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The New Papers of Despereaux



Canale, J.I., Scanferla, C.A., Agnolin, F.L., and Novas, F.E. 2008. New 
carnivorous dinosaur from the Late Cretaceous of NW Patagonia and the evolution 
of abelisaurid theropods. Naturwissenschaften. doi: 10.1007/s00114-008-0487-4.

ABSTRACT: A nearly complete skeleton of the new abelisaurid Skorpiovenator 
bustingorryi is reported here. The holotype was found in Late 
CenomanianâEarly Turonian outcrops of NW Patagonia, Argentina. This new taxon 
is deeply nested within a new clade of South American abelisaurids, named 
Brachyrostra. Within brachyrostrans, the skull shortening and hyperossification 
of the skull roof appear to be correlated with a progressive enclosure of the 
orbit, a set of features possibly related to shock-absorbing capabilities. 
Moreover, the development of horn-like structures and differential cranial 
thickening appear to be convergently acquired within Abelisauridae. Based on 
the similarities between Skorpiovenator and carcharodontosaurid tooth 
morphology, we suggest that isolated teeth originally referred as 
post-Cenomanian Carcharodontosauridae most probably belong to abelisaurids.




Goldberg, E.E., and Igic, B. 2008. On phylogenetic tests of irreversible 
evolution. Evolution 62(11):2727-2741. doi: 10.1111/j.1558-5646.2008.00505.x.

ABSTRACT: "Dollo's law" states that, following loss, a complex trait cannot 
reevolve in an identical manner. Although the law has previously fallen into 
disrepute, it has only recently been challenged with statistical phylogenetic 
methods. We employ simulation studies of an irreversible binary character to 
show that rejections of Dollo's law based on likelihood-ratio tests of 
transition rate constraints or on reconstructions of ancestral states are 
frequently incorrect. We identify two major causes of errors: incorrect 
assignment of root state frequencies, and neglect of the effect of the 
character state on rates of speciation and extinction. Our findings do not 
necessarily overturn the conclusions of phylogenetic studies claiming 
reversals, but we demonstrate devastating flaws in the methods that are the 
foundation of all such studies. Furthermore, we show that false rejections of 
Dollo's law can be reduced by the use of appropriate existing models and model 
selection procedures.
 More powerful tests of irreversibility require data beyond phylogenies and 
character states of extant taxa, and we highlight empirical work that 
incorporates additional information.




Sukhanov, V.B., Danilov, I.G., and Syromyatnikova, E.V. 2008. The description 
and phylogenetic position of a new nanhsiungchelyid turtle from the Late 
Cretaceous of Mongolia. Acta Palaeontologica Polonica 53(4):601-614.

ABSTRACT: This paper describes a new nanhsiungchelyid turtle, Kharakhutulia 
kalandadzei gen. et sp. nov., based on two partial shells and additional shell 
fragments from the lower part of the Bainshire Formation (Upper Cretaceous, 
Cenomanianâlower Turonian) of the Khara Khutul locality of Eastern Mongolia. 
Our phylogenetic analysis places Kharakhutulia kalandadzei as the most basal 
member of the Nanhsiungchelyidae and suggests new relationships within this 
group. Previously reported nanhsiungchelyid specimens from the Khara Khutul are 
reassigned to Nanhsiungchelyidae indet. and Hanbogdemys sp. indet. Thus the 
Khara Khutul includes at least two valid taxa of nanhsiungchelyids. Our 
analysis of the nanhsiungchelyid record in Asia shows that other localities 
have only a single representative of this clade, making Khara Khutul a unique 
site. The basal phylogenetic position of Kharakhutulia kalandadzei emphasizes 
the importance of the study of this and other CenomanianâTuronian
 localities of Asia to better understand the basal diversification of the 
Nanhsiungchelyidae.




Filippi, L.S., and Garrido, A.C. 2008. Pitekunsaurus macayai gen. et sp. nov., 
nuevo titanosaurio (Saurischia, Sauropoda) del CretÃcico Superior de la Cuenca 
Nuequina, Argentina. Ameghiniana 45(3):575-590.

ABSTRACT: A new titanosaur is described, Pitekunsaurus macayai gen. et sp. 
nov., from mudstone levels asigned to Anacleto Formation (Lower - Middle 
Campanian), corresponding to the uppermost beds of the NeuquÃn Group (Upper 
Cretaceous of NeuquÃn Basin). The specimen is represented by braincase, left 
frontal, one tooth, four cervical vertebrae, three dorsal vertebrae, four 
caudal vertebrae, right ulna and scapula, proximal extreme of left femur, rib 
fragments and uncertain remains. Pitekunsaurus is characterized by the 
following autapomorphies: (1) basipterygoid processes broadly separated and 
parallelly projected, (2) anterior cervical vertebrae with small depressions or 
longitudinal grooves in the spinal sector of spinopostzygapophyseal lamina, (3) 
centropostzygapophyseal lamina forked proximally in anterior dorsal vertebrae, 
and (4) posterior centrodiapophyseal lamina with accessory lamina in anterior 
dorsal vertebrae. The existence of two types of articulations in the posterior
 caudal vertebrae, one amphicoelous and another biconvex, indicates a close 
relationship with Rinconsaurus caudamirus Calvo y GonzÃlez Riga, suggesting 
that the caudal morphology of titanosaurs is much more complex and more varied 
than previously supposed.



Matsumoto, R., Suzuki, S., Tsogtbaatar, K., and Evans, S.E. 2008. New material 
of the enigmatic reptile Khurendukhosaurus (Diapsida: Choristodera) from 
Mongolia. Naturwissenschaften. doi: 10.1007/s00114-008-0469-6.

ABSTRACT: New material of the enigmatic diapsid Khurendukhosaurus is described 
from the Mongolian type locality, Khuren Dukh, providing additional data on the 
vertebral column, pelvis, and hind limb. It confirms the choristoderan status 
of the genus and permits a more detailed phylogenetic analysis that supports a 
relationship between Khurendukhosaurus and the long-necked Asian 
Hyphalosauridae. The existence of tall caudal neural spines implies that 
Khurendukhosaurus was a deep-tailed swimmer. This and the open sacral 
costocentral sutures suggest a primarily aquatic lifestyle.




Rougier, G.W., Chornogubsky, L., Casadio, S., PaÃz Arango, N., and 
Giallombardo, A. 2008. Mammals from the Allen Formation, Late Cretaceous, 
Argentina. Cretaceous Research 30(1):223-238. doi: 
10.1016/j.cretres.2008.07.006.

ABSTRACT: A mammalian fauna from the Late Cretaceous locality of âCerro 
Tortuga,â Allen Formation, RÃo Negro Province, Argentina, is described here 
based on a sample, represented by 7 isolated teeth which shows similarities 
with those reported from the Late Cretaceous Los Alamitos Formation. These two 
mammalian faunas largely agree on their overall composition at the 
supraspecific level but new species are recognized for some of the specimens 
described. Small-sized dryolestoids, mesungulatids and ferugliotheriids are 
present in Cerro Tortuga. A new species of Mesungulatum, [Bonaparte, J.F., 
Soria, M.F., 1985. Nota sobre el primer mamÃfero del CretÃcico Argentino, 
Campaniano-Maastrichtiano, (Condylarthra). Ameghiniana 21, 177â183] leads to 
a reassessment of mesungulatid diversity in the Late Cretaceous South American 
mammalian faunas and some provisional considerations on the relative age of the 
mammal-bearing units. The South American Late Cretaceous radiation of
 dryolestoids has its origins in the early Late Cretaceous, at the latest, and 
extends into the Paleocene when their last remnants are obliterated possibly in 
relation to the incoming Laurasian tribosphenic mammals. The Late Cretaceous 
non-tribosphenic mammals have no clear link with the Jurassic and Early 
Cretaceous South American mammals, emphasizing the distinctiveness and episodic 
nature of the Mesozoic South American mammalian assemblages. The scant number 
of fossils and geochronologically discontinuous record may artificially 
accentuate the distinctiveness of the as yet poorly known pre-Late Cretaceous 
South American mammals, in particular if an epiric sea separated South Amerca 
into northen and southern realms.





Varricchio, D.J., Raven, R.F., Wolbach, W.S., Elsik, W.C., and Witzke, B.J. 
2008. Soot and palynologic analysis of Manson impact-related strata (Upper 
Cretaceous) of Iowa and South Dakota, USA. Cretaceous Research 30(1):127-134. 
doi: 10.1016/j.cretres.2008.06.005.

ABSTRACT: The Campanian Manson impact structure of Iowa represents the 
best-preserved, large-diameter complex crater within the continental U.S. To 
assess the timing and potential mode of crater infilling and the possible 
presence of an impact event horizon, we analyzed samples from both within and 
distal to the impact structure for their elemental carbon, soot and 
palynomorphs. Within the impact structure, identifiable soot occurred in 
fragmented impact breccia and suevite but not in lower impact-melt breccia. 
Although most of this soot likely represents reworking of material from older 
Cretaceous marine shales, one high soot concentration occurs with melt material 
in a Keweenawan ShaleâPhanerozoic clast breccia mix. This represents the 
first association of soot and impact-generated materials within an impact 
structure and the best sample candidate for Manson impact-generated soot. No 
palynomorphs occurred in the impact melt breccia. Overlying suevite (Keweenawan 
Shale clast
 breccia) of the central peak yielded sparse and thermally altered 
palynomorphs, indicating deposition prior to full cooling of the crater debris. 
Presence of easily degraded soot also argues for rapid backfilling of the 
crater.
     Distal samples from South Dakota represent the Sharon Springs and Crow 
Creek members of the Pierre Shale 230 km northwest of the Manson impact 
structure. Although containing shocked grains, the Crow Creek preserves no 
soot. In contrast, the Sharon Springs, generally considered as predating the 
Manson impact, has significant soot quantities. Palynomorphs differ markedly 
across the unconformity separating the two members with the Crow Creek 
containing more terrestrial forms, normapolles, and older reworked 
palynomorphs, consistent with a terrestrial impact to the east. Origin of the 
Sharon Springs soot remains unclear. Given soot occurrence within four of the 
five Cretaceous marine units sampled, the relatively shallow, anoxic bottom 
conditions of the Western Interior Cretaceous Seaway may have simply favored 
soot preservation. Until a better understanding of the broader occurrence and 
preservation of soot is achieved, some soot-impact associations will remain 
ambiguous.




Kim, C.-B., Al-Aasm, I.S., Ghazban, F., and Chang, H.-W. 2008. Stable isotopic 
composition of dinosaur eggshells and pedogenic carbonates in the Upper 
Cretaceous Seonso Formation, South Korea: paleoenvironmental and diagenetic 
implications. Cretaceous Research 30(1):93-99. doi: 
10.1016/j.cretres.2008.05.003.

ABSTRACT: Stable isotopic compositions of the pedogenic calcites and calcitic 
dinosaur eggshells analyzed from the Seonso Formation in southern Korea provide 
information on the paleoenvironmental conditions that dominated the region 
during the Upper Cretaceous as well as on the nature of the diagenetic fluids. 
The Î18O values of the calcites recovered from the paleosols (â15.46 to 
â26.22 â VPDB) indicate that they were precipitated and/or altered under a 
high temperature regime, whereas the Î13C values (â3.88 to â7.72 â VPDB) 
suggest that these carbonates received contributions from hydrothermal fluids 
during shallow burial and possibly from C3-type vegetation.
     The Î18O and Î13C of partially to well-preserved calcite eggshells are 
significantly different from those of the paleosols, indicating a departure 
from the earlier environmental conditions. The observed shift in Î18O values 
between the dinosaur eggshells (â3.43 to â14.09 â) and pedogenic calcites 
indicates different environmental and thermal conditions and suggesting two 
possible scenarios; either that the timing of egg laying by the dinosaur and 
the soil formation were not synchronous, or that the dinosaur consumed water 
from the rivers and evaporated ponds. In contrast, isotopic compositions of 
vein calcites cross-cutting paleosols (â19.06 to â21.72 for Î18O, and 
â3.78 to â4.79 for Î13C) reflect their precipitation under hydrothermal 
conditions.
     The narrow range in the Î13C values of the eggshells (â7.04 to â8.69 
â) reflect a uniform source for carbon; mostly representing fresh water 
charged with CO2 from hydrothermal sources as dissolved carbon.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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/

"I have made this letter longer
than usual because I lack the
time to make it shorter."
                      -- Blaise Pascal