Oldest modern bird fossil looks like a duck from the back and a chicken from the front

Science ◽  
2020 ◽  
Author(s):  
Gretchen Vogel
Keyword(s):  
The Condor ◽  
1945 ◽  
Vol 47 (4) ◽  
pp. 175-176
Author(s):  
Frank A. Pitelka
Keyword(s):  

Author(s):  
B. Ya. Kyryliv ◽  
A. V. Hunchak ◽  
I. B. Ratych ◽  
B. V. Gutyj

The article is a summary of the literature on the main aspects of the modern bird feeding system. Theoretical aspects and results of experimental research of scientists on the substantiation of parameters of protein and amino acid nutrition are given, which is an important factor that, under appropriate conditions can significantly guarantee the realization of the genetic potential of corresponding breeds and crosses of poultry. It is shown that an important aspect of protein nutrition is the ratio of feed amino acids. Their negative interaction can be caused by a deficiency of one or more amino acids, an imbalance between them, antagonism, and toxicity. This is accompanied by effects on various physiological and biochemical processes, significantly affects appetite, intestinal absorption, renal reabsorption and transport of amino acids, their catabolism, rate of protein decomposition, synthesis, and formation of toxic metabolic products. The data show that the required level of energy for the bird's body is provided by carbohydrates (mainly of plant origin) and lipids (fat supplements of various origins). It is noted that lipids promote the absorption, transport, and deposition of fat-soluble vitamins. The effectiveness of using fat supplements as energy depends on their source. At the same time, among the indispensable nutrients that have a significant impact on growth intensity, reproductive quality, poultry productivity, and biological value of products, an important role is played by macro-and micronutrients. Many researchers emphasize that along with the use of traditional feeds in poultry feeding, the possibilities of non-traditional cereals rich in protein and lipids are not fully used. A limiting factor in their use is the presence in their composition of anti-nutrients contained in many feeds. Once in the digestive tract of animals, they negatively affect the absorption of feed nutrients. In most cases, the consumption of such feed by animals is manifested in growth retardation, increased feed consumption, hormonal effects, and, less frequently, in the dysfunction of certain organs.


2017 ◽  
Vol 284 (1865) ◽  
pp. 20171050 ◽  
Author(s):  
Shane O'Reilly ◽  
Roger Summons ◽  
Gerald Mayr ◽  
Jakob Vinther

Although various kinds of organic molecules are known to occur in fossils and rocks, most soft tissue preservation in animals is attributed to melanin or porphyrins. Lipids are particularly stable over time—as diagenetically altered ‘geolipids’ or as major molecular constituents of kerogen or fossil ‘geopolymers’—and may be expected to be preserved in certain vertebrate tissues. Here we analysed lipid residues from the uropygial gland of an early Eocene bird using pyrolysis gas chromatography mass spectroscopy. We found a pattern of aliphatic molecules in the fossil gland that was distinct from the host oil shale sediment matrix and from feathers of the same fossil. The fossil gland contained abundant n -alkenes, n -alkanes and alkylbenzenes with chain lengths greater than 20, as well as functionalized long-chain aldehydes, ketones, alkylnitriles and alkylthiophenes that were not detected in host sediment or fossil feathers. By comparison with modern bird uropygial gland wax esters, we show that these molecular fossils are likely derived from endogenous wax ester fatty alcohols and fatty acids that survived initial decay and underwent early diagenetic geopolymerization. These data demonstrate the high fidelity preservation of the uropygial gland waxes and showcase the resilience of lipids over geologic time and their potential role in the exceptional preservation of lipid-rich tissues of macrofossils.


1945 ◽  
Vol 20 (4) ◽  
pp. 390-390
Author(s):  
Henri C. Seibert
Keyword(s):  

Nature ◽  
1946 ◽  
Vol 157 (3987) ◽  
pp. 390-390
Keyword(s):  

The Auk ◽  
1938 ◽  
Vol 55 (3) ◽  
pp. 547-548
Author(s):  
A. L. Rand
Keyword(s):  

Author(s):  
S.I. Tsembalyuk ◽  
A.V. Kisagulov ◽  
А.Е. Nekrasov

The article deals with osteological complexes of the Maray 1 hillfort located in the forest-steppe area of the Ishim River region. The research materials were obtained from the excavations carried out in 2010 and 2019. The main periods of the site habitation recorded for the hillfort are the early chronological horizon represented by the settlement of the Krasnoozerka Culture of the Bronze to Iron Age transitional period (9th–7th c. BC), and the late cultural layer which is marked by the hillfort of the beginning of the Early Iron Age, left by the population of the Baitovo Culture (4th–2nd c. BC). From each layer associated with different periods of the site habitation, archaeo-zoological collections have been selected. The purpose of this work is to determine the type of economy of the Maray 1 population during the two major habitation phases. The essential research materials comprised of oste-ological collections obtained from the Krasnoozerka and Baitovo layers. The research technique included bone determinations based on comparison with the reference skeletal collections from the Museum of the Institute of Plant and Animal Ecology, Ural Branch of the Russian Academy of Sciences (Yekaterinburg), using anatomy atlases [Gromova, 1950]. Determination of subfossil bird bones was carried out in the same institute, and it in-cluded comparison of the bones from the settlement with the reference osteological collection of modern bird spe-cies. The species attribution was based on morphological structure of the bones and their fragments. The oste-ological collection of the Maray 1 hillfort is stored in the Museum under No. 2361. Analysis of the species compo-sition of osteological complexes from the two main habitation periods allowed distinguishing domestic and wild animals, including birds. The proportions of the number of bones and representatives of domestic and wild fauna have been analyzed. In the Krasnoozerka Culture materials, significant predominance of wild animal bones has been determined, which suggests that the economy of the Krasnoozerka settlement was dominated by the appropri-ating activities with a significant role of hunting (mainly elk). In the Baitovo layer, bones of domestic animals signifi-cantly prevail over those of wild fauna, suggesting that the economy was based on producing sectors.


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