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I challenge you to find a single scientific report confirming any of the above

The baby mammoth was presumable Dima - which appears to have drowned in a river around 41,000 years ago....
No, Dima and another juvenile mammoth were discovered in 1977 and 1988 respectively and were not in a frozen state, rather they were "mummified" and have been on exhibition in Helsinki for several years.
References to the mammorth I mentioned:
Stone, R., Siberian mammoth find raises hopes, questions, Science 286:876–877, 1999.
Sarfati, J., Mammoths—riddle of the Ice Age, Creation 22(2):10–15, 2000; p. 11.
Guthrie, R.D., Frozen Fauna of the Mammoth Steppe—The Story of Blue Babe, University of Chicago Press, Chicago, IL, 1990.
Howorth, H.H., The Mammoth and the Flood—An Attempt to Confront the Theory of Uniformity with the Facts of Recent Geology, Sampson Low, Marston, Searle & Rivington, London, p. 54, 1887, reproduced by The Sourcebook Project, Glen Arm, MD.
Baryshnikov, G., Haynes, G. and Klimowicz, J., Mammoths and the mammoth fauna: introduction to the studies of an extinct ecosystem; in: Haynes et al., Ref. 9, p. 5.
Howorth, H.H., The mammoths in Siberia, Geological Magazine 7:550–561, 1880.
Digby, B., The Mammoth and Mammoth-Hunting in North-East Siberia, H.F. & G. Witherby, London, p. 14, 1926.
Farrand, W.R., Frozen mammoths and modern geology, Science 133:729–735, 1961; p. 733.
Vereshchagin, N.K., The mammoth ‘cemeteries’ of north-east Siberia, Polar Record 17(106):3–12, 1974; p. 3.
Alroy, J., Putting North America’s end-Pleistocene megafaunal extinction in context; in: MacPhee, D.E. (ed.), Extinctions in Near Time—Causes, Contexts, and Consequences, Kluwar Academic/Plenum Publishers, New York, NY, pp. 105–143, 1999; p. 105.
Velikovsky, I., Worlds in Collision, Pocket Books, New York, NY, 1950.
Velikovsky, I., Earth in Upheaval, Doubleday & Co., New York, NY, 1955.
Velikovsky, Ref. 58, p. 13.
Hapgood, C.H., Earth’s Shifting Crust—A Key to Some Basic Problems of Earth Science, Pantheon Books, New York, NY, 1958.
Hapgood, C.H., The Path of the Pole, Chilton Book Co., New York, NY, 1970.
Ginenthal, C., The Extinction of the Mammoth, Forest Hills, New York, NY, 1997.
Ukraintseva, V.V., Vegetation Cover and Environment of the ‘Mammoth Epoch’ in Siberia, Mammoth Site of Hot Springs, South Dakota Inc., Hot Springs, SD, pp. 80–98, 1993.
Mithen, S., Simulating mammoth hunting and extinction: implications for the Late Pleistocene of the Central Russian Plain; in: Peterkin, G.L., Bricker, H.M. and Mellars, P. (eds)
I did a paper on this several years ago and still had the references. Sorry for the overkill but maybe you'll find it interesting.