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Heavy pterosaurs and other new papers



From: Ben Creisler
bh480@scn.org

In case these new papers have not been mentioned yet:

Tai Kubo (2010)
Estimating body weight from footprints: Application to 
pterosaurs.
Palaeogeography, Palaeoclimatology, Palaeoecology 
(advance online publication)

The body mass of extinct animals have never been 
estimated from footprints, despite its potential utility. 
To redeem this situation, the relationship between body 
mass and the areas of footprints was derived from 17 
species of modern tetrapods. Body mass of seven 
ichnospecies of pterosaur tracks were estimated, because 
pterosaur body weight is an intriguing topic with 
reference to their flying ability. Estimated body weights 
of pterosaurs range from 110 g to 145 kg. The result 
provides evidence that large pterosaurs are about 10 
times heavier than the heaviest modern bird.

http://www.sciencedirect.com/science?
_ob=ArticleURL&_udi=B6V6R-51D165W-
3&_user=10&_coverDate=11%2F04%
2F2010&_rdoc=22&_fmt=high&_orig=browse&_origin=browse&_zon
e=rslt_list_item&_srch=doc-info(%23toc%235821%239999%
23999999999%2399999%23FLA%23display%23Articles)
&_cdi=5821&_sort=d&_docanchor=&_ct=116&_acct=C000050221&_v
ersion=1&_urlVersion=0&_userid=10&md5=93e40937da2ee15281eb
e89c77bf6ec9&searchtype=a


Jonathan S. Mitchell, Andrew B. Heckert and Hans-Dieter 
Sues (2010)
Grooves to tubes: evolution of the venom delivery system 
in a Late Triassic ?reptile? 
Naturwissenschaften (advance online publication)

Venom delivery systems occur in a wide range of extant 
and fossil vertebrates and are primarily based on oral 
adaptations. Teeth range from unmodified (Komodo dragons) 
to highly specialized fangs similar to hypodermic needles 
(protero- and solenoglyphous snakes). Developmental 
biologists have documented evidence for an infolding 
pathway of fang evolution, where the groove folds over to 
create the more derived condition. However, the oldest 
known members of venomous clades retain the same 
condition as their extant relatives, resulting in no 
fossil evidence for the transition. Based on a comparison 
of previously known specimens with newly discovered teeth 
from North Carolina, we describe a new species of the 
Late Triassic archosauriform Uatchitodon and provide 
detailed analyses that provide evidence for both venom 
conduction and document a complete structural series from 
shallow grooves to fully enclosed tubular canals. While 
known only from teeth, Uatchitodon is highly diagnostic 
in possessing compound serrations and for having two 
venom canals on each tooth in the dentition. Further, 
although not a snake, Uatchitodon sheds light on the 
evolutionary trajectory of venom delivery systems in 
amniotes and provide solid evidence for venom conduction 
in archosaur-line diapsids. 

Cajus Diedrich (2010)
Upper Jurassic tidal flat megatracksites of Germany?
coastal dinosaur migration highways between European 
islands, and a review of the dinosaur footprints .
Palaeobiodiversity and Palaeoenvironments (advance online 
publication)

Dinosaur tracks occur at three vertebrate tracksites in 
north-western Germany, in the acanthicum/mutabilis 
ammonoid biozone of the basal Upper Kimmeridgian (Upper 
Jurassic, KIM 3-4 cycle, 152.70-152.10 Ma). The trackbeds 
are mud-cracked, siliciclastic, tidal sand flat 
biolaminates, overlain by paleosol beds. Channels contain 
rare fossils of sauropod, ornithopod and pterosaur bones 
as well as shark and plant remains. Large sauropod tracks 
of the Elephantopoides type, which have been found in an 
intertidal megatracksite environment to the north of the 
Rhenish Massif, are reviewed herein, together with a 
camptosaurid track type (?Iguanodontipus), the theropod 
track Megalosauropus and possible dryosaurid Grallator 
tracks. These large dinosaur tracks have been reviewed 
and compared to all other known European localities. At 
the Barkhausen tracksite with its important 
ichnoholotypes, trackways of a possible sauropod herd 
consisting of ten small to medium-sized individuals and 
one large individual have been exposed, revealing 
different speeds of travel as well as important social 
behaviour in these large herbivorous dinosaurs. Two 
theropods also left their imprints on the same track 
horizon, one travelling towards the south in a direction 
contrary to the movement of the herd, and the second 
travelling towards the north-west, cutting across the 
other trackways. Five different types of Upper Jurassic 
dinosaur tracks have now been recorded from coastal 
environments scattered around Europe, with the best 
footprint records forming extensive megatracksites in 
biolaminates between Jurassic islands in central Europe. 
These intertidal flats formed periodic bridges between 
the islands, allowing dinosaur interchanges and 
migrations between America and Eurasia, which may help to 
explain the much broader palaeobiogeographic 
distributions of dinosaur species during the Late 
Jurassic. 
http://www.springerlink.com/content/c2506v112560w251/

Also, I don't recall if this Palaeontologica Polonica 
issue has been mentioned. It's been out for a time but it 
has free pdfs describing various archosauromorphs.

EARLY TRIASSIC VERTEBRATE ASSEMBLAGE FROM KARST DEPOSITS 
AT CZATKOWICE, POLAND 

http://palaeontologia.pan.pl/