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RE: Fossils in Argentinosaurus footprints

> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] 
> On Behalf Of Martin Baeker
> Hi folks,
> my google skills have failed me: I have seen a TV documentary 
> which showed an assembly of small fossils inside an 
> Argentinosaurus footprint. However, I'm unable to find any 
> reference for that.
> Any hints to a paper (or if possible a pdf) would be very 
> welcome here...

The sauropod ID (and thus the continent) is totally wrong, but this seems to be 
a misreporting of:

PALAIOS 25(2):112-125. 2010

full access



Three newly discovered bonebeds from the Shishugou Formation of Xinjiang, 
China, are unusual in preserving vertically stacked and articulated to 
associated skeletons of at least 18 small, non-avian theropod dinosaurs in pits 
that are 1–2 m deep. The pits host a soft sediment-deformed mixture of alluvial 
and volcanic mudstone and sandstone. There is no evidence that the pits were 
discrete depressions in the topography that filled through time. Rather, they 
appear to have been highly localized areas of liquefaction caused by 
large-dinosaur (possibly sauropod) trampling of saturated sediments. Evidence 
indicates that the small theropods, and some other small vertebrates, became 
mired and died in these mud-filled pits. High quality skeletal preservation 
suggests that most individuals were buried within days to months after their 
deaths. Carcasses were buried successively, coming to rest above previously 
buried individuals. In some cases, skeletal body parts became separated or were 
removed, probably during scavenging. Given the large sizes of the pits relative 
to the small body sizes of the vertebrates contained within them, we conclude 
that small vertebrates (<3 m long and <1 m tall) were particularly susceptible 
to miring at these sites. Although the small, presumably herbivorous 
ceratosaur, Limusaurus inextricabilis, dominates the combined small theropod 
assemblage from these bonebeds (minimum number of individuals [MNI]  =  15), 
there is no evidence that any biological features other than its small size and 
a large, and possibly, gregarious local population were responsible for its 
becoming mired in large numbers. A bias for small theropods in these bonebeds, 
compared to their relatively low abundance in the overall Shishugou Formation 
fauna, underscores that small theropods are underrepresented in Mesozoic fossil 
assemblages collected from other ancient alluvial and paludal settings.

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
Fax: 301-314-9661               

Faculty Director, Science & Global Change Program, College Park Scholars
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA