Of course it was dead – it was all bones. And the Doctor might be a human oddity in several respects, but he wouldn't send Jack into a monster's lair. Jack retreated slowly, trying not to make his head ache any worse. He could hear the Doctor talking to Eliza: 'There are shells scattered upon the mountains! See, this rock has a grain like wood – you can split it into layers – and look at what's between the strata ! This creature must've been buried in mud – probably the fine dirt that rivers carry – smashed flat, as you can see – its body decomposed leaving a void, later filled in by some other sort of rock – as sculptors cast bronze statues in plaster molds.'