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Great Heaping Gobs of New Papers
That should be read with a Scottish brogue, by the way...
First, a batch from _Cretaceous Research_:
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Matsukawa, M., Lockley, M., and Li, J. 2006. Cretaceous terrestrial biotas
of East Asia, with special reference to dinosaur-dominated ichnofaunas:
towards a synthesis. Cretaceous Research 27(1):3-21. doi:
10.1016/j.cretres.2005.10.009.
ABSTRACT: This paper represents an "editorial" introduction to this issue,
which is one of two special issues of Cretaceous Research on the geology and
paleontology of East Asia. This paper makes special reference to the results
of joint Japanese, Chinese, and North American expeditions that investigated
more than 70 fossil footprint sites and other fossiliferous localities in
China, Japan, Korea, Laos, Mongolia, and Thailand. More than 50 of the track
sites are considered Cretaceous in age, though in some cases dating is
uncertain. We herein present summaries of selected important sites not
previously described in detail based on new maps, tracings, and replicas of
representative type specimens and related materials that have been assembled
in accessible reference collections. Other sites are described in detail
elsewhere in this issue and are placed in broader paleoenvironmental context
in conjunction with papers that deal with floras, invertebrate and
vertebrate body fossils, paleoecosystem reconstruction, and their
stratigraphic, sedimentological, and tectonic settings in the second of the
two special issues.
Preliminary syntheses suggest that Cretaceous vertebrate ichnofaunas of East
Asia contain various distinctive elements that are neither typical nor
common in other regions. These include an abundance and significant
diversity of bird tracks, some with web impressions, various small theropod
tracks including diminutive examples (Grallator and Minisauripus) with foot
lengths of 2.0-3.0 cm, probable small dromeosaurid tracks
(Velociraptorichnus), probable coelurosaurid tracks with bilobed heel
impressions (Siampodus), and various small ornithopod tracks that resemble
Anomoepus. Giant pterosaur tracks (Haenamichnus) are also unique to this
area. A review of the ichnotaxonomy generously accepts about eleven valid
ichnogenera of dinosaurs, two of pterosaurs, and nine of birds. At least ten
other ichnogenera are dubious and among these several have already been
rejected.
A preliminary overview of these ichnotaxa in broader context suggests that
the dominance of bird and theropod ichnotaxa is a valid reflection of a
corresponding dominance of birds and theropod body-fossil taxa. We also note
partitioning of ichnofaunas into saurischian-dominated assemblages from low,
tropical latitudes and semi-arid, inland basin paleoenvironments, and
ornithopod-rich assemblages from higher, more temperate latitudes and humid,
coastal paleoenvironments.
Chen, P.-J., Li, J., Matsukawa, M., Zhang, H., Wang, Q., and Lockley, M.G.
2006. Geological ages of dinosaur-track-bearing formations in China.
Cretaceous Research 27(1):22-32. doi: 10.1016/j.cretres.2005.10.008.
ABSTRACT: In China more than 30 forms of dinosaur tracks at about 50
localities distributed in 16 provinces have been reported. These fossil
footprints have been found in 25 Upper Triassic to Upper Cretaceous
formations. They are the Xujiahe Formation (Upper Triassic), Zhenzhuchong
and Ziliujing formations (Lower Jurassic), Xintiangou and Lower Shaximiao
formations (Middle Jurassic), Penglaizhen Formation (Upper Jurassic), and
Jiaguan and Daergun formations (Upper Cretaceous) in the Sichuan Basin; the
Fengjiahe Formation (Lower Jurassic) and Jiangdihe Formation (Upper
Cretaceous) in the central Yunnan Basin; the Zhiluo Formation (Middle
Jurassic) and Fengjiashan Formation (Lower Cretaceous) in Shaanxi Province;
the Jingchuan Formation (Lower Cretaceous) in Inner Mongolia; the Houcheng
Formation (Upper Jurassic) and Jiufotang Formation (Lower Cretaceous) in
northern Hebei; the Tuchengzi Formation (Upper Jurassic) and Fuxin Formation
(Lower Cretaceous) in western Liaoning; the Laiyang Formation (Lower
Cretaceous) in the Shandong Peninsula; the Tongfosi Formation (Cretaceous)
in eastern Jilin Province; the Hekou Group (Lower Cretaceous) in Gansu; and
the Xiaodong, Qiyunshan, and Nanxiong formations (Upper Cretaceous) in
Hunan, Anhui, and Guangdong provinces, respectively. The invertebrate and
vertebrate fossils including tetrapod footprints reported from some of these
formations are outlined and their biostratigraphic significance and utility
for correlation are discussed.
Lockley, M., Matsukawa, M., Ohira, H., Li, J., Wright, J., White, D., and
Chen, P. 2006. Bird tracks from Liaoning Province, China: new insights into
avian evolution during the Jurassic-Cretaceous transition. Cretaceous
Research 27(1):33-43. doi: 10.1016/j.cretres.2005.10.007.
ABSTRACT: Tracks of shorebird-like species from a small outcrop in the upper
part of the Tuchengzi Formation at Kangjiatun, in the Beipiao area, Liaoning
Province, may be the oldest bird tracks known from China. Formerly
considered Late Jurassic in age, new fission track dates give an age of
145.9 Ma for ash beds associated with dinosaur track-bearing beds from the
middle part of the Tuchengzi Formation outcrops at a nearby locality. Thus,
the age appears to be close to the Jurassic-Cretaceous
(Tithonian-Berriasian) boundary. The precise age of the bird track-bearing
beds has not been determined, but is unlikely to be younger than about 139
Ma, based on dates for the upper part of the Tuchengzi Formation. Thus, the
bird tracks, like the Tuchengzi ichnofauna in general, predate the famous
Yixian Formation, which has produced a different avifauna.
The most distinctive tracks are here named Pullornipes aureus ichnosp. nov.
and are tentatively assigned to the ichnofamily Koreanornipodidae. Other
tracks from the same site appear to represent different ichnotaxa and
therefore indicate the potential to find diverse avian ichnofaunas at this
time. This record supports the evidence that East Asian avian ichnofaunas
are the most diverse known during the Early Cretaceous.
Zhang, J., Li, D., Li, M., Lockley, M.G., and Bai, Z. 2006. Diverse
dinosaur-, pterosaur-, and bird-track assemblages from the Hakou Formation,
Lower Cretaceous of Gansu Province, northwest China. Cretaceous Research
27(1):44-55. doi: 10.1016/j.cretres.2005.10.006.
ABSTRACT: Diverse and well-preserved assemblages of dinosaur (theropod,
sauropod and ornithopod), pterosaur, and bird tracks from the Hekou
Formation (Lower Cretaceous) in the Yellow River (Huang He) valley represent
the first significant fossil footprint discoveries in Gansu Province, China.
However, the sites are large, visually spectacular, and well-exposed thanks
to labor-intensive hand excavation. The sites have the potential for
development as educational and tourist destinations. These sites have become
one of the National Geoparks in China.
Dinosaur tracks include at least two theropod morphotypes that range in size
from about 5 to >30 cm in length. Wide-gauge sauropod tracks (Brontopodus)
range in size from 25 to 90 cm (pes length) and are the best-preserved
examples known from China, with clear claw impressions. One trackway
suggests an accelerating/running individual. Parallel ornithopod trackways
indicate gregarious behavior. An enigmatic trackway may be a manus-only
ornithopod trackway.
A pterosaur trackway (cf. Pteraichnus), the first reported from China,
consists of 24 consecutive footprints, and is the longest, well-preserved
trackway on record. Bird tracks (cf. Aquatilavipes) are also very well
preserved.
The tracks occur at multiple stratigraphic levels in fluvio-lacustrine
sequences of paleosol mudstones and sandstones with mud cracks and wave
ripple marks. A minimum ichnodiversity of eight, the highest reported from
the Cretaceous of China, is estimated. The saurischian component (theropods
and sauropods) compares well with Inner Mongolia ichnofaunas from the Jing
Chuan Formation. However, the co-occurrence of ornithopod and sauropod
tracks is rare in Asia and globally, and compares with assemblages from
South Korea, a similar Cretaceous paleolatitude (ca. 30°).
Kim, J.Y., Kim, S.H., Kim, K.S., and Lockley, M. 2006. The oldest record of
webbed bird and pterosaur tracks from South Korea (Cretaceous Haman
Formation, Changseon and Sinsu Islands): More evidence of high avian
diversity in East Asia. Cretaceous Research 27(1):56-69. doi:
10.1016/j.cretres.2005.10.005.
ABSTRACT: Tracks of web-footed birds and pterosaurs from the Lower
Cretaceous (Aptian-Albian) Haman Formation of Changseon and Sinsu Islands,
respectively (southern coast of Korea), represent the oldest records for
these footprint types in Asia. The morphology of the bird tracks, with
prominent posteriorly directed hallux impression, semi-palmate web, and
small ratio of length to width is similar to Hwangsanipes choughi from the
Upper Cretaceous (Cenomanian) Uhangri Formation. However, they about 20-25%
smaller, and therefore much closer to the size of North American Ignotornis
(size difference less than 10%). The development of the web appears
intermediate in size between Hwangsanipes and Ignotornis. This leads us to
infer a new ichnotaxon herein named Ignotornis yangi. This is the first
Asian report of a named bird track similar to the type material of
Ignotornis from North America.
Pterosaur tracks consist predominantly of clear impressions of tridactyl
mani (length 9-13 cm) characterized by strongly asymmetric digit impressions
that outnumber less-clear elongated pes traces by a ratio of about 10 to 1.
Clusters of short digit impressions or parallel to subparallel scrape marks
indicate incomplete pes traces probably made by swimming animals. The
pterosaur tracks, here provisionally identified as Pteraichnus, represent
the first record of this ichnogenus from Korea. The track maker represents a
species quite different from the giant track maker represented by the
ichnogenus Haenamichnus from the Cenomanian Uhangri Formation, but it is
similar to recent reports of Pteraichnus-like forms from the Lower
Cretaceous of China.
These new records shed light on patterns of bird-track diversity and
abundance in the "mid" Cretaceous of Korea (Aptian-Cenomanian) and show that
at least two quite distinct pterosaurian species existed during this time
span with at least six distinct species of track-making birds. When combined
with additional reports of bird track ichnotaxa from China, the picture
emerges of a remarkably diverse Lower Cretaceous avifauna. Such diversity is
consistent with the skeletal record for this region, though the types of
birds represented by tracks are "shorebird-like" and therefore distinct from
the skeletal avifauna, which consist of birds of the perching type.
The ability of tracks to record whole foot morphology including details of
web and hallux configuration allows for fine discrimination of foot
morphology and comparison with web-footed tracks from other regions and
geologic time periods. As is the case with modern shore birds, Cretaceous
tracks were probably mostly made by adults whose foot size as well as shape
is probably indicative of the identity of the track maker at low taxonomic
levels.
Lockley, M.G., Houck, K., Yang, S.-Y., Matsukawa, M., and Lim, S.-K. 2006.
Dinosaur-dominated footprint assemblages from the Cretaceous Jindong
Formation, Hallyo Haesang National Park area, Goseong County, South Korea:
Evidence and implications. Cretaceous Research 27(1):70-101. doi:
10.1016/j.cretres.2005.10.010.
ABSTRACT: The track-rich Cretaceous Jindong Formation comprises part of an
intra-arc basin, fluvio-lacustrine succession that represents a late stage
in the evolution of the Kyongsang Basin. This formation is replete with
track-bearing levels indicating the activity of many generations of
dinosaurs and birds. The track-rich beds occur in the upper part of the
Hayang Group (Kyongsang Supergroup), which also contains other, underlying
dinosaur-track-bearing formations. However the Jindong Formation and
underlying formations have produced few age-diagnostic body fossils. Altered
volcaniclastic sediments such as are found the Jindong Formation complicate
interpretation of the age of the tracks as discussed in the accompanying
companion paper. Nonetheless such settings provided near optimal conditions
for the formation and preservation of abundant track assemblages
(ichnofaunas), and the Jindong Formation has become an ichnological "cause
celebre" producing impressive statistics on the number of track-bearing
sites, number of track-bearing levels and number of measured trackways.
These data allow various inferences about certain aspects of the population
structure, behavior and distribution of the dinosaurian track makers in
these dinosaur-dominated paleocommunities.
The Jindong Formation and underlying Haman Formation have also yielded many
bird tracks. The complete lack of avian body fossils in Korea and the rarity
of dinosaur skeletal remains means that the footprint record currently
provides the vast majority of the Mesozoic vertebrate evidence available for
the entire Korean peninsula. Thus, the tracks represent a highly significant
addition to the national paleontological heritage of Korea, as well as being
a very important component of the East Asian and global footprint records.
Detailed studies of a 100-200-m-thick succession at the Sangjok Dinosaur
Tracksite National Monument in the Hallyo Haesang National Park area in
Kosong County reveal an average of about two track-bearing levels per meter,
making it one of the richest track-bearing sections on record and providing
evidence of the activity of hundreds of individuals. Many other track sites
are found locally in the Jindong Formation in Kosong County (about 500 km2)
including one described herein from near Gohyeon village where the Jindong
Formation type section is situated. Other track sites can be traced
laterally over larger distances within the Gyeongsang Basin. The composition
of ichnofaunas throughout this region appears remarkably consistent.
The Jindong Formation is one of the few localities where sauropod,
ornithopod, and bird tracks all occur in abundance, probably due to
latitudinal/climatic controls. The sauropod tracks, which include wide-gauge
forms allied to Brontopodus, form the largest brontosaur trackway sample yet
reported but are characterized by a high proportion of small individuals.
Such unusual size-frequency distributions raise interesting ecological and
taphonomic questions about the biasing of the body fossil record towards
large individuals by various physical (preservational) or biological/
ecological controls.
The most abundant dinosaur trackways are those of iguanodontids (cf.
Caririchnium or Iguanodontipus) that often traveled in herds. By contrast,
sauropod tracks show little or no evidence of gregarious behavior and rarely
occur on the same bedding planes as ornithopod trackways. This suggests a
pattern of mutual exclusion or geological segregation between these two
herbivore groups, which indicates that they probably frequented the area at
different times. Sauropod and ornithopod track size-frequency distributions
are also fundamentally different, suggesting that the ornithopods were
mainly sub-adults and adults, whereas the sauropods were predominantly
juveniles. Theropod tracks are uncommon suggesting a low predator:prey ratio
of 1:20.
Bird tracks including the large ichnospecies Jindongornipes kimi, an
intermediate-sized form, Goseongornipes markjonesi ichnosp. and ichnogen.
nov., and a small ichnospecies Koreanaornis hamanensis occur at several
dozen stratigraphic levels in association with nematode trails (Cochlichnus)
and other invertebrate traces. These three ichnospecies are assigned to the
respective ichnofamilies Koreanornipodidae ichnofam. nov., Ignotornidae, and
Jindongornipodidae ichnofam. nov. All these avian footprints are typical of
bird track assemblages in lake shoreline deposits, and indicate the activity
of many generations of waders or shorebirds. We also recognize other, much
less common, small footprint types tentatively attributed to a perching bird
or a diminutive theropod. Collectively the bird tracks indicate the
considerable potential of avian ichnites to provide insight into avian
paleoecology at an early stage in the evolution of Class Aves.
Houck, K.J., and Lockley, M.G. 2006. Life in an active volcanic arc:
petrology and sedimentology of dinosaur track beds in the Jindong Formation
(Cretaceous), Gyeongsang Basin, South Korea. Cretaceous Research
27(1):102-122. doi: 10.1016/j.cretres.2005.10.004.
ABSTRACT: The Jindong Formation was deposited as a thick succession of
fine-grained volcaniclastic sediments in a rapidly subsiding intra-arc
basin. These sediments contain abundant dinosaur and bird tracks that occur
on many bedding planes throughout the approximately 110 m of stratigraphic
section measured for this study. The main lithologies in the Jindong
Formation are ash-rich mudstone, siltstone, and very fine sandstone. Minor
lithologies are coarser sandstone, conglomerate, carbonates, and ash tuff.
The sandstones are feldspathic and lithic arenites and wackes. They contain
plutonic feldspars, volcanic rock fragments, volcanic ash, and a variety of
quartz types. All lithologies show evidence of extensive post-depositional
alteration, including devitrification and replacement of detrital grains by
authigenic minerals. The alterations are typical of burial metamorphism with
high heat flow. Sediments of the Jindong Formation can be grouped into three
facies associations. Association 1 (proximal) comprises 16% of the measured
sections. It consists of various types of bedded, cross-bedded, laminated,
and ripple cross-laminated sandstone and minor conglomerate. These are
interpreted as fluvial or distributary channel and proximal lake deposits.
Association 2 (medial) comprises 53% of the measured sections. It consists
mainly of heterolithic couplets of very fine sandstone and mudstone that are
mm to dm thick. They contain graded bedding, laminations, current ripples,
wave ripples, and mud cracks, and are interpreted as lacustrine hyperpycnal
flow deposits. Association 3 (distal) comprises 31% of the measured
sections. It consists mainly of bedded shale, mudstone, and siltstone. These
are interpreted as distal lake deposits. Associations 2 and 3 contain minor
carbonates, which are interpreted as lacustrine and/or diagenetic in origin,
and minor tuffs, which are interpreted as tephra. Small wave ripples,
dinosaur tracks, invertebrate burrows, and mud cracks are common throughout
the measured sections; thus the Jindong lakes are inferred to have been
shallow and ephemeral in nature. Wave ripple-crest orientations are
consistently WNW-ESE, indicating a prevailing wind direction from the NNE or
SSW. Because the sediments are mostly fine-grained and the ash beds thin,
the study area is inferred to have been in a distal lowland setting, at
least tens of km away from erupting volcanoes. Paleoclimate reconstructions
suggest that the study area had a seasonal climate with wet summers and dry
winters. Cooler, wetter conditions are thought to have prevailed to the
north, and warmer, drier conditions to the south. Modern volcanic arc
environments with seasonal and/or humid climates are characterized by rapid
aggradation of ashy sediment that fills drainages and causes widespread
flooding. This style of sedimentation accounts for the facies found in the
Jindong Formation, as well as the many bedding-plane exposures of tracks.
The unusual occurrence of both sauropod and ornithopod tracks in the Jindong
sections may be the result of a climate boundary that existed in the area at
the time. Facies analysis of track types indicates that various track makers
had the same environmental preferences, and facies association 2 contains
the greatest number of tracks of all types. It is inferred that the tendency
for only one track type to occur on a given bedding plane is the result of
different types of animals visiting the study area at different times,
rather than differing environmental preferences. The Jindong Formation
contains an abundance of subaqueously deposited facies, an abundance of
tracks, and many track levels that were wet when animals were walking on
them. These features are not consistent with previous interpretations of
aridity during Jindong time.
Huh, M., Paik, I.S., Lockley, M.G., Hwang, K.G., Kim, B.S., and Kwak, S.K.
2006. Well-preserved theropod tracks from the Upper Cretaceous of Hwasun
County, southwestern South Korea, and their paleobiological implications.
Cretaceous Research 27(1):123-138. doi: 10.1016/j.cretres.2005.10.003.
ABSTRACT: Abundant dinosaur fossils including footprints, eggs and nests,
teeth, and bones have been found from the Cretaceous nonmarine deposits of
Korea. Among them, dinosaur tracks are the most distinctive, and some
tracksites are among the most famous in the world. Approximately 1500
well-preserved dinosaur footprints, including more than 60 trackways, have
been excavated from the Cretaceous Neungju Group in a quarry in Seoyu-ri,
Hwasun County, Jeollanam-do, South Korea. Unlike other dinosaur fossil sites
in South Korea, most of the tracks found in the area belong to theropods,
especially small-sized theropods. The tracks show significant variation in
size, morphology, and divarication. On the basis of morphology and size, the
theropod tracks have been classified into three types. The first type is
characterized by its small size, wide divarication, and slender digits,
which can be more closely compared to Magnoavipes. The second type shows
slightly thicker digits than the first one and narrow toe impressions and is
similar to Ornithomimipus or Xiangxipus. The footprints of the third type
belong to large theropods and display distinct sharp claw impressions. The
calculated body sizes of the dinosaurs vary between small theropods with an
estimated hip height of 68.4-194.5 cm, and large theropods with a maximum
estimated hip height of 260.9 cm. The variety of morphotypes and sizes of
the footprints and the calculated body sizes indicate that different
theropods with various gaits inhabited in the study area during the
Cretaceous. On the basis of the speed and gait analyses, it is inferred that
the small theropods in the area were trotting, while the large theropods
were walking slowly. The fossil site also shows diverse gaits with unusual
walking patterns and postures in some tracks.
Lockley, M.G., Matsukawa, M., Sato, Y., Polahan, M., and Daorerk, V. 2006. A
distinctive new theropod dinosaur track from the Cretaceous of Thailand:
Implications for theropod track diversity. Cretaceous Research
27(1):139-145. doi: 10.1016/j.cretres.2005.10.002.
ABSTRACT: Highly distinctive, well-preserved, three-toed dinosaur footprints
with bilobed heel impressions from the Cretaceous of Thailand are assigned
to the new ichnotaxon Siamopodus khaoyaiensis. The tracks, which represent
small- to medium-sized gracile theropods, are unlike any previously known
from Thailand or elsewhere. By contrast other robust, small- to medium-sized
theropod tracks with bulbous heel impressions are reported from a new
locality and shown to be similar to Lower Cretaceous tracks from elsewhere
in Asia. When added to previously reported robust, large theropod tracks,
the Cretaceous track record in Thailand appears dominated by a significant
diversity of theropod track types that differ from one locality to the next.
Thus, the track record is in general agreement with the skeletal record of
theropods in Thailand. The occurrence of footprints with bilobed heel
impressions is reviewed briefly.
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Then some from _P^3_, including one on dinosaurs:
Grellet-Tinner, G., Chiappe, L.M., Norell, M., and Bottjer, D. 2006.
Dinosaur eggs and nesting behaviors: a paleobiological investigation.
Palaeogeography, Palaeoclimatology, Palaeoecology 232(2-4):294-321. doi:
10.1016/j.palaeo.2005.010.029.
ABSTRACT: Although dinosaur eggs were first discovered and identified in the
late 1800s, limited attention was given to the scientific value of oological
fossils in contrast to observations based on skeletal features. Here, we
offer a review of Mesozoic saurischian egg materials, in comparison with
extant crocodilians and avians, and their paleobiological interpretation
based either on the presence of embryos in ovo or brooding adults on egg
clutches. Our study focuses on the eggs of the oviraptorid Citipati osmolka
(Mongolia), the troodontid Troodon formosus (North America), the theropod
oospecies Macroelongatoolithus xixiaensis (China), the ornithothoracine bird
(Argentina), an indeterminate theropod (Thailand), and titanosaurs
(Argentina). Results show that (1) many oological characters and
reproductive behaviors associated with modern birds are rooted among
non-avian theropods, (2) there is a reproductive evolutionary cline from
crocodilians to modern birds with (3) a noticeable pattern of coeval
development between the accretion of eggshell layers, origination and size
increased of larger air cells (inferred from egg polar asymmetry), and
brooding/incubating behaviors. Most of these pre-adaptations are grouped in
two main clades of the saurischian cladogram: one at the level of
Oviraptorosauridae and the other at Troodontidae. Although undeniably these
two theropod taxa seem to represent two important phases for the evolution
of avian reproduction, the phylogenetic distance between these clades and
Titanosauria cannot be ignored. As such, the reproductive features that
appeared in concert in oviraptorids might have gradually evolved across more
basal theropod clades. Although Troodon formosus by its egg shape and
nesting behavior seems to be in this study the precursors of modern avian
reproduction, the importance of small-bodied theropods such as those who
laid the Phu Phok eggs cannot be dismissed and the eggs of such dinosaurs
could suggest a closer phylogenetic ties to Aves than troodontids. At a
higher level of inferences, there is a strong possibility that the evolution
of these reproductive features is concurrent with profound physiological and
metabolic changes that occurred in saurischian dinosaurs throughout their
evolution.
Friis, E.M., Pedersen, K.R., and Crane, P.R. 2006. Cretaceous angiosperm
flowers: innovation and evolution in plant reproduction. Palaeogeography,
Palaeoclimatology, Palaeoecology 232(2-4):251-293. doi:
10.1016/j.palaeo.2005.07.006.
ABSTRACT: Information on the fossil record of angiosperms has expanded
dramatically over the past twenty-five years, and in particular the
discovery of numerous mesofossil floras with fossil flowers has added a
completely new element into the study of angiosperm history. A review of the
phylogenetic diversification of angiosperms through the Cretaceous is given
based mainly on the extensive record of fossil flowers and other
reproductive organs. Several major phases in the Cretaceous angiosperm
radiation can be distinguished. These are recognised primarily by structural
and functional traits of the flowers and by pollen features, as well as
distinct changes in the systematic composition of the floras. ANITA grade
angiosperms and Chloranthaceae, as well as other magnoliids, early monocots
and early eudicots, differentiated almost simultaneously during the Early
Cretaceous. There is also strong evidence for extensive diversification of
core eudicots during the Late Cretaceous. In addition to patterns of
phylogenetic diversification, the fossil record of angiosperm flowers also
provides insights into the timing of floral evolution in terms of the
functions of the various kinds of floral organs, as well as accompanying
patterns of ecological diversification.
Clack, J.A. 2006. The emergence of early tetrapods. Palaeogeography,
Palaeoclimatology, Palaeoecology 232(2-4):167-189. doi:
10.1016/j.palaeo.2005.07.019.
ABSTRACT: Study of Devonian tetrapods and their relatives spanning the
so-called 'fish-tetrapod' transition has expanded almost exponentially in
the last 15 years or so. This evolutionary event is now represented by at
least nine named genera of Devonian tetrapod, several new 'near-tetrapods'
and a number of new tetrapods from the Early Carboniferous. The anatomy of
Acanthostega has radically changed ideas about how this transition took
place, and more recently the anatomy of Ichthyostega is being reassessed
with some startling conclusions such as the unique construction of its ear
region. The current state of research on this range of animals is
summarized, followed by a consideration of the acquisition of limbs and
digits among tetrapods including their possible forerunners, the development
of digits and their original function, and the onset of pentadactyly. The
faunal relations and palaeoecological contexts of the Devonian tetrapods are
brought together in an initial though necessarily brief survey, followed by
an assessment of Devonian tetrapod diversity, which is seen to be much
greater than previously realised. Finally, some hopes and ambitions for the
future are set out.
-----------------
....and, lastly, some that aren't about dinosaurs but are kind of
interesting anyway, from _Annales de Paleontologie_:
Antunes, M.T., Balbino, A.C., and Ginsburg, L. 2006. Miocene Mammalian
footprints in coprolites from Lisbon, Portugal. Annales de Paléontologie
92(1):13-30. doi: 10.1016/j.annpal.2005.09.002.
ABSTRACT: For the first time, at least for the Lisbon Miocene series,
uncommon ichnologic evidence has been recognized, i.e. mammalian footprints
in coprolites. Three coprolites were recorded in three successive
stratigraphic units, IVb and Va2 from the Lower Miocene to Vb from the early
Middle Miocene. The largest, tridactyl footprint can be ascribed to a right
foot of a rhinoceros. Size excludes all the rhinocerotids known from the Vb
unit except Hispanotherium matritensis. A smaller coprolite (Va2 unit) shows
a tridactyl, left foot impression of a perissodactyl. It is clearly too
small for a rhinoceros, even for a young one. It seems to have been made by
an Anchitherium Equid. The pes had a plantar pad as still found in the
Mesohippus-Anchitherium lineage but not in more advanced Equids. Both
tridactyl imprints may have been produced by the coprolite-makers. A large
coprolite (IVb unit) that may have been produced by Brachyodus onoideus
shows a few didactyl imprints. An artiodactyl trampled the dung with hoofs
sliding on its surface and producing two incomplete imprints. It also
trampled the dung in a more stable position, producing the best imprint,
whose structure indicates it was produced by the left manus. The lack of
lateral toe marks excludes suids (and Brachyodus, also because its size is
too much small). It is from a small-sized ruminant, most probably a cervid,
genus Procervulus. In all cases, defecation occurred on dry land, albeit in
eventually or seasonally flooded areas near a river.
[Interestingly, I've been contending for years that one of the most
definitive signs of a lack of intelligence on the part of nigh-extinct
horses is that they willingly step in poop; guess this has been going on for
millions of years...]
Antunes, M.T., Balbino, A.C., and Ginsburg, L. 2006. Ichnological evidence
of a Miocene rhinoceros bitten by a bear-dog (Amphicyon giganteus). Annales
de Paléontologie 92(1):31-39. doi: 10.1016/j.annpal.2005.10.002.
ABSTRACT: A rhinocerotid hemimandible, the Iberotherium rexmanueli
zbyszewskii holotype, was bitten by Amphicyon giganteus, a carnivore that
could attack large prey and be an opportunistic scavenger as well. The
large, young adult Iberotherium was not senile and may have been killed by a
single individual or by a pack of Amphicyon giganteus, but disease or
accident may also have caused its death. Alternatively, during a drought
event, a dying or in harsh physical condition rhinoceros may have been
overcome while seeking a water point where ambush would be possible. Death
also may have been a consequence of a major flood. As decay progressed and
the remnants were eventually deposited, parts could have been consumed by
scavengers. After consumption, wet bone surfaces could undergo some
corrosion. Fissures may have resulted from desiccation or mechanical stress.
The hemimandible was abandoned after consumption and left exposed until new
sands were deposited over it.
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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
http://cactus.dixie.edu/jharris/
"Actually, it's a bacteria-run planet, but
mammals are better at public relations."
-- Dave Unwin