Fossil assemblages from the Upper Cretaceous Komen and Tomaj Limestones of Kras (Slovenia)

For fossil assemblages, quantitative size and shape studies are often complicated by diagenetic distortion. Different vertebrate elements, although subjected to similar burial stresses, exhibit deformations based upon their original shapes; this hypothesis is tested here by quantitatively comparing deformed humeri and femora from the Danek Bonebed (a monodominant Edmontosaurus regalis bonebed from the upper Campanian Horseshoe Canyon Formation in Edmonton, Alberta, Canada) with samples of undeformed humeri and femora from modern and fossil assemblages. Analyses suggest that at the Danek Bonebed a strong relationship exists between element length and circumference despite being distorted by crushing deformation. Major and minor axes of the midshaft cross section, however, were not uniformly distorted. Although their anatomical position did not change, the major axis became longer relative to the minor axis in distorted specimens. A regression based on the undeformed humeri was not able to accurately predict circumference in the Danek humeri. Further study might quantify the deformation of other bones in the Danek Bonebed and could be extended to other assemblages and genera. Caution should be taken when conducting studies in which diagenetic crushing may have altered morphological features of fossil vertebrate remains.

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Analysis of Upper Cretaceous Trace-Fossil Assemblages, U.S. Western Interior: ABSTRACT

AAPG Bulletin ◽

10.1306/03b59b7a-16d1-11d7-8645000102c1865d ◽

1982 ◽

Vol 66 ◽

Author(s):

Allen W. Archer, Donald E. Hattin

Keyword(s):

Upper Cretaceous ◽

Trace Fossil ◽

Fossil Assemblages

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Trace Fossil Assemblages of Upper Cretaceous Sand Units, Delaware and New Jersey: ABSTRACT

AAPG Bulletin ◽

10.1306/2f918c6b-16ce-11d7-8645000102c1865d ◽

1980 ◽

Vol 64 ◽

Author(s):

H. Allen Curran, Ronald L. Martino

Keyword(s):

New Jersey ◽

Upper Cretaceous ◽

Trace Fossil ◽

Fossil Assemblages

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Taphonomic analysis of saurischian dinosaurs from the Plottier Formation (Upper Cretaceous), Mendoza, Argentina

Andean geology ◽

10.5027/andgeov46n2-3161 ◽

2019 ◽

Vol 46 (2) ◽

pp. 345 ◽

Cited By ~ 2

Author(s):

Elena Previtera

Keyword(s):

Upper Cretaceous ◽

Holistic Approach ◽

Depositional Environments ◽

Continental Deposits ◽

Wide Range ◽

History Of ◽

Fossil Assemblages ◽

Vertebrate Assemblage ◽

Taphonomic Analysis ◽

Fluvial Environments

The uppermost Cretaceous continental deposits of the Neuquén Basin (west-central Argentina) have yielded a high diversity vertebrate assemblage, including numerous dinosaur species. The Neuquén Group is the richest unit in remains of dinosaur of the basin and comprises the Río Limay, the Río Neuquén and the Río Colorado subgroups. In this group, there is abundance of isolated, disarticulated or partially articulated sauropods and theropods. However, little is known about the taphonomic history of fossil assemblages. In this study, dinosaur remains from the Plottier Formation (late Coniacian-early Santonian) found in the Cerro Guillermo area in southern Mendoza are examined. The investigation of fossil occurrences within the study area revealed the existence of different taphonomic modes, from isolated bones until partially articulated skeletons preserved in deposits of floodplain and fluvial channel settings. SEM-EDS analysis showed the substitution of hydroxyapatite by francolite in the bone microstructure. The presence of fluorine-in one of the cases-suggested a link between the elemental composition and depositional environments: floodplain and fluvial channel. The survey of the vertebrate accumulation types and their sedimentary context allowed documenting a wide range of processes responsible for their genesis, operating within a meandering fluvial environment. This contribution represents a holistic approach about taphonomic history of Cretaceous dinosaurs for assessing the differential preservation of fossil assemblages in fluvial environments.

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Trace Fossil Assemblages as Indicators of Shelf-Sandstone Facies, Upper Cretaceous, Northwestern Colorado: ABSTRACT

AAPG Bulletin ◽

10.1306/2f91a296-16ce-11d7-8645000102c1865d ◽

1981 ◽

Vol 65 ◽

Author(s):

Alan J. Scott, J. Michael Boyles

Keyword(s):

Upper Cretaceous ◽

Trace Fossil ◽

Fossil Assemblages ◽

Sandstone Facies

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Trace fossils and depositional sequences in a clastic shelf setting, Upper Cretaceous of Utah

Journal of Paleontology ◽

10.1017/s0022336000019004 ◽

1990 ◽

Vol 64 (5) ◽

pp. 803-820 ◽

Cited By ~ 68

Author(s):

Robert W. Frey ◽

James D. Howard

Keyword(s):

Upper Cretaceous ◽

Trace Fossils ◽

Trace Fossil ◽

Depositional Sequences ◽

Mancos Shale ◽

Fossil Assemblages

In Coal Creek Canyon, Utah, the Spring Canyon Member of the Blackhawk Formation is divisible into four regressive hemicycles of deposition, each representing the downdip part of a nearshore-to-offshore sequence. The first and fourth hemicycles are best developed. Individual bedding units span middle-shoreface to lower-offshore lithofacies, the latter corresponding to a thin intertongue of Mancos Shale.Trace fossil assemblages include ~22 ichnospecies and 17 ichnogenera: Ancorichnus, Aulichnites, Chondrites, Cylindrichnus, Ophiomorpha, Palaeophycus, Phoebichnus, Planolites, Rosselia, Schaubcylindrichnus, Scolicia, Skolithos, Taenidium, Teichichnus, Terebellina, Thalassinoides, and Uchirites. Diversity and abundance of ichnospecies are greater in nearshore than in offshore lithofacies. Distal deposits are typified by obscure bioturbate textures: Cylindrichnus concentricus, Palaeophycus heberti, and Rosselia socialis are prevalent through the remainder of the lithofacies suite. Ophiomorpha irregulaire and Schaubcylindrichnus coronus are most common in middle-shoreface beds and Chondrites ichnosp. in upper-offshore beds; Ophiomorpha nodosa and O. annulata also are common in this part of the sequence.

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