This action is then applied by the operator to dislodge adhering matrix during preparation. These hand-held tools utilize compressed air in conjunction with an internal piston to drive a carbide stylus in a high-frequency, reciprocating movement. In this paper we investigate bone-surface modifications experimentally imparted by an air scribe, a small pneumatic tool commonly used in museum contexts. Other occurrences, especially subtle and/or isolated traces, require further analysis prior to inferring agency, effector, and timing. Such is the case when cross-cutting relationships can be applied in relation to other taphonomic or diagenetic features preserved on the bone (e.g., staining, root etching, weathering texture) to deduce the relative timing of the trace (i.e., bone-surface mark) generation. In some instances, identifying this modern damage is relatively straightforward. This is potentially problematic because excavation and preparation activities can create additional marks on bone surfaces. Relatively little research has focused on bone-surface modifications imparted during this latter portion of the taphonomic record (though see and references therein). Taphonomic analyses typically occur after bones have been excavated, cleaned, and archived. However, the taphonomic history of a bone or fossil (hereafter, bone) spans from the death of the animal until the present day. Most of these studies focus on biostratinomic (pre-burial) agents. In recent years, an increasing number of bone-modifying agents have been identified, and criteria for identifying their marks have been published ( and refs therein ). The recent discovery that crocodiles can produce linear damage morphologies that may mimic stone-tool marks highlights how descriptions and explanations of previously unexplored bone-surface modifications can dramatically alter interpretations of ancient assemblages.

These analyses, however, first require researchers to rigorously disambiguate between continuums of damage morphologies prior to attributing individual marks to specific agents and effectors (e.g., carnivore tooth, stone tool cutting edge, etc.).

Such studies have proven invaluable in elucidating the diets and paleoecologies of insects, dinosaurs, mammalian carnivores, and Paleolithic hominins, among others. Taphonomic analyses of bone-surface modifications can provide key insights into past biotic involvement with animal remains. 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. 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. Thus, the presence of such features can be used to disprove an air-scribe origin. 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. This morphology can resemble damage imparted by carnivore teeth. The main diagnostic characteristic of air-scribe damage is the occurrence of sequential, variously spaced, sub-millimeter scallop-like stepped bone removals. 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). 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. Relatively little research, however, has focused on bone-surface modifications imparted during specimen preparation. To date, a number of bone-modifying agents have been identified, and criteria for identifying their traces have been published. 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.). 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.

Groove scribe website