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Re: GSA talks about dinosaur-related stuff



PTEROSAUR DIVERSITY PARALLELS  CHANGES IN PALEOENVIRONMENT
MCLAIN, Matthew Aaron, 6 Perigo  Pass, North Creek, NY 12853,
> mmclain@cedarville.edu Pterosaurs were flying archosaurs whose
> fossils have been found on every continent. These fossils first
> appear in rocks of the Late Triassic, and they cease to appear at the
> Cretaceous-Paleogene boundary. The currently unpublished pterosaur
> database PteroTerra records the paleoenvironments and families for
> over 500 specimens. 463 specimens had listed paleoenvironments and
> were utilized for this study. These paleoenvrionments were tallied
> and compared for six portions of the Mesozoic: the Late Triassic,
> Early Jurassic, Middle Jurassic, Late Jurassic, Early Cretaceous, and
> Late Cretaceous. Then, pterosaur families were listed for each
> geologic epoch. The results of these comparisons seem to show a
> change from pterosaurs in marine paleoenvironments in the Early
> Jurassic and Middle Jurassic, to a great diversity of
> paleoenvironments in the Late Jurassic and Early Cretaceous.
> Simultaneously, the number of families present almost doubles from
> the Middle Jurassic to Late Jurassic, and then continues to increase
> into the Early Cretaceous. Thus, it appears that increasing
> morphological diversity in pterosaurs parallels increasing habitat
> diversity.

Counting families as a measure of biodiversity? Seriously?

Was there at least an attempt to count ghost lineages and account for the changing quality of the fossil record, itself dependent on the paleoenvironments?