Statistical studies of paleosecular variation (PSV) are used to infer the structure and behavior of the geomagnetic field. This study presents a new database, PSVM, of high-quality directional data from the Miocene era (5.3 – 23 Ma), compiled from 1,454 sites from 44 different localities. This database is used to model the latitude dependence of paleosecular variation with varying selection criteria using a quadratic form after Model G. Our fitted model parameter for latitude-invariant PSV (Model G a) is 15.7° and the latitude dependent PSV term (Model G b) is 0.23. The latitude invariant term is substantially higher than previously observed for the past 10 Myrs or any other studied era. We also present a new stochastic model of the time-average field, BB-M22, using a covariant giant Gaussian process (GGP) which is constrained using data from PSVM and Earth-like geodynamo numerical simulations. BB-M22 improves the fit to PSVM data relative to prior GGP models, as it reproduces the higher VGP dispersion observed during the Miocene. Our findings suggest a more variable magnetic field and more active geodynamo in the Miocene era than the past 10 Myrs, perhaps linked to stronger driving by elevated core-mantle heat flow. Although our results support that the average axial dipole dominance of the time-instantaneous field was lower than in more recent times, we note that based on inclination anomaly estimates cannot rule out that the Miocene time averaged field resembles a geocentric axial dipole.