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Lakeview New Papers
Lots O' New Stuff (TM), in part 'cuz of the new ish of JVP, but others, too...!
Ye, Y. 2008. A review on the study of Mamenchisaurus; pp. 1-7 in Wang, Y. and
Deng, T. (eds.), Proceedings of the Eleventh Annual Meeting of the Chinese
Society of Vertebrate Paleontology. China Ocean Press, Beijing.
Wang, Q., Bin, L., Kan, Z., Li, K., Zhu, B., and Ji, X. 2008.
Paleoenvironmental Reconstruction of Mesozoic Dinosaurs Fauna in Sichuan Basin.
Geological Publishing House, Beijing, 189 pp.
Knoll, F. 2008. On the Procompsognathus postcranium (Late Triassic, Germany).
Geobios. doi: 10.1016/j.geobios.2008.02.002.
ABSTRACT: A review of the historical background of the material housed in the
Staatliches Museum fÃr Naturkunde (Stuttgart) and ascribed to Procompsognathus
triassicus (Upper Triassic, Germany) is provided. The systematic position of
the postcranial remains is discussed. The combined results of cladistic
analyses suggest that the type material, an incomplete postcranial skeleton in
two pieces (SMNS 12591), is from a theropod close to Segisaurus and
Coelophysis. An isolated manus (SMNS 12352a) is definitely not theropodan, but
could be from any small basal archosaur. The remarkable diversity of the
carnivorous guild that dwelled in southern Germany before the end-Triassic
events is underlined.
Keller, G., Abramovich, S., Berner, Z., and Adatte, T. 2008. Biotic effects of
the Chicxulub impact, K-T catastrophe and sea level change in Texas.
Palaeogeography, Palaeoclimatology, Palaeoecology. doi:
ABSTRACT: Biotic effects of the Chicxulub impact, the K-T event and sea level
change upon planktic foraminifera were evaluated in a new core and outcrops
along the Brazos River, Texas, about 1500 km from the Chicxulub impact crater
on Yucatan, Mexico. Sediment deposition occurred in a middle neritic
environment that shallowed to inner neritic depths near the end of the
Maastrichtian. The sea level fall scoured submarine channels, which were
infilled by a sandstone complex with reworked Chicxulub impact spherules and
clasts with spherules near the base. The original Chicxulub impact ejecta layer
was discovered 45-60 cm below the sandstone complex, and predates the K-T mass
extinction by about 300,000 years.
Results show that the Chicxulub impact caused no species extinctions or
any other significant biotic effects. The subsequent sea level fall to inner
neritic depth resulted in the disappearance of all larger (>150 Îm) deeper
dwelling species creating a pseudo-mass extinction and a survivor assemblage of
small surface dwellers and low oxygen tolerant taxa. The K-T boundary and mass
extinction was identified 40-80 cm above the sandstone complex where all but
some heterohelicids, hedbergellids and the disaster opportunistic guembelitrids
went extinct, coincident with the evolution of first Danian species and the
global Î13C shift. These data reveal that sea level changes profoundly
influenced marine assemblages in near shore environments, that the Chicxulub
impact and K-T mass extinction are two separate and unrelated events, and that
the biotic effects of this impact have been vastly overestimated.
Falkingham, P.L., Margetts, L., Smith, I.M., and Manning, P.L. 2008.
Reinterpretation of palmate and semi-palmate (webbed) fossil tracks: insights
from finite element modelling. Palaeogeography, Palaeoclimatology,
Palaeoecology. doi: 10.1016/j.palaeo.2008.09.011.
ABSTRACT: A track from the Late Cretaceous previously described as being
generated by a semi-palmate bird was studied with the aid of high resolution
laser scanning. Substrate conditions at the time of track formation were
diagnosed (fine grained, soft, waterlogged sediment) and used to constrain a
Finite Element track simulator. The indentation of a non-webbed virtual
tridactyl foot in such conditions created a resultant track with features
analogous to âwebbingâ between digits. This âwebbingâ was a function of
sediment deformation and subsequent failure in 3D, specific to rheology.
Variation of substrate conditions and interdigital angle were incrementally
stepped. Apparent webbing impressions were clearly developed only within a
limited range of sediment conditions and pedal geometry.
The implications of this work are that descriptions of âwebbedâ tracks
should account for the possibility that webbing was indirectly formed through
sediment failure and not necessarily the direct impression of a webbed foot.
Additionally, dating the earliest occurrence of webbed feet in the fossil
record, and potentially extending phylogenetic ranges, should be treated with
caution when based upon evidence from tracks.
Sidor, C.A., Damiani, R., and Hammer, W.R. 2008. A new Triassic temnospondyl
from Antarctica and a review of Fremouw Formation biostratigraphy. Journal of
Vertebrate Paleontology 28(3):656-663. doi:
ABSTRACT: A new temnospondyl, Kryostega collinsoni, gen. et sp. nov., is
described on the basis of a large snout fragment from the Triassic upper
Fremouw Formation of Antarctica. K. collinsoni is characterized by greatly
enlarged teeth of the transvomerine and parachoanal tooth rows, a reduced
transvomerine tooth row, as well as a distinct process on the palatal surface
of the premaxilla. Although key palatal and tabular features are not preserved,
the shape and position of the external naris, choana, and anterior palatal
vacuity suggest that K. collinsoni may be allied to the Heylerosauridae or
basal Mastodonsauridae. The discovery of K. collinsoni in the upper Fremouw is
surprising, given that Triassic vertebrates from Antarctica are typically
considered a subset of coeval taxa from the Karoo Basin of South Africa. Based
on its unique occurrence in Antarctica, K. collinsoni suggests that high
latitude Triassic tetrapods had a more restricted geographic distribution than
considered. Biostratigraphically, the fauna of the upper Fremouw Formation is
best correlated with the Cynognathus Assemblage Zone of South Africa's Beaufort
Group, although the lack of speciesâlevel identifications for many of the
Antarctic fossils precludes a more refined correlation. A review of the
Triassic fossil record identifies several tetrapods that make their first
appearance in the Fremouw, with a later appearance in the Karoo Basin,
suggesting that the high latitude regions of Gondwana might have served as an
important area for speciation.
Parker, W.G., Stocker, M.R., and Irmis, R.B. 2008. A new desmatosuchine
aetosaur (Archosauria: Suchia) from the Upper Triassic Tecovas Formation
(Dockum Group) of Texas. Journal of Vertebrate Paleontology 28(3):692-701. doi:
ABSTRACT: A small aetosaur skeleton collected in 1939 from the Tecovas
Formation of Texas and assigned to Desmatosuchus is reassigned to a new taxon,
Sierritasuchus macalpini. Phylogenetic analysis suggests that Sierritasuchus is
a member of the Desmatosuchinae. It can be distinguished from other
desmatosuchines by two autapomorphies: (1) recurved spines on the lateral
plates that are triangular in cross-section with a sharply ridged anterior
edge; and (2) the presence of a sharp, ventrally oriented ridge on the
posterior faces of the dorsal eminences of the paramedian plates, as well as a
unique combination of characters including the presence of an anterior bar on
the paramedian and lateral plates, a random pattern of ornamentation on the
paramedian plates, and a dorsal eminence that contacts the posterior plate
margin of the paramedian plates. Histological study of the holotypic plates in
combination with comparison to a growth series in Typothorax, and
indicators such as neurocentral suture closure suggests that the specimen is
neither a young juvenile nor a fully-grown adult. The recognition of
morphologically distinct specimens such as the holotype and referred material
of Sierritasuchus demonstrates that past practices of assigning aetosaur
specimens to known taxa based on superficial resemblance has masked diversity
in this clade. Voucher specimens for biochronologic and biogeographic analyses
should be carefully investigated before being used for such studies.
Butler, R.J., Porro, L.B., and Norman, D.B. 2008. A juvenile skull of the
primitive ornithischian dinosaur Heterodontosaurus tucki from the 'Stormberg'
of southern Africa. Journal of Vertebrate Paleontology 28(3):702-711. doi:
ABSTRACT: Heterodontosaurids are an enigmatic group of primitive ornithischian
dinosaurs best known from the Early Jurassic of southern Africa. Because fossil
material is rare and often poorly preserved, the taxonomy, systematics, and
palaeobiology of this clade are controversial. Here we describe a new partial
skull of a juvenile Heterodontosaurus tucki from the 'Stormberg' of South
Africa. This skull provides new information on the cranial anatomy of this
taxon as well as insights into cranial ontogeny, sexual dimorphism and tooth
replacement in heterodontosaurids. Few ontogenetic changes in dental morphology
occur in Heterodontosaurus, supporting previous suggestions that tooth
characters are informative for species-level taxonomy in heterodontosaurids.
Furthermore, the presence of well-developed caniniform teeth in the juvenile
specimen does not support the hypothesis that these represent secondary sexual
characteristics in heterodontosaurids. Computed tomography reveals that
replacement teeth are absent in both juvenile and adult specimens of
Heterodontosaurus; however, the difference in the absolute size of the teeth
between the juvenile and adult specimens demonstrates that replacement must
have occurred during ontogeny.
Canudo, J.I., Royo-Torres, R., and Cuenca-BescÃs, G. 2008. A new sauropod:
Tastavinsaurus sanzi gen. et sp. nov. from the Early Cretaceous (Aptian) of
Spain. Journal of Vertebrate Paleontology 28(3):712-731. doi:
ABSTRACT: The new sauropod dinosaur Tastavinsaurus sanzi, gen. et sp. nov.,
from the early Aptian of Spain is described. The holotype is a partially
articulated skeleton of an adult individual recovered from the Arsis-1 site in
PeÃarroya de Tastavins (Teruel) at the base of the marine Xert Formation. It
is one of the most complete and best-preserved sauropod dinosaur skeletons from
the European Early Cretaceous. The fossil remains comprise the three caudalmost
thoracic vertebrae, part of a fourth, nine thoracic rib fragments, sacrum, 25
caudal vertebrae, 21 chevrons, both ilia, pubes, ischia and femora, right
tibia, right fibula, six metatarsals, and seven pedal phalanges (including four
unguals). The new taxon is defined by 19 autapomorphies. In our cladistic
analysis, Tastavinsaurus is the sister-taxon of the North American Venenosaurus
within Titanosauriformes, which includes the Brachiosauridae, Somphospondyli,
and Titanosauria. The new taxon provides new information about the
diversity of non-brachiosaurid titanosauriforms during the Early Cretaceous in
Europe and paleobiogeographic relationships between Europe and North America.
Benson, R.B.J. 2008. New information on Stokesosaurus, a tyrannosauroid
(Dinosauria: Theropoda) from North America and the United Kingdom. Journal of
Vertebrate Paleontology 28(3):732-750. doi:
ABSTRACT: A partial postcranial skeleton from the Late Jurassic (Tithonian) of
Dorset, England represents a new species of the theropod dinosaur
Stokesosaurus, Stokesosaurus langhami. S. langhami is a member of
Tyrannosauroidea, showing a distinct median vertical ridge on the lateral
surface of the ilium, a prominent shelf medial to the preacetabular notch, a
pronounced ischial tubercle, and a tibia that is elongate relative to the
femur. One of only two definitive Jurassic tyrannosauroids known from more than
isolated elements, it is the largest Jurassic tyrannosauroid reported to date
and provides additional evidence for the presence of relatively small- or
medium-sized basal tyrannosauroids in Asia, North America, and Europe during
the Late Jurassic. The occurrence of Stokesosaurus in the Tithonian of the UK
and USA and the absence of tyrannosauroids in contemporaneous west African
faunas supports the hypothesis of a paleobiogeographic link during the Late
Jurassic between North
America and Europe, to the exclusion of Africa.
Mayr, G., Hazevoet, C.J., Dantas, P., and CachÃo, M. 2008. A sternum of a very
large bony-toothed bird (Pelagornithidae) from the Miocene of Portugal. Journal
of Vertebrate Paleontology 28(3):762-769. doi:
ABSTRACT: The sternum of a very large bony-toothed bird (Pelagornithidae) from
the Miocene of Portugal is described. The three-dimensionally preserved
specimen is one of the largest sterna of a volant bird known to date, and more
complete than the only other pelagornithid sternum reported so far. It is
tentatively assigned to Pelagornis miocaenus Lartet, 1857, which is the only
bony-toothed bird known from the Miocene of Europe. The specimen shows several
unique features, including the presence of a marked cranial projection of the
carina sterni, which probably abutted the extremitas sternalis of the furcula,
and a large, steep-walled opening in the cranial portion of the facies
visceralis. The corpus sterni further has a highly unusual shape in that it is
very deep, with a strongly vaulted facies visceralis. It is likely that these
characteristics are due to anatomical constraints imposed by the very large
size of pelagornithids, which may have reached a wingspan of up to 6 m and
probably were incapable of sustained flapping flight.
Williamson, T.E., and Weil, A. 2008. Metatherian, mammals from the Naashoibito
Member, Kirtland Formation, San Juan Basin, New Mexico and their biochronologic
and paleobiogeographic significance. Journal of Vertebrate Paleontology
28(3):803-815. doi: 10.1671/0272-4634(2008)28[803:MMFTNM]2.0.CO;2.
ABSTRACT: Isolated teeth representing several taxa of metatherian mammals were
recovered from NMMNH locality L-4005 in the Naashoibito Member, Kirtland
Formation, San Juan Basin, northwestern New Mexico. These include fragments of
upper and lower molars and a fragmentary premolar that are referred to
indeterminate âpediomyids,â an isolated p2 or p3 that is referred to an
indeterminate peradectid, and two lower molars, an m1 or m2 and an m4 that are
referable to the hatcheriforme metatherian Glasbius cf. G. intricatus. Two
upper molar fragments are also tentatively referred to Glasbius. These taxa are
part of the Alamo Wash local fauna. Glasbius has been proposed as a potential
first appearance datum for the Lancian North American Land Mammal âageâ
(NALMA). The presence of both Glasbius and the multituberculate Essonodon
within the Naashoibito Member support an age correlative with other formations
producing Lancian faunas. A Lancian age for the Naashoibito Member suggests
that there is a significant disconformity between the top of the late
Campanian De-na-zin Member, which is constrained by radiometric dates to be
about 73 Ma, and the base of the Naashoibito Member. Terrestrial faunas of
Lancian age show differences that have been attributed to provinciality. The
widespread distribution of mammalian index taxa indicates some degree of faunal
homogeneity during this interval, but the refined stratigraphic correlation of
the Alamo Wash local fauna allows us to recognize other taxa as geographically
restricted, as opposed to asynchronous.
Modesto, S.P., and Botha-Brink, J. 2008. Evidence of a second, large
archosauriform reptile in the Lower Triassic Katberg Formation of South Africa.
Journal of Vertebrate Paleontology 28(3):914-917. doi:
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