openings of the respiratory stigmata) that are relatively short. These peritremes are longer in zerconid nymphs, but become shortened when the mite moults to maturity.

Zerconids are another of those mite groups where the vast majority of what has been written about them relates to their basic taxonomy, with little yet known about their natural history. Several genera of zerconids are recognised, distinguished by features such as the shape of the body's various shields and the appearance of various setae. The form of their chelicerae indicates that zerconids are predatory like many other Mesostigmata. Because they are mostly found at ground level rather than on vegetation they have not attracted the economic interest of other predatory mites, but those few species that have been observed feeding were chowing down on nematodes. Mating does not appear to have been directly observed in zerconids, but again their anatomy and comparison with other mesostigs allows us to infer that the male fertilises the female by using his chelicerae to pass a spermatophore from his own genital opening on the underside of the body between the legs to hers. Where she then lays her eggs, and how her offspring spend their time to maturity, seem to be questions still awaiting an answer.


Lindquist, E. E., G. W. Krantz & D. E. Walter. 2009. Order Mesostigmata. In: Krantz, G. W., & D. E. Walter (eds) A Manual of Acarology 3rd ed. pp. 124–232. Texas Tech University Press.

Ujvári, Z. 2012. Draconizercon punctatus gen. et sp. nov., a peculiar zerconid mite (Acari: Mesostigmata: Zerconidae) from Taiwan. Opusc. Zool. Budapest 43 (1): 79–87.

Midges of the Macabre

In a recent post, I commented that derived members of an insect 'order' could sometimes be all but unrecognisable as belonging to that order. Take a look at this:

Miastor sp., copyright Charles Olsen.

Believe it or not, sitting in the middle of that photo is a fully reproductively mature insect (I'm not so sure about the maturity of the other individuals). In fact, it's a fully mature fly. Miastor is a genus of midges found living in rotting wood or fungal fruiting bodies. Members of this genus are found worldwide; I believe that several species are recognised, but distinguishing the individual species is extremely difficult. Miastor exhibit what is called paedogenesis: they can become reproductively mature while still in the larval state. They are not the only genus of the family Cecidomyiidae to exhibit this process; another such genus, Oligarces, is found in similar habitats. Miastor is probably the best known such genus, in part because it has been cultured for study in the laboratory, and in part because of the decidedly macabre way in which its paedogenesis plays out.

Each paedogenetic Miastor larva develops several eggs within its ovaries (generally four to ten or more—Harris 1923). No males are involved in this process: the larvae are parthenogenetic as well as paedogenetic. These eggs hatch while still inside their mother, after which the daughter larvae are nourished by the mother's own tissues. Eventually, the daughters are not born so much as they escape. In the words of Quammen (1985), "While the food lasts, while opportunity endures, no Miastor female can live to adulthood without dying of motherhood". But karma still seems to have its place, because by the time the daughter larvae escape they carry their own fate within them: they emerge with their own eggs already developing inside them.

Metamorphosed male Miastor metraloas, copyright John Plakidas.

In this way, a Miastor colony can go through an entire generation in as little time as two weeks, until changing conditions (such as exhaustion of food supplies, or a change in season) induce a change in tack. Larvae are produced that do not reproduce paedogenetically in the way that their mothers did, but instead pupate in the usual way to emerge as more ordinarily formed midges, both males and females. As with another paedogenetic insect that has already been featured on this site, the beetle Micromalthus debilis, these metamorphosing larvae can be readily distinguished from paedogenetic larvae. Not only do they not produce the precocious reproductive organs of their fellows, but they have visible imaginal discs (the clumps of tissue that develop into adult structures during metamorphosis), and have eyes that are clearly separated on top rather than touching as in paedogenetic individuals (Harris 1923). After the mature adult midges emerge from their pupae, they can disperse in search of new habitats, seeking food for their offspring and mates for themselves in order to begin the cycle again.


Harris, R. G. 1923. Occurrence, life-cycle, and maintenance under artificial conditions, of Miastor. Psyche 30 (3–4): 95–101.

Quammen, D. 1985. Natural Acts. Schocken Books.

The Mongolian Death Worm

This would have been a comment on a recent post by Darren Naish at Tetrapod Zoology on the behaviour of amphisbaenians, but the commenting system they have at Scientific American these days means that any comment on a post more than a couple of days old will never be seen by anyone. As such, I'm posting it up here:

PhilJTerry's comment in response to Darren's post: "As I love introducing cryptozoology into the conversation wherever possible - are Amphisbaenians a likely influence for the Mongolian Death Worm? Can they live in desert environments?"

Image from National Geographic.

For those not already aware, the "Mongolian death worm" or "olgoi-khorkhoi" is a supposedly incredibly dangerous animal found in the deserts of Mongolia. It's first mention in Western literature came in Roy Chapman Andrew's (1926) On the Trail of Ancient Man. Andrews heard about the animal in a meeting with Mongolian officials:

Then the Premier asked that, if it were possible, I should capture for the Mongolian government a specimen of the allergorhai-horhai. I doubt whether any of my scientific readers can identify this animal. I could, because I had heard of it often. None of those present ever had seen the creature, but they all firmly believed in its existence and described it minutely. It is shaped like a sausage about two feet long, has no head nor legs and is so poisonous that merely to touch it means instant death. It lives in the most desolate parts of the Gobi Desert, whither we were going. To the Mongols it seems to be what the dragon is to the Chinese. The Premier said that, although he had never seen it himself, he knew a man who had and had lived to tell the tale. Then a Cabinet Minister stated that "the cousin of his late wife's sister" had also seen it. I promised to produce the allergorhai-horhai if we chanced to cross its path, and explained how it could be seized by means of long steel collecting forceps; moreover, I could wear dark glasses, so that the disastrous effects of even looking at so poisonous a creature would be neutralized. The meeting adjourned with the best of feeling; for we had a common interest in capturing the allergorhai-horhai.

Since then, there have been a number of expeditions have been conducted in search of the Premier's "allergorhai-horhai"; all have come up fruitless. Various opinions have been expressed as to what the stories may have been based on, with the most popular suggestions being some sort of reptile (Darren says in his response to the above comment on the original post that he "could buy that the stories are based on exaggerated tales of erycine boas or something"). For my part, I suspect that the question of the 'original identity' of the Mongolian death worm may be a futile one. When I first heard Andrews' account, I was not reminded of an amphisbaenian or a boa; I was immediately put in mind of a drop bear.

I feel almost certain that Andrews was being told a local tall tale, a popular joke at the expense of visiting travellers. The nature of Andrews' response to the officials suggests that he was in on the joke and more than happy to play his part in communicating it. Admittedly, other accounts of the Mongolian death worm have been recorded at more recent dates. And in the same way, I've never seen a drop bear myself, but I can assure you that my cousin did once and got the fright of his life. Be careful. They're out there.

Scurvy and Cress

Without the subject of today's post, it's just possible that my home country of New Zealand could have had quite a different history. Sometimes, one shouldn't overlook the importance of cress.

Pepperwort Lepidium heterophyllum, copyright Anne Burgess.

Lepidium is a genus of herbs and subshrubs belonging to the Brassicaceae, the same family as cabbages, radishes and cauliflowers. The genus is found worldwide, and more than 150 species have been recognised to date. The fruit is a type of dry capsule called a silicle which is usually dehiscent (one subgroup of Lepidium, previously separated as the genus Cardaria, has indehiscent fruit), with strongly keeled or winged valves, and contains a single pendulous seed in each locule. The seeds are usually copiously covered in mucilage (Mummenhoff et al. 2001). Like other members of the Brassicaceae, Lepidium has not been overlooked for culinary uses. Leaves and stems of number of species in the genus, such as garden cress Lepidium sativum and dittander Lepidium latifolium, are used as pot or salad herbs. A South American species, maca Lepidium meyenii, is grown as a root vegetable.

Because of its wide distribution, some early authors suggested that Lepidium was a very ancient genus whose members had diverged with the break-up of the Mesozoic supercontinents. However, more recent phylogenetic analyses (Mummenhoff et al. 2001) have suggested just the opposite: the crown group of Lepidium may have originated in the Mediterranean-Central Asian region little more than two million years ago. The mucilaginous seeds of many species become sticky when damp, and can easily be carried long distances adhered to birds' feet and other such dispersal agents. Perhaps the most dramatic suggestion of intercontinental dispersal in the genus involves a clade of species found in Australia and New Zealand that phylogenetic analysis suggests originated via hybridisation between two divergent species—with one parent being native to South Africa and the other to California (Mummenhoff et al. 2004).

Cook's scurvy grass Lepidium oleraceum, copyright Andrea Brandon.

It was one of the members of the latter clade that played a small but significant role in New Zealand history. Lepidium oleraceum is an endemic New Zealand species that was once found growing over much of the country. It is commonly known as 'Cook's scurvy grass', because Captain James Cook was able to collect it while surveying New Zealand to provide vitamin C to stave off the scurvy that could have otherwise devastated his crew. Sadly, this once common plant is now extremely rare: the disappearance of mainland-nesting seabirds means that they are no longer around to provide the guano-enriched soils on which this plant thrived. It also proved extremely palatable to introduced herbivores. As a result, Cook's scurvy grass is now almost exclusively found on small offshore islets.


Mummenhoff, K., H. Brüggemann & J. L. Bowman. 2001. Chloroplast DNA phylogeny and biogeography of Lepidium (Brassicaceae). American Journal of Botany 88 (11): 2051–2063.

Mummenhoff, K., P. Linder, N. Friesen, J. L. Bowman, J.-Y. Lee & A. Franzke. 2004. Molecular evidence for bicontinental hybridogenous genomic constitution in Lepidium sensu stricto (Brassicaceae) species from Australia and New Zealand. American Journal of Botany 91 (2): 254–261.

Linnaeus' Infernal Fury

The starting point of modern zoological nomenclature (Clerck notwithstanding) has been established as the tenth edition of Linnaeus' Systema Naturae, published in 1758. Linnaeus divided the animal kingdom between six classes, with vertebrates making up four (Mammalia, Aves, Amphibia and Pisces) and invertebrates assigned to just two. One of these, Insecta, essentially corresponded to modern arthropods, and all other invertebrates were included in the class Vermes, 'worms'. Linnaeus' concept and arrangement of Vermes bears little resemblance to anything that exists in modern zoological classifications; with the study of invertebrate anatomy still in its absolute infancy, he was largely classifying animals based on their overall external appearance alone. One of Linnaeus' orders of Vermes, the 'Intestina', defined as 'simple, shell-less and limb-less', included animals now classified as annelids, nematodes, molluscs and even a chordate (the hagfish Myxine glutinosa). It also included a species whose identity would be debated for the next several decades: the 'infernal fury', Furia infernalis.

A reconstruction of Furia infernalis, from Piter Kehoma Boll.

Furia infernalis was described by Linnaeus as "Corpus filiforme, continuum, aequale, utrinque ciliatum: aculeis reflexis corpori appressis" ('body thread-like, continuous, uniform, ciliated on both sides with reflexed spinules appressed to the body'). It was found in marshes of southern Sweden and Finland. Linnaeus went on to record that F. infernalis was, "Pessima omnium, ex aethere decidua in corpora animalium, ea momento citius penetrat, intra horae quadrantem dolore atrocissimo occidit": the 'worst of all, falling from the sky onto the bodies of animals, into which it rapidly penetrates within a moment, striking [the victim] down with the most atrocious pain within quarter of an hour'. Linnaeus had good reason to highlight this animal's unpleasantness: he had been attacked by one himself when collecting botanical specimens in 1728, and barely escaped the resulting ailment with his life. A more detailed description of "der Höllenwurm" was compiled by Jördens (1802): it was a very slender worm, about the length of a nail, of a pale yellow or fleshy colour (other authors described it as greyish), with one end black. It climbed up standing vegetation, from whence it was carried by the breeze onto the exposed skin of humans and animals into which it rapidly burrowed. For victims, the first sign of its presence was usually a sudden pain in the afflicted spot, like the stab of a needle, and a small black spot marking the worm's entry point. A violent itching followed that developed into severe and extensive inflammation, often accompanied by fever; in the majority of cases, the affliction was so violent that the victim was dead within a matter of days if immediate action was not taken. If applied quickly enough, the worm could sometimes be drawn out with a poultice of fresh cheese curds. Otherwise, treatment required the careful dissection of the worms from between the muscle tissue into which they had entered, a process that (considering the surgical facilities available at the time) must have nearly as hazardous as the original infection.

As can be imagined, the attacks of this animal were greatly feared. In 1823–1824, an epidemic of Furia attacks spread through herds of livestock in Swedish and Finnish Lapland; thousands of head of reindeer perished, as well as countless cattle and sheep. Scavengers such as wolves feeding on the carcasses themselves sickened and died. One account from the time involves a young woman who was shearing wool from a recently deceased sheep (on a waste not, want not principle, I suppose) when she felt the tell-tale sting on a knuckle. Her life was saved by her master who was working nearby, when he quickly chopped off the affected finger with an axe. So great was the devastation that Norway, which had hitherto been free of the worm, passed an edict banning the import of animal furs from affected areas (Brooke 1827).

There were some, however, who greeted the description of Furia infernalis with skepticism. The idea of a tiny worm that somehow flew through the air and caused almost instantaneous mortality seemed fantastic. Even more problematic was the dearth of specimens. Many had seen the wounds caused by the worm and observed its effects; very few had seen the worm itself. Linnaeus himself had only seen a single, very poorly preserved specimen submitted to him by a church pastor. Most of the details about the worm's supposed appearance came from a single source, an article written by Solander, a student of Linnaeus'. The Academy of Sciences at Stockholm, naturally keen to discover all they could about such a scourge afflicting their country, offered generous rewards to anyone who could procure them a genuine specimen; no such specimen was forthcoming. Eventually, a consensus was reached: the worm Furia infernalis was an entirely fabulous animal, with no place in the annals of physical zoology. By 1827, notwithstanding the epidemic of only a few years previously, Brooke was able to comment that one could quite easily accept that something had affected the supposed victims of Furia without presuming that that something had to be the Furia itself. Even Linnaeus eventually came to accept that his inclusion of Furia in the Systema Naturae had been an error.

That Furia infernalis never existed outside the realms of fantasy remains the accepted wisdom to this day. But in that case, what did afflict Linnaeus and other unfortunates wandering the marshes of Sweden in the early 1700s? One thing that struck me was how much I was reminded of the more recent phenomenon here in Australia of 'white-tailed spider bites'. In recent decades, many people (including many medical professionals) have attributed serious ulcerative skin lesions, sometimes so serious that treatments such as skin grafts are required, to the bite of white-tailed spiders Lampona spp., common ground-running spiders often encountered near human dwellings. The actual evidence linking white-tailed spiders to such injuries is minimal; indeed, a clinical survey of 130 confirmed white-tail bites by Isbister & Gray (2003) found not a single incidence of one leading to ulceration. In both the 'Furia attacks' and the 'white-tailed spider bites', it seems likely that the primary culprit is bacterial infections resulting from opportunistic pathogens such as Streptococcus and Staphylococcus species. The initial wound may indeed have been caused by something like an animal bite or sting, or for that matter a splinter or pin-prick. Germ theory would not become widely accepted until the mid- to late 1800s; when Linnaeus compiled the Systema Naturae, flying worms probably seemed as good an explanation as any. The first 'attack' recorded by Furia victims may have simply been the first moment they noticed the infection's symptoms. And the 'worms' dissected out of advanced victims? Personally, I'm inclined to suspect that they may have been small pieces of tissue from the unfortunate sufferers themselves.

The exact causes of the 1823 epidemic are probably lost to history. Brooke (1827) stated that faculty at the Stockholm academy "had been led to consider the disorder by which [the reindeer] were attacked as a particular variety of hydrophobia". He also mentioned another possibility: reindeer were known to be vulnerable to inflammation of the brain, and dissections of the brains of deer killed by this condition sometimes revealed the presence of "a small vesicular worm". We can now recognise these vesicles as the cysts of hydatid tapeworms, which can hatch to cause tapeworm infections in any predator that eats the flesh of their host. So perhaps the 1823 epidemic was caused by a worm after all—just not the worm that was blamed.


Brooke, A. de C. 1827. A Winter in Lapland and Sweden, with various observations relating to Finmark and its inhabitants; made during a residence at Hammerfest, near the North Cape. John Murray: London.

Isbister, G. K., & M. R. Gray. 2003. White-tail spider bite: a prospective study of 130 definite bites by Lampona species. Medical Journal of Australia 179: 199–202.

Jördens, J. H. 1802. Entomologie und Helminthologie des Menschlichen Körpers, oder Beschreibung und Abbildung der Bewohner und Feinde desselben unter den Insekten und Würmern vol. 2. Gottfried Adolph Grau: Hof.

Linnaeus, C. 1758. Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis 10th ed., revised, vol 1. Laurentius Salvius: Copehagen.