Volumen 4. Number 2. Year 2006.

2019-11-06T21:39:50+02:00October 26th, 2019|Volumen 4. Number 2. Year 2006.|

VOLUME 4. NUMBER 2. 2006

Evidence of High-Frequency Storm Disturbance in the Middle Devonian Arkona Shale, Southwestern Ontario.

Cameron J. Tsujita, Carlton E. Brett, Michael Topor, John Topor.


[+info] VOLUME 4. NUMBERS 2. 2006 (1 issue)

The importance of storms as agents of deposition and erosion is obvious in many ancient offshore marine
successions. Indeed, storm-generated shell beds are among the most prominent small-scale features in
otherwise monotonous successions, particularly those dominated by mudstones. Shell beds are usually
interpreted as products of rare episodes of storm-generated disturbance punctuating long periods (tens, to
hundreds, to thousands of years) of quiescence, the shell beds representing storms of greatest severity.
The taphonomic attributes of shell beds in the Middle Devonian Arkona Shale (southwestern
Ontario) indicate that even “simple” shell beds can have complex histories. Shell-rich beds dominated by
well-preserved remains of small rugose corals, spiriferid brachiopods, and a variety of crinoids, are
commonly associated with pavements of shell debris reworked by earlier storms. Taphonomic dissection
of five examples, informally called the lower Arthroacantha bed, the in situ Mucrospirifer bed, the upper
Arthroacantha bed, the auloporid bed, and the Microcyclus bed, reveals a common theme; initial priming
of the seafloor by one or more storms, was followed by colonization of the primed substrate by shelly
benthic fauna which, in turn, was followed by final disturbance and burial of the faunal remains by a later
For storms to have produced multiple signatures in single shell beds of the Arkona Shale, the
frequencies of seafloor disturbance must have been very high, probably on the order of a few years.
Such frequencies are much higher than those implied by stratigraphic occurrences of conspicuous shell beds
(i.e., without considering internal features of the shell beds). This implies that individual shell beds do
not necessarily represent the most severe storms recorded in mudstone successions but can, in some
cases, merely represent the most obvious products of storm disturbance by virtue of their shell content.
Regardless of storm severity, the disturbance of a muddy seafloor lacking abundant shell material would
produce an indistinct mud-on-mud contact that would be much less likely to be noticed than a shell-rich
horizon. By the same token, both low-magnitude (but high-frequency) storms and high magnitude (but
low-frequency) storms can produce shell beds, provided that sufficient shell material is available for
reworking. Obviously, the key to the formation of shell-rich horizon is an abundance of shelly material
on the seafloor. For this, a cause other than storm deposition must be sought; in most cases, these beds
also record interludes of relative sediment starvation and increased seafloor oxygenation.
Interpretations of storm severity from storm-generated shell beds should therefore be approached with
caution and be considered in context of the faunal dynamics and depositional characteristics of a
sedimentary succession as a whole.

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The Taphonomy of Owl-Deposited Fish Remains and the Origin of the Homestead Cave Ichthyofauna.

Jack M. Broughton, Virginia I. Cannon, Shannon Arnold, Raymond J. Bogiatto, Kevin Dalton.


[+info] VOLUME 4. NUMBERS 2. 2006 (2 issue)

We report a case of fish prey dominating the diet of modern barn owls (Tyto alba) and conduct a
descriptive taphonomic analysis on the fish remains the owls deposited. From a sample of 14 barn owl
pellets collected on the floor of a Nevada barn, we identified 3294 tui chub (Gila bicolor) bones. These
remains, derived from very small-sized fish, comprised nearly 90% of the total pellet NISP and were
characterized by relatively complete skeletal part representation, and minimal bone fragmentation and
digestive surface damage. We use this data-set, along with tui chub samples deposited by other agents,
to evaluate the origin of fish remains derived from late Quaternary deposits of Homestead Cave, located
in the northern Bonneville Basin, Utah. Quantitative comparisons of skeletal part representation and
digestive damage show that the Homestead Cave fish assemblage is statistically indistinguishable from
the owl-derived collection but different from chub samples originating from coyote (Canis latrans) scat
and human faeces. Qualitative evaluations of other agents also suggest an owl-based origin of the fauna.
Our analysis calls attention to the important role that owls can play in depositing fish in caves and
rockshelters and provides useful information to researchers interested in deciphering the taphonomic
history of fish remains recovered from these settings around the world.

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Success in Identification of Experimentally Fragmented Limb Bone Shafts: Implications for Estimates of Skeletal Element Abundance in Archaeofaunas.

Travis R. Pickering, Charles P. Egeland, Amy G. Schnell, Daniel L. Osborne, Jake Enk.


[+info] VOLUME 4. NUMBERS 2. 2006 (3 issue)

A strong pattern of high hindlimb representation (especially tibiae) was recognized in our survey of
zooarchaeological analyses that included limb bone shafts in estimates of element abundance in
assemblages from the Old and New Worlds, from widely spread time periods and with various hominid
species that acted as bone accumulators. Inter-element differences in bone mineral density and carcass
transport behavior by hominids do not explain the pattern satisfactorily. We hypothesized that shaft
fragments of hindlimb elements (especially tibiae) might be more “intrinsically identifiable” than are
fragments from other limb bones, and constructed an experiment to test this idea. Whole limb bones
were sectioned into shaft fragments of various sizes using a bandsaw. An experienced faunal analyst
(TRP), who was uninvolved in the bone selection and preparation, was required to identify the fragments
as accurately as possible to specific skeletal element. Identification bouts were divided into 14 individual
sorts, each consisting of 24 randomly assigned specimens. Sorts were constructed to replicate an
increasing degree of communition across three stages: two “Stage I” sorts contain large specimens, four
“Stage II” sorts contain smaller specimens and eight “Stage III” sorts contain the smallest specimens.
Refitting and guessing were not allowed and fragments identified to a non-element-specific category
(i.e.: upper limb segment, humerus or femur; intermediate limb segment, radius or tibia; lower limb
segment, metacarpal or metatarsal; limb bone shaft only) were not counted as a correct identification.
Of 336 total specimens, 195 (58.0 %) were correctly identified to element. Overall, the differences in
proportions of skeletally identified fragments for all six elements are not statistically significant. This
finding seemingly falsifies the hypothesis that shaft fragments from hindlimb elements (especially
tibiae) are more intrinsically identifiable than are fragments of other limb bones. However, our study
also highlights the need for additional testing of the hypothesis since most actual archaeofaunas preserve
many more specimens with complete or nearly complete diaphyseal circumference than does our
experimental sample, which is composed entirely of specimens with preserving <50 % of their original
circumferences. Our results suggest that bone specimen cross-sectional information, mostly lacking in
the experimental sample but not in real archaeofaunas, is one of the most important classes of data on
which accurate identification of shaft fragments are made.

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Volumen 15. Number 1-3. Year 2017.

2019-11-06T23:06:44+02:00October 26th, 2019|Volumen 15. Number 1-3. Year 2017.|

Volumen 15. Number 1-3. Year 2017.

Introduction to the special issue Actualistic Taphonomy in Argentina: Current Status of the Research and Future Perspectives.

Daniela Alunni, María Clara Álvarez.


[+info] VOLUME 15. NUMBERS 1. 2017 (1 issue)

The Salado River Depression was inhabited during the Late Holocene (2400-400 14C YBP) by pottery-maker societies with a hunting-gathering-fishing lifeway. The archaeological remains are deposited in the A horizon of the modern soil, which constitutes a "biomantle" as pedogenetic formation processes predominate. These include an intense biological activity produced by the action of roots and edaphic fauna that promote displacements of objects and their sinking to different depths. Hence the archaeological sites of this microregion are shallow. In order to broaden the knowledge about the action of earthworms in these sites, an actualistic taphonomy experiment was designed. The goal was to observe the activity of these invertebrates and to evaluate their possible incidence as a disturbing agent on small bones deposited on a soil. The aim of this paper is to introduce the methodological design of this experimentation and present the preliminary results. For this purpose, two containers with sediment containing humus and earthworms were placed in the open air. Some selected bones of Dasypus hybridus and Gallus gallus were deposited in each container. The activity of earthworms was observed along one year with a weekly record and was detected as deep as 16 cm. Other features associated -such as burrows- were documented, especially in autumn and winter. No modifications were identified on bone cortical surfaces, though vertical movement of some elements through the sediment is highlighted.

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Actualistic Study of a Dense Concentration of Bone Remains in the Central Plateau of Santa Cruz Province (Argentina).

Laura Marchionni, Eloisa García Añino, Laura Miotti.


[+info] VOLUME 15. NUMBERS 1. 2017 (2 issue)

This work analyzes a modern bone concentration at Cueva 7, in Los Toldos archaeological locality, as part of the taphonomic studies that we have carried out in the northeast of the Central Plateau of Santa Cruz province (Argentina). The goal of this work is to identify the actualistic taphonomic patterns that can contribute to a better interpretation of the archaeological sites in caves or rock shelters where piles or dense bone concentrations were registered in the study region. From the identification of different taxonomic, anatomic, mortality, and bone modification patterns in this highly-dense accumulation, we evaluate the possible causes of its formation, and produce actualistic information which may be of use to learn about the different processes that accumulate and scatter zooarchaeological remains in the cave environments of the study area. The results show a monospecific assemblage integrated by no less than 43 Ovis aries individuals whose death was natural. The accumulation is characterized by a natural disarticulation pattern, which appears to be more accelerated in appendicular elements, a homogenous weathering profile with minor differences that may be associated with the microenvironments recorded inside the cave, and the very low incidence of natural agents, where trampling was the highest. This work thus provides valuable actualistic information that can be used as a parameter in the determination of possible natural contamination in archaeological contexts.

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Naturalistic Observations on the Disarticulation of False Killer Whales (Pseudorca crassidens) Carcasses: Fifteen Years After.

Florencia Borella, Luis A. Borrero.


[+info] VOLUME 15. NUMBERS 1. 2017 (3 issue)

A mass stranding of 181 false killer whales (Pseudorca crassidens) occurred in March 1989 on both sides of the Strait of Magellan. Fifteen years later, taphonomic observations were made on this concentration and the results are presented in this article. In the coast of Bahía Lomas, Tierra del Fuego (Chile), frequencies of articulated elements were quantified following Hill (1979a, 1979b), and a ranking of natural bone disarticulation for whales was proposed. This ranking was made on the basis of skeletons from one species but, given the morphological similarities of Cetaceae, it is possible to suggest that it applies to similarly-sized Odontoceti. Together with other useful taphonomic criteria (weathering and bone preservation), these results can be used to disentangle the origin of whale bone accumulations at coastal archaeological sites in different parts of the world and to estimate the time of burial of zooarchaeological assemblages. In this way, the role of whales in human diet can be discussed in greater detail.

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Natural Accumulation and Distribution of Guanaco Bones in the Southernmost Tip of Tierra del Fuego (Argentina): Taphonomic Analysis and Archaeological Implications.

Daniela V. Alunni, María A. Gutiérrez, Atilio F. Zangrando.


[+info] VOLUME 15. NUMBERS 1. 2017 (4 issue)

In this study we evaluate modern accumulation, dispersion and preservation patterns of guanaco bones (Lama guanicoe) and discuss their implications for the zooarchaeological record of coastal Tierra del Fuego in southern South America. We surveyed four environmental units: the supra-tidal zone, forests, grasslands, and peat bogs. The guanaco assemblages consist of both disarticulated and articulated bones, most represented by limbs and heads (only two nearly complete carcasses were recorded). Natural processes such as marine abrasion largely affected the preservation of specimens, while weathering is a conspicuous effect observed on bones from the forest. Age and sex profiles, as well as variability in preservation, reflect attritional deaths in different time periods. The guanaco seems to be found regularly along the southeast coasts, being an available resource for coastal and marine hunter-gatherers with relatively narrow foraging ranges. The presence of guanaco is higher during autumn and winter. Bone remains are subject to vertical migration in peat bogs, grasslands and other soft substrates, allowing time-averaging of faunal assemblage formations.

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Taphonomic Effects of a Grassland Fire on a Modern Faunal Sample and its Implications for the Archaeological Record.

María C. Álvarez, Agustina Massigoge, Nahuel Scheifler, Mariela E. Gonzalez, Cristian Kaufmann, María A. Gutiérrez, Daniel J. Rafuse.


[+info] VOLUME 15. NUMBERS 1. 2017 (5 issue)

The main objective of this paper is to characterize the pattern of thermal alteration in a sample of modern bones collected after a natural grassland fire in the Pampas region (Argentina). A total of 917 bone remains were recovered, including a variety of different body size taxa. Results suggest that natural grassland fires affect bone remains in a more severe way than previously documented. In general, a high proportion of bones with thermal alteration (70%) was recorded for the different body size categories, with calcined bones dominating the sample. Some differences in relation to the size classes were found; specifically, a higher extension of burning was recorded for the smaller-sized taxa. For the small animals, the homogeneous distribution of the burning damage in long bones and mandibles could help to differentiate a natural grassland fire from cooking, in which the burning pattern would be more heterogeneous.

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The Role of the Accipitriformes Geranoaetus melanoleucus and Geranoaetus polyosoma as Small Mammal Bones Accumulators in Modern and Archaeological Sites from Central Western Argentina.

José Manuel López, Fernando J. Fernández, Claudia I. Montalvo, Horacio Chiavazza, Luciano, J.M. De Santis.


[+info] VOLUME 15. NUMBERS 1. 2017 (6 issue)

Results of the taphonomic analysis of small mammal bone accumulations generated by the accipitriforms Geranoaetus melanoleucus and Geranoaetus polyosoma in several areas from Central Western Argentina (Mendoza Province) are presented here. In order to identify the role that these predators had in the formation of zooarchaeological assemblages, the anatomical representation, bone breakage patterns, and degrees of digestive corrosion were evaluated. According to these taphonomic variables, both G. melanoleucus and G. polyosoma may be placed in the Category 4 (heavy) of modification of prey bones. The results presented here were used as an analytical model for the interpretation of the micromammal fossil record from three archaeological sites in Mendoza Province. This comparison suggests that the skeletal remains recovered from one archaeological site are very close to those produced by G. polyosoma. However, accumulations from the other sites had intermediate values between those of G. polyosoma and G. melanoleucus.

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First Steps into the Microscopic Metrical Characterization of Bone Weathering in a Sample of Modern Guanaco (Lama guanicoe) from Southern Patagonia, Argentina: Implications for Patterns of Intraosseous Differential Preservation.

Natalia Morales, Gustavo Barrientos, Juan Bautista Belardi.


[+info] VOLUME 15. NUMBERS 1. 2017 (7 issue)

In many southern Patagonia archaeological bone assemblages deposited in open-air settings, a remarkable difference in preservation between shafts and epiphyses of guanaco (Lama guanicoe) long bones, leading to an overrepresentation of the latter, has been found. It has been suggested that, in dynamic sedimentary deposits like those investigated in this region, the observed pattern is mainly related to subaerial weathering or to a combination of weathering and abrasion preferentially affecting long bone shafts, processes that may have little relationship with bone mineral density (BMD). In order to investigate in more detail the relationship between weathering and bone mineral density (BMD) and cortical thickness in guanaco long bones, a microscopic (low magnification) metrical analysis of partial cross-sections from a sample of modern radii-ulnae with a various degrees of weathering was performed. Overall, the obtained results suggest that subaerial weathering can suffice to explain the observed archaeological pattern of differential intraosseous preservation, although this inference should be further supported with data from a larger sample including other long bones as well as a more complete record of the weathering sequence.

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Four Decades of Actualistic Carnivore Taphonomy in the Southern Neotropics: A State of the Art.

Mariana Mondini.


[+info] VOLUME 15. NUMBERS 1. 2017 (8 issue)

Based on a bibliographic survey, this paper reviews the state of the art of actualistic taphonomic information of different autochthonous mammalian carnivores in the southern Neotropics. The characteristics of this corpus of data and its implications for the fossil record are analysed. The paper focuses on identifying and discussing those areas of research that are robustly reflected by existing studies. Synthetic discussion of the results of research on the most studied carnivore taxa, types of bone assemblages, actualistic approaches, and ecological zones in the region are presented. While the field of actualistic taphonomic research is well-developed in the region, there are several gaps that require more attention for the future investigation.

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The Taphonomist´s Corner: Regional Taphonomy of cetaceans bones in the “Uttermost part of the earth”.

Florencia Borella.


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