He spoke, and as he spoke death's end closed over his nostrilsRichard Janko ad loc.:
and eyes...
ὣς ἄρα μιν εἰπόντα τέλος θανάτοιο κάλυψεν
ὀφθαλμοὺς ῥῖνάς θ᾽....
The 'end that is death' covers Sarpedon's eyes and nose, i.e. he ceases to see and breathe.