New-ish Papers

["Harris, Jerald" <jharris@dixie.edu>]

Hi All -
     First, some new papers from Chinese journals.  Perhaps most interesting of 
this batch is:
 
Liu, Y., Liu, Y., and Zhang, H. 2006. LA-ICPMS zircon U-Pb dating in the 
Jurassic Daohugou Beds and correlative strata in Ningcheng of Inner Mongolia. 
Acta Geologica Sinica (English Edition) 80(5):733-742. 
ABSTRACT: LA-ICPMS Zircon U-Pb dating is applied to volcanic rocks overlying 
and underlying the Salamander-bearing bed in the Daohugou beds of Ningcheng in 
Inner Mongola and Reshuichang of Lingyuan and Mazhangzi of Jianping in western 
Liaoning. The results indicate that the youngest age of the rocks in Daohugou 
of Ningcheng is 158 Ma, and the oldest one is 164 Ma. Synthesized researches 
indicate that the salamander-bearing beds in Daohugou of Ningcheng, Reshuichang 
of Lingyuan and Mazhangzi of Jianping were developed in the same period. The 
Daohugou beds were formed in the geological  age of 164-158 Ma of the 
middle-late Jurassic. Whilst, the Daohugou beds and its correlative strata 
should correspond to the Tiaojishan Formation (or Lanqi Formation) of  the 
middle Jurassic in northern Hebei Province and western Liaoning Province, based 
on the disconformity between the Daohugou beds and its overlaying beds of the 
Tuchengzi Formation of Late Jurassic and the Jehol Beds of early
 Cretaceous, and the disconformity between the Daohugou Beds and its underlying 
Jiulongshan Formation, which is composed of conglomerate, sandstone, shale with 
coal and thin coal beds.

Also:
 
Cheng, X., and Gao, R. 2006. Simulation of the leg mechanism of a bipedal 
dinosaur. Journal of Mechanical Transmission 30(4):11-13.
 
     All in Chinese, so I can't read a word of it except for the math formulae, 
none of which make sense to me, but...

Fang, X.-S., Zhang, Z.-J., Lu, L.-W., Han, Y.-J., Zhao, X.-J., and Li, P.-X. 
2006. Collision between the Indian plate and the paleo-Asian plate and the 
appearance of Asian dinosaurs. Geological Bulletin of China 25(7):862-873.
 
    Only the abstract is in English, but it seems to say that the authors are 
suggesting that there was an Early Jurassic (yes, Jurassic) collison between 
India and China that explains not only a mountain belt but the dinosaur 
distributions of the time.  _Rhoetosaurus_ also gets a mention, so maybe 
Australia gets dragged in, as well.  Hm.  I propose we call this land mass 
"Pangea."
 
Zhang, H., Liu, X., Yuan, H., Hu, Z., and Diwu, C. 2006. U-Pb isotopic age of 
the lower Yixian Formation in Lingyuan of western Liaoning and its 
significance. Geological Review 52(1):63-71.
 
     Has some interesting correlations between the various named "beds" of the 
unit in various basins.  Lastly:
 
Lü, J., Gao, C., Meng, Q., Liu, J., and Ji, Q. 2006. On the systematic position 
of _Eosipterus yangi_ Ji et Ji, 1997 among pterodactyloids. Acta Geologica 
Sinica (English Edition) 80(5):643-646.
 
     A new specimen of _Eosipterus_ is figured and discussed, and the position 
of the tason in the Ctenochasmatidae is supported.

     In other journals:
 
Tanner, L.H., and Lucas, S.G. 2007. The Moenave Formation: sedimentologic and 
stratigraphic context of the Triassic-Jurassic boundary in the Four Corners 
area, southwestern U.S.A. Palaeogeography, Palaeoclimatology, Palaeoecology 
244(1-4):111-125. doi: 10.1016/j.palaeo.2005.06.039.
 
ABSTRACT: The Moenave Formation was deposited during latest Triassic to 
earliest Jurassic time in a mosaic of fluvial, lacustrine, and eolian 
subenvironments. Ephemeral streams that flowed north-northwest (relative to 
modern geographic position) deposited single- and multi-storeyed trough 
cross-bedded sands on an open floodplain. Sheet flow deposited mainly silt 
across broad interchannel flats. Perennial lakes, in which mud, silt and 
carbonate were deposited, formed on the terminal floodplain; these deposits 
experienced episodic desiccation. Winds that blew dominantly east to 
south-southeast formed migrating dunes and sand sheets that were covered by 
low-amplitude ripples.
     The facies distribution varies greatly across the outcrop belt. The 
lacustrine facies of the terminal floodplain are limited to the northern part 
of the study area. In a southward direction along the outcrop belt (along the 
Echo Cliffs and Ward Terrace in Arizona), dominantly fluvial-lacustrine and 
subordinate eolian facies grade mainly to eolian dune and interdune facies. 
This transition records the encroachment of the Wingate erg. Moenave outcrops 
expose a north-south lithofacies gradient from distal, (erg margin) to proximal 
(erg interior).
     The presence of ephemeral stream and lake deposits, abundant burrowing and 
vegetative activity, and the general lack of strongly developed aridisols or 
evaporites suggest a climate that was seasonally arid both before and during 
deposition of the Moenave and the laterally equivalent Wingate Sandstone. We 
interpret growth of the erg as a consequence of marine regression during the 
latest Triassic through earliest Jurassic that exposed sediments on the coast 
of the back-arc sea to eolian reworking. Tectonic processes that created 
accommodation space enhanced preservation of the erg.

Lucas, S.G., and Tanner, L.H. 2007. Tetrapod biostratigraphy and biochronology 
of the Triassic-Jurassic transition on the southern Colorado Plateau, USA. 
Palaeogeography, Palaeoclimatology, Palaeoecology 244(1-4):242-256. doi: 
10.1016/j.palaeo.2006.06.030.
 
ABSTRACT: Nonmarine fluvial, eolian and lacustrine strata of the Chinle and 
Glen Canyon groups on the southern Colorado Plateau preserve tetrapod body 
fossils and footprints that are one of the world's most extensive tetrapod 
fossil records across the Triassic-Jurassic boundary. We organize these 
tetrapod fossils into five, time-successive biostratigraphic assemblages (in 
ascending order, Owl Rock, Rock Point, Dinosaur Canyon, Whitmore Point and 
Kayenta) that we assign to the (ascending order) Revueltian, Apachean, 
Wassonian and Dawan land-vertebrate faunachrons (LVF). In doing so, we redefine 
the Wassonian and the Dawan LVFs. The Apachean-Wassonian boundary approximates 
the Triassic-Jurassic boundary. This tetrapod biostratigraphy and biochronology 
of the Triassic-Jurassic transition on the southern Colorado Plateau confirms 
that crurotarsan extinction closely corresponds to the end of the Triassic, and 
that a dramatic increase in dinosaur diversity, abundance and body size preceded
 the end of the Triassic.

Golonka, J. 2007. Late Triassic and Early Jurassic palaeogeography of the 
world. Palaeogeography, Palaeoclimatology, Palaeoecology 244(1-4):297-307. doi: 
10.1016/j.palaeo.2006.06.041.
 
ABSTRACT: A new version of global and regional palaeogeographic maps is 
presented for two time intervals. These maps depict the plate tectonic 
configuration, palaeoenvironment and lithofacies during the Late Triassic 
(Carnian-Norian) and Early Jurassic (Hettangian-Toarcian) time. The individual 
maps illustrate the general conditions present during the maximum marine 
transgressions of higher frequency cyclicity within the Absaroka sequence of 
Sloss. During Triassic time Pangaea began to stretch, initiating the rifting 
and future break-up of the supercontinent. The continued northward drift of the 
Cimmerian continent corresponded with the progressive closure and consumption 
of Palaeotethys oceanic crust, and the opening of the Neotethys Ocean. The most 
significant Late Triassic convergent event was the Indosinian orogeny, 
occurring as a result of the consolidation of South China and North China 
blocks. Also, Indochina and Indonesia were sutured to South China. At the same 
time the
 Qiangtang block approached the Eurasian margin. The consolidation of the North 
Chinese and Amurian blocks left open a large embayment of Panthalassa, between 
Amuria and Laurasia, the so-called Mongol-Okhotsk Ocean. Active subduction 
existed along the margin of this ocean, dipping cratonwards towards East 
Siberia. The last collisional events of the Uralian orogeny took place during 
the Triassic and Early Jurassic time. The conclusion of the Uralian orogeny was 
accompanied by uplift of the adjacent areas of Eastern Europe and Western 
Siberia. During the Early Jurassic the Palaeotethys Ocean was finally closed 
and the Cimmerian continent collided with Asia causing the Cimmerian orogeny. 
The time around the Triassic-Jurassic boundary marked an important biotic 
extinction event. Plate tectonic activity caused palaeogeographic and 
palaeoclimatic change, which may have contributed to the mass extinction. From 
the plate tectonic and palaeogeographic point of view the following events could
 have influenced the extinction: 1) the closure o!
f Palaeotethys and assembly of the Asian part of Pangaea; 2) the break-up of 
Pangaea in the future Central Atlantic area and transition from rifting to 
drifting; and 3) the very extensive basaltic volcanism of the Central Atlantic 
Magmatic Province.

Whiteside, J.H., Olsen, P.E., Kent, D.V., Fowell, S.J., and Et-Touhami, M. 
2007. Synchrony between the Central Atlantic magmatic province and the 
Triassic-Jurassic mass-extinction event? Palaeogeography, Palaeoclimatology, 
Palaeoecology 244(1-4):345-367. doi: 10.1016/j.palaeo.2006.06.035.
 
ABSTRACT: We present new data and a synthesis of cyclostratigraphic, 
lithostratigraphic, biostratigraphic, and published magnetostratigraphic and 
basalt geochemical data from eastern North America and Morocco in an attempt to 
clarify the temporal relationship between the Triassic-Jurassic mass extinction 
(~202 Ma) and Earth's largest sequence of continental flood basalts, the 
Central Atlantic magmatic province (CAMP). Newly discovered zones of reverse 
polarity within CAMP flow sequences of Morocco have been hypothesized by 
Marzoli et al. [Marzoli, A., Bertrand, H., Knight, K.B., Cirilli, S., Buratti, 
N., Vérati, C., Nomade, S., Renne, P.R., Youbi, N., Martini, R., Allenbach, K., 
Neuwerth, R., Rapaille, C., Zaninetti, L., Bellieni, G., 2004. Synchrony of the 
Central Atlantic magmatic province and the Triassic-Jurassic boundary climatic 
and biotic crisis. Geology 32, 973-976.] and Knight et al. [Knight, K.B., 
Nomade, S., Renne, P.R., Marzoli, A., Betrand, H., Youbi, N., 2004. The
 Central Atlantic Magmatic Province at the Triassic-Jurassic boundary: 
paleomagnetic and 40Ar/30Ar evidence from Morocco for brief, episodic 
volcanism. Earth and Planetary Science Letters 228, 143-160.] as correlates of 
a very short, uppermost Triassic age reverse chron in the Newark basin, thus 
suggesting that much of the Moroccan CAMP was synchronous with or predates the 
Triassic-Jurassic boundary. Here, however, we explain these apparent reverse 
polarity zones as possible correlatives of poorly sampled lower Jurassic basalt 
flow sequences and overlying strata in eastern North America and lower Jurassic 
reverse polarity sequences recognized by others in the Paris basin. A revised 
Milankovitch cyclostratigraphy based on new core and field data constrains the 
duration of eastern North America basaltic flows to  610 ky after the 
Triassic-Jurassic palynological turnover event. Palynological data indicates 
correlation of the initial carbon isotopic excursion of Hesselbo et al.
 [Hesselbo, S.P., Robinson, S.A., Surlyk, F., Piasecki, S.,!
 2002. Terrestrial and marine extinction at the Triassic-Jurassic boundary 
synchronized with major carbon-cycle perturbation: a link to initiation of 
massive volcanism. Geology 30, 251-254.] at St. Audrie's Bay to the 
palynological turnover event and vertebrate extinction level in eastern North 
America, suggesting a revised magnetostratigraphic correlation and robust 
carbon isotopic tests of the Marzoli-Knight hypothesis. We conclude that as yet 
there are no compelling data showing that any of the CAMP predated or was 
synchronous with the Triassic-Jurassic extinction event.

Simms, M.J. 2007. Uniquely extensive soft-sediment deformation in the Rhaetian 
of the UK: evidence for earthquake or impact? Palaeogeography, 
Palaeoclimatology, Palaeoecology 244(1-4):407-423. doi: 
10.1016/j.palaeo.2006.06.037
 
ABSTRACT: The lower part of the Cotham Member in the Penarth Group (latest 
Triassic, Rhaetian) of the UK incorporates a uniquely extensive metre-scale 
horizon of soft-sediment deformation. Interpreted as a seismite, it shows 
evidence for only a single seismic event even at its thickest development. It 
is recorded from more than forty sites across at least eight discrete 
sedimentary basins covering >250,000 km2, and originally must have covered a 
still larger area. Such a widespread horizon of soft-sediment deformation, 
unique for the UK Phanerozoic and implying a seismic event of exceptional 
magnitude, is difficult to account for by conventional terrestrial mechanisms. 
Contemporaneous volcanism in the Central Atlantic Magmatic Province (CAMP) was 
too far distant to cause the deformation, and the tectonic setting of the 
region was not conducive to earthquakes on this scale. Slump fold long axes 
suggest an epicentre broadly in the southern Irish Sea or St. George's Channel. 
Impact of a
 km-scale asteroid here potentially could produce the observed sedimentological 
effects across the UK, but any late Triassic impact structure would now be 
concealed by a km or more of younger strata. At its thickest development, in 
Northern Ireland, the seismite is succeeded by a rip-up breccia and hummocky- 
and wave-rippled cross stratification. These facies, and their position 
immediately above the seismite, are consistent with the effects of a tsunami 
arising directly from the seismic event. Tentative evidence for a tsunamite of 
this age has also been reported from southern France. The putative tsunamite in 
Northern Ireland is succeeded by a desiccation-cracked hiatus which may 
correlate with a similar hiatus truncating the seismite at sites in southern 
England. The hiatus in southern England correlates closely with a d13C isotope 
excursion that has been traced from eastern Europe across to western North 
America and is associated with significant biotic changes. The ultimate cause
 of the seismite and associated tsunamite r!
emains unclear. No impact crater of appropriate age or location is currently 
known and other evidence for impact at this time is at best equivocal. It is 
considered here that impact of a km-scale asteroid may have caused the observed 
sedimentological effects in the Lilstock Formation across the UK area, but was 
not necessarily a significant contributory factor in the generation of either 
the isotope excursion or of the biotic changes through the Triassic-Jurassic 
boundary interval.

Desojo, J.B., and Báez, A.M. 2007. Cranial morphology of the Late Triassic 
South American archosaur Neoaetosauroides engaeus: evidence for aetosaurian 
diversity. Palaeontology 50(1):267-276. doi: 10.1111/j.1475-4983.2006.00608.x.
 
ABSTRACT: The cranial anatomy of Neoaetosauroides engaeus Bonaparte, 1969 from 
the upper part of the Los Colorados Formation, western Argentina, is addressed 
herein. This description is based on material collected recently, which permits 
a complete restoration of the skull; previously, a partial lower jaw and 
premaxillary and maxillary fragments were the only cranial remains known. 
Unlike other aetosaurs for which the premaxillary dentition is known, in N. 
engaeus the upper tooth row extends anteriorly to reach near the expanded tip 
of the snout; this condition is not compatible with the presence of a 
keratinous beak previously suggested for other aetosaurs. The conical shape of 
the teeth of N. engaeus differs from the slightly compressed teeth of 
Desmatosuchus, Stagonolepis and Typothorax, and the distinctly recurved teeth 
of Aetosaurus and Aetosauroides. This diversity of dental morphology suggests a 
variety of food-item preferences among aetosaurs.

Carpenter, K. 2007. How to make a fossil: part 1 - fossilizing bone. Journal of 
Paleontological Sciences JPS.C.07.0001:1-10.
 
ABSTRACT: Fossils are a physical record of the history of life. Although most 
people know what a fossil is, few have any idea how fossils form, or they have 
misconceptions about the process. In this first article, the processes involved 
in the fossilization of bone are presented, using a Stegosaurus skeleton as an 
example. This case study, based on an actual example, begins with the death of 
the Stegosaurus due to illness and stress brought on by a drought. It continues 
through the stages of decay, which sets the stage for eventual fossilization. 
Although some strictly chemical processes are involved, experimental work has 
shown that the vast majority of the fossilization is due to mineral 
precipitation by bacteria. Bacteria feed on the organic material contained 
within the ones and attach their metabolic waste on various atoms or molecules, 
such as iron or carbonate, dissolved in ground water. The result is the 
formation of minerals, such as iron carbonate (siderite) or calcium
 carbonate (calcite). It is the formation of these minerals that basically 
turns "bone to stone."
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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/
 
"Trying to estimate the divergence times
of fungal, algal or prokaryotic groups on
the basis of a partial reptilian fossil and
protein sequences from mice and
humans is like trying to decipher
Demotic Egyptian with the help of an
odometer and the Oxford English
Dictionary."
               -- D. Graur & W. Martin
                    (_Trends in Genetics_
                    20[2], 2004)