Sgt. Pepper's Lonely Hearts Club New Papers

["Jerry D. Harris" <jharris@dixie.edu>]

Just a couple of new things -- more to follow as I continue to play 
catch-up!


Li, R., Lockley, M.G., Makovicky, P.J., Matsukawa, M., Norell, M.A., Harris, 
J.D., and Liu, M. 2007. Behavioral and faunal implications of Early 
Cretaceous deinonychosaur trackways from China. Naturwissenschaften. doi: 
10.1007/s00114-007-0310-7.

ABSTRACT: Deinonychosaurian theropods, the dinosaurian sister group of 
birds, are characterized by a large raptorial claw borne on a highly 
modified second digit that was thought to be held in a retracted position 
during locomotion. In this study, we present new trackway evidence for two 
coeval deinonychosaurian taxa from the Early Cretaceous of Shandong, China 
that indicate a hitherto unrecognized body size diversity for this period 
and continent. These fossil tracks confirm diversity and locomotory patterns 
implied by phylogeny and biogeography, but not yet manifested in the body 
fossil record. Multiple parallel and closely spaced trackways generated by 
the larger track maker provide the best evidence yet discovered for 
gregarious behavior in deinonychosaurian theropods.

     Clearly the most important paper to come down the pike in quite some 
time...



Makovicky, P.J. 2007. Telling time from fossils: a phylogeny-based approach 
to chronological ordering of paleobiotas. Cladistics 23. doi: 
10.1111/j.1096-0031.2007.00184.x.

ABSTRACT: The potential for using fossils for temporal ordering of 
sedimentary rocks is as old as historical geology itself. In spite of this, 
however, most current biostratigraphic and biochronologic techniques do not 
make use of phylogenetic information, but rely instead on some measure of 
species' presence or absence or their turnover in the fossil record. A 
common phylogenetic approach to biochronology has been to use "stage of 
evolution" arguments, whereas more rigorous, cladogram-based methods have 
been proposed but have seen little use. Cladistic biochronologic analysis 
(CBA) is developed here as a new method for determining biochronologic order 
between paleobiotas based on the phylogenetic relationships of their 
constituent taxa. CBA is adapted from Brooks' parsimony analysis, and 
analyzes syntaxon information from clades that transcend a number of 
paleobiotas to determine relative temporal order among these paleobiotas. 
Because CBA is based on phylogenetic information, it is suited to problems 
where a good fossil record is available, but where stratigraphic or 
chronologic relationships are poorly constrained, such as the terrestrial 
vertebrate record. A practical example, based on the Cenozoic fossil record 
of North America, pits CBA against a test case in which the correct temporal 
order of biotas is known beforehand. The method successfully recovers 
correct temporal order between paleobiotas with reasonable levels of 
support, and is also shown to outperform a previously proposed cladistic 
biochronologic method. In a second example, CBA is used to achieve the first 
empirical temporal ordination for several Late Cretaceous localities in the 
Gobi Desert that produce fossils crucial to the understanding of modern 
amniote clades, but which have poorly resolved temporal relationships. CBA 
is sensitive to large amounts of extinction and poor sampling of the fossil 
record, but problems such as gaps in the fossil record (Lazarus taxa) can be 
dealt with efficiently through a number of a priori and a posteriori scoring 
techniques. CBA offers a novel approach for biochronologic analysis that is 
independent of, but complementary to and readily combinable with other 
chronologic/stratigraphic methods.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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
http://cactus.dixie.edu/jharris/

STORIES IN SIX WORDS OR LESS:

"Machine. Unexpectedly, I'd invented
a time"
              -- Alan Moore

"Easy. Just touch the match to"
              -- Ursula K. Le Guin

"Batman Sues Batsignal: Demands
Trademark Royalties."
              -- Cory Doctorow