Cuban Macaw Ara tricolor in the Upper Pleistocene of Western Cuba.

The Cuban macaw Ara tricolor (Bechstein, 1811) is an extinct species of large parrots. Its historical distribution and ecology are poorly understood. To date, only three late Quaternary paleontological and one archeozoological (17th-18th centuries) finds of the species have been described from central Cuba. A new (fourth) fossil find of the Cuban macaw is described and is a fragmentary carpometacarpus from Upper Pleistocene layers of the El Abrón Cave in the Pinar del Río province. The find provides the first documented evidence of the species from the western part of Cuba. The associated fauna indicates that the Cuban macaw lived in mosaic, semi-open marshy landscapes, which were probably similar to those in the vicinity of Ciénaga de Zapata in modern times.

A Large Marine Bird (Aves: Procellariiformes) from the Eocene of Western Siberia.

The article describes the first find of a bird from the Paleogene of Siberia. A fragment of tibiotarsus from the Eocene Tavda Formation of the Tyumen Region (Western Siberia) is assigned to Procellariiformes. The bird is morphologically closer to Procellariidae, but comparable in size to albatrosses (Diomedeidae) and is assumed to represent the stem members of the family. The find indicated for the first time that either stem albatrosses or similar large Procellariiformes could have had a worldwide distribution as early as the Eocene.

A New Species of Sandgrouse (Aves: Pteroclidae) from the Early Pleistocene of the Crimea.

Sandgrouse (Pteroclidae, Pterocliformes) are specialized ground birds of open arid landscapes with a very poorly studied evolutionary history. In the late Pliocene-early Pleistocene, Pteroclidae are known only from few localities in Southern Europe. The article describes a relatively large fossil sandgrouse from the early Pleistocene of the Taurida cave in the Crimea. This is the first record of Pteroclidae in the ancient faunas of the Black Sea region and Eastern Europe. The unusual structure of the tibiotarsus makes it possible to describe the fossil form from Taurida Cave as a new species, Pterocles bosporanus sp. nov.

Unexpected Find of a Buttonquail (Aves: Charadriiformes: Turnicidae) in the Lower Pleistocene of Crimea.

Buttonquails (family Turnicidae of the order Charadriiformes) are a morphologically specialized group of small, predominantly tropical birds of open landscapes, which is extremely poorly represented in the fossil record. The article describes a fragmentary humerus of a buttonquail from the Lower Pleistocene of the Taurida Cave in central Crimea. This is the first find of the family Turnicidae in Eurasia in a chronological interval from the Pliocene through the Middle Pleistocene. The find highlights the limited nature of available information on the taxonomic composition of Early Quaternary Eurasian avifaunas, even at the family level, and sheds light on the Late Cenozoic evolutionary history of Turnicidae.

New Data on Hesperornithids (Aves: Ornithurae) from the Campanian of the Lower Volga Region (Late Cretaceous, Russia).

Taxonomic diversity of Late Cretaceous hesperornithids (Aves: Hesperornithidae) of European Russia and Eastern Europe as a whole remain poorly understood, and the morphology of these large flightless birds is poorly known. New finds of Hesperornithidae in the Karyakino locality (Saratov oblast, Russia) confirm the coexistence of two forms of these flightless seabirds in the Campanian (mid-Late Cretaceous) of the Lower Volga region. A femur is described for the first time for Hesperornis rossicus Nessov et Yarkov, 1993, indicating that this large species is morphologically distinct from North American H. regalis Marsh, 1872.

Dynamics of the Late Quaternary Avifauna of Western Cuba (Based on Material from El Abrón Cave).

The dynamics of the taxonomic diversity of the birds of Cuba during the Late Pleistocene-Holocene is assessed for the first time using material from El Abrón Cave in the western part of the island. The Upper Pleistocene beds of the locality are characterized by a rich taxonomic diversity of birds, including an abundance of waterbirds and open-landscape inhabitants. For the Holocene, a general decrease in taxonomic diversity and a significant increase in the number of remains belonging to representatives of forest faunas (Picidae) are recorded. Our data indicate a significant transformation of landscapes of western Cuba and the faunistic associations of birds at the end of the Quaternary, which is consistent with paleoclimatic data.

Dyuktai Goose (Anser djuktaiensis) and Hooded Crane (Grus monacha) from the Pleistocene of Central Yakutia.

Bird bones from the Late Pleistocene (31-24 kyr) Ikhine-2 site (Central Yakutia), one of the key Upper Paleolithic sites in northeastern Siberia, have first been studied. This is the northernmost and the oldest bird association in the Pleistocene of Eastern Siberia. Among the bone materials available, the coracoids of the extinct Dyuktai goose (Anser djuktaiensis) and the hooded crane (Grus monacha) are of particular interest. Dyuktai goose is a large representative of the mammoth fauna, originally described from younger deposits (12-13 kyr) in southeastern Yakutia. This is the second find of this species in Russia, which significantly expands our understanding of the geography and time of its distribution. The hooded crane, a rare modern species with a limited habitat area, has first been found in paleontological record. This find indicates the northern distribution of this species during the Late Pleistocene Karginian interstadial. Bones of Anas crecca and Larus canus have also been found at the site.

The Taurida Cave, a New Locality of Early Pleistocene Vertebrates in Crimea.

We describe a vertebrate assemblage from the Pleistocene deposits of the Taurida karst cave discovered in 2018 in central Crimea (Zuya village, Belogorsk raion). The assemblage is correlated with Late Villafranchian faunas of the Eastern Mediterranean and has an approximate age of 1.8-1.5 Ma.

The Earliest Asian Duck (Anseriformes: Romainvillia) and the Origin of Anatidae.

A new species of the extinct duck Romainvillia from the Upper Eocene of Kazakhstan is described. This is the earliest duck from Asia, the first record of Romainvillia beyond France and the first reliable evidence of the presence of Romainvilliinae (regarded here as family) in Asia. This occurrence shows a wide range of Romainvillia and suggests a greater similarity of Late Eocene faunas of Western Europe and Asia than it was previously thought. The origin of Romainvilliidae and their presumable descendants Anatidae may be connected with adaptation to a new biotope, the shallowing Late Eocene epicontinental Asian basins (due to a global decrease in sea level).

A Mass Burial of Fossil Lions (Carnivora, Felidae, Panthera (Leo) ex gr. fossilis-spelaea) from Eurasia.

The vertebrate fauna from the cave deposits in Imanai Cave in the Southern Urals (53°02' N, 56°26'E) has been studied. It contains 715 bones that belonged to at least 11 individuals of fossil lion (Panthera (Leo) ex gr. fossilis-spelaea). It has been established that this is one of the largest Eurasian burial sites of fossil lions. The bones were accumulated due to the natural death of animals inside the cave. The age and sex estimations have shown that at least six adult males and five adult females died there. According to the accompanying fauna, radiocarbon, geochemical, and mineralogical analyses and archaeological finds, the interval of the lion bone accumulation is determined as the first half to middle of Late Pleistocene (OIS 5-3).

Finds of fragmentary bird skeletons in the Middle Miocene of the northern Caucasus.

The first anatomically assembled skeletal remains of Neogene birds in Russia have been found. The head and a fragment of the vertebral column of a duck (Anatidae) and a hind limb of a perching bird (Passeriformes) from the Middle Miocene of the Krasnodar Region (Tsurevsky Formation) comprise the earliest known Miocene birds from European Russia. The skull of a very small duck (smaller than any extant species of Eurasian ducks) shows a combination of morphological characters characteristic of the extant species of Tadorna and Nettapus, and could belong to a representative of the fossil genus Mioquerquedula. This discovery supports a separate generic status for small-sized middle Miocene anatids from Eurasia, and suggests that they were more primitive than the extant Anatinae.

[Stable morphologies and mosaicism in the macroevolution of birds (Neornithes)].

Modern orders of Neornithine birds are separated by distinct morphological gaps, hampering the development of particular models. of macroevolutionary transformations. However, recent decades have witnessed the discovery and extensive study of many fossil groups of birds, which shed light on the origin of modern higher taxa. These fossils further allow analyzing the whole process of the macroevolutionary change in this group of vertebrates during the Cenozoic. Here, a brief review is presented of the "transitional" taxa with special attention to representative of the clade Galloanseres. Almost all transitional groups of fossil birds do display mosaic morphology. It is noted that many stable morphologies (characters and character complexes) persist in different groups, occurring either as primitive states, or as advanced ones. The stable recurrence of these characters is caused by the persistence of stable ontogenetic pathways. On the other hand, independent evolution of various morphologies can be explained by the modular organization of the development. The modularity in the structure of the foot is used here as an example to show a possible way of the origin of the foot in extant perching birds (Passeriformes). The mosaic morphology of the transitional taxa is seen as the only possible way to overcome the evolutionary constraint of the parallel optimization of numerous organismal systems. It is noted that in course of macroevolutionary change, no complete filling of morphological gaps occur. Transitional forms are separated by additional gaps from their ancestors and descendants. Hence, stem groups are seen as the most probable ancestors of crown taxa. It is further noted that the evolutionary formation of some higher taxa of the living birds was initiated by the evolution of advanced morphology of the feeding apparatus and skull, while change in their. postcranial morphology was delayed.