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New Papers of the Roses

Don?t think I?ll need to mention _Raptorex_; I?m betting that many others
have done so already.  But here?s a few other tidbits out lately?this?ll
probably be my last such post for at least a month; I?m headed for England
for SVP and then some touring around the country!

Wible, J.R., Tougier, G.W., Novacek, M.J., and Asher, R.J. 2009. The
eutherian mammal Maelestes gobiensis from the Late Cretaceous of Mongolia
and the phylogeny of Cretaceous Eutheria. Bulletin of the American Museum of
Natural History 327:1-123. doi: 10.1206/623.1.

ABSTRACT: Maelestes gobiensis Wible et al., 2007, is the second new
eutherian mammal to be named from the rich Mongolian Late Cretaceous
locality of Ukhaa Tolgod, Ukhaatherium nessovi Novacek et al., 1997, being
the first. Maelestes is only the seventh Late Cretaceous eutherian known
from the skull and the upper and lower dentitions, and the fifth known from
some postcranial elements. The type and only known specimen, PSS-MAE 607, is
described and illustrated in detail. The type is amended to include: an
incomplete skull, left dentary, atlas, axis, last cervical and first 11
thoracic vertebrae, 11 partial ribs, incomplete scapula, clavicle, humerus,
and proximal radius and ulna. An astragalus on a separate block was referred
to Maelestes by Wible et al. (2007), but it is too large to belong to this
taxon and is removed from the isotype.
     Several corrections and updates are made to the phylogenetic analysis
of Wible et al. (2007). The original analysis and the one in this report
include 408 morphological characters (127 dental, 212 cranial, and 69
postcranial) in Maelestes along with 68 other taxa (four stem therians,
three metatherians, 31 Cretaceous eutherians, 20 extinct Tertiary
placentals, and 11 extant placentals). Maelestes is identified as a member
of Cimolestidae sensu Kielan-Jaworowska et al. (2004) along with the
slightly younger and poorer known North American taxa Batodon Marsh, 1892,
and Cimolestes Marsh, 1889. Cimolestidae, in turn, is grouped with
Asioryctitheria sensu Archibald and Averianov (2006), which includes
monophyletic Mongolian and Uzbekistani clades. The other principal Late
Cretaceous clades are: a Laurasian Zhelestidae; Paranyctoides Fox, 1979
(North American and Uzbekistan) + Eozhelestes Nessov, 1997 (Uzbekistan); and
an Asian Zalambdalestidae. In contrast to some previous analyses, but in
common with Wible et al. (2007), no Cretaceous eutherians are identified as
members of any placental group.

Kundrat, M. 2009. Heterochronic shift between early organogenesis and
migration of cephalic neural crest cells in two divergent evolutionary
phenotypes of archosaurs: crocodile and ostrich. Evolution & Development
11(5):535-546. doi: 10.1111/j.1525-142X.2009.00352.x.

ABSTRACT: Living archosaurs (crocodiles and birds) represent an intriguing
evo-devo model system. Although close in phylogenetic relationship, the two
lineages show considerable divergence in trends of phenotypic evolution. The
head anatomy of recent crocodilians has changed little in comparison with
that of their crocodylomorph ancestors. The head phenotype of the avians
(birds), as well as some non-avian theropods, shows numerous evolutionary
innovations that differ considerably from the crocodylomorph pattern. Most
of the novel head structures, such as features of the craniofacial skeleton,
cranial nerves, head muscles, and integument are derived from the same
cellular source common to all archosaurs, the cephalic neural crest (CNC).
Therefore, other factors must be involved in the developmental disparity of
homologous structures in the aforementioned lineages. The present study
analyzes the earliest developmental events that are associated with the
appearance of the neural crest cells in the two archosaur models: Crocodylus
niloticus and Struthio camelus. I found that both models share unique
developmental features, the presence of an unpaired, rostrally migrating
population of CNC cells, showing that the two are closely related to each
other. On the other hand, the crocodile and the ostrich differ substantially
in (1) timing, (2) duration, and (3) expression patterns of the CNC.
Compared with the crocodile, the CNC cells in the ostrich (1) migrate much
later into the embryonic head, (2) but relocate to their terminal positions
faster, and (3) take specifically directed migratory routes in the
mandibular/oral region and head/trunk-interface regions. I suggest that
accelerated relocation of CNC cells combined with delayed head organogenesis
may represent important innovative conditions in the developmental evolution
of a new archosaur head phenotype.

McGowan, A.J., and Dyke, G.J. 2009. A surfeit of theropods in the Moroccan
Late Cretaceous? Comparing diversity estimates from field data and fossil
shops. Geology 37(9):843-846. doi: 10.1130/G30188A.1.

ABSTRACT: An unusually high proportion of large-bodied carnivorous theropod
dinosaurs has been reported from the Moroccan Late Cretaceous Kem Kem
Formation, a well-known package of North Africa vertebrate fossil?bearing
sediments. We investigate whether recorded proportions of predator and prey
taxa in Kem Kem sediments are real, or an artifact generated by collecting
biases, by comparing field data to counts of fossil vertebrates from
Moroccan fossil shops. The application of common techniques for
standardizing ecological survey data confirms that previous workers have
been misled by the acquisition by museums of specimens from commercial
collectors rather than from detailed field surveying. Claims that an unusual
number of theropod dinosaurs were present in North Africa Late Cretaceous
ecosystems are likely the result of biases due to both commercial activity
and collectorship biases.

Prasad, G.V.R., and Sahni, A. 2009. Late Cretaceous continental vertebrate
fossil record from India: palaeobiogeographical insights. Bulletin de la
Société Géologique de France 180(4):369-381.

ABSTRACT: Geophysical data suggested a minimum of 35 Ma physical isolation
for the Indian plate from the time of its separation from Madagascar around
88 Ma ago to its final collision with Asia in the Early-Middle Eocene (55-50
Ma ago). Such an extended period of segregation of any landmass is expected
to result in genetic isolation of pre-existing populations leading to the
development of endemic biota. Therefore, continental Late Cretaceous biota
of India hold the key to our understanding of effects of long isolation and
northward drift of the Indian plate over different latitudinal belts.
Focused palaeontological research in the last one and half decades on the
Deccan volcano-sedimentary sequences (infra? and intertrappean beds) has
resulted in the recovery of diverse assemblages of vertebrate, invertebrate,
and plant fossils. The Deccan volcano-sedimentary sequences were dated Late
Cretaceous-Early Palaeocene in age based on vertebrate, ostracod, planktonic
foraminiferal, palynofloral and geochronological data. Critical evaluation
of the biota from these strata brings out a complex biogeographical picture.
The Late Cretaceous biota of India include some taxa of Gondwanan affinities
(leptodactylid, hylid and ranoid frogs, madtsoiid and nigerophiid snakes,
pelomedusoid turtles, mesosuchian crocodiles, abelisaurid dinosaurs, and
gondwanathere mammals), Gondwanan relicts (haramiyidan mammals), certain
taxa of Laurasian affinities (pelobatid and Gobiatinae frogs, anguimorph
lizards, eutherian mammals, charophytes), and ostracods of predominantly
endemic nature. Since India was once part of the former Gondwanaland, the
presence of Gondwanan taxa in the Late Cretaceous of India is not anomalous
from a biogeographic point of view. These taxa might have been derived from
Gondwanan stocks that boarded the Indian plate prior to its break-up from
Africa or might represent immigrants from South America that reached the
Indo-Madagascar block via Antarctica and the Kerguelen Plateau/Gunnerus
ridge not later than 80 Ma. However, the presence of Laurasian non-marine
taxa in the northward drifting Indian plate defies palaeogeographical data
showing a wide body of marine water (Tethys) separating India from Asia. In
the light of latest palaeontological, stratigraphic, geochemical and
geophysical data from the northern margin of India, one cannot rule out
dispersals from the northern landmasses across the Kohistan and Dras
island-arcs and Trans-Himalayan magmatic arc. Other biogeographical models,
such as "Out-of-India Dispersals" for many vertebrate, invertebrate, and
plant groups, also deserve a close examination. At present, limited
quantitative fossil data is available to test these biogeographical models.

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

"Education is the only thing people
shell out a lot of money for...and
then do everything possible to avoid
getting their money's worth."

                            -- unknown