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New papers: Kentrosaurus lectotype and dino tracks



From: Ben Creisler
bh480@scn.org

In case these recent papers have not been mentioned yet:

Mallison, Heinrich (2011)
The real lectotype of Kentrosaurus aethiopicus Hennig, 
1915. 
Neues Jahrbuch für Geologie und Paläontologie - 
Abhandlungen 259 (2): 197-206 (February 2011) 
DOI: 10.1127/0077-7749/2011/0114
http://www.ingentaconnect.com/content/schweiz/njbgeol/2011
/00000259/00000002/art00004

A detailed study of the relevant literature reveals that 
contra recent use the lectotype of the stegosaur 
Kentrosaurus aethiopicus Hennig, 1915 is a partial 
individual from excavation 'St' at Kindope, Tendaguru, 
Tanzania in the collection of the Museum für Naturkunde 
Berlin (MB. R.4800.1-37). This significantly influences 
the diagnosis of the taxon, defining several characters 
based on the lectotype instead of referred specimens, 
notably the sub-vertical neural spines of the medial 
third of the tail, and the hook-shaped, anteriorly 
inclined neural spines in the posterior caudals. 


===

P. L. Falkingham, K. T. Bates, L. Margetts and P. L. 
Manning (2011)
The ?Goldilocks? effect: preservation bias in vertebrate 
track assemblages.
Journal of the Royal Society Interface (advance online 
publication)
doi: 10.1098/​rsif.2010.0634 

FREE PDF at:
http://rsif.royalsocietypublishing.org/content/early/2011/
01/12/rsif.2010.0634.abstract

Finite-element analysis was used to investigate the 
extent of bias in the ichnological fossil record 
attributable to body mass. Virtual tracks were simulated 
for four dinosaur taxa of different sizes (Struthiomimus, 
Tyrannosaurus, Brachiosaurus and Edmontosaurus), in a 
range of substrate conditions. Outlines of autopodia were 
generated based upon osteology and published soft-tissue 
reconstructions. Loads were applied vertically to the 
feet equivalent to the weight of the animal, and 
distributed accordingly to fore- and hindlimbs where 
relevant. Ideal, semi-infinite elastic?plastic substrates 
displayed a ?Goldilocks? quality where only a narrow 
range of loads could produce tracks, given that small 
animals failed to indent the substrate, and larger 
animals would be unable to traverse the area without 
becoming mired. If a firm subsurface layer is assumed, a 
more complete assemblage is possible, though there is a 
strong bias towards larger, heavier animals. The depths 
of fossil tracks within an assemblage may indicate 
thicknesses of mechanically distinct substrate layers at 
the time of track formation, even when the lithified 
strata appear compositionally homogeneous. This work 
increases the effectiveness of using vertebrate tracks as 
palaeoenvironmental indicators in terms of inferring 
substrate conditions at the time of track formation. 
Additionally, simulated undertracks are examined, and it 
is shown that complex deformation beneath the foot may 
not be indicative of limb kinematics as has been 
previously interpreted, but instead ridges and 
undulations at the base of a track may be a function of 
sediment displacement vectors and pedal morphology. 
====

Also of interest:
For French readers, there are news story about a new 
theropod found in Aix-en-Provence (a region famous for 
fossil dino eggs) in southern France. It's not been named 
yet, but it's based on part of a skull, described as up 
to 6 meters long in total length, and about 70 million 
years old.
http://www.citylocalnews.com/aix/2011/02/01/un-nouveau-
dino-decouvert


http://www.maxisciences.com/dinosaure/une-nouvelle-espece-
de-dinosaure-decouverte-a-aix-en-provence_art12277.html