Event Title

Using microscopy methods to examine the taphonomy of crayfish (O. rusticus) in fresh water and marine environmental proxies

Location

101 Science & Nursing Building

Start Date

27-4-2018 2:45 PM

End Date

27-4-2018 3:15 PM

Description

Several locally collected specimens of crayfish (Orconectes rusticus) were subjected to burial in clay (Edgar Minerals kaolinite) that had been wetted with tap water, pond water or seawater (salinity = 35ppt), with and without bacteria present for a period of two weeks or one week in order to study the preservational differences in marine and freshwater environments. Observation at the macroscopic scale indicated freshwater specimens were significantly more decayed than salt water specimens, and they were most well preserved when bacteria were present in the salty water. In order to study the taphonomy of these specimens in greater detail, claws and portions of the carapace were examined at the microscopic scale using scanning electron microscopy. Energy dispersive X-ray spectroscopy was also used to identify the elemental composition of the specimens. Closer examination of the specimens revealed significant preservational differences between the proxy environments. The current working hypothesis to explain greater decay of freshwater specimens is that the salts and bacteria in seawater work to alter the pH and Eh of the water, improving preservation.

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Apr 27th, 2:45 PM Apr 27th, 3:15 PM

Using microscopy methods to examine the taphonomy of crayfish (O. rusticus) in fresh water and marine environmental proxies

101 Science & Nursing Building

Several locally collected specimens of crayfish (Orconectes rusticus) were subjected to burial in clay (Edgar Minerals kaolinite) that had been wetted with tap water, pond water or seawater (salinity = 35ppt), with and without bacteria present for a period of two weeks or one week in order to study the preservational differences in marine and freshwater environments. Observation at the macroscopic scale indicated freshwater specimens were significantly more decayed than salt water specimens, and they were most well preserved when bacteria were present in the salty water. In order to study the taphonomy of these specimens in greater detail, claws and portions of the carapace were examined at the microscopic scale using scanning electron microscopy. Energy dispersive X-ray spectroscopy was also used to identify the elemental composition of the specimens. Closer examination of the specimens revealed significant preservational differences between the proxy environments. The current working hypothesis to explain greater decay of freshwater specimens is that the salts and bacteria in seawater work to alter the pH and Eh of the water, improving preservation.