Was watching a show on National Geographic last night about the recent find of a Dinosaur mummy and was wondering about a couple of things. First off, one of the things they were doing on the show was to try and get genetic samples from, well, rock. I guess what happened was that when the dinosaur died it didn’t decompose…and eventually everything, including the soft tissues were fossilized. This is a REALLY rare event I take it. But…well, once it HAS fossilized doesn’t it just turn into rock? I know they weren’t trying to get DNA (which would be long gone), but they still seemed to think they could get something out of it…my question is, why? Wouldn’t it just be sandstone or whatever at that point? I mean, we are talking about over 65 million years ago (actually, IIRC, something like 80-90 million years)…and it’s all turned to stone. There wouldn’t be anything left to get a sample from…right?
My other question has to do with how long (I guess in theory) a mummy COULD last before being either destroyed or turned to stone? I guess what I’m getting at here is…are we likely to find human or animal mummies frozen in glaciers (now that they are melting) from 10’s or 100’s of thousands of years ago (sort of like the Ice Man mummy)? Is there a practical limitation on how long a mummy could last? For bonus…what is the oldest mummy (non-fossilized) currently?
Mummified is not fossilized. Mummified means essentially that the tissue has dried out but is still tissue, not rock. That’s why this dinosaur find is so spectacular. It’s actual soft tissue around the fossilized bones.
I don’t think that is correct. My understanding is that the soft tissue itself has fossilized…i.e. turned to stone. There is no way soft tissue could last 65 million plus years and not be stone.
I could be wrong of course…this is GQ so feel free to provide a cite. I think this stuff is really fascinating.
According to this story, this particular dinosaur mummy actually contains preserved soft tissue. It is not completely mineralized.
Likewise, some years ago a T. rex bone was found that still contained some soft tissue inside.
One problem is the confusion between the terms “fossilized” and “petrified” or “mineralized.”
Strictly speaking, any ancient trace of life is a fossil. This may be actual bone, wood, or other organic material, or may be the remains of such items where the original material has been replaced by minerals, or “petrified.”
The older such material is, the more likely it has undergone this process of mineralization/petrification. That’s what makes this dinosaur mummy so unusual, since it is not entirely mineralized. Note that previous dinosaur “mummies” have been found, but in these cases the flesh, skin, and other soft tissue adhering to the bones had been mineralized. It still retained the form of the flesh, but not the actual material.
“Fossilized” is sometimes used to indicate petrification, but this is not really correct.
Wow…soft tissues can actually last millions of years?!? I totally didn’t get that from the show last night and was wondering why they were trying to get samples from what I thought was rock!
I saw the same show and they made it clear that it wasn’t a real mummy-- no soft tissue left. They were hoping to find some protein molecules in the rock, as they survive longer than DNA. The proteins could then be compared to living relatives (birds or reptiles) to how similar it was. Kind of an indirect way of looking at the DNA.
The dinosaur soft tissue thing has really been siezed upon by the young earth creationists, and as a result, there is a fair bit of loud misinformation floating around about it, including the assertion that the material under discussion is ‘unfossilised’.
AFAIK, what has actually been observed is certain cases where the rigid mineral parts of a fossil have been chemically dissolved to reveal structures composed of pliable material, but apparently not necessarily the original material - it’s been replaced and modified in a similar way that is familiar with hard fossils, it just happens to have been replaced by materials that are flexible when combined in this way. It’s fossilised, just differently.