Posts Tagged ‘arthropods’

Welcome to part 2 of the Arthropods special, and today I’m giving you a whistle-stop tour of the myriapods. This group includes centipedes and millipedes (as well as a couple of less important relatives), with approximately 12,000 species currently known.

Centipedes and millipedes are common enough if you look through leaf litter or under stones and flowerpots in the garden. What’s the difference between centipedes and millipedes? Well, a common mistake is about the number of legs (i.e. 100 for a centipede and 1000 for a millipede – this isn’t true). The number of legs in a centipede varies between 20 to 300, and in millipedes ranges from 36 to 750.

The easy way to distinguish between a centipede and a millipede is to look for the number of legs per body segment. A centipede has 2 legs per body segment and a millipede has 4 legs per body segment. They also differ in terms of diet – centipedes are active hunters and carnivores whilst millipedes are detritivores (eating decaying leaves).

Centipedes and millipedes are a very successful group, and have been around on the Earth for at least 440 million years. An earlier relative of centipedes and millipedes called Arthropleura lived 300 million years ago and was able to reach lengths of 2.5m. This makes it the largest land invertebrate ever, and could grow this large due to higher concentrations of atmospheric oxygen at the time.

So, here are some interesting photos of centipedes and millipedes from around the world. Enjoy!