A dinosaur bone buried for 80 million years has yielded a mix of proteins and microstructures resembling cells. The finding is important because it should resolve doubts about a previous report that also claimed to have extracted dino tissue from fossils.
Proteins such as collagen are far more durable than DNA, but they had not been expected to last the 65 million years since the dinosaurs died out. So palaeontologist Mary Schweitzer of North Carolina State University attracted wide attention when she reported finding first soft tissue and later collagen from a Tyrannosaurus rex leg bone that was intact until it was broken during excavation.Yet critics said the extraordinary claim required extraordinary evidence, and asked for protein sequences, better handling of samples to prevent contamination, and confirmation analyses from other laboratories.
So Schweitzer took a look at the pristine leg bone of a plant-eating hadrosaur that had been encased in sandstone for 80 million years. She and colleagues exhaustively tested the sample, sequencing the proteins they found with a new and better mass spectrometer and sending samples to two other labs for verification.Now they report recovering not just collagen – which conveys little evolutionary information because it is the same in almost all animals – but also haemoglobin, elastin and laminin, as well as cell-like structures resembling blood and bone cells. The proteins should reveal more about dinosaur evolution because they vary much more between species.
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