Earlier this year, I spent some time at Northwestern State University in Northwest Louisiana to scan a collection of Caddo vessels from the Belcher and Gahagan sites. Many of these were illustrated and described by Dr. Clarence Webb; including this effigy vessel from the Belcher site.
Dr. Webb’s illustration (above) and description of this vessel:
Pottery vessel 3 of Burial 15, Belcher Mound, is a bird effigy vessel found with above 2 in NE corner. It is a small bowl of clay tempered ware, black core, and brown-black surface which is polished, with white pigment impressed into the engraved lines. The head is represented by a conical knob projecting at rim level, encircled by 5 parallel lines. The opposite tail is flat, at rim level, bifurcate or half-disc in shape, with 3 parallel arcs on the upper surface. Small flat tabs project from each side to represent wings, each also having 3 parallel arcs on upper flat surface, from base to tip. 3 parallel horizontal lines encircle the body of the bowl, just below the rim, except where they are interrupted by the projections. Convex base.
While yes, this post contains a great interactive figure of an incredible Caddo vessel from the Sam Kaufman site (curated at Southern Methodist University #SMU), I wanted to take a moment to bring us full-circle, and return to the reason that I am scanning all of these vessels. Some time ago, I began getting fascinated by the high degree of variability in Caddo vessel shape and size, and have since also noticed some degree of variation in asymmetry.
At the same time that my interest in this topic began to increase, I also quickly realized just how much room for growth that there was in terms of applying geometric morphometrics to archaeological problems. It took time to get through the literature; and I kept finding new articles and book chapters listed in the references of my readings that had escaped the reach of my initial literature review.
Since I had been tinkering with social networking, I reached out to a colleague to assist me in building a citation network. That network has since been completed, and proved to be an invaluable asset in terms of not only centralizing the archaeological literature associated with geometric morphometrics, but it helped me to identify those works in the geometric morphometric literature that are most often cited (InDegree) and most important (identified using Google’s PageRank algorithm) to the overall network (click here to view the interactive network).
Having made my way through the literature, I began to think through the various methods of landmark and semilandmark applications that were available (based on the numerous research questions that could be asked of these data), and quickly found that the configurations were really only limited by my 3D modeling abilities. At that point, I ventured up to Lakewood, Colorado to spend some time working with the crew at Geomagic, where I learned how to use and employ the various features of Geomagic Design X and Control X (more here). Using these tools, I was able to devise a method of applying landmarks in a replicable manner using reference geometry that was built around the 3D mesh of the ceramic vessel. This first iteration of the landmark and semilandmark configuration worked very well for addressing some of my initial questions (see that in the video below).
From here, things began to get more complex. In October of last year, I headed to Portugal for what would be an important transitional period for my work; learning how to write scripts for, and run the various analyses in, the geomorph package in R. This opened something of a Pandora’s box for me, from which it is very likely that I will never fully recover. Needless to say, shape, form, allometry and asymmetry shifted quickly from a peripheral interest to something of a primary project.
Since then, there have been dozens of iterations and developments in my landmark and semi-landmark configurations and analyses; many of which (particularly those associated with my morphological integration inquiries) are actively evolving. I was fortunate to receive funding for much of this work through the National Center for Preservation Technology and Training (NCPTT); a group that I have really enjoyed collaborating with.
As you interact with this vessel from the Sam Kaufman site, consider where (and how) you would apply landmarks/semi-landmarks to the 3D surface.
In terms of theory, analyses of geometric morphometrics can be couched within several interesting anthropological lines of inquiry that include, but are not limited to, (1) identifying the locus of a specific innovation, (2) the spatial and temporal dynamics of morphological variation for specific elements (neck, body, base, etc.) of ceramic design, (3) identifying or refining social networks used by specific Caddo polities/groups during temporal periods previously defined—primarily—through design-based seriations, (4) intra/inter-polity/group variation of shape, form, allometry and asymmetry for ceramic design, (5) potential trade relationships based upon the presence of a specific shape/form of vessel outside of known (assumed) social boundaries, and (6) the power or influence that shifted among and between polities through time. These considerations could be woven into discussions of communities of practice, craft specialization, ceramic technological organization, politics, religion, and—possibly—inter/intra-polity disputes and warfare. Furthermore, this research design has the capacity to inform greatly upon the evolution of ceramic design as it relates to the shape, form, allometry and asymmetry that occurs in Caddo vessels, and by adding the related qualitative measures to our results we might just have the potential to bolster evidence for human behaviors associated with ceramic production and use within the larger ancestral Caddo territory.
Initially a development in the biological sciences, the study of geometric morphometrics in archaeology will no doubt include some interesting discussions regarding the various analytical and theoretical components that are most appropriate for a cultural system versus a biological system as we continue to press forward. There remains plenty of thinking left to do on this subject, but based upon the preliminary results, the capacity for geometric morphometrics to inform upon issues related to material culture and cultural systems could be enormous.
Beyond the realm of empirical geometric morphometric studies, lies the domain of theoretical morphospace. Biologists have gainfully used theoretical morphospace to aid in clarifying issues of morphological change through time. They have done so by aggregating the results of geometric morphometric studies–a dialogue which would seemingly fit very well within the scope of anthropological and archaeological inquiry. By definition, theoretical morphospace represents the full range of possible morphologies for a group of artifacts; allowing investigators to posit, and contemplate, more- and less-adaptive morphologies (similarities and differences). It is within discussions of theoretical morphological transitions where I see the greatest promise for geometric morphometrics in archaeology; an ambit of inquiry in which the skeleton trees and topological properties of the artifacts tell us a much more dynamic story with regard to the progression of a particular shape (bottle, bowl, olla, etc.) through time. Within the context of my own long-term research design, theoretical morphospace seemingly holds much promise, and may represent the approach needed to identify, unlock and unpack a ceramic morphologicaltransition that remains hidden in the various vessel shapes once employed by Caddo potters.
So, while the 3D images are fun to interact with–and have any number of preservation, access and outreach perks–my intention is to use them to bolster our discussions of shape, form, allometry and asymmetry in Caddo ceramic studies, and to use that evidence to posit a number of novel insights into the highly variable and dynamic prehistoric landscape that the Caddo people once commanded.
Many thanks to the Caddo Nation of Oklahoma and Southern Methodist University (Dr. Sunday Eiselt in particular) for the requisite permissions and access needed to scan this important artifact from the ancestral Caddo territory, and to present the 3D model here in color.
Earlier this year, I spent some time at Northwestern State University in Northwest Louisiana to scan a collection of Caddo vessels from the Belcher and Gahagan sites. Many of these were illustrated and described by Dr. Clarence Webb; including this large Belcher Ridged vessel from the Belcher site.
Dr. Webb’s illustration (above) and description of this vessel:
Pottery vessel from floor of House 7, Belcher Mound A, found in sherds on this floor near an ash bed in SE sector. It is an immense jar of type Belcher Ridged, of which the upper half to three-fifths is preserved, the lower portion missing. It is clay tempered, with smoothed surface, colors vary from buff to gray to dark gray or brown. Shape is barrel-like, with moderately flaring rim. Decorated with vertical applique or pushed-up ridges, spaced 6 mm to 2 mm apart over the body; the outer surface of the rim has vertical incisions.
This Belcher Ridged vessel comes from the Belcher Site in Northwest Louisiana, is curated at Northwestern State University in Natchitoches, Louisiana. Funding to produce this 3D model comes from a grant to Selden from the National Center for Preservation Technology and Training. Many thanks to the Caddo Nation of Oklahoma, and Dr. Pete Gregory for the requisite permissions needed to access and scan this vessel.
Earlier this year, I visited SMU to give a short 3D scanning workshop, and to scan a number of Caddo ceramic vessels that are housed there as part of a larger pilot project with Dr. Sunday Eiselt. I just received permission from the Caddo Nation to post the red-slipped vessels in color, and wanted to share the first of these with you.
Many thanks to the Caddo Nation of Oklahoma, and to SMU for making this project possible.
I was recently afforded the opportunity to visit the National Center for Preservation Technology and Training (NCPTT) in Natchitoches, Louisiana to explore possible uses of profilometry for our 3D research of Caddo ceramics. After manipulating various settings and tweaking scan resolutions, we scanned an arbitrary 1.5cm square on an incised Caddo sherd from 41SY280 (41SY280-17; above and below – sherd courtesy of the United States Forest Service). Those results have provided plenty of food for thought; particularly for morphometric attributes associated with Caddo decorative elements.
The image below is of a single 1.5cm surface profile, and the four large dips seen there are incisions that a Caddo maker scored into the surface of the clay body; likely during the Late Caddo period (ca. 1450-1680) in East Texas.
One of the many useful features of the software is that it can rapidly quantify variation in the scanned surface. The image below depicts the results of that quantification when using the default settings. While I would argue for some modifications to this prior to employing those metrics in an analysis, it did make for some interesting discussions about variation in Caddo decorative elements.
So might it be possible to use this technology to better segregate between the decorative elements (engraved, punctated, incised, trailed, etc.) used by Caddo potters? Maybe. It might also help to better characterize variations in tool use by Caddo ceramicists as they sought to create (and replicate?) specific design elements.
Profilometers are not newcomers to archaeology and have been used in both historic and prehistoric applications (mainly physical properties [primarily topography] and use-wear on lithics), and a review was recently published discussing experimental studies of lithic use-wear.
In terms of ceramics, there was a recent study of Roman potterygraffiti that employed a profilometer.
This has left us with plenty to ponder in terms of the morphological attributes associated with Caddo decorative elements, and I hope to return to NCPTT in the near future to begin working to parse those out.
Many thanks to Jason Church and Tad Britt at NCPTT for taking the time to explain the various aspects of the hardware and software, and for allowing time on the profilometer.
Thanks also to Juanita Garcia and the United States Forest Service, who provided the Caddo sherd from 41SY280 that was scanned with the profilometer, and used in this post.
References made to published literature are hyperlinked within this post above the animation. Link to those by clicking on the bold/color text.
I recently had the opportunity to visit the Caddo Nation’s administrative complex near Binger, OK to create 3D scans/models of Caddo burial vessels, including a few vessels from the Poole Site (3GA3) below, that had been previously repatriated. As the models are completed, they are being added to our digital repository along with photographs and a large number of qualitative and quantitative attributes. Further, data papers are being written for vessels from each site that outline the hardware, software and methods used to generate these scan data. After the data papers are published, all scans from that site are then added to our study of 3D geometric morphometrics and rotational symmetry.
As the collection of 3D scan data continues to grow, so does the complexity of our analyses. It is our hope that we will soon be able to begin comparative morphometric studies of the variable elements (demarcating between the various forms of bottle necks, rims on carinated bowls, shifts in base sizes and shape, etc.) from sites thought to occupy the same temporal period (based on additional data from seriations, design analyses and radiocarbon assays). After that, we can begin to make more meaningful forays into the evolution of the various shapes through time.
While it has taken time to get to this point, we should be able to begin making some substantive leaps in the near future. As with most worthwhile endeavors, taking the time to be skeptical and to refine our approach has proven to be very helpful, and we are indebted to many of our colleagues for their help and constructive criticisms along the way.
None of this would have been possible without the incredible support of our colleagues in the various repositories and museums where we operate, and we are also very thankful to have had the support of and permission of the Caddo Nation to access and document these collections prior to reburial.