A few days back I read about a recent discovery, an even larger protoist named Gromia sphaerica There's a nicer photo of it on the Discovery web site. This is one weird looking beast, and I'd so like to know more about it.
But wait, there's more. It seems that gromia leaves trails as it crosses the sea floor ... trails that are identical to the pre-Cambrian trace fossils which were previously taken as evidence there were multicellular animals before the Cambrian explosion.
I remember being fascinated when I was much younger by the question "what's the largest cell" ... and the answer was "An ostrich egg", which it was, if in a fugacious way. Only now the answer isn't so simple. Sure an ostrich egg is a lot bigger than gromia, but it turns out there are even bigger candidates. Some seaweeds are made up of giant single cells Caulerpa can be up to three metres long, and it's all one cell! Sir Arthur Eddington was right when he said "Not only is the universe stranger than we imagine, it is stranger than we can imagine." and it isn't just the universe, there's enough here at home to baffle and amaze.
Photo credit Eurakalert.org.