An endoskeleton is internal and present in all developed animals, as well as in many of those less developed.
ɐn ˈɛndoʊskˌɛlᵻtən ɪz ɪntˈɜːnəl ænd pɹˈɛzənt ɪn ˈɔːl dɪvˈɛləpt ˈænɪməlz, æz wˈɛl æz ɪn mˈɛnɪəv ðoʊz lˈɛs dɪvˈɛləpt.