Largest organisms photosynthetic unicellular and multicellular protists that are related to land plants. The thallus of the unicellular mermaid's wineglass, "Acetabularia", can grow to several inches (perhaps 0.1 to 0.2 m) in length. The fronds of the similarly unicellular, and invasive "Caulerpa taxifolia" can grow up to a foot (0.3 m) long. A member of the order Cetacea, the blue whale ("Balaenoptera musculus"), is thought to be the largest animal ever to have lived. The maximum recorded weight was 190 metric tonnes for a specimen measuring , whereas longer ones, up to , have been recorded but not weighed. The African bush
Largest prehistoric animals gruiform and largest phorusrhacid or "terror bird" (highly predatory, flightless birds of South America) was "Brontornis", which was about tall at the shoulder, could raise its head above the ground and could have weighed as much as . The immense phorushacid "Kelenken" stood tall with a skull long ( of which was beak), had the largest head of any known bird. The largest North American phorusrhacid is "Titanis", which is about tall, as tall as a forest elephant. The largest-known bird of prey ever was the enormous Haast's eagle ("Harpagornis moorei"), with a wingspan of , relatively short for their