Section through an octopus shows the mouth passing through the brain

Octopuses and other cephalopods are well-known for their exceptional intelligence and complex brains, which appear to outstrip all other invertebrates’. But, they work within one strange constraint – like all other molluscs (snails, slugs, oysters and more), the nerve ring at the centre of their nervous system encircles the oesophagus. In cephalopods, this nerve ring…

#wormwednesday: Scale worm jaws reveal cannibalistic habits

  Most worms seem pretty harmless – no one ever worries about a nasty bite from an earthworm. But they’re not all so benign. Many species of polychaetes have fearsome jaws that they use to feed on unsuspecting prey – including other worms. These alien-looking gnashers are formed from strengthened collagen and can extend all…

Flamingo skull shows adaptations to life feeding upside down

The skull of the flamingo shows several fascinating adaptations for its use in feeding. Flamingos, of course, feed with their heads upside down in water, filtering it for small prey items. Accordingly they have some interesting structural features which differ from other birds – the lower bill is larger and stronger than the upper bill,…

Skull of a python: can snakes hear through their jaws?

The vertebrate ear tends to have three parts: the outer, middle and inner ear. Snakes have greatly reduced outer and middle ears, yet with just the inner ear and one remaining part of the middle ear they are able to hear. The middle ear ossicle has become connected to the jaw, suggesting that vibrations of…

Chiton radula (Chaetopleura articulata) capped with magnetite

Most molluscs (slugs, snails and many shellfish) use a radula to scrape algae and other food from the surface of rocks and shells. It’s a large, complex structure which resembles a giant alien tongue with many rows of teeth, and can be more than half the length of the whole animal! But chitons have an even more…