Raman spectroscopic documentation of Oligocene bladder stone

Abstract

Discovery of a fossil (30-35 million-year-old) urolith from Early Oligocene deposits in northeastern Colorado provides the earliest evidence for the antiquity of bladder stones. These are spherical objects with a layered phosphatic structure and a hollow center. Each layer is composed of parallel crystals oriented perpendicular to the surface. Macroscopic and microscopic examination and X-ray diffraction analysis, along with comparison with 1,000 contemporary uroliths, were used as evidence in the confirmation of this diagnosis. Raman microspectroscopy verified the presence of organic material between layers, confirming its biologic origin.

Nondestructive recognition and differentiation of quasi‐spherical structures of biologic interest

“…Histologic section (destructive analysis) of such concretions (whether biologically or geologically-derived) may identify features that distinguish among them (Biehler-Gomez et al, 2019a), but not always. Sophisticated studies (e.g., Raman spectroscopy) may be required to even prove that they are biologically derived (Marshall et al, 2006(Marshall et al, , 2010Rothschild et al, 2013;Thomas et al, 2007). The potential value offered by analysis of concretions supports their collection and analysis.…”

“…Preliminary study of uroliths and bezoars at the Armed Forces Institute of Pathology Museum (formerly part of the Walter Reed Medical Center) revealed that some uroliths had a unique mammary appearance, but most were macroscopically difficult to distinguish from bezoars (Rothschild et al, 2013). The large sample (approximately 1,000 uroliths) illustrated the breadth of appearances, but was unable to provide diagnostic criteria to distinguish among the various types.…”

“…Specific reports include observation in dog Canis familiaris (Calle, 1988; Clark, 1974; Finco et al, 1970) the maned wolf Chrysocyon brachyurus (Bush & Bovee, 1978), cat Felis domesticus (Bohonowych et al, 1978), the Asian small clawed otter Aonyx cinerea (Calle, 1988), raccoon Procyon lotor (Page & Probst, 1981), ferret Mustela putorius , and mink Mustela vison (Sompolinsky, 1950), harbor seal Phoca vitulina (Stroud, 1979), and nondomesticated llama Lama glama (Kock & Fowler, 1982). Prior to their recognition in the Oligocene (Rothschild et al, 2013), the oldest previously reported urolith (D'Alessio et al, 2005; Shah & Whitfield, 2002; Shattock, 1905) was found in a cave dating back 8,500 years.…”