Incorporating intraspecific variation into dental microwear texture analysis

Area of Science:

• Paleontology
• Zoology
• Bioarchaeology

Background:

• Dental microwear texture analysis (DMTA) quantifies microscopic tooth wear patterns.
• DMTA is crucial for inferring diets of extinct mammals from fossil records.
• Intraspecific variation in tooth wear can obscure dietary signals.

Purpose of the Study:

• To investigate how intraspecific variation in macropodid dental microwear can enhance dietary signal recovery.
• To develop methods for maximizing dietary information from limited fossil data.
• To improve the resolution of dietary reconstructions using DMTA.

Main Methods:

• Applied scale-sensitive fractal analysis and ISO surface texture analysis to macropodid dental microwear.
• Utilized Linear Mixed Effects modeling to incorporate intraspecific factors into interspecific dietary analyses.
• Employed Akaike's Information Criterion for model comparison and independent cross-validation.

Main Results:

• Significant intraspecific variation was found for all analyzed DMTA variables.
• A small number of intraspecific factors were sufficient to improve species differentiation.
• Accounting for specimen variation and sampling location (facet) improved model accuracy.
• Ecoregion, microscope, tooth position, and wear also influenced microwear patterns.

Conclusions:

• Models incorporating intraspecific variation significantly improve the resolution of dietary reconstructions from dental microwear.
• Understanding and modeling intraspecific variation is key to maximizing dietary inferences from fossil macropodids.
• This approach enhances the utility of DMTA for paleoecological studies.