new ref: GALTON. 2005

[Jose Ignacio =?unknown?q?Ruiz-Ome=F1aca?= <jigruiz@unizar.es>]

Peter M. GALTON. 2005.  Bones of large dinosaurs (Prosauropoda and Stegosauria) 
from the Rhaetic Bone Bed (Upper Triassic) of Aust Cliff, southwest England. 
Revue de Paléobiologie, 24(1), 51-74.


Abstract

Five shafts of large long bones of dinosaurs have been found since 1846 in the 
Rhaetic Bone bed of the Westbury Formation (Upper Triassic) at Aust Cliff near 
Bristol, Avon, southwestern England. Two bones (1 lost) are Dinosauria incertae 
sedis and a third (also lost), the longest and best preserved, was probably 
part of a femur of the melanorosaurid prosauropod Camelotia (Upper Triassic, 
England). The width of the other two femoral shafts is greater transversely 
than anteroposteriorly, as in Camelotia. However, these shafts are also 
straight in lateral view, a derived character that occurs only in sauropods and 
stegosaurs and some Cretaceous ankylosaurs and ornithopods. However, the shafts 
are curved in lateral view in basal ankylosaurs and Jurassic ornithopods. 
Unlike the femora of Upper Jurassic sauropods and stegosaurs, in which the bone 
is almost solid, the Aust shafts consist of a thin layer of compact cortical 
bone surrounding a large area, most of which is filled with!
  very lightly constructed cancellous bone. However, cross-sections of the 
humerus just below the deltopectoral crest of the sauropod Isanosaurus (Upper 
Triassic, Thailand) and the stegosaur Dacentrurus (Upper Jurassic, England) are 
intermediate in their histology. The femoral shaft is hollow in some Jurassic 
stegosaurs, though not to the degree shown by those from Aust. The Aust shafts 
are truly columnar, agreeing with those of stegosaurs in the apparent lack of a 
prominent fourth trochanter and of the associated posteromedial depression, 
structures which are prominent in sauropods. These two shafts, with estimated 
femoral lengths of about 1000-1100 mm, are tentatively referred to the 
Stegosauria so stegosaurs probably reached a large size in the Upper Triassic ; 
the earliest definitive record of the group is Middle Jurassic (Bathonian) of 
England

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Galton also discusses and figures:

- Zanclodon cambrensis Newton 1899
- Avalonia sanfordii Seeley 1898
- Picrodon herveyi Seeley 1898