Endogenous proteins found in a 70-million-year-old giant marine lizard

Mosasaurs are a group of extinct varanoid lizards that inhabited marine environments during the Late Cretaceous (approximately 100-65 million year ago).  With their discovery, the scientists Johan Lindgren, Per Uvdal, Anders Engdahl, and colleagues have demonstrated that remains of type I collagen, a structural protein, are retained in a mosasaur fossil. Collagen is the dominating protein in bone.

The scientists have applied a broad spectrum of sophisticated techniques to achieve their results. The scientists have used synchrotron radiation-based infrared microspectroscopy at MAX-lab in Lund, southern Sweden, to show that amino acid containing matter remains in fibrous tissues obtained from a mosasaur bone.  In addition to synchrotron radiation-based infrared microspectroscopy, mass spectrometry and amino acid analysis have been performed.

Previously, other research teams have identified collagen-derived peptides in dinosaur fossils based on, for example, mass spectrometric analyses of whole bone extracts.

The present study provides compelling evidence to suggest that the biomolecules recovered are primary and not contaminants from recent bacterial biofilms or collagen-like proteins.

Moreover, the discovery demonstrates that the preservation of primary soft tissues and endogenous biomolecules is not limited to large-sized bones buried in fluvial sandstone environments, but also occurs in relatively small-sized skeletal elements deposited in marine sediments.