Gromia sphaerica. seems that this is an enlarged form of an amoeba……. that grows up to 1.5 inches in diameter. was discovered in 2000. (i’m 9 yrs late on this news.. )
this is a deep sea creature cell, that is mobile, somehow propelling itself on the sea bed. they can move across terrains, even against currents.
check out the trails these cells leave behind..
apparently, this has caused some major discussion on the evolution of bilaterals, which are organisms like us that have a line of symmetry down the middle. but im not getting into that, cos that includes fossil study and precambrian era which im totally not familiar with…
well, not all single cell organisms are mircoscopic. for one, the eggs that you eat are all single celled. though not accurately considered an organism. the ostrich lays the largest egg, making ostrich egg one of the largest cell ever discovered to date.
the sea pearl or sailors’ eyes is another marine based single cell photosynthetic organism. scientists suggest that the cellular contents can actually break into many protoplasts that form their own cell membrane. technically making it a multicellular organism. its called Valonia ventricosa. its the largest bubble algae that grows to the size of a tennis ball!!!