Does soft tissue in dinosaur fossils argue for a young earth? Well, that all depends on who you ask. If you are a young-earth creationist (YEC) like me you are sure of it, but if you are an evolutionist or old earth creationist you are very dismissive of the whole idea.
A recent article by Dr. Brian Thomas entitled, “Collagen Decays Too Fast for Evolutionary Time,” is one of the latest pieces of research to be published on this topic by a YEC and appears to demonstrate what that title asserts. https://www.icr.org/article/11435 . Thomas shows that “bovine bone collagen held at 59˚F would decay with a half-life of 21,012 years under ideal conditions. At that rate, collagen would not last even one million years.” Let alone the 60-million years required by some soft tissue containing dino fossils according to an evolutionary timeline.
So how do the evolutionists counter research such as this? A good example is an article published by Biologos, a theistic evolution organization (Christians who believe that God used evolution to create.) https://biologos.org/articles/soft-tissue-in-dinosaur-bones-what-does-the-evidence-really-say . You can read it for yourself, but I would like to highlight the final conclusion: “Thus, it is absurd and insupportable to set aside the radioactive dating of these rock layers because some partly degraded soft tissue has been found in dinosaur fossils from those layers.”
It’s only “absurd” to folks at Biologos because they have already decided that the earth is billions of years old. And it seems absurd to me not to accept the evidence that these dinosaurs only died thousands of years ago, probably during the Deluge, because I already know that the earth is young! It alls hangs on presuppositions (faith), not scientific evidence. I believe the earth is young because I believe the Bible describes the earth as young (in the genealogies). So naturally, I think my presuppositions are better than theirs:)