The head of the three-toed sloth swivels 270 degrees thanks to three extra cervical vertebrae.


“Because the three-toed sloth has three extra cervical vertebrae than other mammals, including its close relative the two-toed sloth, it is able to turn its head 270 degrees, or three-quarters the way around.” (Young 1999)

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Bradypus variegatusHee-Jin Jung

Brown-throated SlothBradypus variegatusSpecies