Some More New Papers

["Jerry D. Harris" <jharris@dixie.edu>]

Hi All -

   Some more announcements!  This first one is from a new book that I guess 
must be out now, though it's not listed yet on the Association's web site. 
If anyone knows how to get a hold of it (and how much it costs!), please let 
us know!

Bonnan, M., and Senter, P. 2007. Were the basal sauropodomorph dinosaurs 
Plateosaurus and Massospondylus habitual quadrupeds?; pp. 139-155 in 
Barrett, P.M. and Batten, D.J. (eds.), Evolution and Palaeobiology of Early 
Sauropodomorph Dinosaurs. Special Papers in Palaeontology 77. 
Palaeontological Association, London.

ABSTRACT: The basal sauropodomorph dinosaurs Plateosaurus and Massospondylus 
are often portrayed as habitual quadrupeds that were facultatively bipedal. 
Surprisingly, the functional morphology of their forelimbs has rarely been 
considered when reconstructing their locomotor habits. If Plateosaurus and 
Massospondylus were efficient, habitual quadrupeds we predict that the manus 
would have been pronated such that it produced a caudally directed force in 
parallel with the pes. We articulated and manipulated the forelimbs of 
Plateosaurus, Massospondylus and several extant outgroup taxa (Varanus, 
Alligator, Anser and Struthio) using a standardized protocol. Moreover, we 
compared our results with previously published estimates of forelimb 
movement in saurischian outgroup taxa from Theropoda and Sauropoda and with 
the basal sauropodomorph/sauropod Melanorosaurus. Our results indicate that 
the range of motion in the forelimbs of Plateosaurus and Massospondylus did 
not allow efficient, habitual quadrupedal locomotion. The range of humeral 
flexion and abduction is limited and the articular surfaces of the radius 
and ulna orient the palmar surfaces of the manus medially in 
semi-supination. Active or passive pronation of the manus was not possible 
and the manus could not function in a dynamically similar way to the pes for 
efficient quadrupedal locomotion. Our results also rule out specialized 
forms of quadrupedal locomotion, such as the knuckle-walking gait of some 
mammals. We suggest that most known "prosauropod" trackways were probably 
not made by animals such as Plateosaurus or Massospondylus, but the 
ichnotaxon Otozoum may have been created by animals similar to these taxa. 
Furthermore, we show that trunk and limb ratios do not yield consistent 
results and should not be used solely to determine posture. Although these 
two taxa probably assumed a quadrupedal posture as hatchlings, we show that 
the morphological orientations of the forelimb elements remained consistent 
across ontogeny, precluding efficient, quadrupedal locomotion at any age. As 
with theropods, forelimb use in basal sauropodomorphs is difficult to 
reconstruct and interpret. We speculate that the forelimb could have aided 
in acquiring vegetation or defence in Plateosaurus and Massospondylus only 
if these animals reared or assumed a tripodal posture.

   These for the track-lovers out there:

Hurum, J., Milàn, J., Hammer, Ø., Midtkandal, I., Amundsen, H., and Saether, 
B. 2006. Tracking polar dinosaurs - new finds from the Lower Cretaceous of 
Svalbard. Norwegian Journal of Geology 86:397-402.

ABSTRACT: A new discovery of ornithopod dinosaur tracks from Svalbard is 
described. The Lower Cretaceous (Barremian) section at Isfjorden consists of 
sandstones and interbeds consistent with an alluvial flood plane. The newly 
discovered tracks are situated on two different horizons stratigraphically 
below the original horizon found in 1960. Footprint evidence from Festningen 
and Kvalvågen suggests that during the Early Cretaceous there was a diverse 
dinosaur fauna on Svalbard and that both theropods and ornithopods were 
present at the time.

    -- this one is freely available at 
http://www.geologi.no/data/f/0/09/35/0_22301_0/J._H._Hurum_et_al_lavoppl.pdf.

Mezga, A., Tesovicm, B.C., and Bajraktarevic, Z. 2007. First record of 
dinosaurs in the Late Jurassic of the Adriatic-Dinaridic Carbonate Platform 
(Croatia). Palaios 22(2):188-199. doi: 10.2110/palo.2006.p06-043r.

ABSTRACT: All previously known dinosaur remains on the Adriatic-Dinaridic 
carbonate platform (ADCP) were described from Cretaceous deposits. A new 
trackbearing locality is late Tithonian in age and represents the oldest 
evidence of dinosaurs on the ADCP. The site is in an active quarry near the 
village of Kirmenjak in western Istria. Almost a thousand sauropod 
footprints including 23 single trackways have been found on the outcrop. 
Oval impressions represent pes prints, and horseshoe-shaped impressions 
represent manus prints; pes prints are 23 to 52 cm long. Calculated heights 
at the hip range from 153 to 306 cm. The main direction of dinosaur movement 
was toward the northeast, and some of the individuals were moving together. 
The trackways show a characteristic narrow gauge, and pace and stride 
lengths indicate a slow walk. The footprints are similar to Parabrontopodus 
ichnogenus, and the ichnocoenosis could be assigned to the Brontopodus 
ichnofacies. The presence of the sauropods on the Adriatic-Dinaridic 
carbonate platform during the Late Jurassic could be explained by connection 
with the African continent via its southern margins during emersion.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jerry D. Harris
Director of Paleontology
Dixie State College
Science Building
225 South 700 East
St. George, UT  84770   USA
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
and     dinogami@gmail.com
http://cactus.dixie.edu/jharris/

"Trying to estimate the divergence times
of fungal, algal or prokaryotic groups on
the basis of a partial reptilian fossil and
protein sequences from mice and humans
is like trying to decipher Demotic Egyptian with
the help of an odometer and the Oxford
English Dictionary."
              -- D. Graur & W. Martin (_Trends
                  in Genetics_ 20[2], 2004)