Actualistic Research Research Articles

A downcore increase in time averaging is the null expectation from the transit of death assemblages through a mixed layer

AbstractUnderstanding how time averaging changes during burial is essential for using Holocene and Anthropocene cores to analyze ecosystem change, given the many ways in which time averaging affects biodiversity measures. Here, we use transition-rate matrices to explore how the extent of time averaging changes downcore as shells transit through a taphonomically complex mixed layer into permanently buried historical layers: this is a null model, without any temporal changes in rates of sedimentation or bioturbation, to contrast with downcore patterns that might be produced by human activity. Assuming stochastic burial and exhumation movements of shells between increments within the mixed layer and stochastic disintegration within increments, we find that almost all combinations of net sedimentation, mixing, and disintegration produce a downcore increase in time averaging (interquartile range [IQR] of shell ages), this trend is typically associated with a decrease in kurtosis and skewness and by a shift from right-skewed to symmetrical age distributions. A downcore increase in time averaging is thus the null expectation wherever bioturbation generates an internally structured mixed layer (i.e., a surface, well-mixed layer is underlain by an incompletely mixed layer): under these conditions, shells are mixed throughout the entire mixed layer at a slower rate than they are buried below it by sedimentation. This downcore trend created by mixing is further amplified by the downcore decline in disintegration rate. We find that transition-rate matrices accurately reproduce the downcore changes in IQR, skewness, and kurtosis observed in bivalve assemblages from the southern California shelf. The right-skewed shell age-frequency distributions typical of surface death assemblages—the focus of most actualistic research—might be fossilized under exceptional conditions of episodic anoxia or sudden burial. However, such right-skewed assemblages will typically not survive transit through the surface mixed layer into subsurface historical layers: they are geologically transient. The deep-time fossil record will be dominated instead by the more time-averaged assemblages with weakly skewed age distributions that form in the lower parts of the mixed layer.

A functional investigation of southern Cape Later Stone Age artefacts resembling aerophones

This paper describes possible sound-producing artefacts from two Later Stone Age deposits in the southern Cape, South Africa. Implements previously described as a ‘wirra wirra’ or ‘pendant’ from Klasies River main site (KRM), a ‘woer woer’ or ‘bullroarer’ and four ‘pendants’ from Matjes River (MR) are analysed and their sound producing qualities assessed through an actualistic research programme. For comparative purposes, a replica of an ethnographic ‘spinning disk’ was also spun and its sound recorded. All of the implements, except the MR ‘woer woer’ produced a sustained, pulsed, whirring sound when spun. Minor adjustments to the MR 5135 replica resulted in successful sound production. The frequency range of the KRM replica and ethnographic KK058 implement produced a frequency variation of between 52 Hz and 200 Hz. The frequency range of the pendant replicas varied from 55.55 to 250 Hz, comparable to other bullroarers. Spinning produces use-wear predominantly on the left laterals of the perforations, whereas pendant use produces use-wear along the upper sector of the perforation, thus allowing us to distinguish these two uses based on the placement of use-wear. We conclude that one of the bone artefacts previously thought to be a pendant, MR 40, most likely functioned as an instrument to produce sound. This investigation thus experimentally confirms that earlier hypotheses that the ‘wirra wirra’ from KRM and the ‘bullroarer’ from MR were aerophones are judicious. In addition we demonstrate for the first time that some archaeological pendants, such as MR 40, may have been used as free aerophones or bullroarers.

Evaluating fish processing patterns in the lower stream of the Colorado River (eastern Pampa-Patagonian transition, Argentina): An experimental work

Fish processing and consumption became an increasing part of the subsistence patterns in the lower stream of the Colorado River (Buenos Aires province, Eastern Pampa-Patagonian transition, Argentina) during the Middle and Late Holocene (ca. 6000–250 years BP). Freshwater and marine fish specimens recovered from the zooarchaeological assemblages of these periods exhibit processing cutmarks. Since cutmarks are unusual traits in this type of prey and actualistic research related to fish processing are not abundant, an experimental study was performed. The objective was to determine whether the activities related to fish butchering generate cutmarks and, in that case, if a pattern in the distribution of the marks is found in specific anatomic units. Results indicate that independently from the kind (Perciformes or Siluriformes) and size of fish, as well as the type of lithic raw materials used in the butchering process, cutmarks were consistently found on vertebrae. Despite two different methods of butchering employed for Perciformes and Siluriformes, the filleting stage produced the highest frequency of cutmarks. Nevertheless, results obtained in the experimental work show differences when comparing with archaeological assemblages. A combination of factors related to variations in butchering processes, the butchery skill, the employment of specific methods of cooking, and taphonomic factors, could be the causes of the differences.

The utility of captive animals in actualistic research: A geometric morphometric exploration of the tooth row of Alligator mississippiensis suggesting ecophenotypic influences and functional constraints.

Captive broad snouted crocodylians are generally thought to have wider, shorter rostra than their wild counterparts. Interpreted to reflect morphological change in response to the conditions of captivity, this qualitative pattern could affect the utility of these animals in a variety of fields of research. However, due to relative ease of access and availability of life history data, captive animals are often utilized in actualistic research. Thus, this issue should be addressed in more detail. Here we explore snout shape variation between captive and wild members of Alligator mississippiensis using two-dimensional (2D) morphometric techniques. Several landmark schemesare used to assess the utility of different aspects of morphology in distinguishing the groups. While statistical analyses consistently differentiated between the groups, the area of morphospace occupied by wild members of A. mississippiensis generally overlapped with the larger area encompassing the captive specimens. This indicates that the captive condition is not as uniform as previously thought and instead encompasses a large spectrum of morphologies, ranging from the stereotypical broad, shortened snouts to outlines that are indistinguishable from the wild morphotype. These results align well with the interpretation that this change reflects an extreme example of ecophenotypy, since ranched, farmed, or zoo organisms are held in an array of enclosures, ranging from indoor, climate controlled pens to outdoor, more natural areas. This variation in environments should be reflected in different reactions to the animals' surroundings, resulting in a broad spectrum of morphotypes. While wild specimens are still preferred, especially for fine scale analyses, these results indicate that not all captive members of A. mississippiensis exhibit the extreme morphological alterations often cited in the literature. Weighing the conditions in which the animals are held and exploring the possibility of morphological differences against the benefits of using captive specimens should be part of any actualistic study. J. Morphol. 277:866-878, 2016. © 2016 Wiley Periodicals, Inc.

Location and Position in Archaeology: Revisiting the Original Association of a Folsom Point with Bison Ribs

The proveniences (locations) of artifacts have long been critically important to archaeological interpretation. Although of major importance to site formation studies, positional attributes of artifacts (e.g., orientation, dip, which side is up) are seldom mentioned. When discovered in 1927, the in situ association of a Folsom projectile point with two ribs of a Pleistocene form of bison was interpreted as indicative of the contemporaneity of the three items, and thus was taken as evidence for the Pleistocene age of humans in North America. The locational and positional attributes of the two ribs and the point relative to one another suggest it is improbable that the point was deposited simultaneously with the two ribs as a result of it being embedded in the animal's flank, which is not to say the three items are not depositionally and temporally associated. Previously unmentioned positional attributes of the items making up the original Folsom association exemplify the importance of such attributes. New understanding of the original association underscores that actualistic research is required to identify the kinds of positional attributes important to questions regarding site formation and site structure.

The role of small carnivores in the movement of bones: implications for the Pampas archaeofaunal record, Argentina

The use of the same spaces and prey by humans and carnivores often leads to the formation of complex faunal assemblages, in which the anatomical and taxonomic composition results from the combined action of these agents. The aim of this paper is to evaluate bone movement based on actualistic research in the Pampas region of Argentina, with an emphasis on the action of carnivores as agents responsible for transport and accumulation of bone. Number of taxa, percentage of specimens affected by carnivores in each environmental context, skeletal representation and carnivore modifications on European hare from the hills and the coast, and bone movement are discussed. The implications of our actualistic results for the regional archaeological record are also addressed. All of the sampled environments presented evidence of carnivore modifications, with percentages between 9 % (coast) and 40 % (hills). This information demonstrates that this agent plays an active role in the formation of modern bone assemblages in the Pampas region and provides a frame of reference for exploring interpretations about the low percentages of carnivore activity recorded in the archaeological record of the region. We argue that carnivores not only modify an assemblage by incorporating or destroying bones, but also by moving them to other locations. Consequently, carnivore effects on site formation in the Pampas region should not be underestimated when their marks are scarce.

Pattern and variety: Remembering Stanley A. Ahler's contributions to Plains Village archaeology

During his 40-year career, Stanley A. Ahler consistently applied a coherent set of theoretical principles and methodological practices to his studies of Plains Village communities in the Middle Missouri subarea. For Ahler, modes of human behavior could only be understood and explained within the context of behavioral diversity and so he regarded the detection of variation within the material record as a crucial component of archaeological research. Ahler's studies of household and community variation in the Middle Missouri embody the best qualities of processual archaeology: a willingness to challenge previous interpretations; a commitment to actualistic research and interdisciplinary collaboration; a desire to understand the complexities of human behavior; and a belief in the importance of public archaeology. In pursuing this program, Ahler and his many collaborators transformed how archaeologists think about Plains hunter-farmers.

The "bear" essentials: actualistic research on Ursus arctos arctos in the Spanish Pyrenees and its implications for paleontology and archaeology.

Neotaphonomic studies of large carnivores are used to create models in order to explain the formation of terrestrial vertebrate fossil faunas. The research reported here adds to the growing body of knowledge on the taphonomic consequences of large carnivore behavior in temperate habitats and has important implications for paleontology and archaeology. Using photo- and videotrap data, we were able to describe the consumption of 17 ungulate carcasses by wild brown bears (Ursus arctos arctos) ranging the Spanish Pyrenees. Further, we analyzed the taphonomic impact of these feeding bouts on the bones recovered from those carcasses. The general sequence of consumption that we charted starts with separation of a carcass’s trunk; viscera are generally eaten first, followed by musculature of the humerus and femur. Long limb bones are not broken open for marrow extraction. Bears did not transport carcasses or carcass parts from points of feeding and did not disperse bones appreciably (if at all) from their anatomical positions. The general pattern of damage that resulted from bear feeding includes fracturing, peeling, crenulation, tooth pitting and scoring of axial and girdle elements and furrowing of the upper long limb bones. As predicted from observational data, the taphonomic consequences of bear feeding resemble those of other non-durophagus carnivores, such as felids, and are distinct from those of durophagus carnivores, such as hyenids. Our results have paleontological and archaeological relevance. Specifically, they may prove useful in building analogical models for interpreting the formation of fossil faunas for which bears are suspected bone accumulators and/or modifiers. More generally, our comparative statistical analyses draw precise quantitative distinctions between bone damage patterns imparted respectively by durophagus (modelled here primarily by spotted hyenas [Crocuta crocuta] and wolves [Canis lupus]) and non-durophagus (modelled here by brown bears and lions [Panthera leo]) carnivorans.

A taphonomic study of the African wild dog (Lycaon pictus)

Carnivore taphonomy has been traditionally used for the interpretation of archaeological sites in order to discriminate human-generated or modified from non-anthropic bone assemblages. In most of this actualistic research, the focus has mainly been placed on hyenas and felids, neglecting other carnivores. This paper analyzes the taphonomic impact of the African wild dog (Lycaon pictus) on equid bones and compares it with the bone modification patterns produced by other canids, such as wolves (Canis lupus) in order to compare medium-/large-sized canid variability on bone modification patterns and elaborate a referential framework which could be feasibly applied to the zooarchaeological record to detect canid intervention on archaeological assemblages in the past.

Feeding behaviour and taphonomic characterization of non-ingested rabbit remains produced by the Iberian lynx (Lynx pardinus)

The rabbit (Oryctolagus cuniculus) is usually the most abundant taxon found in the Palaeolithic and Epipalaeolithic archaeological sites of southern Europe and the Mediterranean Basin. These accumulations may be the result of different abiotic factors, biotic agents and/or the interaction of both. For these reasons, over the last decades actualistic research has been conducted on different predators of rabbits. Among them, the Iberian lynx (Lynx pardinus) is an excellent candidate for study because: 1) its diet is based almost exclusively on this leporids and 2) its historical distribution overlaps with one of the most interesting areas for small game research, the Iberian Peninsula and southern France. Here we present the taphonomical analysis of non-ingested rabbit remains collected from two Iberian lynx captive breeding centers located in southern Spain. Our results show: i) predominance of the distal segment of the appendicular skeleton; ii) variable breakage patterns, with a high proportion of whole bones of the autopodium and heavy breakage of the zeugopodium and stylopodium; iii) rare bone surface modifications. Comparison of these results with those obtained for other terrestrial carnivores, such as the fox, reveals great similarities, the only difference being the more abundant tooth marks present on fox non-ingested rabbit assemblages.

Some Comments on the Archaeology of Slave Diets and the Importance of Taphonomy to Historical Faunal Analyses

The archaeology of enslaved peoples carries great value as the material culture often represents the only documentation of their lives. Slave diet has been a major focus within the archaeology of enslaved Africans in North America, but a number of influential faunal analyses such as those from Cannon's Point, Georgia, and Monticello, Virginia, are problematic due to the limited use of taphonomic investigations. At these sites, patterns identified in the faunal remains were attributed to human behavior, but instead the patterns are more plausibly the result of methodological issues and destructive taphonomic processes acting on the bones post-depositionally. The importance of applying taphonomic research to historic faunal analyses is illustrated through a reanalysis of the fauna from the South African Castle of Good Hope's Granary which was originally attributed to slaves. In the end, this review of previous slave diet studies and reanalysis of the Granary faunal remains seeks to emphasize further integration of taphonomic and actualistic research into historical period zooarchaeology.

Actualistic research into dynamic impact and its implications for understanding differential bone fragmentation and survivorship

The relationship between bone mineral density and archaeological bone survivorship has played a critical role in zooarchaeological and taphonomic studies in recent decades. Numerous studies have suggested that higher-density skeletal element portions survive more frequently than lower-density element portions when archaeological assemblages are affected by some taphonomic processes. Interpretations of density mediated destruction have become commonplace in the archaeological literature, and are often used to explain the absence of certain bone elements and element parts in zooarchaeological assemblages. This study explores the effects of rockfall on bovid elements in varied environmental conditions and the differential survivorship of their element parts, and has implications for understanding the taphonomic processes through which bones are subjected to dynamic loading. Actualistic rockfall experiments conducted on twelve samples of frozen, fresh, and semi-dried bovid bones reveal that the generally low-density epiphyseal ends of bone elements resist fracture and analytical deletion with more frequency than the higher-density diaphyses. This evidence suggests that bone density does not correlate with likelihood of breakage or effective archaeological “destruction” when rockfall and other processes that result in dynamic impact are in action. While this research does not question the relationship between bone mineral density and the likelihood for archaeological survivorship as the result of some taphonomic processes, it presents one specific set of taphonomic processes that result in the differential survivorship of low density bone elements parts and the fragmentation and destruction of higher density element parts. This research presents evidence that shows that dynamic impact is a process capable of fragmenting and sometimes destroying high-density elements while low-density elements survive.

Lewis R. Binford's Impact on Zooarchaeology

Zooarchaeology asked the same research questions and answered them the same ways between 1950 and 1980. Change occurred when actualistic research revealed that the taphonomy of a collection of faunal remains could significantly skew interpretations. Lewis Binford's ethnoarchaeological work among Alaskan Inuit peoples focused on how human behaviors created bone assemblages and how carnivore behaviors influenced those bone assemblages. That research provided new interpretive models based on the frequencies of prey-carcass parts and their economic utility. Binford published a wealth of actualistic data and his models on economic utility in his 1978 book <i>Nunamiut Ethnoarchaeology.</i> In his 1981 book <i>Bones: Ancient Men and Modern Myths</i> and his 1984 book <i>Faunal Remains from Klasies River Mouth</i>, he used the Nunamiut models and suggested that our early hominid ancestors scavenged much of the meat they consumed contrary to the then popular view that those ancestors were hunters. Binford's legacy to zooarchaeology can be considered revolutionary in a Kuhnian sense because that legacy comprises major alterations to how we analyze and interpret faunal remains, as well as significant changes to what we think we know about the behaviors of our early hominid ancestors.

Modeling ground slate knife production and implications for the study of household labor contributions to salmon fishing on the Pacific Northwest Coast

Despite longstanding anthropological concerns with the origins of intensive delayed-return subsistence economies and the timing of the development of increasingly complex political systems on the Northwest Coast, the use and production of slate knives—one of the most archaeologically visible tools used to process seasonally available salmon—has received little attention in the archaeological literature. This can be attributed, in part, to the persistence of artifact typologies that have failed to generate behavioral implications for variability in slate artifact assemblages. In this article, I use data derived from ethnographic, experimental, and actualistic research to develop an approach to the classification of slate artifacts expected of knife-production activities. Emphasis is placed on framing slate knife production as a temporally emergent and situated activity, but also as an operational sequence that can be modeled due to regularity in the decisions and motions expected of tool makers producing functionally specific tools. Using slate assemblages recovered during the partial excavation of seven Late and Contact period Coast Salish houses in southern British Columbia, I then evaluate and demonstrate the utility of this approach by considering variability in household labor contributions to salmon fishing.

Taphonomic implications of roosting behavior and trophic habits in two species of African owl

As some of the most common predators of micromammals, owls are implicated in the formation of many fossil assemblages. Actualistic research on owl-accumulated assemblages has tended to focus on owls roosting in caves. Comparatively few data are available on the roosting behavior, and prey preference of owls in open habitats. This paper presents observations on the roosting and prey habits of two sympatric species of owl in the Serengeti region of northern Tanzania, the Barn Owl, Tyto alba affinis, and the Spotted Eagle Owl, Bubo africanus. The Barn Owl and Spotted Eagle Owl are found to segregate by roosting habit, with Barn Owls occupying cavity roosts and Eagle Owls appearing on the ground or in tree crowns. Previous studies comparing these two species suggested a close similarity in trophic habits. A comparison of large samples (MNI = 1012) at cavity and exposed roosts shows identical taxonomic representation, though differences are found in the relative abundance of some taxa and significant differences in prey body mass.

Distinguishing Climate in the Soil Record Using Chemical Trends in a Vertisol Climosequence from the Texas Coast Prairie, and Application to Interpreting Paleozoic Paleosols in the Appalachian Basin, U.S.A.

A suite of Vertisols (clay-rich soils with high shrink-swell potential) were examined across a climosequence (climatic transect) in twelve soil pits from the Coast Prairie of Texas in order to determine if mean annual precipitation (MAP) exerts a control on the chemistry of these soils, and if the observed chemical trends are useful for interpreting paleoclimate records of paleoVertisols in the geologic record. The precipitation regime of the climosequence spans a range between 144 and 86 cm/year, with moisture regimes classified as udic, udic-ustic, ustic, and aridic-ustic, in a general northeast to southwest direction. Other soil-forming factors, such as soil age (<35–40 ka), parent material (fluviodeltaic Beaumont Formation of late Pleistocene age), landscape (low-relief coastal plain), and vegetation (prairie or mixed woody shrubs), are relatively constant across the climosequence. Climate-sensitive chemical proxies of MAP identified include dithionite citrate-extractable Fe (Fedith), acid oxalate-extractable Fe (Feoxal), CaCO3 equivalent (CaCO3equiv), S, and ammonium acetate-extractable Na, K, and Mg (Naacet, Kacet, and Mgacet, respectively), which vary across the climosequence because of differences in effective depths of leaching and intensity of wetting and drying cycles. These standard USDA wet-chemical climate proxies are related to bulk (oxide or element) chemistry of soils and paleosols measured using XRF, which supports the use of geochemical climate proxies for interpreting the paleoclimate records of paleoVertisols. Application of the chemical index of alteration minus potash (CIA-K) geochemical climofunction to late Mississippian paleosols from the Appalachian basin of the eastern U.S. demonstrates evidence for a shift from a lower to a higher MAP paleoclimate that is consistent with previous paleoclimate models and with observed morphological changes in the paleosols. We advocate actualistic research using bulk chemistry of soils and paleosols as a means of obtaining soil information useful for interpreting paleosols in the geological record.

Importance of limb bone shaft fragments in zooarchaeology: a response to “On in situ attrition and vertebrate body part profiles” (2002), by M.C. Stiner

M.C. Stiner's (J. Archaeol. Sci. 29 (2002) 979) recent defense of anatomical regions profiling (ARP) prompted this response, because conclusions drawn from a large body of actualistic research, generated by numerous zooarchaeologists over the past 30+ years, are consistent in highlighting the differential survivorship of intra-element portions of limb bone specimens. Further, these results argue for the rigorous identification of limb bone shaft specimens and their systematic inclusion in the analyses of archaeofaunas. Stiner's “flexible hunter-scavenger” model of Neandertal ecology in coastal Italy is based, in part, on results from ARP, a technique that we believe does not fully recognize and incorporate these important findings.

Mobility strategies and site structure: a case study of Inamgaon

Mobility change and its archaeological indicators is one aspect that has been dealt with extensively in archaeological literature. Archaeologically, movement change has been understand at two levels, at the level of the region and at the level of a single site. This present work is a methodological exercise which seeks to understand mobility change from the archaeological record of a single site, ie, Inamgaon by reanalysing earlier arguments and bringing some new methods in this respect using actualistic research as a heuristic device to understand archaeological patterning. Criteria used by researchers to understand mobility change like house shape, form, change in organic remains, maintenance behaviour, spatial patterning have been critically assessed and used in this respect. The Chalcolithic site of Inamgaon situated in the western part of India has been taken up as a case study for this purpose.

Patterns of Appendicular Skeletal Disarticulation: A Taphonomic Investigation of the Hudson-Meng Bonebed

Information from published taphonomic research concerning bison disarticulation frequencies is compared with additional primary data from several recent bison mortality sites to aid in the assessment of patterns of appendicular skeletal disarticulation within a large Paleoindian bison bonebed. Variation in the composition of articulatedbison skeletal segments from the 1991-96 excavations at the Hudson-Meng site (25SXJJ5), Sioux County, Nebraska, is compared with a combined data set of actualistic research from several modern bison mortality sites. Comparison of naturally occurring skeletal disarticulation patterns and archaeologically recorded patterns of disarticulation at Hudson-Meng aids in evaluating the formational history of the bonebed. These data indicate that the patterns of disarticulation from within the main bonebed level at Hudson-Meng closely resemble those from modern mortality sites.

Shell Beds as paleoecological puzzles: A case study from the Upper Permian of the Paraná Basin, Brazil

Microstratigraphic, sedimentological, and taphonomic features of the Ferraz Shell Bed, from the Upper Permian (Kazanian-Tatarian?) Corumbatai Formation of Rio Claro Region (the Parana Basin, Brazil), indicate that the bed consists of four distinct microstratigraphic units. They include, from bottom to top, a lag concentration (Unit 1), a partly reworked storm deposit (Unit 2), a rapidly deposited sandstone unit with three thin horizons recording episodes of reworking (Unit 3), and a shell-rich horizon generated by reworking/winnowing that was subsequently buried by storm-induced obrution deposit (Unit 4). The bioclasts of the Ferraz Shell Bed represent exclusively bivalve mollusks.Pinzonellaillusa andTerraia aequilateralis are the dominant species. Taphonomic analysis indicates that mollusks are heavily time-averaged (except for some parts of Unit 3). Moreover, different species are time-averaged to a different degree (disharmonious time-averaging). The units differ statistically from one another in their taxonomic and ecological composition, in their taphonomic pattern, and in the size-frequency distributions of the two most common species. Other Permian shell beds of the Parana Basin are similar to the Ferraz Shell Bed in their faunal composition (they typically contain similar sets of 5 to 10 bivalve species) and in their taphonomic, sedimentologic, and microstratigraphic characteristics. However, rare shell beds that include 2–3 species only and are dominated by articulated shells preserved in life position also occur. Diversity levels in the Permian benthic associations of the Parana Basin were very low, with the point diversity of 2–3 species and with the within-habitat and basin-wide (alpha and gamma) diversities of 10 species, at most. The Parana Basin benthic communities may have thus been analogous to low-diversity bivalve-dominated associations of the present-day Baltic Sea. The ‘Ferraz-type’ shell beds of the Parana Basin represent genetically complex and highly heterogeneous sources of paleontological data. They are cumulative records of spectra of benthic ecosystems time-averaged over long periods of time (102–104 years judging from actualistic research). Detailed biostratinomic reconstructions of shell beds can not only offer useful insights into their depositional histories, but may also allow paleoecologists to optimize their sampling designs, and consequently, refine paleoecological and paleoenvironmental interpretations.