SOFIA, July 29 (Reuters) - The remains of what is believed to be an ancient mammoth ‌have been revealed in northern Bulgaria, after Danube ‌River water levels receded to a record low level, the BTA ​news agency reported on Wednesday, citing historians. The animal's remains were found on Wednesday by a local resident of the Ryahovo village, who noticed the unusual find ‌on the river bed. ⁠Villagers then alerted specialists in the Regional History Museum in the nearby town of ⁠Ruse. Danube levels ​have fallen to record lows in recent weeks following the summer's prolonged heat waves and drought ​that have ‌affected rivers across Europe including key waterways such ​as the Rhine. (Reporting by Stoyan Nenov, writing ​by Daria Sito-Sucic; Editing by)