Tag Archives: Tanya Lewis

World’s Largest Spider Found – Ack!

Goliath encounter: Puppy-sized spider surprises scientist in rainforest

theraphosa4

The South American Goliath birdeater (Theraphosa blondi) is the world’s largest spider, according to Guinness World Records. Its legs can reach up to one foot and it can weight up to 6 oz.. (Piotr Naskrecki)

Piotr Naskrecki was taking a nighttime walk in a rainforest in Guyana, when he heard rustling as if something were creeping underfoot. When he turned on his flashlight, he expected to see a small mammal, such as a possum or a rat.

“When I turned on the light, I couldn’t quite understand what I was seeing,” said Naskrecki, an entomologist and photographer at Harvard University’s Museum of Comparative Zoology.

A moment later, he realized he was looking not at a brown, furry mammal, but an enormous, puppy-size spider.

Known as the South American Goliath birdeater (Theraphosa blondi), the colossal arachnid is the world’s largest spider, according to Guinness World Records. Itsleg span can reach up to a foot (30 centimeters), or about the size of “a child’s forearm,” with a body the size of “a large fist,” Naskrecki told Live Science. And the spider can weigh more than 6 oz., about as much as a young puppy, the scientist wrote on his blog. [See Photos of the Goliath Birdeater Spider]

Some sources say the giant huntsman spider, which has a larger leg span, is bigger than the birdeater. But the huntsman is much more delicate than the hefty birdeater comparing the two would be “like comparing a giraffe to an elephant,” Naskrecki said.

The birdeater’s enormity is evident from the sounds it makes. “Its feet have hardened tips and claws that produce a very distinct, clicking sound, not unlike that of a horse’s hooves hitting the ground,” he wrote, but “not as loud.”

Prickly hairs and 2-inch fangs

When Naskrecki approached the imposing creature in the rainforest, it would rub its hind legs against its abdomen. At first, the scientist thought the behavior was “cute,” he said, but then he realized the spider was sending out a cloud of hairs with microscopic barbs on them. When these hairs get in the eyes or other mucous membranes, they are “extremely painful and itchy,” and can stay there for days, he said. [Creepy-Crawly Gallery: See Spooky Photos of Spiders]

But its prickly hairs aren’t the birdeater’s only line of defense; it also sports a pair of 2-inch-long  fangs. Although the spider’s bite is venomous, it’s not deadly to humans. But it would still be extremely painful, “like driving a nail through your hand,” Naskrecki said.

And the eight-legged beast has a third defense mechanism up its hairy sleeve. The hairs on the front of the spider’s body have tiny hooks and barbs that make a hissing sound when they rub against each other, “sort of like pulling Velcro apart,” Naskrecki said.

Yet despite all that, the spider doesn’t pose a threat to humans. Even if it bites you, “a chicken can probably do more damage,” Naskrecki said.

Bird eater or mostly harmless?

Despite its name, the birdeater doesn’t usually eat birds, although it is certainly capable of killing small mammals. “They will essentially attack anything that they encounter,” Naskrecki said.

The spider hunts in leaf litter on the ground at night, so the chances of it encountering a bird are very small, he said. However, if it found a nest, it could easily kill the parents and the chicks, he said, adding that the spider species has also been known to puncture and drink bird eggs.

The spider will eat frogs and insects, but its main prey is actually earthworms, which come out at night when it’s humid. “Earthworms are very nutritious,” Naskrecki said.

Birdeaters are not very common spiders. “I’ve been working in the tropics in South America for many, many years, and in the last 10 to 15 years, I only ran across the spider three times,” Naskrecki.

After catching the specimen he found in Guyana, which was female, Naskrecki took her back to his lab to study. She’s now deposited in a museum.

 

Leave a comment

Filed under Animals, Humor and Observations

The making of a mysterious Renaissance map

The making of a mysterious Renaissance map

By Tanya Lewis

Published October 25, 2013

LiveScience
  • cartamarina1

    The Carta Marina, made in 1516, relied on detailed knowledge from nautical charts and books. (COURTESY OF THE LIBRARY OF CONGRESS AND THE JAY I KISLAK FOUNDATION.)

NEW YORK –  Not much is known about how Renaissance cartographer Martin Waldseemller created his 1516 “Carta marina” world map, possibly the most up-to-date conception of the world at the time.

But scholar Chet Van Duzer offered a rare peek into Waldseemller’s process Tuesday night (Oct. 22) during a talk here at the New York Public Library.

“A careful analysis of his sources allows us to go inside his workshop in Saint-Di [in France] and essentially watch him at work as he made the Carta marina,” Van Duzer, who is based at the Library of Congress, said in his talk. [See Photos of the Mysterious Carta Marina Map]

Van Duzer and his colleague John Hessler recently published a book on Waldseemller’s works entitled “Seeing the World Anew: The Radical Vision of Martin Waldseemller’s 1507 & 1516 World Maps,” (Levenger Press, 2012).

Waldseemller is best known for his 1507 world map, the first to call the New World “America.” The cartographer began his career, Van Duzer said, by basing his maps on those of the Alexandrine geographer Claudius Ptolemy from the second century A.D. These maps were based on geographic descriptions in books, rather than direct maritime knowledge.

But in making the Carta marina, printed just nine years later, Waldseemller abandoned his older sources in favor of contemporary nautical charts, maps of maritime regions and coastlines that seafaring explorers of the time would have used.

“When he came to create his new monumental world map, the Carta marina, Waldseemller made a choice between these two competing cartographic systems, the Ptolemaic tradition and the nautical chart tradition,” Van Duzer said “and he based his map on nautical charts.”

Waldseemller based the Carta marina‘s coastlines on a nautical chart made by Nicolo de Caverio of Genoa in about 1503. The two maps have similar coastal place names and layouts. For example, the shapes of Greenland, the eastern coast of South America and Africa are nearly identical.

One major difference is that the Carta marina omits a large part of northeast Asia and Japan probably because these regions were relatively unknown to European explorers, Van Duzer said.

Unlike the Caverio map, Waldseemller’s map is crowded with descriptive texts and illustrations of royal rulers.

The Carta marina depicts King Manuel of Portugal riding a sea monster near the southern tip of Africa, symbolizing Portugal’s control of the sea route between Africa and India. The image was most likely inspired by an image of Neptune riding a sea monster in Italian printmaker Jacopo de Barbaris print of Venice, Van Duzer said.

The map also includes an image of Noah’s Ark resting in the mountains of Armenia, probably based on similar images in other nautical charts of the time, Van Duzer said.

The Carta marina depicts India as a land of animalistic people and barbarism. For instance, there’s an image of “suttee,” the Hindu practice of a widow burning herself to death on the funeral pyre of her husband. Other less well-known areas, such as America, contain images of cannibalism.

Despite these seemingly outdated images, the Carta marina still represents a leap forward in cartography, because Waldseemller relied on much more updated sources than he did for his earlier 1507 map. In addition to nautical charts, Van Duzer’s analysis reveals, the Renaissance cartographer relied on books written by recent explorers.

“The Carta marina is Waldseemllers most original creation,” Van Duzer said. “He began his cartographic career by redrawing Ptolemy, but ended it by creating something entirely new, a mosaic image of the world with each stone of his own careful choosing.”

2 Comments

Filed under Humor and Observations