Leionucula was named by Quenstedt (1930) [Sepkoski's age data: K Haut-l R Sepkoski's reference number: 789]. It is extant.

It was reranked as Nucula (Leionucula) by Moore (1976), Malumian et al. (1978), Moore (1983), Gliozzi and Malatesta (1983), Bernard (1983), Covacevich and Frassinetti (1986), Stilwell and Zinsmeister (1992), Chiesa et al. (1995), Frassinetti (1997), Frassinetti and Covacevich (1999) and Stilwell et al. (2004).

It was assigned to Nuculominae by Stilwell (1993); to Nuculoida by Sepkoski (2002); to Nucula by Moore (1976), Malumian et al. (1978), Moore (1983), Gliozzi and Malatesta (1983), Bernard (1983), Covacevich and Frassinetti (1986), Stilwell and Zinsmeister (1992), Chiesa et al. (1995), Frassinetti (1997), Frassinetti and Covacevich (1999) and Stilwell et al. (2004); and to Nuculidae by Eames (1951), Vokes (1980), Lamprell and Healy (1998), Todd (2001), Spencer et al. (2004) and Kaim et al. (2014).