The fossil spider's body length is 1.65 centimeters, and its first leg length is 5.82 centimeters. "It's the largest fossil spider—and great to have both male and female," says Paul Selden. (Credit: U. Kansas)

This is the biggest fossil spider ever found

Jurassic spider fossils used to be extremely rare finds. The first was discovered in Russia and described in 1984—another was found three years later. But that remained the totality of the fossil record.

Then, in the twenty-first century, farmers in the area of Daohugou, China—just inside Inner Mongolia—began turning up Jurassic-period arachnids on a hillside. Because of the proliferation of these Chinese discoveries, these days a few hundred specimens are known to science.

“Village farmers dig pits to extract the fossils, which are mainly insects and the occasional spider or other animal, and experts from the university in Beijing travel there, usually during the New Year holiday, and sort through the finds,” says Paul Selden, professor of invertebrate paleontology with the department of geology at the University of Kansas.

Selden is part of a team that recently described the largest-known fossil spider ever unearthed. They report their findings in the latest issue of Naturwissenschaften.

(Credit: U. Kansas)
(Credit: U. Kansas)

This specimen’s body length is 1.65 centimeters, and its first leg length is 5.82 centimeters.

Part of the family?

“It’s unique because it’s intermediate between the more primitive kinds of the araneomorph, or ‘true’ spiders, and the well-known orbweavers that we see around us commonly today,” Selden says. “While it’s the largest known fossil spider, it’s not the largest spider, which is a Brazilian tarantula.”

The giant fossil spider is considered to be the male version of a female spider found a short time ago in the same locality, called Nephila jurassica. But because some of its physical characteristics are different from the Nephila genus, the latest discovery has spawned an entirely new scientific name.

“Because the male shows features that are not consistent with the placement of the species in Nephila or, indeed, the family Nephilidae, the species was given a new genus name and a new family erected to accommodate the new genus,” says Selden, who also serves as the Paleontological Institute’s director at the university’s Biodiversity Institute.

Tiny details

As with most fossil spiders, the features needed to precisely place the species among spider families were not sufficiently preserved. Scientists must have an exhaustive look at foot claws, hairs, and genital organs. As luck would have it, the volcanic ash beds at Daohugou are exceptional for preserving such fine details.

“Scanning electron microscopy came to the rescue with some of these features, such as the structure of the hairs, and helped to place the species more accurately,” says Selden. “This is the first time this technique has been used on fossil spiders in the rock.”

Selden says that one of the most interesting aspects of this study is how it relates to work being done in molecular systematics on living spiders. “This research relies on fossils to calibrate the data points and give an idea about when the genes for particular traits evolved,” he says.

“When the female was first placed in Nephila, it seemed to throw the existing family tree out of kilter. My colleagues doing the molecular work hypothesized that N. jurassica was actually a primitive orbweaver. Now, the discovery of the male and this detailed research has corroborated their predictions.”

Clues to the climate

He says that the discovery tells scientists that the abundant insect life in this area during the Middle Jurassic was preyed upon, as today, by large, web-dwelling spiders. Importantly, he says the find helps inform humans about its own future on the planet.

“First, it is an amazing spider,” Selden says. “It’s the largest fossil spider—and great to have both male and female. Second, research into the anatomy reveals details of how it lived and interacted with its insect prey.

“These give clues to what the climate was like at the time, and we can then track the fate of these ecosystems as they evolved through time and changing environments. Understanding the processes involved helps us to predict how manmade changes might affect the Earth’s climates and biodiversity.”

Selden collaborated with Professor Dong Ren of at Capital Normal University.

Source: University of Kansas

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7 Comments

  1. Jbelkin

    Americans have no frame if reference when u use centimeters. This article is meaningless to Americans as we do not use centimeters as a measurement – u might as well use cubits or le …

  2. What

    You can literally just google a conversion in like 2 seconds. Doesn’t mean the entire article is immediately meaningless to all Americans.

  3. Jacob

    The vast majority of the world uses the metric system. Get with the times Jbelkin, USA isn’t the centre of the universe.

  4. James Acton

    You mean Jbelkin, this article is useless to willfully ignorant Americans – like yourself.

    As already stated, the rest of the world uses the metric system. Academics in these fields use the metric system. And by “Americans” I’m sure you mean USA residents… further proving your tiny tiny view of the world.

  5. Babu G. Ranganathan

    NOT MILLIONS OF YEARS OLD! Evolutionary dating methods are not infallible science, are based on certain built-in assumptions, and have been proven to be contradictory and inconsistent. Please read my popular Internet article, ARE FOSSILS REALLY MILLIONS OF YEARS OLD?

    There is absolutely no proof of macro-evolution in the fossil record. The fossils of all species are found complete (not partially-evolved) with no evidence of actual transition from one kind to another. There are no fossils of fish, for example, with part fins, part feet to show that transition occurred from fins to feet. Besides this, partially-evolved species would be unfit for survival while waiting to be completed over millions of years.

    The fossils show that all life came into existence as complete and fully-formed from the beginning, which is only possible by creation.

    Sincerely,
    Babu G. Ranganathan*
    (B.A. Bible/Biology)

    Visit my newest Internet site: THE SCIENCE SUPPORTING CREATION

    Author of the popular Internet article, TRADITIONAL DOCTRINE OF HELL EVOLVED FROM GREEK ROOTS

    *I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I’ve been privileged to be recognized in the 24th edition of Marquis “Who’s Who in The East.”

    NATURAL LIMITS TO EVOLUTION: Only evolution within biological “kinds” is genetically possible (i.e. varieties of dogs, cats, etc.), but not evolution across biological “kinds” (i.e. from sea sponge to human). How could species have survived if their vital tissues, organs, reproductive systems, etc. were still evolving? Survival of the fittest actually would have prevented evolution across biological kinds! A true transitional form would be unfit for survival. For example, “if a leg of a reptile were to evolve (over supposedly millions of years) into a wing of a bird, it would become a bad leg long before it became a good wing” (Dr. Walt Brown, scientist and creationist). Survival of the fittest actually would have prevented evolution across biological kinds! Read my Internet article: WAR AMONG EVOLUTIONISTS! (2nd Edition).

    Natural selection doesn’t produce biological traits or variations. It can only “select” from biological variations that are possible and which have survival value. The real issue is what biological variations are possible, not natural selection. Only limited evolution, variations of already existing genes and traits, is possible. Nature is mindless and has no ability to design and program entirely new genes for entirely new traits. Evolutionists believe and hope that, over supposedly millions of years, random genetic mutations caused by environmental radiation will generate entirely new genes. This is total blind and irrational faith on the part of evolutionists. It’s much like believing that randomly changing the sequence of letters in a romance novel, over millions of years, will turn it into a book on astronomy! That’s the kind of blind faith macro-evolutionists have.

    Genetic information, like other forms of information, cannot arise by chance, so it is far more logical to believe that the genetic and biological similarities between species are due to a common Designer (Creator) who designed similar functions for similar purposes in all the various forms of life.

    Visit my latest Internet site: THE SCIENCE SUPPORTING CREATION .

    I discuss: Punctuated Equilibria, “Junk DNA,” genetics, mutations, natural selection, fossils, dinosaur “feathers,” the genetic and biological similarities between various species, etc., etc.

    Babu G. Ranganathan*
    B.A. Bible/Biology

    Author of popular Internet article, TRADITIONAL DOCTRINE OF HELL EVOLVED FROM GREEK ROOTS

    *I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I’ve been privileged to be recognized in the 24th edition of Marquis “Who’s Who in The East” for my writings on religion and science.

  6. Rod

    oh my god “Babu G. Ranganathan” … it seems you really believe what you are writing.

    You are very scary.

  7. Jesus Christ

    Babu G Ranganathan I cant believe you really believe that nonsense. Everybody know religion is the greatest lie ever told. You cant be that stupid. Carbon dating isnt a conspiracy theory dumbshit.

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