The Wikipedia article:

> A dolos ... is a type of tetrapod

but also, the Wikipedia article for tetrapod:

> One of the earliest designs is the Tetrapod, invented in 1950. Other proprietary designs include the Modified Cube (United States, 1959), the Stabit (United Kingdom, 1961), the Akmon[W] (The Netherlands, 1962), the Dolos (South Africa, 1963), the Stabilopod [ro] (Romania, 1969),[7] the Seabee (Australia, 1978), the Accropode[W] (France, 1981), the Hollow Cube (Germany, 1991), the A-jack[W] (United States, 1998), the Xbloc[W] (The Netherlands, 2001) and KOLOS[W] (India, 2010) among others.

I have put Ws next to ones with their own Wikipedia page.