54500 is a Postal Code.
- 54500 a.k.a. Dieffenbach's rail: Dieffenbach's rail was a species of bird from the Rallidae family. It was endemic to the Chatham Islands and referred to as meriki, or mehoriki, by the indigenous Moriori. The only recorded living specimen of Dieffenbach's rail was captured in 1840 by Ernst Dieffenbach, who is commemorated in the scientific and common name of the species. It became extinct due to hunting and introduced predators, perhaps soon after 1840.
- also known as 獃秧雞
- 54500 a.k.a. Spiegler-Brooke syndrome is a gene.