Semester of Graduation

Spring 2026

Degree

Master of Arts (MA)

Department

Geography and Anthropology

Document Type

Thesis

Abstract

This study examines the effect of surface type on decomposition rates and postmortem interval (PMI) estimation in southeastern Louisiana, a humid, subtropical environment. Accurate PMI estimation remains one of the most complex challenges in forensic anthropology due to the variability introduced by intrinsic and extrinsic factors. The role of surface type, however, remains underexplored and inconsistently reported in the literature.

To address this gap, ten domestic pig (Sus scrofa) hind limbs were placed on five surface types: natural grass (control), sand, gravel, concrete pavers, and tarpaulin (n=2 per surface). Specimens were observed over 65 days at Louisiana State University’s (LSU) Forensic Taphonomy Education and Research Facility (FTERF) in East Baton Rouge Parish, Louisiana. Decomposition stages were assessed using the Megyesi et al. (2005) Total Body Scoring (TBS) system (limb section only) and the Galloway et al. (1989) stage model. ADD values were calculated using locally recorded temperature data to evaluate thermal input across specimens. Insect activity surface temperatures, and specimen temperatures were also documented.

Results indicate that surface type influenced decomposition progression, though patterns varied by scoring method. Sand and gravel specimens progressed to skeletonization within the study period, while concrete, tarp, and control specimens largely remained in advanced decomposition. Tarp and gravel exhibited the highest average surface temperatures, while concrete demonstrated the lowest. Insect colonization patterns also differed, with sustained maggot activity most evident in sand specimens and reduced persistence observed on tarp.

A retrospective analysis of 21 forensic cases from southern Louisiana was then conducted to contextualize experimental findings. ADD ranges associated with early, advanced, and skeletonization stages generally overlapped with experimental trends, though variability in casework emphasized the influence of uncontrolled environmental factors.

Overall, this research supports the importance of regional, surface-specific considerations in PMI estimation and contributes to the development of localized forensic taphonomic standards for humid, subtropical environments.

Date

3-27-2026

Committee Chair

Juliet Brophy

LSU Acknowledgement

1

LSU Accessibility Acknowledgment

1

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