Taphonomic Agents Research Articles

The Role of Bubo virginianus magellanicus as Rodent Bone Accumulator in Archaeological Sites: A Case Study for the Atuel River (Mendoza, Argentina)

AbstractMicromammalian bone assemblages from modern pellets of the strigiform Bubo virginianus magellanicus, from the upper Atuel River (southern Mendoza, Argentina), were taphonomically analysed. The results allow us to place B. v. magellanicus in the category of intermediate modification (Category 2). This sample has also been compared with results from other members of this genus, in order to classify B. v. magellanicus as a taphonomic agent. The participation of the Bubo species in archaeological accumulations has been documented, but in Argentina, the role of B. v. magellanicus has been reported up to the present. It is partly because of the sequence of one archaeological site in the south of Mendoza Province called Laguna El Sosneado‐3 (LS‐3). However, considering the absence of a current taphonomic model of this owl, this participation was mentioned as a hypothesis. In the current investigation, archaeological and modern samples have been compared. The results indicate that the skeletal element assemblages recovered from LS‐3 were accumulated by strigiform birds. Taphonomical evidence of light modifications on units I and IV indicates that Tyto alba (Category 1) was probably the main species involved in these units, whereas the taphonomical evidence on skeletal element assemblages recovered from units II and III suggests the action of a strigiform with a major category of modification such as B. v. magellanicus. Copyright © 2015 John Wiley & Sons, Ltd.

Bird-bone modifications by Iberian lynx: A taphonomic analysis of non-ingested red-legged partridge remains

The Iberian lynx (Lynx pardinus) is a significant taphonomic agent in Iberian ecosystems. Its diet is based almost exclusively on rabbits and it is complemented mainly with birds from the Phasianidae, Anatidae and Corvidae families. We present here the results of actualistic taphonomic research conducted to assess modifications produced by Iberian lynx on non-ingested red-legged partridge (Alectoris rufa) remains. Through anatomical representation, breakage patterns and bone surface modifications we were able to establish the main characteristics of the taphocoenosis of the Iberian lynx regarding one of their complementary preys. The results revealed low survival of entire carcasses, remains mainly of offal and feathers – that are barely preserved in archaeological fossil records –, and some skeletal remains. Anatomically there was greater evidence of thoraxes, especially pelvis/synsacrum and adjoining ribs, and distal portions of wings and legs. Breakage was nominal with a high survival of whole elements, but none of the major long-bone remains were complete. The bones in the meaty parts (wings/humeri, drumsticks/femurs and tibiae and breasts/sternums), were very fragmented. Tooth marks were rare and occurred mainly in the form of notches on fractured edges none of which had opposite tooth marks. A comparison of our results with those obtained for the main prey of lynxes – rabbits – indicated a lower survival of bird remains. This differential taphonomic pattern must be related to the anatomy of the prey and the anatomical distribution of meaty parts which are the main interest of the predator.

Observations on seaweed attachment to bivalve shells in Peter the Great Bay (East Sea) and their taphonomic implications

Observations in beach, intertidal and upper subtidal environments in Peter the Great Bay (north-western East Sea) have shown that attached algae were found on empty shells of 13 species of epifaunal and infaunal bivalve mollusks. Thirteen algae species were identified on empty dislodged shells but more than 50 species are known to be epibiotic on living bivalves. The dislodgement of shells with attached algae takes place in semi-enclosed, low-energy areas, as well as those which are open and affected by strong wave action, indicating the large scale of this phenomenon. The significance of seaweed transportation of living mollusks and their empty shells in the coastal zone, involving both taphonomic and ecological processes, is stressed. Algae appear to be a taphonomic agent and play a similar role as compared to birds or hermit crabs, but they act passively and contribute to environmental mixing in death assemblages in coastal environments.

What is the taphonomic agent responsible for the avian accumulation? An approach from the Middle and early Late Pleistocene assemblages from Payre and Abri des Pêcheurs (Ardèche, France)

The acquisition of quick-flying small prey has been a widely discussed topic over the last decades, especially since the emergence of archaeological bird collections more ancient than expected, with evidence of anthropogenic processing. Residue analyses carried out on stone tools at the Payre site in France (MIS 8–5) suggest human activity on birds; however, no direct analyses have been carried out on avian specimens from the site. Similarly, no detailed data from numerous bird bones have been obtained from a nearby site, Abri des Pêcheurs (MIS 5–3), which could also provide important information about subsistence strategies in the region. Bird bones from both sites were analyzed here within the framework of the taphonomic methodology and identified a wide variety of avian specimens, suggesting nocturnal raptors and small mammal carnivores as main accumulator agents. Despite the anthropogenic activity at Payre proposed from lithic residue and use-wear analyses, bird bones do not reveal any hominid intervention. Our attempt here is to explain this apparent contradiction and discuss possible hypotheses regarding the presence of avian specimens at both archaeological sites.

Potential Use of Bacterial Community Succession in Decaying Human Bone for Estimating Postmortem Interval.

Bacteria are taphonomic agents of human decomposition, potentially useful for estimating postmortem interval (PMI) in late-stage decomposition. Bone samples from 12 individuals and three soil samples were analyzed to assess the effects of decomposition and advancing time on bacterial communities. Results indicated that partially skeletonized remains maintained a presence of bacteria associated with the human gut, whereas bacterial composition of dry skeletal remains maintained a community profile similar to soil communities. Variation in the UniFrac distances was significantly greater between groups than within groups (p<0.001) for the unweighted metric and not the weighted metric. The members of the bacterial communities were more similar within than between decomposition stages. The oligotrophic environment of bone relative to soft tissue and the physical protection of organic substrates may preclude bacterial blooms during the first years of skeletonization. Therefore, community membership (unweighted) may be better for estimating PMI from skeletonized remains than community structure (weighted).

Experimental archaeology in a mid-latitude periglacial context: insight into site formation and taphonomic processes

Experiments have been carried out at two sites in periglacial (MAAT ≈ 0 °C) and alpine (MAAT ≈ 4 °C) contexts in the Pyrenees, including open-air and cave loci, to document in detail the role of site formation processes and taphonomic agents in the degradation of archaeological assemblages. In both sites, the experimental cells have undergone significant changes over the five years of measurements. These are marked by slow downslope creep of lithic artefacts due to solifluction, rain creep, and the impact of debris fallen from the wall in the cave. The behaviour of bone material was significantly different from that of lithics, due to the activity of scavengers. This was responsible for scattering a high proportion of bone remains, and displacements were typically significant. Such activity was also responsible for a high number of bone elements being lost (1/3 to 2/3 of the bones). Weathering, mostly cracking and exfoliation, also affected dry bone material in the open-air cells. The measurements have highlighted the specific nature of the cave context, which plays a protective role for bone remains against meteoric agents. The talus at the entrance of the cavity was also characterized by a strong spatial heterogeneity in sedimentary processes, which may generate a differential preservation of the assemblages.

Virtual taphonomy: A new method integrating excavation and postprocessing in an archaeological context.

The objective of this paper was to integrate excavation and post-processing of archaeological and osteological contexts and material to enhance the interpretation of these with specific focus on the taphonomical aspects. A method was designed, Virtual Taphonomy, based on the use and integration of image-based 3D modeling techniques into a 3D GIS platform, and tested on a case study. Merging the 3D models and a database directly in the same virtual environment allowed the authors to fully integrate excavation and post-processing in a complex spatial analysis reconnecting contexts excavated on different occasions in the field process. The case study further demonstrated that the method enabled a deeper understanding of the taphonomic agents at work and allowed the construction of a more detailed interpretation of the skeletal remains than possible with more traditional methods. The method also proved to add transparency to the entire research process from field to post-processing and interpretation. Other benefits were the timesaving aspects in documentation, not only in the excavation process but also in post-processing without creating additional costs in material, as the equipment used is available in most archaeological excavations. The authors conclude that this methodology could be employed on a variety of investigations from archaeological to forensic contexts and add significant value in many different respects (for example, detail, objectivity, complexity, time-efficiency) compared to methods currently used.

Expansion of the referential framework for the rabbit fossil accumulations generated by Iberian lynx

The Iberian lynx is an endemic predator of the Iberian Peninsula currently restricted to southern Spain. It is one of the primary predators of rabbits in Iberian ecosystems and probably an important taphonomic agent. Few experimental taphonomic research has focused specifically on this aspect because the Iberian lynx is currently the world's most endangered feline. During the late Pleistocene and early Holocene its home range spread to the whole Iberian Peninsula and Southern France. From an anthropological point of view, Southwestern Europe is one of the major areas of interest for studies of leporid fossil accumulations because some archaeological sites show a clear anthropogenic exploitation of rabbits and hares by Neanderthals and Anatomically Modern Humans. This research is framed within the study of variability in the taphonomic signal of the Iberian lynx. In this paper a set of rabbit bones eaten by a female lynx and her cubs during the denning season which takes around two months has been studied. The experimental assemblage has been characterized using the anatomical representation of the remains, breakage patterns and damage modifications preserved on bone surfaces. The taphonomic data are discussed along with data from the literature of the ethology of the Iberian lynx. The characteristics of the taphonomic modifications are very similar in non-ingested remains altered by adults documented in previous works, and non-ingested remains modified by the litter, in terms of anatomical profile, breakage and tooth mark frequency. The main difference is the presence of specific small tooth marks caused by infant individuals. It is concluded that the Iberian lynx may be a significant source of rabbit bone accumulations in caves and shelters, but exclusively during its breeding season. The presence of bones of mixed origin in the final set (non-ingested and ingested) is inferred as a taphonomic signal feature of Iberian lynx. The expansion of the referential framework will allow us to strongly discriminate the role of hominids and lynxes in fossil accumulations of rabbits, especially when this kind of preys was usually exploited and accumulated by the hunter–gatherers in caves and shelters.

Recovering data from historical collections: stratigraphic and spatial reconstruction of the outstanding carnivoran record from the Late Pleistocene Equi cave (Apuane Alps, Italy)

Equi Terme is a hamlet located in northern Tuscany, in Apuan Alps regional Park. An outstanding fossil vertebrate collection housed in Florence is the result of excavations in the Equi cave and shelter during the period 1911–1919. This faunal assemblage (associated with Mousterian artefacts) may be correlated with the middle of MIS 3. All of the specimens recovered at Equi early in the last century were collected with attention to their stratigraphical positions. Detailed field annotation for nearly every specimen allowed us to organize them and attempt a stratigraphical and spatial reconstruction of the fossiliferous deposits.We present the results of the study of the spatial and stratigraphic distribution of the carnivoran species in the Equi cave and shelter, and re-evaluate the taphonomic agents of accumulation and the fossil distribution within the stratigraphic record. In particular, we evaluated the distribution of Panthera pardus, which, unusually for Europe, is abundant in the Equi cave assemblage.This analysis highlights the importance of the re-evaluation of historical collections and allows for future comparisons with data from more recent excavations at the Equi site. The analysis also provides an account of the distribution of carnivorans throughout the stratigraphic record. The constant presence and the predominance of leopards and wolves over lions and smaller carnivorans, allow for evaluations of their ethology and may be related to a short period of sediment accumulation.

Scavenging in Northwestern Europe: A Survey of UK Police Specialist Search Officers

Physical search methods used by police specialist searchers are based on counter-terrorism methods and not on the search and recovery of outdoor surface deposited human remains, nevertheless these methods are applied to scenes involving human remains. Additionally, there is limited published forensic literature within Northwestern Europe on the potential taphonomic agents within this region that are capable of modifying human remains through scavenging, scattering and removal. The counter-terrorism basis in physical search methods and the gap in published forensic literature regarding scavenging in this region can potentially impede searchers’ abilities to adapt physical search methods to their full efficiency in the search and recovery of scavenged human remains. This paper analysed through a questionnaire survey of 111 police specialist searchers, within the U.K., the impact of animal scavenging on the search and recovery of human remains.According to questionnaire respondents’ experiences and knowledge, the occurrence of scavenging at scenes in which respondents took part in a physical search for human remains was common (63.46%,n= 66) and happened most frequently with surface deposits (68.25%,n= 43). Scavenging resulted in the recovery of incomplete sets of remains (59.79%, n= 58) and influenced search perimeters (58.33%, n= 35). Scavenging also affected recovery rates at scene searches (80.43%,n= 74) that included the use of cadaver dogs with police handlers. The impact scavengers within this region have on different crime scene scenarios and search methods is not reflected in current published literature or search standards.

The Avifauna of Southern Istria (Croatia) During the Late Pleistocene: Implications for the Palaeoecology and Biodiversity of the Northern Adriatic Region

ABSTRACTThis paper presents palaeoecological and taphonomic analyses of bird remains from Late Pleistocene sediments from two caves in southern Istria, Šandalja II and Ljubićeva pećina. Most of the identified species are found today in Istria and along the Adriatic coast, although the presence of ptarmigan (Lagopus mutus) and willow grouse (L. lagopus) indicates colder conditions than those characteristic of the region today. Taxa from both sites are characteristic of open, forest‐steppe, rocky, forest, and mixed biotopes. These sites differ somewhat in avifaunal composition — aquatic‐adapted taxa are only found at Šandalja II, probably reflecting differences in human activities and in their geographic settings. Likewise, only Šandalja's assemblages show an increase in the representation of forest‐adapted taxa over time. These data from the bird remains complement reconstructions based on mammalian assemblages from these sites. Different taphonomic agents accumulated the bird bones, and bone surface modifications show that birds of prey, small carnivores, and Late Upper Palaeolithic people helped accumulate these remains. The important Late Pleistocene avifaunal assemblages from southern Istria indicate that a mosaic of habitats was present during the Late Pleistocene and a deep time depth to the rich biodiversity of the region today. Furthermore they suggest that the exposed Adriatic Plain supported a diverse and rich biome. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Towards the identification of a new taphonomic agent: An analysis of bone accumulations obtained from modern Egyptian vulture (Neophron percnopterus) nests

This paper presents the results of a study of bones recovered in various current Egyptian vulture (Neophron percnopterus) nests in a Mediterranean region of the Iberian Peninsula. The Egyptian vulture, a diurnal, scavenging, rupicolous bird of prey, is one of four vulture species that currently inhabit the Iberian Peninsula. An analysis of the remains found in the nests confirms that it has a heterogeneous diet that includes remains from human activities (butchery and food production) and the carcasses of dead animals, although it is possible that they also prey on small-sized taxa. The taphonomic study determines these birds' capability of transporting, accumulating and altering bone remains. Some of the elements show marks caused by beak and/or claw impacts brought about primarily during feeding, which have characteristic typologies. Despite the fact that this is not a bone-eating vulture, it can also be seen that some bones are swallowed. The characteristics of the bone set studied here are important for establishing the origin of bone accumulations on archaeological sites.

Study of the SHK Main Site faunal assemblage, Olduvai Gorge, Tanzania: Implications for Bed II taphonomy, paleoecology, and hominin utilization of megafauna

Recent excavations at the SHK Main Site, Olduvai Gorge, Tanzania, have unearthed a dense concentration of stone tools and faunal remains. Here, we describe how the site contributes to the understanding of hominin subsistence strategies and paleoecology during Bed II times (1.78–1.34 Ma). This palimpsestic site is located within, and on the over-bank of, a river channel. Taphonomic analyses suggest that a heterogeneous set of taphonomic agents played a role in the accumulation and modification of the faunal assemblage. Although hominins played a rather marginal part in this assemblage's faunal accumulation and modification, the recovered faunal assemblage includes evidence that is consistent with hominin exploitation of hippopotamus and equid. This evidence underscores the possibility that by 1.5 Ma hominins were diversifying their diet and enlarging their ecological niche by exploiting, probably opportunistically, megafaunal remains more commonly than previously documented. Taphonomic spatial analysis shows differences in bone preservation and modification according to whether faunal specimens were located inside the river channel or on its over-bank. We also show that spatial taphonomic analysis can contribute to the understanding of palimpsest-site formation, as well as to the reconstruction of diverse taphonomic agents responsible for that formation. A comparative analysis of taxonomic diversity between SHK versus other upper Bed II sites supports the notion that the environment was fairly open prior to the beginning of the Bed III deposits. The large number of lithic artifacts concentrated at the SHK Main Site, when considered in conjunction with the small amount of evidence for carcass-processing, suggests that hominins engaged in a diversity of activities beyond butchery.

Taphonomic comparison of bone modifications caused by wild and captive wolves (Canis lupus)

This work presents data obtained from experiments conducted on wild and captive wolves. Actualism is a very useful tool for taphonomic studies, as it allows us to understand the behavior of fauna in the past. However, not many past experimental studies have dealt with wolves as taphonomic agents. The results of the study show that wolves modify animal carcasses in advanced stages that include fracturing the bones in order to consume the marrow. By comparing captive and wild wolves, we observe that captive wolves often modify ungulate carcasses to a greater degree than do wild wolves. Moreover, factors such as the size of the ungulate and the period of availability of the carcass influence the type and degree of bone alteration. Tooth mark dimensions also allow us to compare wolves with other large carnivores and reveal that wolves differ significantly from large felids and ursids, and they have more in common with hyenids.

Osteophagia and bone modifications by giraffe and other large ungulates

Ungulates often gnaw on animal bones, antlers, horns, and ivory in order to maintain certain nutritional requirements. The resulting modifications to bones and other skeletal elements have been variously described and reported, but are largely absent from most taphonomic reference works. Previous accounts of such gnawing behaviors have been restricted to smaller ungulates. Here we provide detailed description of large ungulates gnawing on bones from similarly sized animals, namely giraffe, camel, and cattle, from Africa, Australia, and North America. Large ungulates will often select fresh bones for gnawing, but will also target dry and weathered bones. Surface modifications are variable, ranging from tooth depressions, punctures, and grooves, to scooping out damage, polishing, and splintering. Similar features are prevalent in carnivore- and porcupine-gnawed bone assemblages, but the effects of large ungulate gnawing can be readily distinguished from those taphonomic agents. Ungulate gnawing may also vary in relation to body size, in that smaller ungulates impact skeletal elements differently than larger ungulates.

Taphonomic signatures in molluscan fossil assemblages from the Holocene lagoon system in the northern part of the coastal plain, Rio Grande do Sul State, Brazil

Molluscan shell accumulations (shell beds) are very common in shallow marine and estuarine environments in South America and also on the continental shelf between Argentina and southern Brazil. The development of these shell beds is restricted to the Quaternary, and can provide a great opportunity for taphonomic studies, which are rare in this geographic location. This study investigates the influence of environmental processes on the destruction of biological remains in a subtropical lagoonal setting by describing the taphonomic signatures occurring in the mollusk shells from the Tramandaí Lagoon, northeastern Rio Grande do Sul State, Brazil. This lagoon system originated during the regressive phase that followed a transgressive maximum at 6.0–6.5 ka BP. The taphonomic variables (fragmentation, margin modification, surface alteration, hinge fine scale alteration and corrosion degree) and their damage states were recorded for 1000 shells of Erodona mactroides. The shells were recovered from two outcrops 8 km apart. 14C-AMS dating were performed on the shells of E. mactroides from those outcrops, which yielded similar ages (from 1060 to 1490 cal yrs BP). The ages would indicate that the Tramandaí Lagoon occupied a larger area and must have been subjected to very rapid progradation towards its present position. Several taphonomic variables, such as fragmentation, surface alteration, and corrasion extent and oxidation, presented significant differences (p < 0.01) between the two outcrops. This may be due to some natural variation of the estuarine and lagoonal environments or differences within the taphonomically active zone (TAZ). Dissolution seems to be a leading taphonomic agent in lagoonal environments. The shells from the two outcrops are within the TAZ and, due to intense dissolution, they will most likely leave no geological record.

Crocodyliform Feeding Traces on Juvenile Ornithischian Dinosaurs from the Upper Cretaceous (Campanian) Kaiparowits Formation, Utah

Crocodyliforms serve as important taphonomic agents, accumulating and modifying vertebrate remains. Previous discussions of Mesozoic crocodyliform feeding in terrestrial and riverine ecosystems have often focused on larger taxa and their interactions with equally large dinosaurian prey. However, recent evidence suggests that the impact of smaller crocodyliforms on their environments should not be discounted. Here we present direct evidence of feeding by a small crocodyliform on juvenile specimens of a ‘hypsilophodontid’ dinosaur from the Upper Cretaceous (Campanian) Kaiparowits Formation of southern Utah. Diagnostic crocodyliform bite marks present on a left scapula and a right femur, as well as a partial probable crocodyliform tooth crown (ovoid in cross-section) preserved within a puncture on the right femur, comprise the bulk of the feeding evidence. Computed tomography scans of the femoral puncture reveal impact damage to the surrounding bone and that the distal tip of the embedded tooth was missing prior to the biting event. This is only the second reported incidence of a fossil crocodyliform tooth being found embedded directly into prey bone. These bite marks provide insight into the trophic interactions of the ecosystem preserved in the Kaiparowits Formation. The high diversity of crocodyliforms within this formation may have led to accentuated niche partitioning, which seems to have included juvenile dinosaurian prey.

Taphonomic studies with wild brown bears (Ursus arctos) in the mountains of northern Spain

In this work we present data obtained from experiments with wild brown bears from the Cantabrian Mountains in northern Spain. Our results show that wild brown bears do not take carcasses to their dens, but can displace them by tens of meters before eating them, and the remains can become dispersed some meters around the place where the carcass is consumed. The long bones of large-sized carcasses show no fractures, but they do show tooth marks (scores, pitting, punctures and furrowing) especially on the cancellous bone of the epiphyses. Ribs and vertebrae show fractures and furrowing. The innominate also shows furrowing on cancellous bone of the ilium and ischium. The results of this study are in agreement with previous work and also shed some light on the behavior of this carnivore in the wild. The data gathered are of great importance when interpreting paleontological and archaeological sites where the bear is a likely taphonomic agent.

Large carnivores as taphonomic agents of space modification: an experimental approach with archaeological implications

At most Pleistocene archaeological sites it is difficult to observe structured complex spatial behaviour. This common phenomenon could be a taphonomic issue. Problems in the preservation of the original spatial intra-site distribution could be related to hominid–carnivore alternation in the use of space. In the present paper we analyse the results of our experimentation with large extant carnivores (bears, wolves, hyenas and lions) and propose these animals acted as hearth and hearth-related assemblage modifiers. In this sense, the role of carnivores in the modification of these elements can cause problems in the interpretation and visibility of modern and complex behaviour in the conception of space in the archaeological record.

Chacarita Project: Conformation and analysis of a modern and documented human osteological collection from Buenos Aires City – Theoretical, methodological and ethical aspects

Osteological reference collections play a key role in bioanthropological research; they allow the development and testing of methods for sexing and ageing individuals using various bone and dental attributes. This paper presents the first stage results of the ongoing Chacarita Research Project, which aims to generate and study a reference collection of adult skeletons representative of the contemporary population of Buenos Aires city. The Chacarita Collection consists of unclaimed human remains of individuals of known nationality, sex, age, cause and date of death from the Chacarita Public Cemetery. Unlike other similar endeavours, this sample has been completely exhumed using archaeological techniques. So far, a total of 146 adult skeletons have been recovered (60 females – 41.1% and 86 males – 58.90%), the majority of which have ages-at-death in the range of 71–90 years. They were born primarily in Argentina (n=133; 91.1%), although other nationalities are also represented. Dates of death range between 1987 and 2000. In the short term, the osteological study of this collection will allow assessment of the performance of classical methods of sex determination and age-at-death estimation in a local setting. A special priority will be given to the study of osteological changes in individuals over 50 years. As the sample is being retrieved by exhumation, the impact of taphonomic agents on the most diagnostic bone structures is also being assessed. In the long term, this osteological collection will be available to generate new population-specific techniques and to develop comparative biological studies.