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Introducing Smeagol the Eyeless Arachnid

Smithsonian Magazine

In damp, dark caves underground, there dwells a pale creature twisted by its association with the dark. No, the newly discovered species isn’t Gollum from J.R.R. Tolkien’s epic fantasy books, The Lord of the Rings and The Hobbit, but the scientists who found the creature were inspired by the likeness, reports Rachel Feltman for The Washington Post.

The creature is a type of harvestmen, or daddy longlegs, a group of arachnids that look similar to, but are not, spiders. The newly found Iandumoema smeagol get’s is species name from the creature Gollum—who was called Sméagol before he was corrupted by the power of the One Ring—and lurks in caves in Minas Gerais, in Brazil, the researchers report in Zookeys. ​

Unlike spiders, harvestmen have fused body parts, so their cephalothorax (head plus thorax) and abdomen appear as one. They usually have two legs that are significantly longer than the others, whereas spiders have similarly-sized legs. Colloquially, the arachnids can be called daddy longlegs, but some other, unrelated creepy-crawlies share that moniker.

"Its name matches its biology," arachnid expert Christopher Buddle, who was not involved in the discovery,  tells Brian Clark Howard of National Geographic. Similar to the fictional Sméagol, I. smeagol  scavenges for carcasses of other invertebrates and lives close to underground water. Yet unlike related cave-dwelling arachnids, not to mention Gollum, the generations of living in darkness left the newly discovered creature without its eyes (and most pigmentation), reports Sam Wong for New Scientist.

Unfortunately, this new species is under threat, Wong reports. The species’ specialization and small area of habitation mean it is especially vulnerable to activities that could threaten that habitat including deforestation and limestone mining nearby.

Though this blind arachnid isn’t the first time scientists named a species after Gollum, perhaps this famous name can help bring this creature enough recognition for a little protection.


Smithsonian Libraries

Watch the Unnerving Gait of This 410 Million-Year-Old Arachnid

Smithsonian Magazine

Arachnophobes of the world, this is where it all started.

Roughly 410 million years ago, the trigonotarbids walked the Earth. One of the first land predators, the now-extinct order of arachnids are an ancient relative of modern spiders (though not a direct ancestor). Trigonotarbids died out around 300 million years ago, but in their heyday these  were “top dog of the food chain,” according to palaeontologist Russell Garwood in a press statement from the University of Manchester. In a new study, Garwood and colleagues have tried to recreate the arachnid's gait. The creepy crawly creature in the video above is the result.

In the 1920s, scientists dug up pristine trigonotarbid fossils just a few millimeters long from a site outside the Scottish town of Rhynie. Using modern techniques, Garwood and his colleagues studied the incredibly well-preserved fossils, reproducing the structure of the arachnid's legs, says Jonathan Amos for the BBC. In an interview with Amos, Garwood explained how they turned the arachnid's anatomy into motion.

"We could see the articulation points in the legs," explained Dr Garwood.

"Between each part of the leg, there are darker pieces where they join, and that allowed us to work out the range of movement.

"We then compared that with the gaits of modern spiders, which are probably a good analogy because they have similar leg proportions. The software enabled us to see the centre of mass and find a gait that worked. If it's too far back compared to the legs, the posterior drags on the ground. The trigonotarbid is an alternating tetrapod, meaning there are four feet on the ground at any one time."

Figuring out how ancient species walked and moved is incredibly difficult—just ask the paleontologists who spent decades misrepresenting Tyrannosaurus rex as an upright, lumbering Godzilla-esque beast. That Garwood and colleagues could pull this from a fossil is awesome, which still does nothing to change the fact that how arachnids walk is super creepy.

H/T io9

Les arachnides de Belgique / por Léon Becker

Smithsonian Libraries
Also available online.


ENT copy 39088007472699 has ptie 2,3 and plates bound together.

ENT copy 39088007472715 has ptie. 1. and ptie. 1, plates, bound together.

[Iconographie des crustacés et des arachnides de l'Égypte / par J.-Cés. Sauvigny]

Smithsonian Libraries
Extracted from: France. Commission des sciences et arts d'Égypte. Description de l'Égypte. Histoire naturelle. Atlas.

Title written in pencil on front free endpaper. DSI

Each plate is printed on double leaves.

Each plate has a range of dates engraved at the bottom, e.g. "Dessiné et gravé en 1805-1812."

Also available online.

SCNHRB copy 39088009225178 has stamp: Library, Division of Crustacea.

SCNHRB copy has a handwritten list ([3] p.) of the plates, with the names of the species depicted on them, tipped in at the front of the volume.

SCNHRB copy has photocopies of 4 articles related to this work inserted in a pocket at the end of the volume. The articles include: 1. Sherborn, C. Davies. "On the dates of the natural history portion of Savigny's 'Description de l'Égypte," from Proc. Zool. Soc. London (1897), p. 285-288; 2. Dr. H. G. Bronns Klassen und Ordnungen des Tierreichs, fünfter Bd., I. Abt., 7. Buch (Decapoda), p. 1926, 2019; 3. Stebbings, G. "Report on the scientific results of the voyage of H.M.S. Challenger ... 1873-76," Zoology, v. 29, p. 127, 120; 4. Audouin, Victor. Explication sommaire des planches des crustacés de l'Égypte et de la Syrie, [2], 79-98 p.

SCNHRB copy has later red buckram library binding with gilt-lettered spine.


Jumping Spiders Are the Only Arachnids Known to Provide ‘Milk’ For Their Young

Smithsonian Magazine

The southeast Asian jumping spider, or Toxeus magnus, is unusual in more ways than one. Not only does it bear a striking resemblance to a long-legged ant, but it also appears to be the only arachnid known to “milk” its young—an unprecedented behavior newly published in the journal Science.

In this case, “milk” is worth writing in quotation marks because the sugar-, fat- and protein-filled droplets produced by jumping spider mothers don’t technically meet the parameters of the word—containing lactose produced by mammary glands—as it’s used in relation to mammals. Still, Ben Guarino writes for The Washington Post, the fluid fulfills the basic purpose of milk: offering nourishment to offspring via what Sasha Dall, a University of Exeter biologist who was not involved in the research, describes as “some aspect of yourself.”

Lead author Zhanqi Chen of the Chinese Academy of Sciences launched the study after noticing the jumping spider’s odd communal tendencies. Most spiders are solitary creatures, The Atlantic’s Ed Yong notes, but T. magnus cluster in family groups, with young spiderlings staying in their mothers’ nests for an extended period of time.

To better understand this unusual behavior, Chen and his colleagues reared jumping spiders in the lab and tracked how long it took babies to leave the nest. Surprisingly, neither newborns nor mothers ventured beyond the nest in search of food for 20 days, leading the scientists to wonder how the vulnerable young arachnids managed to not only survive, but significantly grow in size.

Upon closer inspection, the team observed the mother transferring drops of a sustaining liquid (later revealed to contain four times the protein of cow’s milk) from her abdominal epigastric furrow to the nest during the first week post-birth. Once the one-week mark passed, spiderlings drank fluid directly from the mother’s body, crowding around in a manner eerily similar to suckling puppies.

According to The New York Times’ Douglas Quenqua, T. magnus moms even produced the milk-like fluid after their roughly 20-day-old offspring began leaving the nest to forage for food. Suckling only stopped when the babies reached 40 days old, at which point they gained a bit of independence but still returned to the nest for the night.

The baby spiders crowd around their mother in a manner similar to that of suckling puppies (Rui-Chang Quan)

Interestingly enough, Jason G. Goldman reports for National Geographic, only females were permitted to continue nursing beyond sexual maturity. Males received the short end of the stick; Motherboard’s Becky Ferreira says the mothers actually attacked their adult sons and chased them out of the nest, perhaps to prevent inbreeding between brothers and sisters. Given their newfound ability to forage for food, this exclusion didn’t necessarily doom them to an early death.

The scientists ran through multiple scenarios to better assess the importance of jumping spider milk production, alternately blocking the mothers’ epigastric furrows by covering them with Wite-Out and preventing mothers from nursing beyond day 20.

Spiders that only received milk for the first 20 days of their lives—but still benefitted from the presence of a maternal figure beyond this point—emerged with fewer parasites than those who lost both milk and mothers at the 20-day mark.

Of 187 spiderlings spread out across 19 nests, those that enjoyed both maternal care and a consistent diet of milk exhibited a survival rate of 76 percent. Survival amongst those who lost their mothers after 20 days dropped to about 50 percent.

Jumping spiders are far from the only non-mammals known to produce a milk-like nutritious substance. As Ryan F. Mandelbaum explains for Gizmodo that cockroaches, pigeons, tsetse flies and earwigs have all been observed engaging in the mammalian practice. The key difference, according to The Post’s Guarino, is that mammals possess a specialized organ designed for lactation. So far, researchers have not identified an equivalent gland in non-mammals.

Chen tells The Atlantic’s Yong that he and his colleagues “have no idea” why the unusual practice evolved amongst jumping spiders specifically. He proposes, however, that the sustenance boost equips the tiny arachnids , which measure just a millimeter long, for life in a competitive, predator-filled environment.

Some scientists still have questions surrounding the discovery: Joshua Benoit of the University of Cincinnati was not involved in the study, but he tells Gizmodo that it’s unclear whether jumping spiders would return to their mothers beyond the 20-day mark in the wild. Nathan Morehouse, another Cincinnati scientist not involved in the study, adds that the new research doesn’t account for why the spiders nurse for so long or why other arachnid species don’t produce milk.

For now, these queries remain unanswered. But given the revelatory nature of the study, it’s likely that follow-up research will join the mix soon.

As Chen concludes in a statement, "We anticipate that our findings will encourage a reevaluation of the evolution of lactation and extended parental care and their occurrences across the animal kingdom."

Coxal glands of the arachnids, by B.H. Buxton. With 43 plates, a frontispiece and 7 figures in the text

Smithsonian Libraries
Cover title.

Also available online.


Extrait recherches zoologiques dans les serres du Muséum de Paris : E. André, Formicides : E. Simon, Arachnides : A. Dollfus, Crustacés isopodes terrestres : Dautzenberg, Mollusques : Chevreux, Amphipodes

Smithsonian Libraries
Title and imprint from cover.

Extrait from La Feuille des jeunes naturalistes, revue mensuelle d'histoire naturelle, 1er avril 1896, 3rd série, no. 306.

INVZ copy mq1523517 is no. 9 in a vol. with binder's title: Amphipodes, mélanges. Bound together subsequent to publication. DSI

Also available online.


Considérations générales sur l'ordre naturel des animaux composant les classes des crustacés, des arachnides, et des insectes : avec un tableau méthodique de leurs genres, disposés en familles / par P.A. Latreille

Smithsonian Libraries
Also available online.


SCNHRB copy (39088013487145) has stamped on half title: Invertebrate Zoology, Crustacea; on t.p.: Smithsonian Institution National Museum; acc. no stamps: 419632; 158552.

SCNHRB copy has pencilled acc. no., 419632, on half title.

SCNHRB copy has ms. note on front free endpaper: Re-bound 1942. Bound in brown library buckram, title in gilt on spine, stamped at foot: U.S.N.M.; marbled edges and endpapers.

Histoire naturelle des crustacés, des arachnides et des myriapodes / par M. Lucas ; ouvrage accompagné de 46 planches gravées sur acier représentant plus de 300 sujets

Smithsonian Libraries
"Paris.--Imprimerie de Terzuolo ..." -- Verso of series t.p.

Text printed in double columns.

For tomes 1-2 of this series see Castelnau, Francis, comte de. Histoire naturelle des insectes, coléoptères. For tome 3 see Blanchard, Émile. Histoire naturelles des insectes; orthoptères, etc.

Nissen, C. Zoologische Buchillustration, Bd. 1, no. 2579; also no. 838

BM (Nat. hist.), v. 3, p. 1188

Also available online.

SCNHRB has three copies.

SCNHRB c. 1 (39088015703549) stamped on series t.p. and t.p.: Maurice Dalibert ... Caen.

SCNHRB c. 1 stamped on verso of t.p.: Smithsonian Institution U.S. National Museum [acc. no.] 338835.

SCNHRB c. 1 bound in brown library buckram, title in gilt on spine.

SCNHRB c. 2 has stamps: Division Marine Invertebrates, carded Aug. 1956; Invertebrate Zoology, Crustacea; Smithsonian Library, July 19, 1956.

SCNHRB c. 2 (39088015703580) is bound in a color-printed paperboard binding for Oeuvres complètes de Buffon, t. 1, issued by the same publisher (Duménil); however, there is no apparent bibliographical link between the two works and the binding appears to have been applied to this copy by mistake.

SCNHRB c. 3 (39088015703622) has all plates bound-in at end, with one additonal plate.

SCNHRB c. 3 quarter bound in purple cloth and marbled paper boards, title in gilt on spine.


Les crustacés, les arachnides et les insectes : distribués en familles naturelles : ouvrage formant les tomes 4 et 5 de celui de M. le baron Cuvier sur Le règne animal (deuxième édition) / par M. Latreille

Smithsonian Libraries
"Imprimerie d'Hippolyte Tilliard"--Verso of half title.

Also available online.

SCNHRB copy (39088013486873, 39088013486915) stamped on verso of t.p.'s: Smithsonian Institution National Museum Apr 15 1948 [acc. no.] 336896 [&] 336850.

SCNHRB copy bound in blue library buckram, title in gilt on spine, marbled edges.


The animal kingdom arranged in conformity with its organization / by the Baron Cuvier ; the Crustacea, Arachnides and Insecta, by P.A. Latreille ; translated from the French, with notes and additions, by H. M'Murtrie ; in four volumes, with plates

Smithsonian Libraries
Translation of part of Le règne animal.

"Philadelphia: Printed by James Kay, Jun. & Co. printers to the American Philosophical Society"--Verso of t.p.

Plates signed: Laurillard del., Tucker sct.

Errata: v. 4, p. [546].

Also available online.


SCNHRB has four copies, copies 3 & 4 are incomplete.

SCNHRB c. 1 has bookplate of G. Brown Goode, U.S. National Museum.

SCNHRB c. 1 inscribed in different inks on t.p.'s: Presented to O.T. Mason by Joseph Libbey; Henry R. Schoolcraft; [on v. 1 t.p. only]: Presented to Mr. G. Brown Goode by his friend & admirer O.T. Mason.

SCNHRB c. 1 blind-embossed on t.p.'s: Smithsonian Institution National Museum [acc. no.] 290995-290998.

SCNHRB c. 1 bound in blue library buckram, title in gilt on spine, marbled edges.

SCNHRB c. 2 lacking pl. III in v. 3 and pl. II & III in v. 4.

SCNHRB c. 2 stamped at head of t.p.: S.F. Baird.

SCNHRB c. 2 stamped on t.p.: Library, U.S. National Museum Smithsonian Institution Feb 14 1882 [ms. acc. no.] 124677, 124518-124520.

SCNHRB c. 2 inscribed in ink on last leaf of v. 1: Henry McElfresh February 22, 1848.

SCNHRB c. 2 bound in black library buckram, title in gilt on spine.

SCNHRB c. 3 lacking v. 1.

SCNHRB c. 3, v. 2 inscribed in ink on original front free endpaper: Henry McElfresh February 22, 1848.

SCNHRB c. 3 blind-embossed on t.p.'s: Smithsonian Institution National Museum [ms. acc. no.] 206885.

SCNHRB c. 3 bound in black library buckram, title in gilt on spine.

SCNHRB c. 4 has v. 2 only.

SCNHRB c. 4 bound in brown library buckram, title in gilt on spine.

The animal kingdom, arranged according to its organization, serving as a foundation for the natural history of animals : and an introduction to comparative anatomy / by Baron Cuvier ; with figures designed after nature: the Crustacea, Arachnides, & Insecta, by M. Latreille ; translated from the latest French edition ; with additional notes, and illustrated by nearly 500 additional plates ; in four volumes

Smithsonian Libraries
The plates, except a few portraits, have been bound separately.

Added title pages, engraved, with imprint date of 1834. Atlas vols. has engraved title pages only, with imprint date of 1837.

Translated by Henry MacMurtrie--Cf. Brit. Mus. cat. New ed.

Vol. 1, p. 197-204 repeated in numbering, with an *.

Includes biographical sketches and portraits of Cuvier, J.J. Audubon, Linnaeus, G.L. Buffon, P.A. Latreille, William Spence, and William Kirby.

Some of the plates hand-colored.

Also available online.


SCNHRB has two copies, one incomplete.

SCNHRB c. 1 stamped on t.p.'s: Smithsonian Institution National Museum [acc. no.] 290773-290776.

SCNHRB c. 1 bound in black library buckram, title in gilt on spine.

SCNHRB c. 2 consists of v. 4, text & plates, only.

SCNHRB c. 2 bound in black library buckram, title in white on spine.

Deadly Tricks of Spiders Without Webs

Smithsonian Environmental Research Center
by Kristen Minogue There’s a reason cobwebs make popular Halloween decorations. Spiders rival with snakes, birds and clowns for the most feared creatures in the animal kingdom. But some of nature’s creepiest arachnids don’t build webs at all. They ambush their prey in much more beguiling settings. Like flowers. That’s a favorite haunt of the crab spider, […]

Bug Bites: Scorpion Lobster Frittata

Smithsonian Channel
Adventurous eaters will want to sink their teeth into chef Joseph Yoon's shockingly tasty arachnid omelet. From the Series: Bug Bites: Scorpion Lobster Frittata

Incredible: This Underwater Spider Has an Actual Scuba Tank

Smithsonian Channel
The scuba spider is the only arachnid to live exclusively underwater, despite lacking gills. Its secret, like its name suggests, is a makeshift oxygen supply. From: CRAZY MONSTERS: Spiders

What is an Arthropod?

Smithsonian Education
Dan Babbitt, manager of the Smithsonian’s Insect Zoo, shows why the name of the zoo is a little imprecise. The Insect Zoo is home to all five major groups of arthropods—insects, arachnids, crustaceans, millipedes, and centipedes—all of which Babbitt defines.

Picture of the Week — Ancient Spider in 3-D

Smithsonian Magazine

Eophrynus prestivicii (left) and Cryptomartus hindi are species of spiders that lived about 300 million years ago. Discovering the details of their biology from fossils isn't easy, especially since these arachnids were only about an inch long. So scientists from England and Germany took more than 3000 X-ray images of each fossilized spider with a CT scanning device and created 3-D computer models of the ancient arachnids.

The models revealed details that couldn't be seen from gazing at the fossils: E. prestivicii (first video below), which had long legs that could have enabled it to run and chase its prey, had defensive spikes on its back. The scientists say the spikes might have helped protect the spider from amphibian predators.

The way in which the two sets of front legs of C. hindi angle toward the front has led the scientists to think that this species might have been an ambush predator. C. hindi also had mouth appendages called pedipalps, which are present in some rare species of modern spiders and help them to manipulate prey.

All images courtesy of the Natural History Museum and Imperial College London.

How One Brave Spider Floated Thousands of Miles to Colonize a New Continent

Smithsonian Magazine

Some baby spiders can float for tens or even hundreds of miles, buoyed by strips of silk and carried aloft by the wind. But even for these resourceful youngsters, making a journey of more than 6,000 miles across choppy ocean sounds fairly improbable. That’s why researchers have long assumed that one genus of spider found in both Africa and Australia must have ended up on both continents tens of millions of years ago, as supercontinent Gondwana slowly cleaved apart.

A new genetic analysis challenges that scenario, however. Remarkably, scientists now argue that these arachnids actually made the pilgrimmage via makeshift rafts, long after the modern continents had been established. 

"While their survival of such a journey may be difficult to picture, these spiders may be actually better suited to dispersal via rafting than we’d initially think," says Sophie Harrison, a biologist at Australia’s University of Adelaide, of the Australian species Moggridgea rainbowi. The trait could make these inch-long arachnids such effective ocean voyagers is described in the name of their taxonomic family: trapdoor spiders.

Like many arachnids, trapdoor spiders make burrows to hide and rest in. But they also augment their burrows with a hatch that can be pulled tightly shut (hence the name). Within that sealed burrow, which is usually lined with silk, the spider enjoys a comfortable, relatively climate-controlled environment, Harrison said. Furthermore, trapdoor spiders have relatively slow metabolisms, meaning it's feasible that they could survive an extended ocean journey.

"In some ways, they are better suited to this type of dispersal than other species which have undergone transoceanic dispersal via rafting," says Harrison, whose findings were published today in the journal PLOS ONE. Indeed, scientists have found evidence of other spiders taking intercontinental cruises, such as the small arachnids from the genus Amaurobioides, which likely floated on bits of wood or plant from Chile to Africa to Australia. 

Yet Harrison's proposal goes against what most scientists thought about how trapdoor spiders ended up in Australia, not to mention common sense.

Along with many other creatures, it had been thought that these spiders were separated from their companions by the slow breakup of the supercontinent Gondwana as the Earth's tectonics plates shifted. After all, Moggridgea rainbowi hardly shows any wanderlust, often making its own burrow just a few feet away from where it was born. And anyways, how could even the most adventurous spider traverse an ocean?

In 2013, Harrison was researching how armored trapdoor spiders have diversified into different species over time for her PhD. When studying some specimens she had acquired from a wildlife photographer and "trapdoor spider enthusiast" Nick Birks, she and her colleagues noticed that these trapdoor spiders appeared to be very closely related to their African ancestors—more so than one would expect for two species that had split so long ago.

Using genetic analysis of the two species, Harrison found that the two species appeared to have split off from each other in separate evolutionary paths somewhere in the range of 2 to 16 million years ago, long after Gondwana broke up around 100 million years ago.

Clearly, the slow tectonic shift scenario didn’t fit. But that timeline also had the spiders making the voyage long before the first humans arrived in Australia about 65,000 years ago, meaning that they didn’t hitch a ride like so many other species, either. "This left long-distance dispersal as the most plausible option for their method of arrival into Australia," Harrison says.

How this process started is a mystery, but it could have started with burrows of trapdoor spiders being knocked into the ocean by a landslide or uprooting tree, and then being carried by the ocean currents in their snug confines. 

Miquel Arnedo, an evolutionary biologist at the University of Barcelona who has extensively studied the dispersal of species across long distances, questions the precision of some of the calculations used by Harrison's team, noting that he would have liked to see alternate methods of estimating the rate of genetic mutation . However, even accounting for the differences that other methods might produce, Arnedo says, the calculations still make it likely that the Gondwana breakup wasn't involved in the journey of these spiders.

Rafting spiders is not unprecedented; in 2014, Arnedo published a genetic study finding that a related species of trapdoor spider, Titanidiops canariensis, rafted its way onto the Canary Islands from mainland Africa. Still, he says that the distances trapdoor spiders would need to cover to make the leap Harrison describes would be astonishing. 

"The evidence presented in this new [study] increased the traveled distance by 100-fold," says Arnedo, who was not involved in Harrison's research, via email. "All in all, I think the evidence presented is compelling."

Encyclopédie méthodique, ou, par ordre de matières / par une société de gens de lettres, de savans et d'artistes ; précédée d'un vocabulaire universel, servant de table pour tout l'ouvrage, ornée des portraits de MM. Diderot & d'Alembert, premiers èditeurs de l'Encyclopédie

Smithsonian Libraries
Text in two columns.

T.p. vignettes.

Each section has separate t.p.

Volumes of plates have title: Tableau encyclopédique et méthodique des trois règne de la nature.

Plates for ptie. 18 and 24 engraved by Deseve, Louvet, Benard, Drouet or Barrow; Deseve also artist.

"Discours préliminaire et plan du dictionnaire des insectes", by Mr. Mauduyt. Plates engraved under the direction of the abbé Bonnaterre.

A new and enlarged edition of Diderot's Encyclopédie, arranged as a system of separate dictionaries; published by Charles Panckoucke, 1782-92, continued by Henri Agasse, 1792-1813, and Mme. la veuve Agasse, 1813-32.

Described in Graesse, Trésor de livres rares et précieux, t. 2, p. 474-477, as being complete in "102 livraisons ou 337 parties, format 166 vol. et demi de texte et 51 parties reformat 6439 pl. in 4⁰."

BM(NH) cat., p. 527-528.

Proc. ZSL, 1893, p. 582-584 & 1899, p. 595.

Graesse, t.2, p. 474-477.

Also available online.

SCHNRB volumes in brown buckram library binding; gilt-stamped spine.

SCHNRB plate volumes (pties. 18 and 24) appear to be folio format with numbers as signatures.

SCHNRB copy has 142 p. of text for ptie. 18 (of plates) bound with plates and text of ptie. 24.

SCHNRB volumes have embossed stamp: Smithsonian Institution National Museum. Partie 18 has stamp: Smithsonian Libraries Feb. 17, 1959.

1-24 of 91 Resources