Microstructural and biomolecular preservation is reported in fossils as old as the Triassic. Such preservation suggests unusual taphonomic conditions. We collected fragments of fossil whale bone from silty, tuffaceous, and diatomaceous rocks of the middle-upper Miocene portion of the Pisco Formation. The whale fossils within the region are generally well-preserved and mostly articulated, including some specimens with in situ baleen. Due to the depositional setting associated with the preservation of these fossils, they could be expected to be favorable candidates for the preservation of cellular microstructures and/or original biomolecules. To test this hypothesis, fossil whale bone fragments were subjected to microscopic analysis and EDTA-mediated demineralization to release extractable materials. Microscopy of partially demineralized fossil bones revealed quartz-permineralized osteocyte-like and vessel-like structures. Protein assay (micro-Bicinchoninic Acid Assay) of the supernatants obtained from demineralized fossils yielded 12 to 19.5 μg of protein per gram of bone. MALDI-TOF analysis of the extracted protein demonstrated the presence of approximately 5 kD molecules in one fossil sample, consistent with the presence of highly fragmented polypeptides. An LC-MS/MS analysis of the fragmentation pattern of the tryptic digest of extracted protein was performed. However, attempted protein identification was unsuccessful. Nevertheless, this study first documents the microstructural preservation with some silicification of the fossil whale bones of the Pisco Formation, and then quantifies extractable protein from these bones. It adds to the growing body of reports of microstructural and organic preservation in fossils.

This study presents evidence of pre-mortem traumatic injury and its sequalae on multiple Edmontosaurus annectens skeletal elements recovered from a largely monodominant Cretaceous (Maastrichtian) bonebed. The sample consists of 3013 specimens excavated and prepared from two quarries, of which 96 elements manifest one or more macroscopic bone abnormalities and 55 specimens display pathology attributable to physical trauma. Evidence of traumatic pathology is strongly associated (P < .05) with body region, occurring disproportionately in the caudal vertebrae. Pre-mortem fractures with subsequent bone remodeling and hypertrophic ossification of caudal neural spines are present principally in the middle and mid-distal regions of the tail, while fractures of the vertebral centra are present primarily in the distal tail region. Other skeletal regions, such as chevrons, phalanges of the manus and ribs display unambiguous evidence of healed trauma, but with less frequency than the tail. These findings, in combination with current understanding of hadrosaurian tail biomechanics, indicate that intervertebral flexibility within the middle and mid-distal region of the tail likely rendered these caudal vertebrae more susceptible to the deleterious effects of repeated mechanical stress and subsequent trauma, potentially accompanying running locomotion and other high-impact herd interactions. Healed fractures within the region are also suggestive of accumulated injuries due to a combination of tail usage in defense and possibly accidental bumping/trampling associated with gregarious behavior.

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