Mammal-like reptiles

In the transition towards mammals, the features of a typical intermediate group, the Pelycosaurs (Permian, mammal-like reptiles, Fig. 1.2) probably reflect those now seen in tme mammals. The early mammals presumably maintained the oral sampling of odours, as suggested at a... 

Duvall D. (1986). A new question of pheromones Aspects of possible chemical signalling and reception in the mammal-like reptiles. In Ecology and Biology of Mammal-like Reptiles (Hotton N., et al., eds.). Smithsonian Institution, Washington D.C., pp. 219-238. 

Duvall D., King M. and Graves B. (1983). Fossil and comparative evidence for possible chemical signaling in the mammal-like reptiles. In Chemical Signals in Vertebrates 3 (Muller-Schwarze D. and Silverstein R., eds.). Plenum, New York, pp. 25-44. 

After a warm period, in the Pangea/Panthalassa arrangement of Earth about 210 My ago, the end-Triassic mass mortality caused the disappearance of mammal-like reptiles leaving place to the dinosaurs, the first angiosperms, and the first mammals. 

Triassic Period The first period of the Mesozoic Era between 225 and 185 million years ago. Pangaea began to breakup during this time. The ancestors of dinosaurs were present, as were early mammals and mammal-like reptiles. 

There are two main models that attempt to explain the success of the dinosaurs. According to one, dinosaurs out-competed the mammal-like reptiles over a long period of time due to superior adaptations such as upright walking. The other model, which is supported by fossil evidence, says that the dinosaurs took advantage of openings created by two mass extinctions. By the end of the Triassic, dinosaurs had taken over the land. They were dominant for 165 million years, from the Late Triassic until their extinction at the Cretaceous-Tertiary (K-T) boundary some 65 million years ago. This massive extinction may have taken place in only a week or lasted for tens of thousands of years this has not been determined yet, but further study may provide an answer. One prominent theory for the cause of this... 

Permian 290 Myr All land united in one large continent - Pangaea large glaciers form. Reptiles, including mammal-like forms, radiate amphibians decline diverse orders of insects evolve. Conifers appear. Mass extinction at end of period (ca. 95% of all species disappear)... 

Wild and domestic animals, including mammals, birds, reptiles and insects, are likely to harbour enteric pathogens and are therefore potential transmitters to agricultural environments and produce. For instance, Salmonella spp. has been isolated from the intestinal tracts of most warm-blooded and many cold-blooded animals. 

L-Amino acid oxidase is a flavoenzyme that catalyzes the oxidative deamination of L-amino adds. L-Amino acid oxidase activities have been detected in mammals, birds, reptiles, invertebrates, molds, and bacteria [54]. L-Amino acid oxidases show the typical absorption spectrum due to the presence of a molecule of non-covalently bound FAD per subunit (with maxima at 465 and 380nm) they behave like flavoprotein oxidases, as in the case of D-amino acid oxidase. L-Amino add oxidase isolated from rat liver was reported to utilize flavin mononudeotide (FMN) as a co-enzyme, but since it is more active on L-hydroxy acids than on amino adds, it was thus considered as an L-hydroxy add oxidase. Even a partially purified L-amino acid oxidase from turkey Uver appeared to have FMN as a co-factor. 

In terrestrial animals, cyclodienes such as dieldrin, like other refractive lipophilic pollutants, can be excreted in their unchanged forms, notably with lipoproteins, which are exported into milk (mammals), eggs (birds, reptiles, insects), or developing... 

Reptiles like the snake and the lizard cannot regulate their body temperature, and adopt the temperature of their environment (i.e., they are poikilother-mic) - so they cannot survive extremes which put their body cells, and particularly their enzyme systems, at risk. By contrast, we can shiver or sweat to increase or reduce our core temperature, and so human beings can function effectively in a much wider range of temperature than can reptiles. What has this to do with drugs and other ingested chemicals In just the same way as we mammals have evolved to be relatively independent of environmental temperature so we also have developed a system of screening and filtering out chemical substances that present themselves to us in our diet and from other sources. 

Some parts of the brain, like the cerebral cortex, are much more highly evolved in humans than in other animals. The pineal gland, however, is a very basic organ that first evolved in primitive species. It is found in lampreys, fish, amphibians, and reptiles, as well as in mammals. The hormone melatonin has also been found in insects and plants. 

The analysis that follows begins with a consideration of the proximate causes of systemic endothermy, an issue that can be approached by asking, How does an ectothermic vertebrate like a reptile differ from a mammal in terms of mechanisms for supporting endother-... 

Substantial differences in the amounts of heat generated by the proton futile cycle seem likely to distinguish mitochondria of reptiles and mammals (Brand et al., 1991). Leakiness of the inner mitochondrial membrane, expressed as flux per unit area, was four- to fivefold higher in the rat relative to A. vitticeps... 

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