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New Papers on a Plane

Andrew R.C. Milner came up with that subject line (!), and SP oriented me toward some of the papers below. And we all know what happens when paleo papers get loose in small, confined spaces...

None of these directly pertain to dinosaurs, but I thought they'd be of interest to some on the list! First, a couple of popular articles (in Spanish); they have quite excellent illustrations:

Apesteguía, S. 2007. La evolución de los lepidosaurios. Investigación y Ciencia 367:54-63.

Apesteguía, S. 2007. Lepidosaurios en movimiento: de los lagartos a las serpientes. Investigación y Ciencia 371:55-61.

More on the Chicxulub impact:

Wittmann, A., Kenkmann, T., Hecht, L., and Stöffler, D. 2007. Reconstruction of the Chicxulub ejecta plume from its deposits in drill core Yaxcopoil-1. Geological Society of America Bulletin 119(9):1151-1167. doi: 10.1130/B26116.1.

ABSTRACT: Formation conditions of suevite-like impactites from an 100 m thick drill core sequence through the Cretaceous-Tertiary Chicxulub crater were reconstructed from empirical data obtained by petrologic and image analytical methods. The temporal evolution of the cratering process from the initial stage of excavation to the collapse of the ejecta plume is evidenced by the petrographic characteristics and modal composition of the suevitic rocks, including the size distribution and shape parameters of melt particles. Emplacement of the lowermost suevitic deposits likely started in the first minute after the impact by the passing ejecta curtain that interacted with the expanding ejecta plume. These ejecta deposits were capped by a tongue of coherent impact melt that was transported outward from the crater center during the collapse of the central uplift 5 min after impact. On top of this brecciated impact melt rock, the collapsing ejecta plume deposited air-fall suevites. The basal air-fall unit, Middle Suevite, may have been deposited due to a density current-like clumping of hot debris. With progressive cooling, regions of the ejecta plume were entrained in its collapse that produced vapor condensates, accretionary rims, and different oxygen fugacities. After cooling progressed, atmospheric conditions began to reestablish over the crater and turbulence decreased, supposedly after the first 10 min of initial ejecta plume collapse. This led to a winnowing out of fine matrix material and distinct sorting. However, due to aquatic reworking, only material that was deposited until 1 h after cessation of turbulent atmospheric conditions was retained.

And lastly, a fun little paper documenting that yes, at least some crocodylians shed "tears" while eating (and doing some other activities, too), at least some of the time:

Shaner, D.M., and Vliet, K.A. 2007. Crocodile tears: and thei eten hem wepynge. Bioscience Journal 57(7):615-617. doi: 10.1641/B570711.

ABSTRACT: Whether crocodiles shed tears while eating has been fodder for fable and controversy for hundreds of years. We present the first unequivocal evidence that crocodilians lacrimate during meals and that they do so in a peculiar fashion.

I never knew that this tearing action had a technical name, but it's a fabulous one: prandial lacrimal ebullition. Gonna hafta use that one sometime... (Reminds me of Dr. McCoy's excuse for getting in to the hospital room to rescue Chekov in "Star Trek IV," wheeling a moaning Dr. Gillian Taylor on a gurney into an operating room:

KIRK: Out of the way!

GUARD: Sorry, Doctor, I have strict orders...

[Gillian moans in pain]

McCOY: My God man. Do you want an acute case on your hands? This woman has immediate post-prandial, upper-abdominal distention!

[they enter the OR]

KIRK: What did you say she has?

McCOY: Cramps. )

Jerry D. Harris
Director of Paleontology
Dixie State College
Science Building
225 South 700 East
St. George, UT  84770   USA
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
and     dinogami@gmail.com


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