CONULARIIDS

Volumen 1 Issue 3 Year 2003

2020-03-27T20:44:09+02:00October 26th, 2019|Volumen 1. Issue 3. Year 2003.|

VOLUME 1. NUMBER 3. 2003

Experimental Effects of Water Abrasion on Bone Fragments.

Yolanda Fernández-Jalvo

Keywords: TRANSPORT, SEDIMENT, WATER STREAM, EXPERIMENT, ABRASION, ROUNDING

[+info] VOLUME 1. ISSUE 3. 2003 (1 issue)

Water transport is a frequent taphonomic agent in continental environments that may affect and disturb original bone associations. Fossil allochthony occurs as a result of resedimentation (before burial) and/or secondary deposition (after initial burial) altering palaeoenvironmental and palaeoecological indications provided by fossils. Skeletal element sorting or preferred orientations of fossils are evidence of fluvial transport as studied by several authors. Bone surface abrasion is another trait recorded on fossils that may provide evidence of water transport in a fossil association. Results of a preliminary experiment on the effects of abrasion have shown characteristic differences relating to the type of sediment (coarse to fine) and the type of bone involved (fresh, dry, weathered or fossil). This indicates that the effects and consequences of water transport on bone associations can be identified from traits of abrasion. This paper also considers other experiments involving abrasion on large and small mammal bones and owl pellets.

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Some Middle Paleozoic Conulariids (Cnidaria) as Possible Examples of Taphonomic Artifacts.

Marcello Guimarães Simões*, Sabrina Coelho Rodrigues, Juliana de Moraes Leme, Heyo Van Iten.

Keywords: TAPHONOMY, TAPHONOMIC ARTIFACTS, CONULARIIDS, CNIDARIA, DEVONIAN

[+info] VOLUME 1. ISSUE 3. 2003 (2 issue)

Conulariids provide good examples of how biometric and other characters that have been used to diagnose fossil species can be affected by taphonomic processes, possibly leading to the erection of taphonomic taxa, or taphonomic artifacts. Based on analysis of the taphonomy of Conularia quichua Ulrich from the Devonian Ponta Grossa of southern Brazil, we argue that caution must be exercised when using biometric and other characters to diagnose conulariid species. For example, measurements of the spacing of the transverse ribs must be corrected for compaction of the theca parallel to its long axis. C. quichua oriented at high angles to bedding almost always exhibit this kind of deformation, which if not corrected for results in substantial additional measurement error. Similarly, the value of the apical angle of C. quichua differs between compressed and uncompressed specimens, making it difficult to measure this character with a high degree of consistency and reproducibility. Other characters (geometry of the transverse ribs, presence or absence of interspace ridges and nodes) used to diagnose conulariids are susceptible to modification and information loss through weathering. In reviewing published descriptions of other conulariids, we have found that certain species may be taphotaxa. Future descriptions of new species should be based on collections encompassing the known spectrum of preservational patterns. Also, the erection of new conulariid taxa should be based as much as possible on complete or nearly complete specimens, and morphometric comparisons should be made using specimens showing similar patterns of preservation.

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Smothered Scampi: Taphonomy of Lobsters in the Upper Cretaceous Bearpaw Formation, Southern Alberta.

Cameron J. Tsujita.

Keywords: BURROWS, CONCRETIONS, CRETACEOUS, CRUSTACEANS, DECAPODS, DIAGENESIS, PHOSPHATE, TAPHONOMY

[+info] VOLUME 1. ISSUE 3. 2003 (3 issue)

Phosphatic concretions, containing remains of the lobster Palaeonephrops browni (Whitfield), are described from the Upper Cretaceous Bearpaw Formation of southern Alberta. Two modes of burial are interpreted to have enhanced the preservation potential of the lobsters: (1) burial of remains by volcanic ash, and (2) burial of remains within burrows due to sediment injection during storms. The latter mode of burial is indicated for the majority of the specimens studied, suggesting that the exceptional preservation of Palaeonephrops, and probably some other fossil decapod taxa may have been more strongly influenced by their life-habits than previously assumed. Within-burrow preservation of lobster specimens also demonstrates that obrution is not only important for the preservation of faunal elements residing on the sea-floor, but can also bias the preservation of some deep infaunal taxa. Following rapid burial, the preservation potential of the lobster remains was further enhanced by virtue of its phosphate-bearing cuticle, upon which, early diagenetic phosphate cements were preferentially precipitated. Further phosphate precipitation resulted in the entombment of the remains within phosphatic concretions, further protecting them from destructive taphonomic processes.

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Volumen 4. Issue 4. Year 2006.

2020-03-28T19:18:11+02:00October 26th, 2019|Volumen 4. Issue 4. Year 2006.|

VOLUME 4. NUMBER 4. 2006

By Ice Age Spotted Hyenas Removed, Cracked, Nibbled and Chewed Skeleton Remains of Coelodonta antiquitatis (BLUMENBACH 1799) from the Lower Weichselian (Upper Pleistocene) Freeland Prey Deposit Site Bad Wildungen-Biedensteg (Hessia, NW Germany).

Cajus G. Diedrich

Keywords: WOOLLY RHINOCEROS, SKELETON AND BONE TAPHONOMY, ICE AGE SPOTTED HYENA, PREY DEPOSIT FREELAND SITE, EARLY UPPER PLEISTOCENE

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

Eighty percent of 74 fragmentary cranial and postcranial bones of the Upper Pleistocene woolly rhinoceros Coelodonta antiquitatis (BLUMENBACH 1799) from the Lower Weichselian (65.000-90.000 BP, OIS 5, Upper Pleistocene) ice age spotted hyena open air prey deposit site Biedensteg at Bad Wildungen (Hessia, NW-Germany) exhibit crack, bite and nibbling marks. The skeletal remains represent at least five woolly rhinoceros individuals. Individual carcasses of an early adult female and a calf have been identified. Both show carcass disrupting and destruction by the hyenas in form of partly articulated bones, bone cracking, nibbling and chewing. Articulated parts of the skeletons were removed from the carcass and were stored in mud pits with other prey bones. The long bones, which are filled completely by the bone spongiosa, were generally not cracked, but are always gnawn intensively starting from the joints, while the hyenas mostly left the bone shaft intact. Such bone spongiosa was also not uncommon in hyena coprolites at the site. Typical bone destruction stages are represented. Those described in detail here include the cranium, scapula, humerus, ulna, radius, femur, tibia, pelvis but also vertebrae and costae. The woolly rhinoceros bones at the Bad Wildungen-Biedensteg freeland prey deposit site take 53% of the prey animal bones of Crocuta crocuta spelaea (Goldfuss 1823) and prove with other prey bones a mixed feeding onto all huge ice age mammals. Remains of Mammuthus antiquitatis, Bison priscus, Equus ferus przewalskii, Megaloceros giganteus, Rangifer tarandus, Ursus spelaeus and C. c. spelaea itself are included in the hyeana-modified fauna with 5-12% each showing signs of scavenging. The high percentage of the Coelodonta bones results more of the fact, that those are, such as mammoth bones, the most massive ones of ice age animals. The taphonomic comparison of C. antiquitatis carcasses and bones of Westphalian cave and freeland hyena den and prey deposit sites indicate the most important destruction impact of woolly rhinoceros carcasses by the Upper Pleistocene spotted hyena.

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Possible Taphonomic Bias in the Preservation of Phosphatic Macroinvertebrates in the Uppermost Maquoketa Formation (Upper Ordovician) of Northeastern Iowa (North-Central USA).

Heyo Van Iten, Michael Lichtenwalter, Juliana de Moraes Leme, Marcello Guimarães Simões.

Keywords: TAPHONOMY, PRESERVATIONAL BIAS, PHOSPHATIC FOSSILS, CONULARIIDS, SPHENOTHALLUS, ORDOVICIAN

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

Examination of acid digestion residues can be an indispensable tool in the detection and identification of fragmentary remains of rare and/or fragile, macroinvertebrate fossils preserved in shallow shelf carbonates. We recovered submicroscopic fragments of phosphatic conulariid, Sphenothallus (Cnidaria), and ?Trematis (Linguliformea) skeletons from a slab of highly fossiliferous lime packstone from the uppermost Brainard Shale Member of the Maquoketa Formation (Richmondian, Upper Ordovician) of northeastern Iowa, USA. The bedding planes of this and four similar Brainard Member slabs (total upper bedding surface area approximately 0.38 m2) lack macrofossil specimens of these three taxa, which have never previously been reported from this rock unit. Analysis of the preservation of the abundant calcitic fossils revealed evidence of wave current action, including pervasive disarticulation of the brachiopods, echinoderms, and trilobites, and bimodal alignment of the narrowly conical Cornulites shells and elongate Eoplectodonta valves, almost all of which are also oriented convex up. These results are consistent with the hypothesis that storm wave activity on the Brainard Member sea floor fragmented originally macroscopic conulariid, Sphenothallus, and ?Trematis skeletons, making it difficult to detect these taxa at low magnifications and thus making it appear that they were absent in the original bottom community. Together with results of similar studies of other Paleozoic rock units, our investigation suggests that there is a systematic, taphonomic bias against conulariids, Sphenothallus, and linguliform (phosphatic) brachiopods in storm-influenced shelf deposits.

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Taphonomic analysis of Plant Remains Contained in Carnivore Scats in Andean South America.

Mariana Mondini, M. Fernanda Rodríguez.

Keywords: CARNIVORE SCATS, PLANT REMAINS, POACEAE, TAPHONOMY, ROCKSHELTERS, ANDES, SOUTH AMERICA

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

Plant remains contained in carnivore scats from Puna rockshelters in the Argentinean Andean Puna are analysed. Only 31% of the scats (n=16) contained plant remains, all of them corresponding to the Poaceae family. Most of these are leaf and culm parts, and only in one case seeds were identified, possibly also corresponding to the same family. The lack of fleshy fruit seeds suggests a different pattern of plant intake as compared to other areas, possibly just for purging here. Plant anatomical structure has suffered no damage from digestive acids but some softening, and all anatomical features are perfectly recognizable. Plants can thus then enter the fossil record in rockshelters in the region via carnivore scats, and this should be taken into account, especially as these are the same kind of plants most commonly introduced by humans in the past according to the regional archaeological record.

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