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 litoptern was "Macrauchenia", which had three hoofs per foot. It was a relatively large animal, with a body length of around . The largest notoungulate known of complete remains is "Toxodon". It was about in body length, and about high at the shoulder and resembled a heavy rhinoceros. Although is not complete, the preserved fossils suggests that "Mixotoxodon" were the most massive member of the group, with a weight about . The largest-known oxyaenid was "Sarkastodon" weighing in at . The largest hyaenodontid was "Megistotherium" at 500 kg. The largest mesonychid was "Mongolonyx robustus". This predator would have been tall