Journal Abstracts

[Miles Constable at Edmn <ConstableM@mail.edm.ab.doe.ca>]

Thud, thud, thud, thud.
No that is not the sound of a tyrranosaur persuing it's prey, it is the 
sound of me hastily backpedalling. My edition of Current Contents on 
Diskette is oriented towards environmental biology and so appears not to 
extract the major paleontological journals. So, I will post what I have. I 
may rectify the oversight in the future.

The first two articles are not directly dinosaurian in nature but are very 
related to their ecology, ie. temperature estimates and insect assemblages 
for the Cretaceous.

Sellwood, B.W., Price, G.D., Valdes, P.J.,"Cooler estimates of cretaceous 
temperatures. Nature, August 11, 1994. 370, 6489, 453-455.
"The Cretaceous period is thought to have been warmer than the present, with 
higher concentrations of atmospheric greenhouse gases such as carbon 
dioxide. It has therefore been suggested that this time period could be used 
by modellers as an analogue for future climate change. But the Cretaceous 
Equator-to-Pole temperature gradient was flatter than today's, leading some 
to suggest that Cretaceous climate arose from a combination of factors, with 
higher atmospheric carbon dioxide concentrations leading to general warming, 
and other factors, such as increased ocean heat transport, leading to 
flattening of the latitudinal temperature gradient. Here we report new 
records of ocean palaeotemperature for Cenomanian sites in the Atlantic and 
Pacific oceans which, together with a re-evaluation of published data, cast 
doubt on the idea that the Cretaceous period was generally warmer. These 
data confirm that the latitudinal temperature gradient was flatter, but 
suggest that the global mean temperature, was much cooler than previously 
believed, with minimum mean equatorial temperatures close to present values 
and polar temperatures close to 0 degrees C. In the light of these findings, 
the climatic role of atmospheric carbon dioxide in determining Cretaceous 
climate is unclear, suggesting that the Cretaceous cannot be used as an 
analogue for future climate change."

Pike, E.M.."Historical Changes in Insect Community Structure as Indicated by 
Hexapods of Upper Cretaceous Alberta (Grassy Lake) Amber", Canadian 
Entomologist, May-June 1994.126, 3, 695-702.
"Species richness and relative abundance of arthropod taxa from an Upper 
Cretaceous (Campanian: 75 Mya) amber deposit in Alberta are described. About 
130 hexapod species have been recognized to date from this deposit, making 
it the most diverse Cretaceous insect assemblage so far known. Taxa present, 
in order of abundance, are Hemiptera (66 specimens per kg), Diptera (28), 
Acari (21), Hymenoptera (13), Aranaea (12), Psocoptera (4), Coleoptera (2), 
Blattodea (1), Thysanoptera (1), and Trichoptera (0.6). Representatives of 
Lepidoptera, Collembola, Dermaptera, Mantodea, Phasmatodea, and 
Ephemeropteraare are also present. In the total of 65 identified families, 
15 are extinct. Only one of about 77 genera identified in this deposit is 
extant. All recognized species are extinct. In comparison, virtually all 
families reported from Baltic and Dominican Republic ambers are extant, as 
are the majority of the genera. Morphology and feeding structures are well 
within the variation seen in modem insects. It is hypothesized that the 
taxonomic structure of modem insect communities was well established before 
the end of the Cretaceous and that the structure and interrelationships of 
insect guilds were also very similar to those of today."

Unwin, D.M., Bakhurina, N.N.,"Sordes pilosus and the nature of the pterosaur 
flight apparatus". Nature, September 1, 1994. 371, 6492, 62-64.
"It is now generally accepted that pterosaurs, Mesozoic reptiles, were true 
fliers, but the nature of their flight apparatus is still much disputed. 
Evidence has been presented in favour of bird-like reconstructions with 
narrow, stiff wings free of the legs and bat-like reconstructions with 
extensive wings incorporating both fore and hind limbs, but the Solnhofen 
Limestone pterosaurs, upon which these models are based, are not 
sufficiently well preserved to resolve these conflicting interpretations. 
Here we present a new model, founded on Sordes pilosus from the Jurassic of 
middle Asia, in which exceptionally well preserved wing membranes show that 
the hind limbs of pterosaurs were intimately involved in the flight 
apparatus; connected externally to the main wing membrane and internally by 
a uropatagium, controlled by the fifth toe. Sordes also reveals that, 
uniquely among flying vertebrates, pterosaurs had a structurally 
non-homogenous flight surface with a stiffened outer half and a softer, more 
extensible inner region."