Wasp
The largest social wasp is the Asian giant hornet, at up to in length. The various tarantula hawk wasps are of a similar size and can overpower a spider many times its own weight, and move it to its burrow, with a sting that is excruciatingly painful to humans. The solitary giant scoliid, "Megascolia procer", with a wingspan of 11.5 cm, has subspecies in Sumatra and Java; it is a parasitoid of the Atlas beetle "Chalcosoma atlas". The female giant ichneumon wasp "Megarhyssa macrurus" is long including its very long but slender ovipositor which is used for boring into wood and inserting eggs. The smallest wasps are solitary chalcid wasps in the family Mymaridae, including the world's smallest known insect, "Dicopomorpha echmepterygis" (139 micrometres long) and "Kikiki huna" with a body length of only 158 micrometres, the smallest known flying insect.
American bison
Two subspecies or ecotypes have been described: the plains bison ("B. b. bison"), smaller in size and with a more rounded hump, and the wood bison ("B. b. athabascae")—the larger of the two and having a taller, square hump. Furthermore, the plains bison has been suggested to consist of a northern plains ("B. b. montanae") and a southern plains ("B. b. bison") subspecies, bringing the total to three. However, this is generally not supported. The wood bison is one of the largest wild species of bovid in the world, surpassed by only the Asian gaur and wild water buffalo. It is the heaviest, and second tallest extant land animal after moose in the Americas.