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Despicable New Papers
In addition to the references below, many of you may be interested in this
thus-far paperless report:
Hone, D.W.E., and Watabe, M. 2010. New information on scavenging and
selective feeding behaviour of tyrannosaurs. Acta Palaeontologica Polonica.
ABSTRACT: Feeding traces for carnivorous theropod dinosaurs are typically
rare but can provide important evidence of prey choice and mode of feeding.
Here we report a humerus of the hadrosaurine Saurolophus which was heavily
damaged from feeding attributed to the giant tyrannosaurine Tarbosaurus. The
bone shows multiple bites made in three distinctive styles termed
‘punctures’, ‘drag marks’ and ‘bite-and-drag marks’. The distribution
of these bites suggest that the animal was actively selecting which biting
style to use based on which part of the bone was being engaged. The lack of
damage to the rest of the otherwise complete and articulated hadrosaur
strongly implies that this was a scavenging event, the first reported for a
tyrannosaur, and not feeding at a kill site.
Li, J., Bai, Z., Lockley, M., Zhou, B., Liu, J., and Song, Y. 2010. Dinosaur
tracks in Wulatezhongqi, Inner Mongolia. Acta Geologica Sinica
84(5):723-742. ABSTRACT: The Institute of Geo-environment Inspection in Nei
Menggol found the dinosaur footprints near Hailiutu, the capital town of
Wulatezhongqi, Nei Menggol in 2006. In the tracksite, 119 vertebrate tracks
were recognized, including theropod tracks:Eubrontes glenrosensis and
Kayentapus hailiutuensis ichnosp. nov, ornithopod tracks: Anomoepus
intermedius, and crocodile tracks, Batrachopus. The track bearing layer
consists of an undulating exposure of coarse sandstone containing scour
features indicating flow towards the southeast. The track makers of the
footprints studied here are suggested respectively to be Megalosaurus,
Dilophosaurus and Hypsilophodont. The assemblage of the tracks in Hailiutu
is similar to that found in the Lower Jurassic of Podole area, Poland. Then
the age of the tracks bearing beds are identified to be Early Jurassic.
Hailiutu area had many intermountain basins with plentiful rain in Early
Jurrasic. Class Reptilia Order Sauroschia Suborder Theropoda Infraorder
Canrnosauria Ichnofamily Grallatoridae Lull 1904 Ichnogenus Kayentapus
Welles 1971 Kayentapus hailiutuensis Ichnosp. nov Diagnosis: Small to medium
sized bipedal tridactyl, the digital divarication angles are large, II 40°
III 43° IV, no manus or caudal trace.
Klein, H., and Lucas, S.G. 2010. The Triassic footprint record of
crocodylomorphs -- a critical re-evaluation; pp. 55-60 in Milàn, J., Lucas,
S.G., and Spielmann, J.A. (eds.), Crocodyle Tracks and Traces. New Mexico
Museum of Natural History and Science Bulletin 51. ABSTRACT: Based on
skeletal evidence in the Upper Triassic, the evolution of crocodylomorphs
and their closest sister-groups began earlier in the Triassic. Although
Middle Triassic strata thus far lack crocodylian skeletons, preserved
footprints could possibly close this gap. Unfortunately, their
identification by characteristic features of the pes and manus imprints is
difficult. The oldest definitive ichnological evidence of crocodylomorph
tracks is of latest Triassic age, and these tracks represent sphenosuchians
or protosuchians. Several Triassic ichnotaxa (including some chirotherians)
that have been attributed to sphenosuchians show differences in the
proportions and function of digits as well as overall size and trackway
pattern that do not support identification of crocodylomorphs as their
trackmakers. Nevertheless, given the fragmentary skeletal record, a
relationship of some chirothere footprints to unknown crocodylomorphs
Lockley, M.G., Lucas, S.G., Milàn, J., Harris, J.D., Avanzini, M., Foster,
J.R., and Spielmann, J.A. 2010. The fossil record of crocodylian tracks and
traces: an overview; pp. 1-13 in Milàn, J., Lucas, S.G., and Spielmann,
J.A. (eds.), Crocodyle Tracks and Traces. New Mexico Museum of Natural
History and Science Bulletin 51. ABSTRACT: This volume fills a gap in the
ichnological literature on crocodylian tracks and other traces (bite marks
and coprolites). The definition of Crocodylia is presently in flux as both
crown-based and stem-based definitions are present in the literature. The
present volume provides articles focused on reports of new crocodylian track
records from the Triassic, Jurassic, Cretaceous and Miocene, crocodylian
neoichnology and new occurrences of crocodylian coprolites and bite marks.
The global geographic distribution of crocodylian tracks is summarized, and
the influence of Characichnos and Hatcherichnus ichnocoenoses/ichnofacies on
global archetypal ichnofacies is discussed.
Langereis, C.G., Krijgsman, W., Muttoni, G., and Menning, M. 2010.
Magnetostratigraphy - concepts, definitions, and applications. Newsletters
on Stratigraphy 43(3):207-233. doi: 10.1127/0078-0421/2010/0043-0207.
ABSTRACT: The most characteristic feature of the Earth's magnetic field is
that it reverses polarity at irregular intervals, producing a 'bar code' of
alternating normal (north directed) and reverse (south directed) polarity
chrons with characteristic durations. Magnetostratigraphy refers to the
application of the well-known principles of stratigraphy to the pattern of
polarity reversals registered in a rock succession by means of natural
magnetic acquisition processes. This requires that the rock faithfully
recorded the ancient magnetic field at the time of its formation, a
prerequisite that must be verified in the laboratory by means of
palaeomagnetic and rock magnetic techniques.
A sequence of intervals of alternatively normal or reverse polarity
characterized by irregular (non-periodic) duration constitutes a distinctive
pattern functional for correlations. Over the last 35 Myr, polarity
intervals show a mean duration of ~300,000 years, but large variations occur
from 20,000 yr to several Myr and even up to tens of Myr. By correlating the
polarity reversal pattern retrieved in a rock succession to a reference
geomagnetic polarity time scale (GPTS), calibrated by radioisotopic methods
and/or orbital tuning, the age of the rock succession can be derived.
Magnetostratigraphy and correlation to the GPTS constitute a standard dating
tool in Earth sciences, applicable to a wide variety of sedimentary (but
also volcanic) rock types formed under different environmental conditions
(continental, lacustrine, marine). It is therefore the stratigraphic tool of
choice to perform correlations between continental and marine realms.
Finally, we emphasise that magnetostratigraphy, as any other stratigraphic
tool, works at best when integrated with other dating tools, as illustrated
by the case studies discussed in this paper.
Quental, T.B., and Marshall, C.R. 2010. Diversity dynamics: molecular
phylogenies need the fossil record. Trends in Ecology and Evolution. doi:
10.1016/j.tree.2010.05.002. ABSTRACT: Over the last two decades, new tools
in the analysis of molecular phylogenies have enabled study of the
diversification dynamics of living clades in the absence of information
about extinct lineages. However, computer simulations and the fossil record
show that the inability to access extinct lineages severely limits the
inferences that can be drawn from molecular phylogenies. It appears that
molecular phylogenies can tell us only when there have been changes in
diversification rates, but are blind to the true diversity trajectories and
rates of origination and extinction that have led to the species that are
alive today. We need to embrace the fossil record if we want to fully
understand the diversity dynamics of the living biota.
Miyashita, T., Tanke, D.H., and Currie, P.J. 2010. Variation in premaxillary
tooth count and a developmental abnormality in a tyrannosaurid dinosaur.
Acta Palaeontologica Polonica. ABSTRACT: Premaxillary tooth count tends to
be stable amongst toothed dinosaurs, and most theropods have four teeth in
each premaxilla. Only one case of bilaterally asymmetric variation is known
in theropod premaxillary dentition, and there is no record of ontogenetic or
individual variation in premaxillary tooth count. Based on these
observations, a tyrannosaurid left premaxilla with three teeth (TMP 2007.20.
124) is an interesting deviation and represents an unusual individual of
Daspletosaurus sp. with a developmental abnormality. The lower number of
teeth is coupled with relatively larger alveoli, each of which is capable of
hosting a larger than normal tooth. This indicates that tooth size and
dental count vary inversely, and instances of reduction in tooth count may
arise from selection for increased tooth size. On the other hand, the
conservative number of premaxillary teeth in most theropods implies strong
developmental constraints and a functional trade-off between the dimensions
of the premaxillary alveolar margin and the size of the teeth. In light of
recent advances in the study of tooth morphogenesis, tooth count is a
function of two parameters: dimensions of an odontogenic field for a tooth
series, and dimensions of tooth positions. A probable developmental cause
for the low tooth count of TMP 2007.20.124 is that the dimensions of the
alveoli expanded by approximately a third during tooth morphogenesis.
Numerical traits such as tooth count are difficult to treat in a
phylogenetic analysis. When formulating a phylogenetic character, a
potential alternative to simply counting is to rely on the morphological
signature for developmental parameters that control the number of the
element in question.
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
The way to a man's heart is through
-- old proverb
"The way to a man's heart is through
the fourth and fifth ribs."
-- Katchoo (and others)