May of 2026 marks the 150th anniversary of the outstanding biologist and geo­grapher, theorist and historian of science, Academician, Moscow University graduate Leo S. Berg (1876–1950), who became famous during his life as the greatest ichthyologist in our country. He published numerous papers with descriptions of single fish species, as well as general monographs on the ichthyofauna of our country and its regions. He also focused on fishing, domestic aquaculture and zoogeographical zoning by ichthyofauna. The article discusses L.S. Berg’s research on palaeontology, which began during his expeditions to the Aral Sea in 1899–1906. He studied the Meso-Cenozoic deposits of the Aral coastline and their fossil fauna. Since the 1930s, Leo Berg continued his palaeoichthyological research, studying in detail the Late Paleozoic, Mesozoic and Cenozoic actinopterygian and other fishes. He described a number of fossil taxa of ichthyofauna and critically revised the system of fossil agnathans and fishes. The article provides brief biographical information of L.S. Berg, one of the classics of world ichthyology in the 20th century.

The position of the nasal sacs and nostrils, as well as some features of the brain structure in antiarchs (placoderm fishes) are analyzed, based mainly on the examples of Bothriolepis and Asterolepis. A new possible reconstruction of the olfactory system and brain in antiarchs is proposed. The paired nasal sacs are closely located to the anterior wall of the telencephalon; tracti olfactorii are absent; telencephalon is situated anterior to the diencephalon, as it was reconstructed for other placoderms; and the epiphysis process is elongated. The mesencephalon, cerebellum and medula oblongata, bearing the fossa romboidea, are placed posterior to the diencephalon in the otico-occipital part of the endocranium.

The gallery of artistic portraits of outstanding Russian and foreign naturalists, consisting of sculptures and paintings, occupies an important place in the exposition of the Earth Science Museum at Moscow State University. The 270th anniversary of the Moscow State University named after Lomonosov and 75th anniversary of its Earth Science Museum is an occasion to turn to the activities of scientists directly related to Moscow University. The portraits of paleontologists of the 19th – first half of the 20th century, which were at the beginning of the science of fossil organisms at Moscow University, are shown in the museum halls. They have contributed to the development of this science, as well as museology at the university, and laid the foundation for modern research and teaching paleontological courses. Among them are the learners of Johann Gotthelf Fischer von Waldheim (1771–1853) – Charles Roulier (1814–1858) and Grigory E. Shchurovsky (1803–1884), Vladimir O. Kovalevsky (1842–1883), Aleksei Petrovich (1854–1929) and Maria Vasilievna (1854–1938) Pavlovs, and Aleksei Alekseevich Borisyak (1872–1944). Brief biographical information of the scientists is provided. Their contribution to the development and organization of paleontological research at Moscow University is shown.

The palaeoichthyological collection from the Bilovo locality in the Tver’ region (Famennian of the Main Devonian field), currently housed at the Andreapol Museum of Local History, is continued to be studied. Placoderm fishes of the family Bothriolepididae Cope predominate in the ichthyocomplex of this locality. Rare plates of large-bodied Bothriolepis sp. with a flattened armor were found at the Bilovo locality in clay deposits in addition to numerous remains of crested bothriolepidids. The material on Bothriolepis sp. is represented by three posterior medio-dorsal plates only. These plates are described, figured and compared with a similar material on Late Devonian bothriolepidids from the Main Devonian field and other regions. A brief characteristic of the Bilovo locality is given as well.