  We present an analysis of the number density of galaxies as a function of
stellar mass (i.e., the stellar mass function, SMF) in the COSMOS field at
z~3.3, making a comparison between the SMF in overdense environments and the
SMF in the coeval field. In particular, this region contains the Elent\'ari
proto-supercluster, a system of 6 extended overdensities spanning ~70 cMpc on a
side. A clear difference is seen in the high-mass slope of these SMFs, with
overdense regions showing an increase in the ratio of high-mass galaxies to
low-mass galaxies relative to the field, indicating a more rapid build-up of
stellar mass in overdense environments. This result qualitatively agrees with
analyses of clusters at z~1, though the differences between protocluster and
field SMFs at z~3.3 are smaller. While this is consistent with overdensities
enhancing the evolution of their member galaxies, potentially through increased
merger rates, whether this enhancement begins in protocluster environments or
even earlier in group environments is still unclear. Though the measured
fractions of quiescent galaxies between the field and overdense environments do
not vary significantly, implying that this stellar mass enhancement is ongoing
and any starbursts triggered by merger activity have not yet quenched, we note
that spectroscopic observations are biased towards star-forming populations,
particularly for low-mass galaxies. If mergers are indeed responsible, high
resolution imaging of Elent\'ari and similar structures at these early epochs
should then reveal increased merger rates relative to the field. Larger samples
of well-characterized overdensities are necessary to draw broader conclusions
in these areas.
