  The distribution of galaxies in the stellar specific angular momentum versus
stellar mass plane ($j_{\star}$-$M_{\star}$) provides key insights into their
formation mechanisms. In this paper, we determine the location in this plane of
a sample of ten field/group unbarred lenticular (S0) galaxies from the CALIFA
survey. We performed a bulge-disc decomposition both photometrically and
kinematically to study the stellar specific angular momentum of the disc
components alone and understand the evolutionary links between S0s and other
Hubble types. We found that eight of our S0 discs have a distribution in the
$j_{\star}$-$M_{\star}$ plane that is fully compatible with that of spiral
discs, while only two have values of $j_{\star}$ lower than the spirals. These
two outliers show signs of recent merging. Our results suggest that merger and
interaction processes are not the dominant mechanisms in S0 formation in
low-density environments. Instead, S0s appear to be the result of secular
processes and the fading of spiral galaxies after the shutdown of star
formation.
