Arthropleura - The Largest Arthropod That Ever Existed / Documentary (English/HD)

Can you possibly imagine an era when gigantic sized arthropods roamed and ruled the earth? You don’t have to imagine that hard, meet Arthropleura: the largest known invertebrate to have lived on land! Growing to such gigantic size and amassing such tremendous weight, it is perhaps a blessing that it has gone into extinction. Several fossils of this creepy behemoth have been found in several parts of the world. However, there has never been any complete fossil. Arthropleura was first discovered in 1854 by Jordan and Meyer. Its name — “Arthropleura” is a Greek word which literally means “Jointed ribs”. It is an ancient ancestor of modern day millipedes and centipedes. It is believed to be most closely related to modern day Penicillata; which is a group of arthropods that includes several tiny bristle millipedes (polyxenus) which are predominantly found in dry habitats of the eastern parts of North America. The name Jointed Ribs is particularly descriptive of this arthropod because it has a very long body that is composed of as many as 30 jointed segments. Given these numerous jointed segments, an Arthropleura is estimated to have measured between 8 to 10 feet (about 2.5 to 3 meters) long! In fact, some researchers believe that there might have been larger specimens since no complete fossil has ever been discovered! Millions of years ago, there existed a super-continent called Laurasia. Due to several factors and particularly the shift in tectonic plates, this continent broke into two giving us what we call Europe and North America. That’s where Arthropleura lived. As a result, Arthropleura lived in Europe and North America especially in areas such as Scotland, Germany, North America, and North-eastern part of the U.S. where several fossils have been discovered. It lived during the Carboniferous Era and the Permian Era which is about 345 to 295 million years ago! The Carboniferous period was a time in earth’s history in which the earth had about 50% more oxygen than it does today. The presence of this higher oxygen ratio in the atmosphere was what made these arthropods to get so big and long. Researchers are still not sure about the diet of Arthropleura. While earlier research suggests that Arthropleura might have been an omnivore or a carnivore, more recent research affirms that they must have been herbivores and didn’t hunt other animals. Otto Kraus, a German researcher and expert on present day millipede studied the contents of the gut of a sample discovered in Scotland and was convinced that Arthropleuras were herbivores. The content of the sample’s gut contained fossils of ancient fern-like plants and fossilized pollens. Some other researchers believe that juvenile Arthropleura might have been a carnivore, learning to digest plant matter and switching to a herbivorous diet only upon attainment of adulthood. The reason why there are divergent opinions with regard to its diet is that there have never been found fossils of its mouth part. This is also while many believe it was a herbivore since non-fossilization of its mouth suggests that the mouth was made of soft matter which wouldn’t have been the case for a carnivorous animal. Arthropleura is therefore thought to be one of the first herbivorous animals to have ever walked the earth! But as mentioned, it’s still possible that Arthropleura was carnivorous. Given the Carboniferous period in which it existed, its armor plates which are surprisingly thinner than expected, its lengthy size, venomous stingers, and a relatively aggressive attitude, the Arthropleura is believed to have had no natural predators — not even humans! Though Arthropleura shared its environment with other large animals such as Meganeura which had wings longer than 2 feet (60 cm), it nonetheless had nothing to fear as no other animal would dare prey on it. Though it was completely blind, it however, had a good sense of smell and touch through the use of its antennae. While some researchers believe that it also had a thin, long, metallic-looking tube located behind its mandibles through which it can inject venom, some other researchers argue that it may have been non-venomous. From the research of Otto Kraus and an expert on ancient arthropods — Carsten Brauckmann, they believe that the armor of the Arthropleura is relatively thin which is partly why they believe this arthropod had nothing to fear. It even had a soft underbelly which it would often expose when it rears itself up in response to an intrusion or challenge. It is unfortunate that it became extinct about 290 million years ago. It probably became extinct due to climatic change as the earth became drier and hotter than its preferred cool, wet habitat. Narrator: Larry G. Jones