She will send you an invitation that you will receive at the counter. Once the thirty dinosaur bones have been found, send their contact details to Deborah via post and wait 24 hours for her answer. Unfortunately, it is impossible to complete this quest until you have completed the main story, as some of the bones are in Austin, an area you cannot enter because of the mercenaries who instantly kill you on sight. You can spot them more easily with the Lynx Eye, which will make them shine yellow. You don't need to pick up the bones, just send him a letter by post with the information and this good lady will take care of the rest. You can start tracking them and recording their coordinates (in play) as early as Chapter 2, preferably after you have accepted Deborah MacGuiness's quest, just north of Flatneck Station.
Bones are on the ground and are easily confused with common animal carcasses, which can make them difficult to find unless you look for them specifically and know where to look. There are a total of thirty dinosaur bones in Red Dead Redemption 2, such as Dream Catchers, all of which are required to validate 100% progress and are included in the collectibles category.
