  We demonstrate a novel mechanism for producing dark compact objects and black
holes through a dark sector, where all the dark matter can be dissipative.
Heavy dark sector particles with masses above $10^4$ GeV can come to dominate
the Universe and yield an early matter-dominated era before Big Bang
Nucleosynthesis (BBN). Density perturbations in this epoch can grow and
collapse into tiny dark matter halos, which cool via self interactions. The
typical halo size is set by the Hubble length once perturbations begin growing,
offering a straightforward prediction of the halo size and evolution depending
on ones choice of dark matter model. Once these primordial halos have formed, a
thermal phase transition can then shift the Universe back into radiation
domination and standard cosmology. These halos can continue to collapse after
BBN, resulting in the late-time formation of fragmented dark compact objects
and sub-solar mass primordial black holes. We find that these compact objects
can constitute a sizable fraction of all of dark matter. The resulting
fragments can have masses between $10^{20}$ g to $10^{32}$ g, with radii
ranging from $10^{-2}$ m to $10^5$ m, while the black holes can have masses
between $10^{8}$ g to $10^{34}$ g. Furthermore, a unique feature of this model
is the late-time formation of black holes which can evaporate away today. We
compare where these objects lie with respect to current primordial black hole
and MACHO constraints.
