Arthropleura

Arthropleura Temporal range: Upper Carboniferous to Earliest Permian
File:Arthropleura model FMNH.jpg
A model of Arthropleura at the Field Museum in Chicago.
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Myriapoda?
Class:	Arthropleuridea
Order:	Arthropleurida
Family:	Arthropleuridae
Genus:	Arthropleura

Arthropleura was a 0.3–2.6 metre (1–8.5 feet) long relative of centipedes and millipedes, native to the Upper Carboniferous (340-280 million years ago) of Nova Scotia, the United States (Illinois, Ohio and Pennsylvania) and Scotland. It was the largest known land invertebrate of all time, and would have had few predators.

What Arthropleura ate is a matter of debate among scientists, as none of the fossils have the mouth preserved. However, it is reasonably certain that it would have had a sharp and powerful set of jaws. Based on this assumption, it used to be thought that Arthropleura was carnivorous, but recently discovered fossils have been found with pollen in the gut, suggesting that the creature ate plants. It is possible that the smaller Arthropleura species were vegetarian, while the largest ones were omnivorous, using their jaws to tackle vegetation, as well as to hunt small animals and insects. It is estimated that the average Arthropleura could have eaten its way through a ton of vegetation a year.

Fossilized footprints from Arthropleura have been found in many places. These appear as long, parallel rows of small prints, which show that it moved quickly across the forest floor, swerving to avoid obstacles, such as trees and rocks. When moving at speed, its body would stretch and become longer, giving it a greater stride length and thus allowing it to move faster.

As it moved about, Arthropleura would have brushed against many different type of plant, and may have helped the forest reproduce by moving pollen or spores about the place. It is also thought that Arthropleura was capable of travelling under water, and that it may have returned to lakes and rivers in order to moult its shell. This would have made it vulnerable to attack by large fish and amphibians. On land an adult Arthropleura would have had few enemies.

Arthropleura evolved from crustacean-like ancestors in the Carboniferous, and was able to grow larger than modern arthropods, partly because of the high percentage of oxygen in Earth's atmosphere at that time, and because of the lack of large terrestrial vertebrate predators. Fossil tracks of an arthropod date back to the Silurian are sometimes attributed to either Arthropleura, or a Silurian to Early Devonian millipede called Eoarthropleura. Arthropleura became extinct at the start of the Permian period, when the moist climate began drying out, destroying the rainforests of the Carboniferous, and allowing the desertification characteristic of the Permian. Because of this, oxygen levels in the atmosphere began to decline to more modest levels. None of the giant arthropods could survive the new dry, lower-oxygen climate.

Like its descendants, Arthropleura was a herbivore, and was covered in a thick tough armour-like skeleton. Even though it was not a carnivore, it had a very powerful bite.

Species of Arthropleura include:

• Arthropleura armata Jordan & Mayer 
• Arthropleura moyseyii : fossils at Bickershaw, Lancashire, UK

Its tracks have the ichnotaxon name Diplichnites cuithensis  and have also been found in the Cutler Group in El Cobre Canyon, New Mexico, U.S.

In popular culture

File:Arthropleura.jpg

Arthropleura (right) depicted fighting a Proterogyrinus in Walking With Monsters

Arthropleura was featured in the BBC series Walking With Monsters (2005) as well as in Prehistoric Park (2006). It was also used as the central time-shifted creature in the second episode of the ITV series Primeval (2007), although the production increased the Arthropleura to six meters in length, and gave it a venomous bite.

External links

• "Arthropleuridea". University of Maryland Department of Entomology.
• [1] "Exceptionally preserved fossils from Bickershaw, Lancashire UK (Upper Carboniferous, Westphalian A (Langsettian))"
• [2] Arthropleura tracks found at Crail, Fife in Scotland.

References

• 2005: BBC Television Series Walking with Monsters by Tim Haines
• 2006: ITV Television Series Prehistoric Park Episode 5
• 2006: The Complete Guide to Prehistoric Life. Pg. 37. Canada: Firefly Books Ltd.
• 2007: ITV Television Series Primeval Episode 2 by Impossible Pictures