Paleoenvironment

Glimpses of Ancient Norwalk and Wilton

by Timothy Ives

published by Archaeological and Historical Services, Inc. (2011)

This booklet provides a glimpse of the ancient and changing landscape of Norwalk and Wilton (Connecticut) as informed... more This booklet provides a glimpse of the ancient and changing landscape of Norwalk and Wilton (Connecticut) as informed by the archaeological investigation of Site 103-49. In doing so, it highlights the value of the land as a cultural resource and provides an example of how professional archaeology operates in the State of Connecticut.

Note: This booklet reports on CT Archaeological Site No. 103-49, a multicomponent site that yielded a Paleoindian lithic assemblage.

Determining the Genesis and Cultural Significance of Deep Soil Features at Southeastern Connecticut’s Preston Plains Site

by Timothy Ives

Ph.D. dissertation, University of Connecticut (2010)

Archaeologists excavating Archaic and Woodland Period sites on sandy, unconsolidated soils in the Northeastern U.S.... more Archaeologists excavating Archaic and Woodland Period sites on sandy, unconsolidated soils in the Northeastern U.S. have identified deep soil features (hereafter DSFs) that are challenging to interpret.  Though hundreds of these basin-shaped features have been recorded, archaeologists do not agree as to whether or not they are anthropogenic.  Competing hypotheses have suggested that DSFs constitute the remnants of semi-subterranean pit houses, or, alternately, soil disturbances generated by naturally occurring tree throws.  This dissertation presents a case study of a DSF complex at southeastern Connecticut’s Preston Plains Site.  Its analytical design combines scholarship, empirically-based data assessments, and hypothesis testing to holistically inform an interpretation of the genesis and cultural significance of DSFs here.  Its results discount the pit house hypothesis while supporting the tree throw hypothesis according to multiple lines of evidence.  A simple and flexible model is proposed to explain how tree throws are modified through time to express the variety of forms and stratigraphies observed in DSFs.  Furthermore, it is determined that the pit-and-mound microtopographies afforded by ancient tree throws at Preston Plains were targeted by small groups of Late Archaic Period (ca. 5000-3000 BP) foragers as elements of short-term residential sites.  While archaeologists have already determined that Mesolithic and early Neolithic Europeans utilized such topographies as site elements, this study provides the most detailed set of supporting evidence of such behavior to date.

Tree Throws and Site Selection: Late Archaic Period Occupation at the Preston Plains Site in Southeastern Connecticut.

by Timothy Ives

forthcoming publication in Northeast Anthropology, Vol.77 (2009)

Several Archaic and Woodland period sites in the New England and the Middle Atlantic contain deep soil features (DSFs)... more Several Archaic and Woodland period sites in the New England and the Middle Atlantic contain deep soil features (DSFs) that have become objects of a pit house versus tree throw debate. Contributing to this debate, a case study of a DSF complex at southeastern Connecticut’s Preston Plains Site argues that tree throws generated such features, and proposes how long-term processes transform tree throw disturbances into the varied expressions DSFs exhibit.  Most important, local Late Archaic Period (ca. 5-3000 B.P.) foragers appear to have centered some of their short-term residential sites on tree throw hollows.  In view of similar patterns from Mesolithic and early Neolithic European sites, these findings highlight what is likely an under-recognized and globally relevant aspect of human behavior in forested landscapes.

Geological History and Paleoenvironment (at the Parkhill Site)

by Christopher J. Ellis

co-authored with Alan V. Morgan and John H. McAndrews, 2000. Chapter 2 in "An Early Paleoindian Site Near Parkhill, Ontario" by Christopher J. Ellis and D. Brian Deller, pp. 9-30. Canadian Museum of Civilization, Hull, Quebec.

The context of Stw 573, an early hominid skull and skeleton from Sterkfontein Member 2: taphonomy and paleoenvironment

by Jason Heaton

Co-authored with Travis Pickering and Ron Clarke, 2004, in the Journal of Human Evolution

The reconstructed taphonomic and paleoenvironmental contexts of a ca. 4 million-year-old partial hominid skeleton (Stw... more The reconstructed taphonomic and paleoenvironmental contexts of a ca. 4 million-year-old partial hominid skeleton (Stw 573) from Sterkfontein Member 2 are described through presentation of the results of our analyses of the mammalian faunal assemblage associated stratigraphically with the hominid. The assemblage is dominated by cercopithecoids (Parapapio and Papio) and felids (Panthera pardus, P. leo, Felis caracal, and Felidae indet.), based on number of identified specimens, minimum number of elements and, minimum number of individuals. In addition, the assemblage is characterized by a number of partial skeletons and/or antimeric sets of bones across all taxonomic groups. There is scant indication of carnivore chewing in the assemblage. These observations, in addition to other taphonomic data, suggest that the remains of many animals recovered in Member 2 are from individuals that entered the cave on their own—whether accidentally by falling through avens connecting the cave to the ground surface above or by intentional entry—and were then unable to escape, rather than primarily through systematic collection by a biotic, bone-accumulating agent. The taphonomic conclusion that animals with climbing proclivities (i.e., primates and carnivores) are preferentially preserved over other taxa, ultimately because of those proclivities, urges caution in assessing the fidelity of the assemblage for reconstruction of the Member 2 paleoenvironment. With that caveat, we infer that the Member 2 paleoenvironment was typified by rolling, rock-littered and brush- and scrub-covered hills, indicated by the abundant F. caracal and cercopithecoid fossils recovered and the identified presence of the extinct Caprinae Makapania broomi. In addition, the valley bottom may have retained standing water year-round, perhaps supporting some tree cover—a setting suitable for the well-represented ambush predator P. pardus and suggested by the presence of Alcelaphini. Finally, the reconstructed taphonomic and paleoenvironmental settings of Sterkfontein Member 2 are compared to penecontemporaneous sites in South and East Africa.

Small mammal remains from Cueva Huenul 1, northern Patagonia, Argentina: Taphonomy and paleoenvironments since the Late Pleistocene

by Ramiro Barberena

F. FERNANDEZ, P. TETA, R. BARBERENA, U. PARDIÑAS
(Quat. Int. In press).

Small mammal samples from the archaeological sequence of Cueva Huenul 1 (CH1, Neuquén Province, Argentina) are... more Small mammal samples from the archaeological sequence of Cueva Huenul 1 (CH1, Neuquén Province, Argentina) are described, and taphonomic and paleoenvironmental conditions assessed. This site is located near the steppe-monte ecotone in the northernmost Patagonia. Small mammal remains (NISP ¼ 1426, MNE ¼ 1409, MNI ¼ 87) were recovered from Late Pleistocene (13,800e11,800 14C BP), Early Holocene (9500 14C BP) and Late Holocene layers (1400 14C BP). Taphonomic analysis indicates that the CH1 assemblage is an archaeofaunistic owl pellet accumulation. It has a good post-depositional preservation since it was rapidly incorporated in the sedimentary matrix, although it previously experienced trampling action. From latest Pleistocene to Late Holocene, the assemblages are mainly composed by the sigmodontines Eligmodontia spp. and Phyllotis xanthopygus, and the caviomorphs Microcavia australis and Ctenomys sp., suggesting in overall terms a marked ecological stability. CHl is one of the few sites where the PleistoceneeHolocene transition is represented by faunal evidence. The latest Pleistocene sample spanning 13,800 and 11,800 14C BP indicate scrub steppe with substantial open ground and rocky exposition; one Early Holocene sample (9500 14C BP) suggests a more heterogeneous environment as evidenced by the first occurrence of Akodon iniscatus and Euneomys chinchilloides. In this context, CH1 assemblages do not reflect the small mammal community
reworking that putatively accompanied the Pleistocene-Holocene transition.

Palaeoecological and palaeoenvironmental influences revealed by long-bone palaeohistology: the example of the Permian branchiosaurid Apateon

by J.Sébastien Steyer

NEW DATA ON THE FLORA AND FAUNA FROM THE ?UPPERMOST CARBONIFEROUS-LOWER PERMIAN OF BUXIERES-LES-MINES, BOURBON L'ARCHAMBAULT BASIN (ALLIER, FRANCE). A PRELIMINARY REPORT

by J.Sébastien Steyer

New Permian tetrapod footprints and macroflora from Turkey (Cakraz Formation, northwestern Anatolia): Biostratigraphic and palaeoenvironmental implications

by J.Sébastien Steyer

The Gobi Region During the Younger Dryas

by Joshua Wright

with Lisa Janz, in Hunter-Gatherer Transitions Through the Younger Dryas: A global perspective. Ed. M.Eren. Left Coast Press (2012)

Grain size distribution analysis of sediments containing Younger Toba Tephra from Ghoghara, Middle Son valley, India

by Michael Petraglia

The Miguasha Fossil-Fish-Lagerstätte: a consequence of the Devonian land–sea interactions

by Richard Cloutier

Authors: Cloutier, R., J.-N. Proust & B. Tessier
Year: 2011
Reference: Palaeobiodiversity and Palaeoenvironments

The evolution of vertebrate assemblages in terms of fluctuating environments has rarely been investigated for the... more The evolution of vertebrate assemblages in terms of fluctuating environments has rarely been investigated for the Devonian period. Variation of biodiversity (richness, abundance and species composition) in the diverse Devonian fish assemblage of the Escuminac Formation (Quebec, Canada) is analysed in response to changes in lithofacies, depositional environment and taphonomy through time. Five sequences within an inner wave-dominated estuary show shifts in continentalisation. Although a ubiquitous fish assemblage is identified throughout the formation, species are more diversified and species composition is better structured during relative sea-level rise than during still-stand and relative sea-level fall. Konservat and Konzentrat Fossil-Lagerstätte horizons occur in the transgressive phase of the sequences.

Isotopic evidence for massive oxidation of organic matter following the Great Oxidation Event

by Alex Brasier

Kump, Junium, Arthur, Brasier, Fallick et al. 2011 Science paper on the Shunga-Francevillian d13C excursion. Now available on the Science Express website.

Now available on Sciencemag.org Now available on Sciencemag.org

Distribution history and climatic controls of the Late Miocene Pikermian chronofauna

by Jussi Eronen

The Late Miocene development of faunas and environments in western Eurasia is well known, but the climatic and... more The Late Miocene development of faunas and environments in western Eurasia is well known, but the climatic and environmental processes that controlled its details are incompletely understood. Here we map the rise and fall of the classic Pikermian fossil mammal chronofauna between 12 and 4.2 Ma, using genus-level faunal similarity between localities. To directly relate land mammal community evolution to environmental change, we use the hypsodonty paleoprecipitation proxy and paleoclimate modeling. The geographic distribution of faunal similarity and paleoprecipitation in successive timeslices shows the development of the open biome that favored the evolution and spread of the open-habitat adapted large mammal lineages. In the climate model run, this corresponds to a decrease in precipitation over its core area south of the Paratethys Sea. The process began in the latest Middle Miocene and climaxed in the medial Late Miocene, about 7– 8 million years ago. The geographic range of the Pikermian chronofauna contracted in the latest Miocene, a time of increasing summer drought and regional differentiation of habitats in Eastern Europe and Southwestern Asia. Its demise at the Miocene-Pliocene boundary coincides with an environmental reversal toward increased humidity and forestation, changes inevitably detrimental to open-adapted, wide-ranging large mammals.

Fossil mammals resolve regional patterns of Eurasian climate change over 20 million years

by Jussi Eronen

Fossil teeth of terrestrial plant-eating mammals offer a new, quasi-quantitative proxy for environmental aridity that... more Fossil teeth of terrestrial plant-eating mammals offer a new, quasi-quantitative proxy for environmental aridity that resolves previously unseen regional features across the Eurasian continent from 24 to 2 million years ago. The pattern seen prior to 11 million years ago are quite different from today’s. Thereafter, a progressively modern rainfall distribution developed at about 7 to 5 million years ago when East Asia remained unexpectedly humid while Europe
experienced a transient phase of strong aridity. Mean hypsodonty is a geographically extensive and stratigraphically well-resolved palaeoprecipitation proxy that can be used to constrain the regional details of vegetation and climate models.

Late Miocene and Pliocene large land mammals and climatic changes in Eurasia

by Jussi Eronen

The fossil teeth of land mammals offer a powerful tool to map the regional details of past climate change in the... more The fossil teeth of land mammals offer a powerful tool to map the regional details of past climate change in the terrestrial realm. We use mean plant-eater hypsodonty (molar crown height) of late Neogene mammal localities to map late Miocene and Pliocene palaeoprecipitation on the Eurasian continent and, with higher temporal resolution, in Europe. The results show that the mid-latitude drying in Eurasia affected the central parts of the continent first and that the drying of western Europe after about 7–8 Ma seems to have coincided roughly in time with a return to more humid conditions in eastern Asia, with a return to a drier east and more humid west in the Pliocene. Within Europe, the hypsodonty-based palaeoprecipitation maps suggest that the sequence from MN 9 to MN 12 (ca. 11.1–6.8 Ma) was dominated by an east– west (continental-marine) humidity gradient, which gradually intensified and with a shift of dryer conditions eastwards in MN 12 (ca. 7.5 Ma). This was partly overlain from MN 13 onwards by a north–south oriented gradient, which persisted at least to the end of the Pliocene. The maps for both the earliest late Miocene (MN 9, ca. 11.1–9.7 Ma) and the earliest Pliocene (MN 14, ca. 4.9–4.2 Ma) show very low regional differentiation, possibly suggesting perturbed phases in the evolution of the mammal communities. Analysis of hypsodonty and dietary structure of the mammalian plant-eater community in Europe during the entire interval shows that the Miocene–Pliocene boundary was marked by a strong decrease in mesodont species and mixed feeders, and an increase in brachydont species and omnivores. In this view, the shift in the latest Miocene from east–west to partly north–south-polarised hypsodonty patterns corresponds mainly to an increase in hypsodont species and grazers. It seems probable that the east–west gradient was primarily driven by precipitation, while the north–south gradient would also have been strongly influenced by temperature-related effects of humidity.

The Mio-Pliocene European primate fossil record: dynamics and habitat tracking

by Jussi Eronen

We present here a study of European Neogene primate occurrences in the context of changing humidity. We studied the... more We present here a study of European Neogene primate occurrences in the context of changing humidity. We studied the differences of primate localities versus non-primate localities by using the mammal communities and the ecomorphological data of the taxa present in the communities. The distribution of primates is influenced by humidity changes during the whole Neogene, and the results suggest that the primates track the changes in humidity through time. The exception to this is the Superfamily Cercopithecoidea which shows a wider range of choices in habitats. All primate localities seem to differ from non-primate localities in that the mammal community structure is more closed habitat oriented, while in non-primate localities the community structure changes towards open-habitat oriented in the late Neogene. The differences in primate and non-primate localities are stronger during the times of deep environmental change, when primates are found in their preferred habitats and non-primate localities have faunas better able to adapt to changing conditions.

Continental-scale hypsodonty patterns, climatic paleobiogeography and dispersal of Eurasian Neogene large mammal herbivores

by Jussi Eronen

he dispersal of land mammals depends not only on the availability of physical connections but also on the presence of... more he dispersal of land mammals depends not only on the availability of physical connections but also on the presence of habitats that can support viable populations. Here we use mean molar hypsodonty of large mammal plant-eaters to map environmental conditions in Eurasia during the Neogene in order to establish a framework for discussing the distribution and dispersal of Neogene land mammals. The first Early Miocene centres of hypsodont faunas are seen in Iberia and central Asia. In the Middle Miocene Iberian values are low and a strong East-West contrast is seen with-in Europe, with another centre of hypsodonty developing in eastern Asia. From the Late Miocene onwards we show a pattern of high values in the central part and low values in the humid areas of western Europe and southern China (no suitable data are now available for southernmost Asia). This pattern has remained relatively stable since the Late Miocene, with only regional changes and a general increase in the overall level of hypsodonty. These results suggest that the hypsodonty pattern is primarily controlled by climatic effects of Himalayan-Tibetan uplift, specifically to the drying and increased seasonality of humidity predicted by climate models, rather than to the cooling that would have been most noticeable in the northern half of the continent. The strong and persistent relationship between position on the continent and relative degree of hypsodonty suggests that adaptation to local conditions by natural selection has been the main determinant of ungulate hypsodonty in the Neogene. Alogical consequence of this would be that regional climatic conditions have been a major determinant of the geographic ranges of individual species throughout the Neogene, except perhaps at times of major faunal turnover. For example, an initial dispersal of hipparionine horses across the arid Central Asia appears highly improbable compared with dispersal along a more humid northern route, and the apparently early arrival of hipparions in Spain may well reflect this circumstance.

Wetland paradise lost: Miocene community dynamics in large herbivorous mammals from the German Molasse Basin.

by Jussi Eronen

Questions: What was the distribution of fossil mammal taxa in the Miocene German Molasse Basin? Were there changes in... more Questions: What was the distribution of fossil mammal taxa in the Miocene German Molasse Basin? Were there changes in community structure during the terrestrial development of the Molasse Basin? Were community dynamics similar in the Molasse Basin to those in the rest of Europe?

Data: We gathered the available Miocene large mammal herbivore occurrences from the southern German Molasse Basin [museum data mainly from Munich (Germany), with additional data from museums in Stuttgart (Germany) and Vienna (Austria)]. We used public data from NOW (Neogene of the Old World database, http://www.helsinki.fi/science/now) for comparison and as the source of ecological data for the species.

Methods: We combined ecological data from the NOW database with distributions of herbivorous mammals within the Molasse Basin. We plotted the occurrences of taxa on a base map, and used the associated body size and dietary categories to plot these data on the map. We investigated the differences in the structure of communities in different time periods. We compared different time periods and differences among areas. We also compared the Molasse Basin and NOW data.

Conclusions: The evolution of large-mammal communities in the Molasse Basin occurred in two phases: build up and decline. The build-up phase was characterized especially by a high abundance of small-sized browsers and mixed feeders. The diversity was especially high during the built-up phase, indicating a highly differentiated wetland habitat. The decline phase saw a very different community structure with fewer mixed feeders and with larger sized mammals dominating. The difference between these phases was largely the consequence of regional extinctions of species and genera. The Molasse Basin community dynamics also differ from those of the rest of Europe (NOW data).

Strengthened East Asian summer monsoons during a period of high-latitude warmth? Isotopic evidence from Mio-Pliocene fossil mammals and soil carbonates from …

by Jussi Eronen

The East Asian monsoons have fluctuated in concert with high-latitude warmth during the past several hundred thousand... more The East Asian monsoons have fluctuated in concert with high-latitude warmth during the past several hundred thousand years, with humid summer monsoon-dominant climates characterizing warm intervals, including interglacials and interstadials, and arid winter monsoon-dominant climates characterizing cool intervals, including glacials and stadials. Of the states comprising the mid-Pleistocene to recent climatic regime, interglacials are most similar in terms of high latitude ice volumes and temperatures to those extant during the late Miocene and early Pliocene. Thus, an important question is whether Mio-Pliocene climates in northern China were analogous to a hypothetical ‘prolonged interglacial state,’ with increased summer monsoon precipitation and expansion of forest and steppe environments at the expense of desert environments. We utilize new and previously published carbon isotopic data from fossil teeth and soil carbonates to place constraints on paleovegetation distributions and to help infer the behavior of the monsoon system between ∼ 7 and 4 Ma. We find that plants using the C4 photosynthetic pathway—which today are largely grasses found in regions with warm season precipitation—were present in northern China by late Miocene time, demonstrating that the C4 expansion in China was not significantly delayed compared to the global C4 event. During the late Miocene–early Pliocene interval, soil carbonate and tooth enamel δ13C data indicate: 1) that nearly pure C3-plant ecosystems existed in the southern Chinese Loess Plateau (CLP), and therefore ecosystems there were dominated by woody dicot, herbaceous dicot, or cool-season grass vegetation (or a combination of these), and 2) that the CLP was characterized by a pattern of northward-increasing C4 vegetation and aridity. Utilizing a broadened conceptual model for interpreting δ13C data, and citing independent faunal, floral, and lithostratgraphic data, we
suggest that these patterns reflect northward expansion of forest and steppe ecosystems and relatively humid monsoon climates during the late Miocene and early Pliocene. An important implication of this interpretation is that the forcing mechanism illuminated by the temporal correlation during the Pleistocene between warm high latitudes and strong East Asian summer monsoons is a robust feature of the Eurasian tectonic–climatic system that predates the Plio-Pleistocene climatic reorganization.