Cosmological dinosaurs
  The hypothesis of existence of primordial black holes with large masses (\geq 10^6 M\odot), formed at the earliest stages of the Universe evolution, is considered in the paper. The possibility does not contradict some theories, see e.g. Barkana & Loeb (2001), and may match new observational data. In particular, this scenario of evolution could describe some peculiarities in distant galaxies and quasars. Calculations of evolution of central body mass in protogalaxies for different initial conditions are presented. It is shown that the sufficient rate of BH mass growth is not achieved in the standard scheme without complex additional assumptions. Moreover, the appearance of a primordial black hole in the epoch of primordial nucleosynthesis could significantly change the chemical composition around it. This can lead to different exotic stars with low mass and nonstandart metals enrichment. The proposed scheme is not considered as universal. On the other hand, if only tiny part of existed objects have the considered nature, it gives a unique possibility to study extremal stages of matter and fields evolution in our Universe. 
V. K. Dubrovich and S. I. Glazyrin
astro-ph.CO