[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Mammal scavenging on Buitreraptor bones + non-dino papers

Ben Creisler

A number of recent papers that may be of interest:

Federico A. Gianechini & Silvina de Valais (2015)
Bioerosion trace fossils on bones of the Cretaceous South American
theropod Buitreraptor gonzalezorum Makovicky, Apesteguía and Agnolín,
2005 (Deinonychosauria).
Historical Biology (advance online publication)

The ichnological record provides valuable information on the
lifestyle, behaviour, and other palaeobiological and palaeoecological
aspects of the biota. Here, we describe an interesting case of
bioerosion trace fossils in bones of Buitreraptor gonzalezorum
Makovicky, Apesteguía and Agnolín, 2005, a deinonychosaurian theropod
from the fossiliferous locality of La Buitrera, Río Negro, Patagonia,
Argentina. The trace fossils are morphologically diverse and preserved
in a great percentage of the skeleton, including the jaw, vertebrae
and limbs. Four main groups of trace fossils have been informally
named as Parallel-Edge Furrows, Overlapped Grooves, Punctures and
Lined. Parallel-Edge Furrows are in turn subdivided into four
subgroups: isolated furrows, parallel pairs, opposed pairs and a
combination of parallel and opposed pairs. The bioerosion trace
fossils were probably generated by scavenging activities, and the
semi-articulated preservation of the skeleton and the small size of
each individual trace indicate small-sized tracemakers. Mammals are
the main candidates although some traces may have been generated by
crocodyliforms and insects such as dermestids and termites. This
evidence provides additional information about palaeoenvironmental
conditions, taphonomic processes, taxonomic diversity and ecological
relationships that characterised this part of northern Patagonia at
Early Cretaceous times.


NOTE: open-access pdf link not yet posted

Liu Jun (2015)
New discoveries from the Sinokannemeyeria-Shansisuchus Assemblage
Zone: 1. Kannemeyeriiformes from Shanxi, China.
Vertebrata PalAsiatica (advance online)

Recently, some new tetrapod fossils were collected along the Yellow
River in Shanxi Province. From the Member I of the Tongchuan Formation
at Baidaoyu in Linxian County, at least one species of
Parakannemeyeria, and one new species of Sinokannemeyeria, S.
baidaoyuensis, are identified. The new species is characterized by
prefrontal anterior extension level to posterior margin of postnarial
excavation. From the Ermaying Formation in Liulin County, a third
kannemeyeriid genus is identified for the
Sinokannemeyeria-Shansisuchus Assemblage. The new findings increase
the content and time extension of the Sinokannemeyeria-Shansisuchus


In open access:

Tatsuya Hirasawa & Shigeru Kuratani (2015)
Evolution of the vertebrate skeleton: morphology, embryology, and development.
Zoological Letters 1:2
DOI: 10.1186/s40851-014-0007-7

Two major skeletal systems—the endoskeleton and exoskeleton—are
recognized in vertebrate evolution. Here, we propose that these two
systems are distinguished primarily by their relative positions, not
by differences in embryonic histogenesis or cell lineage of origin.
Comparative embryologic analyses have shown that both types of
skeleton have changed their mode of histogenesis during evolution.
Although exoskeletons were thought to arise exclusively from the
neural crest, recent experiments in teleosts have shown that
exoskeletons in the trunk are mesodermal in origin. The enameloid and
dentine-coated postcranial exoskeleton seen in many vertebrates does
not appear to represent an ancestral condition, as previously
hypothesized, but rather a derived condition, in which the enameloid
and dentine tissues became accreted to bones. Recent data from
placoderm fossils are compatible with this scenario. In contrast, the
skull contains neural crest-derived bones in its rostral part. Recent
developmental studies suggest that the boundary between neural crest-
and mesoderm-derived bones may not be consistent throughout evolution.
Rather, the relative positions of bony elements may be conserved, and
homologies of bony elements have been retained, with opportunistic
changes in the mechanisms and cell lineages of development.


A. G. Ponomarenko, D. S. Aristov, A. S. Bashkuev, Yu. M. Gubin, A. V.
Khramov, E. D. Lukashevich, Yu. A. Popov, L. N. Pritykina, S. M.
Sinitsa, N. D. Sinitshenkova, et al. (2014)
Upper Jurassic Lagerstätte Shar Teg, southwestern Mongolia.
Paleontological Journal 48(14) : 1573-1682
DOI: 10.1134/S0031030114140160

One of the most interesting Mesozoic Lagerstätten, Shar Teg in
southwestern Mongolia, is reviewed. The geological structure and
oryctocoenoses of Shar Teg are described. Shar Teg is one of the most
diverse Jurassic Lagerstätten in terms of fossils represented. Fossils
from Shar Teg include aquatic and terrestrial plants, mollusks,
crustaceans, insects, fishes, amphibians, reptiles, and mammals.
Insects are the most diverse group. To date, a total of 297 species of
161 families and 22 orders have been described or recorded in Shar
Teg, making it possible to reconstruct comprehensively the Jurassic
biota of the locality. The oryctocoenosis composition is peculiar; it
includes only six species described from other localities. The
oryctocoenosis appears to link the faunas of eastern Asia, Central
Asia, and Europe. A total of 31 new species are described.


In open access:

Craig R. McClain, Meghan A. Balk, Mark C. Benfield, Trevor A. Branch,
Catherine Chen, James Cosgrove, Alistair D.M. Dove, Lindsay C.
Gaskins, Rebecca R. Helm, Frederick G. Hochberg, Frank B. Lee, Andrea
Marshall, Steven E. McMurray, Caroline Schanche, Shane N. Stone &
Andrew D. Thaler (2015)
Sizing ocean giants: patterns of intraspecific size variation in
marine megafauna.
PeerJ 2:e715
doi: http://dx.doi.org/10.7717/peerj.715

What are the greatest sizes that the largest marine megafauna obtain?
This is a simple question with a difficult and complex answer. Many of
the largest-sized species occur in the world’s oceans. For many of
these, rarity, remoteness, and quite simply the logistics of measuring
these giants has made obtaining accurate size measurements difficult.
Inaccurate reports of maximum sizes run rampant through the scientific
literature and popular media. Moreover, how intraspecific variation in
the body sizes of these animals relates to sex, population structure,
the environment, and interactions with humans remains
underappreciated. Here, we review and analyze body size for 25 ocean
giants ranging across the animal kingdom. For each taxon we document
body size for the largest known marine species of several clades. We
also analyze intraspecific variation and identify the largest known
individuals for each species. Where data allows, we analyze spatial
and temporal intraspecific size variation. We also provide allometric
scaling equations between different size measurements as resources to
other researchers. In some cases, the lack of data prevents us from
fully examining these topics and instead we specifically highlight
these deficiencies and the barriers that exist for data collection.
Overall, we found considerable variability in intraspecific size
distributions from strongly left- to strongly right-skewed. We provide
several allometric equations that allow for estimation of total
lengths and weights from more easily obtained measurements. In several
cases, we also quantify considerable geographic variation and
decreases in size likely attributed to humans.