What is the largest arachnid that has ever lived? -

The term “arachnids” probably conjures up visions of spiders: from creepy, creepy things spinning silently from webs in the corner of the room to large, hairy creatures with fangs – like the mythical Shelob or Aragog – stalking you in the dark. . But just how big (and fierce) can these arachnids get? Better yet, who was the greatest to have ever lived?

Answering this question is deceptively simple. Arachnids are eight-legged arthropods, which means that this group contains not only spiders but also scorpions and ticks among others, much smaller and rarer groups. Of these, spiders are the most diverse group of arachnids (the 50,000th species was recently discovered, and this number should increase). The problem is that exactly what counts as an arachnid is a bit of an open question.

Arachnids are part of a larger group of arthropods called chelicerae. The chelicerae are subdivided into smaller groups, with the arachnids being one group and the horseshoe crabs (in the order Xiphosura) and sea scorpions (Eurypterida) being separate but related to the arachnids.

According to Russell Bicknell, a paleontologist at the University of New England in Australia, this is the traditionally accepted phylogeny. But one paper came out recently that suggested that was wrong, and suggested that horseshoe crabs and sea scorpions actually nest in arachnids.”

Related: Why do Cambrian creatures look so weird? The Eurypterids, shown here in this illustration, were the largest species of arachnid to ever live, rivaling humans in size.

The Eurypterids, shown here in this illustration, were the largest species of arachnid to ever live, rivaling humans in size. (Image credit: estt/Getty Images)

Thomas Hegna, assistant professor of paleontology at the State University of New York (SUNY) in Fredonia, who was not involved in the new study, told Live Science in an email that the new phylogeny, based on molecular analysis, implies some terrestrial chelicerae groups (spiders and scorpions) predated marine groups (horseshoe crabs and sea scorpions). However, despite the fact that this claim is well supported by genetic evidence, it is inconsistent with the fossil record.

This may sound like paleontological pedantry, but it actually makes a huge difference when it comes to determining the largest arachnid of all time.

According to the traditional view of the arachnid family tree (ignoring horseshoe crabs and sea scorpions), the largest living arachnid is probably a spider.

There are two spiders that make great contenders for the title of “World’s Largest Spider”. The largest known spider by mass is the Goliath Bird Eater (Theraphosa blondi)a 6-ounce (170-gram) spider whose body can reach up to 5 inches (12 centimeters) in length, a number that reaches 11 inches (28 cm) when its legs are included, according to the American Association for the Advancement of science (AAAS).

If one is to judge the size of a spider instead by the diameter of its leg span, then the largest spider could very well be the giant hunter spider (Maxima heteropodslisten)), which has a leg span of about 1 foot (30 cm) in diameter, making it about the size of a dinner plate. Despite its size, this spider was only discovered in 2001.

When we delve into the fossil record, we find that the largest arachnid of all time was probably not a spider, but a scorpion. Brontoscorpion anglicus was a scorpion that lived during the Silurian-Devonian era (between 350 million and 450 million years ago) and reached lengths of almost 3 feet (1 m) long – five times longer than the longest living scorpion today. However, the caveat here is that the only example of this species was described from a single fossilized finger, so the true size of the animal is an educated guess.

Related: Is each spider web unique?

These animals are the largest known arachnids, both living and extinct, as arachnids are traditionally defined. But if sea scorpions and the horseshoe crab are indeed considered arachnids, as new research might suggest, then the largest living arachnid is no longer a spider, but rather a horseshoe crab.

The largest living species of horseshoe crab, Tachypleus tridentatus, could reach 31 inches (79.5 cm) in diameter.

The largest living species of horseshoe crab, Tachypleus tridentatus, could reach 31 inches (79.5 cm) in diameter. (Image credit: Jaap Bleijenberg / Alamy)

The largest living species of horseshoe crab surpasses the largest living spiders. Tachypleus tridentatus, the largest of this group, can reach heights of 31 inches (79.5 cm) and weigh up to 9 pounds (4 kilograms), according to a 2017 study published in the Asia-Pacific Biodiversity Journal.

As for the largest species of all time, the title would likely go to a member of the now-extinct sea scorpions, a group scientifically known as the eurypterids. Fossils suggest that many of these ancient marine predators even rival humans in size.

The largest species in this group was Jaekelopterus rhenaniae, a species discovered in 2007 that had claws up to 18 inches (46 cm) long. From the claws, researchers estimated that its body was about 8 feet (2.5 m) long, making it not only the largest potential arachnid, but the largest member of the entire group that contains spiders. arachnids, chelicerae.

Originally posted on Live Science.

#largest #arachnid #lived

Please follow and like us:

Time may not exist – but that’s okay

Byadmin April 24, 2022

Does time exist? The answer to this question may seem obvious: of course it is! Just look at a calendar or a clock. But developments in physics suggest that the non-existence of time is an open possibility, and one that we should take seriously. How is that possible, and what would that mean? It will…

Science

Scientists model the surface of Titan, Saturn’s largest moon

Byadmin April 26, 2022

Saturn’s largest moon, Titan, is surprisingly similar to Earth in landscape formations, according to new models produced by planetary scientists. Seen from space, the moon, larger than the planet Mercury, has other similarities to Earth – including rain-filled rivers, lakes and seas – although on Titan rain is liquid methane , falling through nitrogen winds….

Science

Here’s why hibernation in space might not be possible for humans after all

Byadmin April 30, 2022

Sending humans virtually anywhere in space beyond the Moon pushes the logistics of health, food, and psychology to limits we are only beginning to grasp. A basic solution to these problems in science fiction is to simply put Void Travelers to bed for a while. In a state of sleep close to hibernation or torpor,…

Science

These meteorites contain all the building blocks of DNA

Byadmin April 28, 2022April 29, 2022

Three meteorites contain the molecular building blocks of DNA and its cousin RNA, scientists have recently discovered. A subset of these building blocks had previously been detected in meteorites, but the rest of the collection seemed mysteriously absent from space rocks – until now. The new discovery supports the idea that around four billion years…

Science

Why hugs are so nice: Scientists discover a circuit that transmits a “nice touch” to the brain

Byadmin April 28, 2022

Hugs, holding hands and stroking give us a psychological boost that is known to be important for emotional well-being and healthy development. But until now, it was not known why we derive pleasure from this kind of touch. Today, researchers at Washington University School of Medicine in St. Louis have identified a neural circuit that…

Science

Zero-index metamaterials offer new insights into the foundations of quantum mechanics

Byadmin April 27, 2022

An illustration of a near-zero index metamaterial shows that as light passes through, it travels in a constant phase. Credit: Second Bay Studios/Harvard SEAS In physics, as in life, it’s always good to see things from different angles. Since the beginning of quantum physics, the way light travels and interacts with the matter around it…

Cookie	Duration	Description
cookielawinfo-checkbox-analytics	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional	11 months	The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
viewed_cookie_policy	11 months	The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.

Similar Posts

Leave a Reply Cancel reply

Follow Us