Frozen Baby Mammoth, Russia

Based on studies of their close relatives the modern elephants, mammoths probably had a gestation period of 22 months, resulting in a single calf being born. Their social structure was probably the same as that of African and Asian elephants, with females living in herds headed by a matriarch, whilst bulls lived solitary lives or formed loose groups after sexual maturity.
Well-preserved specimens and prospects of cloning
In May 2007, the carcass of a one-month-old female woolly mammoth calf was discovered in a layer of permafrost near the Yuribei River in Russia, where it had been buried for 37,000 years. Alexei Tikhonov, the Russian Academy of Science's Zoological Institute's deputy director, has dismissed the prospect of cloning the animal, as the whole cells required for cloning would have burst under the freezing conditions. Nonetheless, DNA is expected to be well-enough preserved to be useful for research on mammoth phylogeny and perhaps physiology. However, Dr Sayaka Wakayama from the RIKEN Center for Developmental Biology in Kobe, Japan, believes that a technique she has used to clone mice from specimens frozen for sixteen years could be used successfully on recovered mammoth tissue: she cites that in her experiments the dead mice had been frozen to -20°C under simulated natural conditions, without using the usual preservative chemicals.