22 June 2013

aristotle's lantern

a little while back i found the shell of a green sea urchin washed up on secret beach. it was only a couple of centimetres wide. when i got it home i found it was very smelly and had the dried remains of the urchin inside. i gave it a scrub and then dug out the inside debris with the tip of a needle. most of it had rotted away. to my amazement the last little bit came out with a tiny white seed head-like structure attached. excitedly i ran for my very old observer's book of the sea and seashore and looked up urchins. and there on the page was a picture of this amazing little thing - 'aristotle's lantern' (mouth of sea urchin).

it's absolutely fascinating. it's the chewing organ of the urchin and is composed of 50 skeletal elements worked by 60 muscles. and my one is just tiny - only a centimetre tall. you can read more about it on the natural history museum website here.


  1. Lovely photos, Jo.... It's an amazing structure, isn't it? Thanks for sharing this - reminded me of my days dissecting marine invertebrates and my fascination with the way they are built!

  2. it's seeing things like this that make me feel i'd like to have done marine biology..... rather than fine art. but there are also a million other things i'd like to have studied too. it's stunning isn't it x