Complex sentence: In November 2013, an international team of archaeologists digging under the temple discovered the remains of an ancient tree shrine dated before 550 BCE, which is possibly the earliest evidence of Buddhist structures ever found and possibly the first archaeological evidence of Gautama Buddha's life.
Split into simpler sentences: In November 2013, an international team of archaeologists digging under the temple discovered the remains of an ancient tree shrine dated before 550 BCE. The researchers speculated that the site is the earliest evidence of Buddhist structures and the first archaeological evidence of Gautama Buddha's life.