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Singin' In The New Papers
...or "New Papers in the Rain," I suppose (another credit to Sarah S. for
First, a new dromaeosaurid, brought to my attention by Kazuo Takahashi:
Lü, J.-C., Xu, L., Zhang, X.-L., Ji, Q., Jia, S.-H., Hu, W.-Y., Zhang,
J.-M., and Wu, Y.-H. 2007. New dromaeosaurid dinosaur from the Late
Cretaceous Qiupa Formation of Luanchuan area, western Henan, China.
Geological Bulletin of China 26(7):777-786.
ABSTRACT: A new dromaeosaurid dinosaur Luanchuanraptor henanensis gen. et
sp. nov. is erected based on the following characters: about 24 posterior
serrations per 5 millimeters on the posterior carnia of teeth; the proximal
and posterior extensions of the haemal arch are short and trifurcated; the
elongated prezygapophyses of the distal-most caudal vertebrae wrapped the
preceding vertebra and the caudal vertebrae bear a low, blade-like neural
spine between the prezygapophyses; the medial surface of the coracoid is
strongly concave; the shaft of the humerus is straight and the deltopectoral
crest extends over almost the proximal half of the humerus. Luanchuanraptor
henanensis represents the first dromaeosaurid dinosaur found outside the
Gobi region and northeastern China in Asia.
Then some anatomy stuff:
Tsuihiji, T. 2007. Homologies of the iliocostalis, iliocostalis, and
hypaxial muscles in the anterior presacral region of extant Diapsida.
Journal of Morphology 268(11):986-1020. doi: 10.1002/jmor.10565.
ABSTRACT: Homologies of muscles of the m. longissimus and m. iliocostalis
groups in the dorsal and cervical regions, as well as those of the
subvertebral muscles and mm. intercostales externi that continue from the
dorsal into the cervical regions, in extant Diapsida are proposed based on
detailed dissections and published accounts of lepidosaurs, crocodylians,
and birds. The morphology of tendons and innervation patterns suggest that
the avian m. iliocostalis in the dorsal region include the homologs of both
m. longissimus and m. iliocostalis in non-avian diapsids. The conserved
nature of the morphology of tendons in palaeognath birds also revealed that
the avian mm. intertransversarii in the cervical region consist of muscles
of the both m. longissimus and m. iliocostalis groups despite having been
treated as a single series of muscles, and thus are not homologous with
muscles of the same name in Lepidosauria or Crocodylia. The avian mm.
inclusi that lie medial to mm. intertransversarii are homologous with mm.
intercostales externi in Lepidosauria and mm. intercostales externi and m.
scalenus combined in Crocodylia. Innervation patterns suggest that a muscle
(m. iliocostalis capitis) connecting the atlas rib and occiput in Crocodylia
includes contributions from the subvertebral layer and m. cucullaris
complex, and possibly m. iliocostalis as well. The present findings may
serve as a basis for revising the currently used avian nomenclature so that
it will reflect homologies of muscles with their non-avian counterparts.
And last, a couple new papers on the Morrison and Cedar Mountain Formations:
Greenhalgh, B.W., and Britt, B.B. 2007. Stratigraphy and sedimentology of
the Morrison-Cedar Mountain Formation boundary, east-central Utah; pp.
81-100 in Willis, G.C., Hylland, M.D., Clark, D.L., and Chidsey, T.C., Jr.
(eds.), Central Utah - Diverse Geology of a Dynamic Landscape. Utah
Geological Association Publication 36. Utah Geological Association, Salt
ABSTRACT: The Cedar Mountain Formation has been the focus of numerous
paleontological and geological studies aimed at understanding Early
Cretaceous dinosaurs and tectonics. A major problem in these studies is that
the contact between the Upper Jurassic Morrison and Lower Cretaceous Cedar
Mountain Formations is notoriously difficult to identify where the Buckhorn
Conglomerate is absent. Our stratigraphic and sedimentologic analysis of
these formations in Utah and Colorado permits accurate recognition of this
previously enigmatic contact. The top of the Morrison Formation is marked by
increases in chert-pebble lags and channelized conglomerates overprinted by
paleosols that exhibit iron concentrations, manganesecoated grains, intense
red-purple-green mottling, and bleaching. These features indicate a period
of reduced accommodation in the Tithonian.
Where the basal Cedar Mountain Formation consists of the Buckhorn
Conglomerate or a pebbly mudstone (debritic facies) of the Yellow Cat
Member, comprising slightly reworked, angular fragments of Morrison
Formation regolith, the formational contact occurs at the base of these
members. The Buckhorn Conglomerate and the debritic Yellow Cat pebbly
mudstone facies (1) interfinger with each other, indicating time
equivalancy, (2) typically grade upsection into sandstones, and (3) comprise
a depositional system that locally removes part or all of the paleosol that
elsewhere caps the Morrison Formation. In the absence of the Buckhorn and
debritic Yellow Cat facies, a fine-grained, maroon, calcareous paleosol
marks the base of the Cedar Mountain Formation.
A calcrete/silcrete paleosol complex, indicative of a
multi-million-year depositional hiatus, commonly overprints the top of the
Buckhorn Conglomerate, portions of the Yellow Cat Member, and in some cases,
the Morrison Formation paleosol. Above the calcrete, the Cedar Mountain
Formation consists of finegrained overbank deposits with caliche nodules or
calcrete horizons (Ruby Ranch Member) and isolated to amalgamated sandstone
lenses and beds.
Kowallis, B.J., Britt, B.B., Greenhalgh, B.W., and Sprinkel, D.A. 2007. New
U-Pb zircon ages from an ash bed in the Brushy Basin Member of the Morrison
Formation near Hanksville, Utah; pp. 75-80 in Willis, G.C., Hylland, M.D.,
Clark, D.L., and Chidsey, T.C., Jr. (eds.), Central Utah - Diverse Geology
of a Dynamic Landscape. Utah Geological Association Publication 36. Utah
Geological Association, Salt Lake City.
ABSTRACT: A bentonitic ash bed 8.7 m below the top of the Upper Jurassic
Morrison Formation near Hanksville, Utah, has been dated by laser ablation
multi-collector inductively coupled plasma mass spectrometry and gives a
single-crystal U-Pb zircon age of 149.0 +2.5/-2.2 Ma. This age is
statistically the same as the 149.3 ± 0.5 Ma age of an ash bed located 0.5 m
below the top of the Brushy Basin Member of the Morrison Formation near
Notom, Utah, about 25 km to the west. The Hanksville section has a short
section of possible Cedar Mountain Formation (between 0.4 and 7.3 m thick)
on top of the Morrison section. Two young contaminant zircons with a peak
age of 122.5 Ma in the Brushy Basin ash sample indicate that the Cedar
Mountain sediments present here are from the lowermost part of the Cedar
Jerry D. Harris
Director of Paleontology
Dixie State College
225 South 700 East
St. George, UT 84770 USA
Phone: (435) 652-7758
Fax: (435) 656-4022
STORIES IN SIX WORDS OR LESS:
"Machine. Unexpectedly, I'd invented
-- Alan Moore
"Easy. Just touch the match to"
-- Ursula K. Le Guin
"Batman Sues Batsignal: Demands
-- Cory Doctorow