ɪɾ ɪz θˈɔːt tə hɐvbɪn ɐ bˈɛɾɚ swˈɪmɚ ðɐn mˈoʊst əv ɪts ɹˈɛlətˌɪvz bɪkˈʌz ʌv ɪts pˈaʊɚfəl tˈeɪl, stˈeɪbɪlˌaɪzɪŋ dˈoːɹsəl fˈɪn ænd ðə kˈiːlʃˈeɪpt hˌaɪdɹədaɪnˈæmɪk ˈɛdʒᵻz ʌv ɪts hˈɛd ʃˈiːld.
It is thought to have been a better swimmer than most of its relatives because of its powerful tail, stabilizing dorsal fin and the keel-shaped hydrodynamic edges of its head shield.