Yuri Orlov

(1893-1966).
Director of the Paleontological Institute, USSR Academy of S. A. Orlov (1893 - 1966). A significant part of his scientific activities took work on extinct mammals. First steps S. A. Orlov in paleontology were made in 1925, when he was in Kazakhstan excavated pozdnepliotse-new mammalian fauna on the river. Ishim. These field studies provided material for his first paleozoology-profit publications. In subsequent years he led many major excavations mammals. In 1928-1930 he. It digs out one of the richest in Asia locations hipparion fauna on the river. Irtysh, near r. Pavlodar, then in North Kazakhstan - Oligocene location Askazan Agyspe-sor and the Caucasus - the location gipparinovoy fauna in Gakh acceptance, as well as in Kyrgyzstan and many other parts of the Soviet Union, moreover, and abroad - in Mongolia and China. Materials on hipparion and indrikoterievym mammal fauna, obtained by S. A. Orlov, served as the basis for creating a series of his works, and many Soviet paleontologists and zoologists.
The scientific work of S. A. Orlova in paleontology mammals differ profound morphofunctional approach to the test material. In this was a serious biological preparedness of this scientist, who came in paleontology, with solid research experience in the field of comparative histology and anatomy of invertebrates.

Research S. A. Orlova in paleontology mammals are devoted to morphology, taxonomy and phylogeny of camels, saber-toothed cats, iktiteriev, hyenas, badgers and martens. In the study of mammals Neogene he compared them in detail, . insofar as fossil bone material, . with related forms and tried to restore muscle, . its function and thus obtain more accurate data on the paleoecology and phylogeny of fossil animals.,
. In one of his early work on the saber-toothed tiger (1936) S
. A. Orlov, not only revealed some primitive features of the skeleton of these unusual predators are extinct, but tried to show the adaptive significance of its various features based on a comparison with the skeleton and musculature of modern cats and other predators. In the same way he VPO ^ investigation examined the fossil badgers, martens, hyenas, etc.
One of the most interesting and original works of S. A. Orlova - description of the Pavlodar fauna representative of a new family of primitive pinnipeds - semantora. He thoroughly studied the osteology semantora, reconstruct its musculature, found out the mechanics of limbs and concluded primitiveness of this animal. The structure of the hip, foot, ankle and hip muscles showed that semantor moved in the water type seal. Other features of the skeleton: the presence of joints between the phalanges, . moderate length extreme metapody, . position of the acetabulum of the pelvis, . structure of the spine - suggest maintaining the ability to land through the movement and bring together semantora with otters,
. The discovery and study semantora revealed the origin of pinnipeds, particularly seals, from vydroobraznyh predators. Analysis of the adaptation of the predator, this S. A. Orloff, remains true to this day.
Guided by the principles and methods developed in. O. Kovalevsky and A. A. Borisyak, SW. A. Orlov founded a new direction paleobiologicheskih research in our country - paleoneurology. Paleoneurology - section of paleontology, which reconstructs and investigates the structure of the brain of extinct animals in the natural ebb, preserved in the cranial cavity.
In 1949, Mr.. YU. A. Orlov published an article 'paleoneurology as one of the sections of vertebrate paleontology'. Here, he outlined an entire program of work in the domestic paleoneurology and highlighted some features of the brain of a number of fossil mammals, including halikoteriya - fillotilona (now Borisyak), which was studied in detail Borisyak. After examining the brain and especially the cerebellum fillotilona, SW. A. Orlov confirmed the correctness of the conclusion of a. A. Bo risyaka about his unusual adaptations and lifestyles. In this article, Yuri pointed, . that one of the most interesting problems paleoneurology - question about the speed of evolution of the brain in different groups of fossil vertebrates, . especially mammals, . in the history of which the brain play a primary role,
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Of great interest is the work of S. A. Orlov on fossil marten new allotted subfamily peruniina. In considering this work should be noted that it was written back in the prewar period, but the coincidence was not published in time. This work is devoted to a giant skull that looked like a bear and a wolverine martens from meoticheskoy hipparion fauna Grebenikov village, South-Western Ukraine. Yuri called her Perunium named Old Slavonic god of thunder and lightning Perun, the species name - urzogulo notes the similarity with the bear and wolverine. However, one kind of honey badger S. A. Orlov peruniuma allocated in a separate subfamily peruniin Sem. martens.
. We give a classical description of the skull and teeth of three representatives of a new subfamily, . of which the main object, . most fully presented in fossil form - perunium - combines the features of mustelids similar to modern Wolverine, . and also has a number of signs, . common with bears,
. Description given in a comparative perspective with other members of the weasel.
S. A. Orlov with exceptional skill connoisseur of Neurology describes the morphology and functional properties of brain peruniuma, reduced by the natural ebb (fingerprint) of the cranial cavity. As is known, natural or artificial casts of the brain make it possible to study its structure (gyrus, sulcus, surface vessels, etc.) and, consequently, its functional characteristics and certain features of animal life. The latter becomes available, because between the cyto-architectonics of the brain - cortical fields, sulci and gyri is a definite relationship. The external relief of the brain gives some idea of the most probable location of cortical fields, and consequently, the localization of brain function. We peruniuma been possible to study the cerebral hemisphere and cerebellum. Large cerebral hemisphere with bulky temporal, parietal and occipital lobes, particularly their structures show great similarity of the brain with the brain peruniuma bears, but the structure of the Sylvian fissure and the cerebellum similar to those for martens.
. Then S
. A. Orlov describes the structural features of the skull and cranial mechanics apparatus peruniuma. A connection of the structure of the skull with muscles masticatory apparatus, and subtly analyzed the functional significance of its individual elements. The structure of the jaws shows the weakness of chewing muscles and their adaptation to the unilateral cutting, and not to peregryzaniyu large prey.



Tide brain peruniuma (left) and scheme gyri.


Then S. A. Orlov describes a way of life and causes of extinction of this kind of predator. Features of the morphology of the skull shows, . that perunium was mainly carnivorous animal, . but the weakness of jaw muscles and predatory teeth indicates, . that the main food peruniuma were small vertebrates - rodents, . birds, . frog,
. Analysis of cerebral ebb peruniuma confirms the conclusion about the nature of power and points to the hard work of the trunk, head and limbs, suggests preservation of the ability to climbing trees. Strong development of the temporal, parietal and occipital lobes hemispheres indicate enhanced function of hearing and vision. On the other hand, peruniuma poorly developed frontal lobes and convolutions. This kind of inadaptive specialization of the brain, according to S. A. Orlova, could disastrously affect the fate of these predators in changing the conditions of existence in the second half of the Pliocene, when the forest and moist steppe were replaced by dry steppes and semi-deserts. Peruniumy extinct, replaced by new, more advanced predators. YU. A. Orlov showed the example peruniuma that the improvement in the evolution of one body, even such as the brain, is relative and, despite some progress, can not prevent extinction.
His works S. A. Orlov laid the foundations PALEONEUROLOGICAL research in our country. As you know, he also is credited with organizing a series of paleontological centers in various academic institutions throughout the country. An example may be fruitfully employed in the departments paleozoology Institute of Zoology of the Academy of Sciences in Kiev, at the Academy of Sciences of the Kazakh SSR in Alma-Ata, and others.