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Some More New Papers
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
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
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
225 South 700 East
St. George, UT 84770 USA
Phone: (435) 652-7758
Fax: (435) 656-4022
"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
-- D. Graur & W. Martin (_Trends
in Genetics_ 20, 2004)