Comment by throwaway173738
3 months ago
I read somewhere that the first invertebrate animal ate and excreted through the same butthole-shaped oriface.
3 months ago
I read somewhere that the first invertebrate animal ate and excreted through the same butthole-shaped oriface.
Some still do: it's called a gastrovascular cavity, and is present in marine invertebrates such as Cnidaria (jellyfish, coral polyps, anemones), Ctenophores (comb jellies); Platyhelminthes (flatworms, tapeworms).
Yeah, I learnt about this from the amazing Max Bennett book: A brief history of intelligence.