  We investigate the mechanical response of jammed packings of circulo-lines,
interacting via purely repulsive, linear spring forces, as a function of
pressure $P$ during athermal, quasistatic isotropic compression. Prior work has
shown that the ensemble-averaged shear modulus for jammed disk packings scales
as a power-law, $\langle G(P) \rangle \sim P^{\beta}$, with $\beta \sim 0.5$,
over a wide range of pressure. For packings of circulo-lines, we also find
robust power-law scaling of $\langle G(P)\rangle$ over the same range of
pressure for aspect ratios ${\cal R} \gtrsim 1.2$. However, the power-law
scaling exponent $\beta \sim 0.8$-$0.9$ is much larger than that for jammed
disk packings. To understand the origin of this behavior, we decompose $\langle
G\rangle$ into separate contributions from geometrical families, $G_f$, and
from changes in the interparticle contact network, $G_r$, such that $\langle G
\rangle = \langle G_f\rangle + \langle G_r \rangle$. We show that the shear
modulus for low-pressure geometrical families for jammed packings of
circulo-lines can both increase {\it and} decrease with pressure, whereas the
shear modulus for low-pressure geometrical families for jammed disk packings
only decreases with pressure. For this reason, the geometrical family
contribution $\langle G_f \rangle$ is much larger for jammed packings of
circulo-lines than for jammed disk packings at finite pressure, causing the
increase in the power-law scaling exponent.
