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Re: The New Papers of Despereaux



Thank you so much, Jerry.


www.mesozoico.com.ar info@mesozoico.com.ar Daniel M. Puglisi Administrador

Jerry D. Harris escribiÃ:
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