Have not been able to find this information elsewhere or possibly I was not using the right search criteria, and perhaps no one else has noticed or cared but since the beginning I have noticed that the quadrupedal sentinels appear as a life form in the visor with a red dot. After destroying or killing the quadrupedal sentinel the red dot appears underneath a floating red “contact lens.” Although not tracking or logging the probability of the quadrupedal sentinels showing as an unscanned creature in the visor before destroying is probably 90 to 100 percent of the time and perhaps 80 to 90 percent after destroying.
It is not possible to be credited as a scanned creature although I have on occasion spent a bit of time trying to resolve this. Especially back in the original release I also noted that when this occurred I was rarely, if ever, able to find the very last missing creature.
Thank You