Morphological characteristics of preparator air-scribe marks: Implications for taphonomic research

PLoS One. 2018 Dec 20;13(12):e0209330. doi: 10.1371/journal.pone.0209330. eCollection 2018.

Abstract

Taphonomic analyses of bone-surface modifications can provide key insights into past biotic involvement with animal remains, as well as elucidate the context(s) of other biostratinomic (pre-burial) processes, diagenesis, excavation, preparation and storage. Such analyses, however, first require researchers to rigorously disambiguate between continuums of damage morphologies prior to attributing individual marks to specific actors and effectors (e.g., carnivore tooth, stone tool cutting edge, etc.). To date, a number of bone-modifying agents have been identified, and criteria for identifying their traces have been published. Relatively little research, however, has focused on bone-surface modifications imparted during specimen preparation. Herein we report that air scribes, small pneumatic tools commonly used for preparation in museum contexts, can generate unintentional marks that may mimic surficial modification caused by carnivores. To aid investigators in assessing the hypothesis that a mark in question is derived from air-scribe preparation activities, we provide high-resolution, detailed morphological information imaged with scanning electron microscopy (SEM). The main diagnostic characteristic of air-scribe damage is the occurrence of sequential, variously spaced, sub-millimeter scallop-like stepped bone removals. This morphology can resemble damage imparted by carnivore teeth. In contrast to marks produced by trampling, stone tools and carnivores, however, no continuous internal features, such as linear microstriations, were observed within grooves produced by the air scribe. Thus, the presence of such features can be used to disprove an air-scribe origin. A culmination of the morphological criteria presented herein, cross-cutting relationships with other surficial features (e.g., diagenetic discoloration, weathering textures), the position of occurrence, and an overall contextual framework for the assemblage is suggested for accurate identification of such traces. The ability to recognize or disprove air-scribe damage will allow researchers to confidently proceed with interpreting past biological and sedimentological interactions with animal remains.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Bites and Stings / pathology
  • Body Remains / anatomy & histology
  • Body Remains / ultrastructure
  • Bone and Bones / anatomy & histology
  • Bone and Bones / ultrastructure
  • Carnivora
  • Fossils / anatomy & histology*
  • Fossils / ultrastructure
  • Humans
  • Microscopy, Electron, Scanning
  • Museums
  • Paleontology / instrumentation
  • Paleontology / methods*
  • Specimen Handling / instrumentation
  • Specimen Handling / methods
  • Surface Properties

Grants and funding

Funding for this project was provided by a Baylor University graduate research grant (GRG-typeR-#2) awarded to LAW, and a National Science Foundation grants BCS-1524036 and BCS-1524041 awarded to JVF and KMB. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.