tˈɛɹæspiz ˈɔːlsoʊ hˌæd sʌm stˈɪf spˈaɪks ˌɔn ɪts bˈæk, pˈɑːsᵻbli ɐn ɐdˈɪʃənəl fˈɔːɹm ʌv pɹətˈɛkʃən ɐɡˈɛnst pɹˈɛdəɾɚz.
Pteraspis also had some stiff spikes on its back, possibly an additional form of protection against predators.