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Re: Ceratopsid controversy

Original Message by Stephan Pickering
Sunday, 22 December 2002 16:50

> REPLY: One of the best, and rather thorough,
> explications of this (ceratopsids probably did not
> gallop like rhinos) remains:
> Dawn Adams, 1989. Structure and function in the
> ceratopsian forelimb. Ph.D. dissertation, Univ.
> California Berkeley, 1-379.

Probably much easier to get is

Gregory S. Paul & Per Christiansen: Forelimb posture in neoceratopsian 
dinosaurs: implications for gait and locomotion, Paleobiology 26(3), 450 -- 
465 (2000)

Abstract: "Ceratopsid dinosaurs traditionally have been restored with 
sprawling forelimbs and were considered unable to run at high speeds. An 
alternative view restores the ceratopsids as rhinoceros-like with 
parasagittal forelimb kinematics and the ability to run faster than extant 
elephants. Several anatomical difficulties concerning the mounting of 
ceratopsid skeletons with nearly parasagittal forelimbs stem not from the 
forelimb itself, but from errors in rib and vertebral articulation. Matching 
a skeletal restoration to a probable ceratopsid trackway [*Ceratopsipes 
goldenensis*] shows that the hands were placed directly beneath the glenoids, 
and that manual impressions were directed laterally [not much], not medially 
as in sprawling reptiles. Pedal impressions in trackways are medial to the 
manual impressions, owing to the slightly averted elbow and to the 
asymmetrical distal femoral condyles, which directed the crus [lower leg] 
slightly medially. The limbs of ceratopsians of all sizes display substantial 
joint flexure, strongly indicating that the elephantine forelimb posture that 
has sometimes been suggested as the alternative to a sprawling posture is 
erroneous. The articular surfaces of uncrushed ceratopsian scapulocoracoids 
and forelimb joints confirm that the forelimb operated in a near-parasagittal 
plane with the elbows only slightly averted. The maximal running speed of 
even the largest ceratopsids is inferred to have significantly exceeded that 
of elephants [which don't run in the first place, as is said later] and was 
probably broadly similar to that of rhinos."

> Others have investigated the subject -- unfortunately,
> without giving Dawn the credit she richly deserves.

Paul & Christiansen do cite
"Adams, D. 1991. The significance of sternal position and orientation to 
reconstruction of ceratopsid stance and appearance. Journal of Vertebrate 
Paleontology 11(Suppl. 3):14A.",
though as far as I can find now only here (p. 455f.):

"In articulated, dorsoventrally compressed ceratopsid fossils (Brown 1917: 
Figs. 3, 4, Plate XVII; Lull 1993: Plate IVA) the posterolateral corner of 
the paired sternals articulates with the distal ends of the anterior dorsal 
ribs. This is the normal tetrapod condition, and restorations that depict 
ceratopsian sternals widely separated and far anteroventrally to the ribs 
(Lull 1933: Plate IIA; Osborn 1933; Erickson 1966) are probably erroneous, as 
also concluded by Adams (1991) and Ford (1997)."

Looks like they, as an example, didn't know the dissertation.

> Her dissertation is available at University Microfilms
> International.

And then you need another university library with a device to read 
microfilms. :-(