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 monotreme (egg-laying mammal) ever was the extinct long-beaked echidna species known as "Zaglossus hacketti", known from a couple of bones found in Western Australia. It was the size of a sheep, weighing probably up to . The largest cingulate known is "Doedicurus", at long and reaching a mass of approximately "Glyptodon" easily topped and . The largest-known animal of this group was "Deinogalerix", measuring up to in total length, with a skull up to long. It occupied the same ecological niche as dogs and cats today. The largest-known prehistoric lagomorph is Minorcan giant lagomorph ("Nuralagus rex") at . The largest-known