Scutoid

The scutoid has hit the news as a 'new' shape discovered in the structure of the epithelia. See the article in Nature https://www.nature.com/articles/s41467-018-05376-1 Previously the cells were assumed to be prisms or frustrums where the upper and lower faces have the same number of edges, but the scutoid has different numbers of edges (here 5 and 6), the difference being made up by a triangular face with a vertex lying between the upper and lower faces.

Ed Pegg https://math.stackexchange.c