The Nash Specimen (BRCM 2021.10)

The Nash Specimen (BRCM 2021.10) is a slab of sandstone from Lower Jurassic strata, likely from the Portland or adjacent Middletown quarries of Connecticut that contains a highly unusual and unique association of theropod dinosaur footprints and bone casts. The slab is on public display at the Bruce Museum in Greenwich, CT. <br> The Nash Specimen, much like the only other known example of this mode of preservation (MOS 2001.248), preserves the natural bone casts of a single or multiple early theropod dinosaurs. In comparison to MOS 2001.248, the bone casts of the Nash Specimen were similarly transported by flowing water after the death and disarticulation of the animal(s). In both instances of preservation, the bones were deposited with a strong current as indicated by “v” shaped scour marks and the orientation of the bones being both parallel and or perpendicular to the flow of water. The Nash Specimen reveals bone casts with longitudinal cracks, gouges, and breaks like MOS 2001.248, which indicates a level of damage before and during the preservation of the bones as casts. In line with Getty and Bush’s (2011: 411) hypothesis on bone cast formation, the Nash Specimen provides a comparative case where bone compression, fracturing, and eventual subsurface chemical dissolution is the most parsimonious hypothesis to explain the observed taphonomic features.