Vertebrate Taphonomy Research Articles

Sedimentology and vertebrate taphonomy of the Tritylodon Acme Zone: a reworked palaeosol in the Lower Jurassic Elliot Formation, Karoo Supergroup, South Africa

A semi-continuous bed of pedogenic nodule conglomerates in the floodplain deposits of the Lower Jurassic Elliot Formation (upper Karoo Supergroup) of South Africa, is interpreted as a lag deposit that resulted from an extended period of floodplain degradation. The large-scale geometry of the conglomerate bed resembles a sheet-with-holes, only 0.5–1.25 m thick, yet it covers at least 11,000 km 2 of the northwestern part of the Elliot outcrop area. It is commonly underlain by eroded remnants of a calcic palaeosol and grades upwards into a fully-preserved calcic vertisol. The conglomerate contains reworked pedogenic nodules, mudrock pebbles and numerous fossils of the advanced cynodont Tritylodon . Fossils of Tritylodon occur in such abundance that this interval has been dubbed the Tritylodon Acme Zone. This study uses field observations of the sedimentology, palaeopedology and vertebrate taphonomy of the Tritylodon Acme Zone to reconstruct the geomorphological history and the time constraints involved in the formation of this lag conglomerate and associated palaeosols. Paleosols in the loessic siltstones below the Tritylodon -rich conglomerate are characterised by a rectilinear pattern of large sandstone-filled shrinkage cracks which are commonly offset by small slickensided arcuate shear planes. The fissures in the lower palaeosol are heavily calcretized and some contain vertically stacked calcareous nodules. The upper palaeosol is characterised by similar vertical fissures except that they are filled with siltstone and mudstone and are rarely calcretized. The upper palaeosol contains scattered pebble-sized calcareous nodules along with vertical and horizontal rhizocretions and termitaria-like burrowed sandstone pods. Both palaeosols are interpreted as calcic vertisols formed in clay-rich alluvium on seasonally wet floodplains under warm semi-arid climatic conditions. The relatively high abundance of Tritylodon fossils in the nodule-conglomerate is attributed to regional denudation of an estimated 3–5 m of fossil-bearing calcareous soil resulting in reworking of the resistant glaebules and partlymineralised bones into a lag deposit. Most of the bones occur as disarticulated and broken elements in multitaxa, bonebed-type accumulations within shallow depressions scoured into the underlying alluvium. Haematite perimineralization of bone is ubiquitous and its precipitation on the surfaces of brittle-fractured bone surfaces is evidence that many of the bones were mechanically broken by reworking after they had been buried for long enough to become partially calcified. A time-restored stratigraphic column gives an estimated 50,000 yr for the accumulation of the 2.25 m of Tritylodon Acme zone strata. Using figures derived from studies of modern landscapes, it is estimated that the Tritylodon conglomerate itself records a period of floodplain incision in this part of basin during the earliest Jurassic times, which lasted for some 30,000 yr.

Sedimentology and vertebrate taphonomy of bone-bearing facies from the Clockhouse Rock Store (Weald Clay, late Hauterivian), Capel, Surrey, UK

The Clockhouse Rock Store [TQ 174 384] has for the past twenty years been a major source of Wealden insect fossils, but the presence of vertebrate remains has only been briefly documented. Nine distinct vertebrate-bearing facies are described here. Sedimentary structures in the sandstones indicate fluvial deposition. Taxa recorded include hybodont sharks, holostean-grade and teleost fish and goniopholidid crocodiles. The vertebrate fossils show taphonomic features confirming deposition by rivers.

Vertebrate Taphonomy. R. Lee Lyman, Cambridge University Press, Cambridge Manuals in Archaeology, 1994. ISBN 0‐521‐452155 (hardback), 0‐521‐45804 (paperback)

International Journal of OsteoarchaeologyVolume 5, Issue 4 p. 394-395 Book Review Vertebrate Taphonomy. R. Lee Lyman, Cambridge University Press, Cambridge Manuals in Archaeology, 1994. ISBN 0-521-452155 (hardback), 0-521-45804 (paperback) David Overstreet, David Overstreet Great Lakes Archaeological Research Center, Milwaukee, WisconsinSearch for more papers by this author David Overstreet, David Overstreet Great Lakes Archaeological Research Center, Milwaukee, WisconsinSearch for more papers by this author First published: December 1995 https://doi.org/10.1002/oa.1390050411Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume5, Issue4December 1995Pages 394-395 RelatedInformation

Vertebrate taphonomy

Vertebrate taphonomy

Preservational, paleoecological and evolutionary patterns in the Paleogene of Wyoming-Montana and the Neogene of Pakistan

Abstract Contributions to this special issue have compared the tectonic settings, fluvial systems, paleoclimates, paleofloras and faunas, vertebrate taphonomy, and mammalian paleoecology and evolution from two long, continental records of Cenozoic ecosystems. In this concluding paper, we summarize highlights of earlier papers to provide an overview of similarities and differences between these Paleogene and Neogene records. The relative influences of tectonic, climatic, and fluvial processes on lithofacies, environments of fossil preservation, and the productivity of the fossil record are compared for each sequence. Tectonism was the primary control on sediment accumulation rate and the distribution of major depositional environments in each basin. Fossil productivity, species richness, and the distribution of fossil localities among fluvial environments change across formation boundaries in each sequence. The taxonomic, temporal, and spatial resolution of vertebrate assemblages varies among fluvial environments and differs between the two sequences. As a result, the Paleogene record is better suited for detailed study of evolutionary change within local lineages and the Neogene record for detailed paleocommunity reconstruction. Several aspects of biotic change are considered. (1) The timing and magnitude of mammalian faunal turnover in relation to climatic change are evaluated in terms of three models of evolutionary change within ecosystems: Van Valen's “Red Queen model,” Stenseth and Maynard Smith's “stationary model,” and Vrba's “turnover-pulse model.” In both records, climatic change was accompanied by change in faunal composition and ecological structure, but both pulsed and diachronous biotic change, at a resolution of about 0.5 m.y., also occurred over periods when no significant climatic change was discernible. This pattern best matches the predictions of the Red Queen model. (2) In both records, the rate of mammalian faunal turnover (first and last appearances of taxa) is not highly correlated with standing richness, suggesting that paleocommunities were not a equilibrium richness on these time scales. (3) In the Paleogene record, plant species richness declined while mammalian species richness increased. (4) In each sequence, some episodes of mammalian faunal turnover were in step with changes in size or trophic structure, while other changes in faunal composition entailed no corresponding change in ecological structure. While both records would benefit from improved paleoclimatic, temporal, species-level, and ecomorphological resolution, this initial synthesis suggests that both physical and biotic factors were important influences on faunal composition, the timing and rate of turnover, and ecological structure in these paleocommunities.

Vertebrate Taphonomy of Late Permian Floodplain Deposits in the Southwestern Karoo Basin of South Africa

The predominantly fluvial strata of the Late Permian Beaufort Group in the southwestern Karoo Basin contain numerous fossils of therapsid reptiles. This study investigates the taphonomy of these fossils and the sedimentology of the floodplain deposits in which they are most commonly preserved. Taphonomic assessment of 329 in itu fossils along 3 cliff exposures included data on disarticulation, bone weathering, attitude of skulls, bone color, type of perimineralization and degree of pre-fossilization damage. This led to the recognition of 6 «taphonomic pathways» along which bones entered the rock record. Three floodplain facies, channel-bank, proximal floodplain and distal floodplain, that were previously defined on sedimentological and pedological criteria also have taphonomically discrete attritional bone assemblages

Controls on fluvial systems in the Siwalik Neogene and Wyoming Paleogene

The 3-km thick Neogene Siwalik Group (Himalayan foredeep in northern Pakistan) and the 2-km thick Paleogene Fort Union/Willwood Formations (Bighorn Basin, Wyoming) both preserve long records of fluvial deposition adjacent to rising mountain belts. Depositional environments and associated habitats change with spatially varying physiography and deposition by river systems that may differ greatly in size, sediment loads, depositional rates, drainage of adjacent floodplains, and taphonomy of organic remains. At times, some environments may not be preserved; for example, avulsion of channels to low areas removes more deposits of channel-distal environments as avulsions increase relative to net sediment aggradation rates. Recognition of such large-scale biases is important because they represent time scales over which long term paleoecological change is reconstructed, and requires knowledge of how drainage systems changed in time and space within these evolving basins.The Siwalik Group was deposited by large rivers that filled a basin extending at least 1000 km along its axis and 150–250 km away from the mountain front. Despite the scale of these rivers relative to Siwalik exposures, transitions between different fluvial systems have been recognized. For example, a 1-km thick sequence bridging the boundary between Chinji and Nagri formations records displacement of a smaller river system (width < 2 km; depth 5-10 m; discharge 1000-1500 m3/s) by a larger system (width <5 km; depth 15-30 m; discharge at least 5,000-10,000 m3/s), with an associated upsection increase (30 to 70%) in the proportion of channel sandstones, increased mean sediment accumulation rates (150 to 300 m/my), decrease in poorly drained floodplain deposits and well developed paleosols, marked decrease in abundance of faunal remains, and a major change in faunal composition. Stratigraphically higher (Dhok Pathan Fm.), there is a lateral transition between deposits of dissimilar, coeval river systems with corresponding differences in local paleoenvironments and vertebrate taphonomy. Although upsection changes in environments and vertebrate faunas may generally reflect extrabasinal controls such as tectonism and climate change, our studies emphasize the importance of recognizing deposits from different contemporaneous river systems before inferring such large-scale controls on paleoenvironmental change through time.The Bighorn Basin is an intermountain foreland basin extending 200 km along its axis and about 80 km across. A large portion of this basin is exposed, and thus it is possible to reconstruct the distribution of river systems and the spatial paleoenvironments in more detail than in the Siwaliks. The Bighorn Basin was traversed along its axis by an early Eocene, north-south flowing river that was joined by smaller rivers flowing transverse to the axis. The proportion of channel sandstones decreases upsection (50 to 25%) from the Fort Union to the Willwood Fm. The proportion of channel sandstones and the abundance of well developed paleosols decrease with increasing net sediment aggradation rates. Although channel deposits are concentrated along the basin axis in a more complex way in some stratigraphic intervals, it is unclear to what extent these changes reflect deposition by different rivers versus extrinsically controlled changes within individual river systems.

Fluvial processes and vertebrate taphonomy: the upper cretaceous Judith River formation, South-Central dinosaur Provincial Park, Alberta, Canada

Superb three-dimensional exposures of the Upper Cretaceous Judith River Formtion in the badlands of Dinosaur Provincial Park, Alberta offer excellent opportunities for the integration of sedimentological and architectural analysis of an ancient coastal plain sequence with taphonomic investigations of rich vertebrate assemblages. Based upon two detailed lithofacies studies, a fluvial, meandering-channel depositional model has been developed for the upper 60 m of the Judith River sequence in the south-central area of the Park. Using this model, major taphonomic modes of occurrence of vertebrate remains found within the study sequences are readily explicable in terms of the sedimentological context of their host lithofacies. The sequences studied are composed of four main lithofacies: (1) trough cross-bedded sandstone; (2) large-scale inclined heterolithic strata (IHS); (3) sandstone with large-scale inclined bedding (IBS); and (4) shale. IHS and IBS units are interpreted as products of point-bar lateral accretion within large, meandering, freshwater-dominated, coastal plain rivers. Trough cross-bedded sandstone sequences are recognized as being genetically related to overlying IHS (or IBS) units, and formed as contemporaneous channel bottom and lower point-bar deposits. Shale sequences represent a variety of floodplain deposits including immature paleosols. Within the detailed study areas vertebrate fossils occur as articulated skeletons, bonebeds and isolated skeletal elements. All of these three major taphonomic occurrence modes are dominantly associated with lower levels of trough cross-bedded sandstone sequences indicating preferential preservation of vertebrate material at deeper levels within palaeochannels. Three categories of bonebeds have been recognized within the sequences studied: (1) high diversity, and (2) low diversity, macrovertebrate accumulations; and (3) microvertebrate sites. High diversity bonebeds occur at or near the bases of trough cross-bedded sandstone sequences and formed as channel lag deposits. Two low diversity bonebeds, one dominated by the disarticulated remains of Styracosaurus, the other by Centrosaurus, are associated with pointbar deposits. Both are believed to represent the end products of mass deaths of herding ceratopsians, perhaps by drowning as animals attempted to cross flooded rivers. Microvertebrate sites, generally associated with trough crossbedded sandstone sequences within the areas studied, represent mechanical accumulations of the most resistant skeletal components. The presence of both “fresh” and abraded vertebrate elements within most of the bone-bearing lithofacies units reflects variations in bone sources and transportation histories. Highly abraded “bone pebbles” represent skeletal elements that underwent several cycles of river transport, deposition and exhumation. From observations made outside the areas studied in detail, the integrated sedimentologic-taphonomic model proposed herein appears to be valid for correlative strata elsewhere within Dinosaur PPark. Thus the model may serve as a useful aid for future taphonomic and palaeoecological research at this famous dinosaur site.

Toward the Identification of Formation Processes

Research in experimental archaeology, ethnoarchaeology, geoarchaeology, and vertebrate taphonomy has appreciably increased our general understanding of the formation processes—cultural and natural—of archaeological sites. In synthesizing some of these recent advances, this paper focuses on the traces of artifacts and characteristics of deposits that can be used to identify the formation processes of specific deposits. These observational phenomena are grouped into three basic categories that structure the presentation: (1) simple properties of artifacts, (2) complex properties of artifacts, and (3) other properties of deposits. Also considered is the way in which prior knowledge can help the archaeologist to cope with the large number of processes and the nearly infinite combination of them that may have contributed to the specific deposits of interest. Several analytical strategies are proposed: (1) hypothesis testing, (2) multivariate analysis, and (3) use of published data to evaluate formation processes. This paper demonstrates that the identification of formation processes, which must precede behavioral inference and be accomplished by any research endeavor that uses evidence from the archaeological record, can become practical and routine.

Fossils in the Making. Vertebrate Taphonomy and Paleoecology. Papers from a conference, Burg Wartenstein, Austria, July 1976. Anna K. Behrensmeyer and Andrew P. Hill, editors. University of Chicago Press, Chicago, 1980. xii + 338 pp., illus., biblio., index. $18.00 (cloth), $7.00 (paper).

Fossils in the Making. Vertebrate Taphonomy and Paleoecology. Papers from a conference, Burg Wartenstein, Austria, July 1976. Anna K. Behrensmeyer and Andrew P. Hill, editors. University of Chicago Press, Chicago, 1980. xii + 338 pp., illus., biblio., index. 7.00 (paper). - Volume 47 Issue 1

Fossils in the Making: Vertebrate Taphonomy and Paleoecology. Anna K. Behrensmeyer , Andrew P. Hill , Karl W. Butzer , Leslie G. Freeman

Previous articleNext article No AccessNew Biological BooksFossils in the Making: Vertebrate Taphonomy and Paleoecology. Anna K. Behrensmeyer , Andrew P. Hill , Karl W. Butzer , Leslie G. Freeman Allen KeastAllen Keast Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 56, Number 4Dec., 1981 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/412448 Copyright 1981 Stony Brook Foundation, Inc.PDF download Crossref reports no articles citing this article.

: Fossils in the Making: Vertebrate Taphonomy and Paleoecology . Anna K. Behrensmeyer, Andrew P. Hill.

: Fossils in the Making: Vertebrate Taphonomy and Paleoecology . Anna K. Behrensmeyer, Andrew P. Hill.

Taphonomy in the Making - Fossils in the Making: Vertebrate Taphonomy and Paleoecology.Anna K. Behrensmeyer and Andrew P. Hill (eds.). University of Chicago Press; Chicago. 1980. xii + 338 pp. Cloth, $18.00; Paper, $7.00.

Taphonomy in the Making - Fossils in the Making: Vertebrate Taphonomy and Paleoecology.Anna K. Behrensmeyer and Andrew P. Hill (eds.). University of Chicago Press; Chicago. 1980. xii + 338 pp. Cloth, 7.00. - Volume 7 Issue 2

The Progress of Taphonomy: Fossils In the Making . Vertebrate Taphonomy and Paleoecology. Papers from a conference, Burg Wartenstein, Austria, July 1976. Anna K. Behrensmeyer and Andrew P. Hill, Eds. University of Chicago Press, Chicago, 1980. xii, 338 pp., illus. Cloth, $18; paper, $7. Prehistoric Archeology and Ecology.

The Progress of Taphonomy: <i>Fossils In the Making</i> . Vertebrate Taphonomy and Paleoecology. Papers from a conference, Burg Wartenstein, Austria, July 1976. Anna K. Behrensmeyer and Andrew P. Hill, Eds. University of Chicago Press, Chicago, 1980. xii, 338 pp., illus. Cloth, $18; paper, $7. Prehistoric Archeology and Ecology.

Procedures in vertebrate taphonomy; notes on a Uganda Miocene fossil locality

Before palaeoecological statements are made concerning the assemblage of fossil vertebrates at a particular site it is essential to understand the factors which have controlled bone accumulation. In this way some allowance can be made for the biases which must inevitably cause a fossil collection to differ from the living community or communities from which it was derived. In addition to conventional sedimentological techniques and the study of fossils merely as the remains of animals this can be partly achieved by treating bones as an integral part of the sediment. Such studies are the concern of taphonomy (Gk. tapho— burial, nomos —law) which deals with the processes potentially leading to the fossil-ization of an animal ( Efremov 1940 ). The differences between a fossil assemblage and the original community are particularly great in the case of terrestrial vertebrates, which seldom accumulate in autochthonous circumstances. It is therefore surprising that techniques familiar in invertebrate palaeontology seem rarely to have been applied to terrestrial vertebrates, where perhaps there is a greater need. Most previous work is in fairly recent archaeological contexts, though Voorhies (1969) and Dodson (1971) provide more strictly geological examples. This note records an attempt to establish a number of simple parameters of a vertebrate assemblage. It is hoped that other workers may be able to supply similar, or suitably modified, information concerning vertebrate accumulations that they investigate, which will then provide a basis for useful comparison. Bukwa II is an early Miocene fossil locality situated on the northeastern slopes of Mount