At one time, Mononykus was proposed as a member of the family, but this was rejected by Chen and coauthors in a 1998 paper; they considered the similarities between Mononykus and the compsognathids to be an example of convergent evolution.
Jedno vrijeme je i Mononykus bio predložen za pripadnika porodice, ali su to Chen i koautori odbili u svom članku iz 1998. godine; smatrali su sličnosti između Mononykusa i drugih kompsognatida primjerom konvergentne evolucije.