[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Juravenator "proto-feathers" and other new papers



From: Ben Creisler
bh480@scn.org

In case these articles have not been mentioned yet:


Chiappe, Luis M.; Göhlich, Ursula B.
Anatomy of Juravenator starki (Theropoda: Coelurosauria) 
from the Late Jurassic of Germany. 
Neues Jahrbuch für Geologie und Paläontologie - 
Abhandlungen, 258(3): 257-296 (December 2010)
DOI: 10.1127/0077-7749/2010/0125

We provide a detailed study of the morphology of the 
holotype of Juravenator starki from the Late Jurassic of 
the Solnhofen area of southern Germany. The incompletely 
ossified surface of multiple bones and lack of several 
skeletal fusions indicate that Juravenator starki is 
based on an immature specimen. Nonetheless, numerous 
unique morphologies and bone proportions distinguish this 
taxon from Compsognathus longipes, the only previously 
named non-avian theropod dinosaur from the Late Jurassic 
of the Solnhofen Archipelago. Yet, its skeletal anatomy 
is most similar to that of Compsognathus and other 
theropods that have often been regarded as closely 
related to the latter - sometimes within a monophyletic 
Compsognathidae. Juravenator is characterized by having a 
small size (∼ 0.75-meter-long in the holotype) with few 
maxillary teeth, lack of a premaxillary-maxillary 
diastema, an antorbital fenestra subequal in length to 
orbit, an elongate scapula that is narrowest at its neck, 
a proportionally short humerus and high and abruptly 
tapered manual claws, and bow-like zygapophysial 
articulations in the mid-caudal vertebrae. Portions of 
the epidermis preserved mainly along the tail provide the 
only glimpse of the morphology of the skin of basal 
coelurosaurs, and structures newly revealed under UV 
light hint at the possibility of filamentous 
integumentary structures - akin to those interpreted as 
proto-feathers in other basal coelurosaurs - also 
covering the body of this dinosaur. The discovery of 
Juravenator has provided evidence of morphologies - from 
details of the skull to the epidermis - that are poorly 
known in other theropods interpreted as at or near the 
base of Coelurosauria, and thus contributes significantly 
to our understanding of the evolutionary history of this 
clade. The exquisitely preserved holotipic skeleton adds 
significantly to the meager record of small-bodied Late 
Jurassic theropods. 

http://www.ingentaconnect.com/content/schweiz/njbgeol/2010
/00000258/00000003/art00001


The Paludititan paper also officially published in this 
issue of Neues Jahrbuch, but it's been available for a 
time online already and discussed in the DML.


Also, since the Koreanosaurus paper was NOT published in 
the December issue, it means that the official 
publication date will be in 2011.
====================
Michael E. Burns, Philip J. Currie, Robin L. Sissons and 
Victoria M. Arbour (2010)

Juvenile specimens of Pinacosaurus grangeri Gilmore, 1933 
(Ornithischia: Ankylosauria) from the Late Cretaceous of 
China, with comments on the specific taxonomy of 
Pinacosaurus. 
Cretaceous Research (advance publication)
 doi:10.1016/j.cretres.2010.11.007 

Four juvenile specimens referable to Pinacosaurus 
grangeri (Ankylosauria: Dinosauria) are described from 
the Campanian (Upper Cretaceous) locality Bayan Mandahu 
in northern Inner Mongolia Autonomous Region (People's 
Republic of China). The specimens all preserve the skulls 
as well as, in some cases, mandibles, postcrania, and 
armour. They are not taphonomically deformed by expanding 
matrix distortion, unlike many Gobi specimens, including 
the holotype of P. grangeri. Bayan Mandahu is also the 
type locality for Pinacosaurus mephistocephalus. The 
proximity in space and time of these two closely related 
species warrants a generic and specific revision for 
Pinacosaurus. The distinction of the two species is based 
on characters of the squamosal dermal elaborations, 
cranial roof posterior to the orbits, premaxillary notch, 
and distal margin of the ilium. Although a relatively 
well-represented ankylosaur taxon, the phylogenetic 
position of Pinacosaurus has not been unequivocally 
resolved. A new analysis recovers Pinacosaurus as the 
most basal member of the Ankylosaurinae.

http://www.sciencedirect.com/science?
_ob=ArticleURL&_udi=B6WD3-51J9DCH-
1&_user=10&_coverDate=11%2F24%
2F2010&_rdoc=3&_fmt=high&_orig=browse&_origin=browse&_zone
=rslt_list_item&_srch=doc-info(%23toc%236755%239999%
23999999999%2399999%23FLA%23display%23Articles)
&_cdi=6755&_sort=d&_docanchor=&_ct=14&_acct=C000050221&_ve
rsion=1&_urlVersion=0&_userid=10&md5=d37d79eedabc5c9638588
84dcb0718a5&searchtype=a


Martin G. Lockley, Ri-Hui Li, , Masaki Matsukawa, Mingwei 
Liu and Kebai Wang (2010)
An unusual theropod track assemblage from the Cretaceous 
of the Zhucheng area, Shandong Province, China.
Cretaceous Research (advance publication)
doi:10.1016/j.cretres.2010.10.006 


More than 125 footprints of theropods from the Cretaceous 
Longwangzhuang Formation have been mapped in a 
preliminary study at a site in the Zhucheng region of 
China. The tracks represent at least three morphotypes. 
The largest morphotype is a large theropod (footprint 
length ?30 cm) represented by a single trackway and an 
isolated natural cast. At least 10 trackways assigned to 
the new ichnospecies Corpulentapus lilasia represent a 
medium-sized biped (footprint length ?13 cm) with very 
short,wide, robust, ?tulip-shaped? tracks and long steps 
(?5 x footprint length), and a short central digit (III) 
indicating weak mesaxony. Corpulentapus trackways are 
narrow and theropod-like even though track morphology is 
convergent with the footprints of some ornithopods. The 
third morphotype, made by a medium-sized grallatorid 
track maker (ichnogenus Paragrallator), is about the same 
size (? 13 cm) as the robust morphotype, but far more 
elongate and gracile, with an elongate central digit 
(III) indicating strong mesaxony. This ichnotaxon 
requires detailed comparison with Grallator sensu 
stricto.The contrast in morphology between the two common 
morphotypes is striking and demonstrates that two 
distinct medium-sized taxa of presumed theropod affinity 
frequented the same habitat in significant numbers. No 
non-theropod tracks are currently known from this 
locality.

http://www.sciencedirect.com/science?
_ob=ArticleURL&_udi=B6WD3-51JPWJ9-
2&_user=10&_coverDate=11%2F26%
2F2010&_rdoc=2&_fmt=high&_orig=browse&_origin=browse&_zone
=rslt_list_item&_srch=doc-info(%23toc%236755%239999%
23999999999%2399999%23FLA%23display%23Articles)
&_cdi=6755&_sort=d&_docanchor=&_ct=14&_acct=C000050221&_ve
rsion=1&_urlVersion=0&_userid=10&md5=e264a73470b9e1897dd57
3b1c589f182&searchtype=a

Anthony Romilio and Steven W. Salisbury (2010)
A reassessment of large theropod dinosaur tracks from the 
mid-Cretaceous (late Albian?Cenomanian) Winton Formation 
of Lark Quarry, central-western Queensland, Australia: A 
case for mistaken identity 
Cretaceous Research (advance publication)
doi:10.1016/j.cretres.2010.11.003 

Multivariate analysis is used to differentiate shape 
variations between ichnites of theropod and ornithopod 
dinosaurs. Tracks of an alleged theropod cf. 
Tyrannosauropus from the mid-Cretaceous (late Albian?
Cenomanian) Winton Formation of Lark Quarry, central-
western Queensland, Australia were examined and foot 
shape ratios calculated. Multivariate analysis of these 
shape variables indicates this track-maker was an 
ornithopod dinosaur. A strong morphological similarity 
exists between the Lark Quarry ichnites and those of the 
iguanodontian ichnotaxon Amblydactylus gethingi. 
Considering the grade of ornithopod this ichnogenus is 
thought to represent (a non-hadrosaurid styracosternan) 
and the age and geography of Lark Quarry, we suggest that 
the track-maker may have been a dinosaur similar to 
Muttaburrasaurus langdoni.