  We determined astrophysical and dynamical parameters of the open clusters
(OCs) NGC 2587, Collinder 268 (Col 268), Melotte 72 (Mel 72), and Pismis 7 from
Gaia DR2 photometric/astrometric data and a new technique, fitCMD. fitCMD
provides (Z, Age(Gyr)) as (0.025, 0.45) for NGC 2587, (0.0025, 0.5) for Col.
268, (0.011, 1.25) for Mel 72, and (0.008, 1.00) for Pismis 7, respectively. As
compared to Gaia DR2 distances, the obtained photometric distances from fitCMD
provide somewhat close distances. For NGC 2587 and Mel 72, both distances are
in good concordance. Except for NGC 2587, the ages of the remaining OCs are
higher than their relaxation times, which suggests that they are dynamically
relaxed. NGC 2587 did not undergo dynamical evolution. Mel 72 and Pismis 7 with
relatively flat MF slopes indicate signs of a somewhat advanced dynamical
evolution, in the sense that they appear to have lost a significant fraction of
their low-mass stars to the field. Pismis 7's negative/flat MFs indicates that
its high mass stars slightly outnumber its low mass ones. Given its mild
dynamical evolution, the high mass stars move towards the central region, while
low-mass stars are continually being lost to the field. Col 268 presents small
dimensions which suggest a primordial origin. The outer parts of Mel 72 and
Pismis 7 - with large cluster radii expand with time, while Mel 72's core
contracts because of dynamical relaxation (Figs. 10e--f).

Astrophysics of Galaxies