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
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
localities of Asia to better understand the basal diversification of the
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
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
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.
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
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
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:
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
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
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
225 South 700 East
St. George, UT 84770 USA
Phone: (435) 652-7758
Fax: (435) 656-4022
"I have made this letter longer
than usual because I lack the
time to make it shorter."
-- Blaise Pascal