[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Gone With The New Papers

Another new issue of _Cretaceous Research_, with three goodies in it:

Salgado, L., Coria, R.A., Magalhaes Riberio, C.M., Garrido, A., Rogers, R., Simón, M.E., Arcucci, A.B., Rogers, K.C., Carabajal, A.P., Apesteguía, S., Fernández, M., García, R.A., and Talevi, M. 2007. Upper Cretaceous dinosaur nesting sites of Río Negro (Salitral Ojo de Agua and Salinas de Trapalcó-Salitral de Santa Rosa), northern Patagonia, Argentina. Cretaceous Research 28(3):392-404. doi: 10.1016/j.cretres.2006.06.007.

ABSTRACT: Twenty three different sites in two areas of Río Negro Province (Salitral Ojo de Agua and Salitral de Santa Rosa-Salinas de Trapalcó), preserving eggs and eggshells from the Allen Formation (Upper Cretaceous) were studied, and five egg levels were identified. Three different types of eggshell were recognized. Eggs possessing thick eggshells of Type 1 are abundant in both areas, sometimes associated with eggs having thinner shells. Eggs of eggshell Type 1 are included in the oofamily Faveoloolithidae of the parataxonomic classification. Eggshell Type 2 is subdivided into two groups (Types 2A and 2B), mostly based on the mean thickness of the eggshells and other parameters. Eggs of eggshell Type 2 are assigned to the oofamily Megaloolithidae of the parataxonomic classification, and ascribed to titanosaurs. A third type of eggshell (Type 3) is only recorded at one of the localities (Salitral Ojo de Agua, egg level 2). This type is intimately associated with theropod bones, and its microstructure agrees with an assignation to the Theropoda. It is assigned to the oofamily Elongatoolithidae.

Garrison, J.R., Jr., Brinkman, D., Nichols, D.J., Layer, P., Burge, D., and Thayn, D. 2007. A multidisciplinary study of the Lower Cretaceous Cedar Mountain Formation, Mussentuchit Wash, Utah: a determination of the paleoenvironment and paleoecology of the Eolambia caroljonesa dinosaur quarry. Cretaceous Research 28(3):461-494. doi: 10.1016/j.cretres.2006.07.007.

ABSTRACT: A quarry within the Cedar Mountain Formation in Mussentuchit Wash, Emery County, Utah, produced a fossil assemblage containing the remains of at least eight juvenile iguanodontid dinosaurs (Eolambia caroljonesa). The Cedar Mountain Formation lies stratigraphically between the Tithonian-Berriasian (Upper Jurassic) Brushy Basin Member of the Morrison Formation and the Cenomanian (Upper Cretaceous) Dakota Formation. Detailed stratigraphic, sedimentological, geochronological, palynological, and paleontological data have been collected along a measured section at the site of the Cifelli #2 Eolambia caroljonesa Quarry. These data provide a chronostratigraphic and a biostratigraphic framework for the Cedar Mountain Formation and allow a detailed reconstruction of the paleoenvironment and the paleoecology of the local paleogeographic area from which E. caroljonesa have been recovered.
Three 40Ar/39Ar ages ranging from 96.7 to 98.5 Ma have been obtained three stratigraphically distinct altered volcanic ash layers within the Mussentuchit Member, one of which passes through the E. caroljonesa quarry, that indicate that the quarry is latest Albian in age and that the stratigraphic boundary between the Mussentuchit Member of the Cedar Mountain Formation and the overlying Dakota Formation is at or near the Albian/Cenomanian boundary.
Sedimentological and biostratigraphic data suggest that significant long-term and short-term climatic changes are recorded in the Cedar Mountain Formation. During deposition of the lower part of the formation, climatic conditions were warm and arid to semi-arid. During deposition of the upper part of the formation, conditions became more humid. The progressive change in climatic conditions was probably related to the transgression of the Mowry Sea from the north. Cyclic sedimentation in the Mussentuchit Member suggests high-frequency changes from wet to dry periods.

Averianov, A.O. 2007. Theropod dinosaurs from Late Cretaceous deposits in the northeastern Aral Sea region, Kazakhstan. Cretaceous Research 28(3):532-544. doi: 10.1016/j.cretres.2006.08.008.

ABSTRACT: Seven theropod taxa (Tyrannosauridae indet., Ornithomimidae indet., Therizinosauroidea cf. Neimongosaurus sp., Therizinosauroidea indet., Caenagnathidae indet., Dromaeosaurinae indet., and Velociraptorinae indet.) have been identified from the Santonian Bostobe Formation, and four taxa (Tyrannosauridae indet., Ornithomimidae indet., Therizinosauroidea indet., and Dromaeosauridae indet.) are known from the underlying Turonian Zhirkindek Formation of the northeastern Aral Sea region in Kazakhstan. These theropod faunas are similar in composition to faunas from the Turonian Bissekty Formation of Uzbekistan, Santonian Yalovach Formation of Tajikistan, and Turonian-Santonian Irendabasu and Bayanshiree (upper part) formations of northern China and southern Mongolia. The therizinosauroid cf. Neimongosaurus sp., known from an isolated femur, is the only theropod taxon from Kazakhstan currently identifiable to generic level. A therizinosauroid similar to Neimongosaurus is reported here for the first time; this genus was known previously from the Irendabasu Formation of northern China.

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

"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)