Every son of Adam will be devoured by the earth with the exception of the tail-bone from which he was created and from which he will be reconstituted. (Using translation from Abū Dāʾūd 4743)
قَالَ رَسُولُ اللهِ ﷺ كُلُّ ابْنِ آدَمَ تَأْكُلُهُ الْأَرْضُ إِلَّا عَجْبَ الذَّنَبِ فَإِنَّهُ مِنْهُ خُلِقَ وَفِيهِ يُرَكَّبُ