one time i ran over a turtle after getting dropped off of the back of a paceline. i'd just finished pulling and didn't speed up enough at the end and couldn't quite catch them. as i was being dropped i looked down in time to see a little teensy turtle, probably the size of a little debbie oatmeal pie.
the sound of its shell crushing under my wheels was gross. the incident was quite appropriate since i'd just been dropped for not being fast enough.
i didn't stop, but the whole thing traumatized me for the rest of the ride.