Although prehistoric sites frequently contain numerous fragments and traces of many different kinds of colouring matter, intensive study of this type of archaeological remains began only recently. Such studies, aimed at determining how raw materials formed and changed over time, and how they were transported by the groups of humans who used them, are extremely valuable as they reveal shared strategies, that is, cultural traditions and the spaces in which they developed. The scope of this paper focusses on the description of the main geological contexts in which ferruginous colouring materials form and are found. In the framework of a collective research program called Pigmentothèque (iron- and manganese-rich rocks and minerals library), geological surveys are conducted taking into consideration the geological settings in which colouring materials are present and using a common record and sampling methodology which is followed by petrophysical, mineralogical and chemical analyses based on a shared procedure and vocabulary. In order to go beyond descriptions based solely on colour and chemical composition, we describe the great variety of iron-rich materials that can be used to obtain colouring matter. This diversity in the formation and evolution of iron-rich materials must be taken into account when trying to understand past humans’ choices of raw materials, their provenance and the anthropogenic and natural modifications they have undergone. We also describe criteria for recognising cohesive remains of colouring matter during archaeological excavations, so these artefacts can take their place alongside other mineral resources in helping improve our understanding of past societies.
Located in
Library
/
RBINS Staff Publications 2021
Prior to the present revision the taxon Labidodemas comprised Labidodemas americanum, L. pertinax, L. rugosum and L. semperianum. An up-to-date re- evaluation of the group proved that at least four additional species need to be assigned to it. Three of these are new to science: one has recently been discovered in the shallow waters of KwaZulu-Natal, Republic of South Africa; one originates from Low Island, Australia, and was erroneously identified as L. semperianum, and one stems from South-West Sulawesi, again erroneously identified as L. semperianum. In addition, Holothuria maccullochi, classified in the monotypic subgenus Irenothuria, and Holothuria proceraspina are assigned to Labidodemas; the former as a valid species and the latter as a synonym of L. semperianum. Annotated taxonomic descriptions, distribution maps and an identification key are given. The new observation that L. americanum possesses Cuvierian tubules suggests that its rank remains at generic level rather than at family level as was recently proposed.
Located in
Library
/
RBINS Staff Publications
