"Gorgeous, exceedingly intuitive, well conceived, well rendered and performs well." - Rob Taylor
4 years in development with leading dinosaur experts and international collaborators, hundreds of references, 350,000 words, 1400+ illustrations.Click for details
| See also: | New dinosaur species of 2008 |
| Top dinosaur paleo stories of 2008 | |
| New dinosaur species of 2007 |
ADEOPAPPOSAURUS MOGNAI
Adeopapposaurus mognai, gen. et sp. nov. with Comments on Adaptations of Basal Sauropodomorpha
Martínez, R.N. 2009. Journal of Vertebrate Paleontology 29:142-164.
Abstract:
Prosauropods are basal sauropodomorphs that were the major terrestrial
faunal components from the Norian until their extinction during
the Toarcian. Their status as a natural group is debatable.
In the present work I describe Adeopapposaurus mognai,
a new sauropodomorph from the Cañón del Colorado Formation,
in northwestern Argentina. Diagnostic autapomorphies and combination
of characters of Adeopapposaurus include a series of
large foramina in a sub-vertical row on the lateral surface
of the premaxilla; strongly rugose depression bordered by a
protuberance with a series of foramina in a sub-vertical row,
on the lateral surface of the anterior end of the dentary; eleven
anteroposteriorly elongated cervical vertebrae and thirteen
dorsal vertebrae with neural arches taller than the respective
centra. Phylogenetically Adeopapposaurus is resolved
as the sister group to Massospondylus; differing from
the latter based on differences in mandible and premaxilla and
addition of one dorsal vertebra to the neck. The specimens described
here reveal numerous herbivorous adaptations, including the
presence of a highly vascularized bony plate in the premaxilla
and dentary, which indicates that it had a horny beak.
Journal of Vertebrate Paleontology: Adeopapposaurus mognai, gen. et sp. nov. (Dinosauria: Sauropodomorpha), with Comments on Adaptations of Basal Sauropodomorpha (Subscription required)
ALBALOPHOSAURUS YAMAGUCHIORUM
A New Ornithischian Dinosaur from the Lower Cretaceous Kuwajima Formation of Japan
Tomoyuki Ohashi and Paul M. Barrett
Abstract: A new ornithischian dinosaur, Albalophosaurus yamaguchiorum gen. et sp. nov., is described on the basis of a partial skull and lower jaw recovered from the Lower Cretaceous Kuwajima Formation (Tetori Group) of central Japan. The specimen exhibits a unique suite of characters in the dentition, maxilla, and dentary. A phylogenetic analysis recovers Albalophosaurus as a basal member of Ceratopsia: however, this placement is weakly supported and no unambiguous ceratopsian synapomorphies can be identified in the material. This new taxon should, therefore, be regarded as Cerapoda incertae sedis until further material is discovered. Nevertheless, Albalophosaurus offers additional information on the diversity of east Asian dinosaur faunas during the Early Cretaceous and represents only the third valid dinosaur taxon to be described from Japan.
Paper: A New Ornithischian Dinosaur from the Lower Cretaceous Kuwajima Formation of Japan (Subscription required)
ANCHIORNIS HYXLEYI
A new feathered maniraptoran dinosaur fossil that fills a morphological
gap in avian origin
Xing Xu, Qi Zhao, Mark Norell, Corwin Sullivan, David Hone, Gregory
Erickson, XiaoLin Wang, FengLu Han, and Yu Guo
Abstract:
Recent fossil discoveries have substantially reduced the morphological
gap between non-avian and avian dinosaurs, yet avians including Archaeopteryx differ from non-avian theropods in their
limb proportions. In particular, avians have proportionally
longer and more robust forelimbs that are capable of supporting
a large aerodynamic surface. Here we report on a new maniraptoran
dinosaur, Anchiornis huxleyi gen. et sp. nov., based
on a specimen collected from lacustrine deposits of uncertain
age in western Liaoning, China. With an estimated mass of 110
grams, Anchiornis is the smallest known non-avian theropod
dinosaur. It exhibits some wrist features indicative of high
mobility, presaging the wing-folding mechanisms seen in more
derived birds and suggesting rapid evolution of the carpus.
Otherwise, Anchiornis is intermediate in general morphology
between non-avian and avian dinosaurs, particularly with regard
to relative forelimb length and thickness, and represents a
transitional step toward the avian condition. In contrast with
some recent comprehensive phylogenetic analyses, our phylogenetic
analysis incorporates subtle morphological variations and recovers
a conventional result supporting the monophyly of Avialae.
Paper: A new feathered maniraptoran dinosaur fossil that fills a morphological gap in avian origin (Subscription required)
ANGULOMASTACATOR
DAVIESI
An Enigmatic New Lambeosaurine Hadrosaur (Reptilia: Dinosauria) from the Upper Shale Member of the Campanian Aguja Formation of Trans-Pecos Texas
Jonathan R. Wagner and Thomas M. Lehman
Paper: An Enigmatic New Lambeosaurine Hadrosaur (Reptilia: Dinosauria) from the Upper Shale Member of the Campanian Aguja Formation of Trans-Pecos Texas (Subscription required)
ARENYSAURUS ARDEVOLI
The last hadrosaurid dinosaurs of Europe: A new lambeosaurine from the Uppermost Cretaceous of Aren (Huesca, Spain).
Pereda-Suberbiola, Xabier; José Ignacio Canudo; Penélope Cruzado-Caballero; José Luis Barco; Nieves López-Martínez; Oriol Oms; and José Ignacio Ruiz-Omeñaca
Abstract:
A new hadrosaurid dinosaur, Arenysaurus ardevoli gen. et sp. nov., from the Late Maastrichtian of Aren (Huesca, South-central Pyrenees) is described on the basis of a partial, articulated skull, mandibular remains and postcranial elements, including vertebrae, girdle and limb bones. Arenysaurus is characterized by having a very prominent frontal dome; nearly vertical prequadratic (squamosal) and jugal (postorbital) processes, and deltopectoral crest of the humerus oriented anteriorly. Moreover, it possesses a unique combination of characters: short frontal (length/width approximately 0.5); midline ridge of parietal at level of the postorbital-squamosal bar; parietal excluded from the occiput; squamosal low above the cotyloid cavity. A phylogenetical analysis indicates that Arenysaurus is a rather basal member of Lambeosaurinae and the sister-taxon to Amurosaurus and the Corythosaurini-Parasaurolophini clade. The phylogenetic and biogeographical relationships of Arenysaurus and other lambeosaurines suggest a palaeogeographical connection between Asia and Europe during the Late Cretaceous.
Paper: The last hadrosaurid dinosaurs of Europe: A new lambeosaurine from the Uppermost Cretaceous of Aren (Huesca, Spain) (Subscription required)
AUSTRALOVENATOR WINTONENSIS
New mid-Cretaceous (late Albian) dinosaurs from Winton, Queensland, Australia. (2009)
Scott A. Hocknull, Mathew A. White, Travis R. Tischler, Alex G. Cook, Naomi D. Calleja, Trish Sloan, David A. Elliott
Abstract:
Background
Australia's dinosaurian fossil record is exceptionally poor compared
to that of other similar-sized continents. Most taxa are known
from fragmentary isolated remains with uncertain taxonomic and
phylogenetic placement. A better understanding of the Australian
dinosaurian record is crucial to understanding the global palaeobiogeography
of dinosaurian groups, including groups previously considered
to have had Gondwanan origins, such as the titanosaurs and carcharodontosaurids.
Methodology/Principal Findings
We describe three new dinosaurs from the late Early Cretaceous
(latest Albian) Winton Formation of eastern Australia, including;
Wintonotitan wattsi gen. et sp. nov., a basal titanosauriform; Diamantinasaurus matildae gen. et sp. nov., a derived lithostrotian
titanosaur; and Australovenator wintonensis gen. et sp. nov.,
an allosauroid. We compare an isolated astragalus from the Early
Cretaceous of southern Australia; formerly identified as Allosaurus sp., and conclude that it most-likely represents Australovenator sp.
Conclusion/Significance
The occurrence of Australovenator from the Aptian to latest Albian
confirms the presence in Australia of allosauroids basal to the
Carcharodontosauridae. These new taxa, along with the fragmentary
remains of other taxa, indicate a diverse Early Cretaceous sauropod
and theropod fauna in Australia, including plesiomorphic forms
(e.g. Wintonotitan and Australovenator) and more derived forms
(e.g. Diamantinasaurus).
Paper: A New Mid-Cretaceous (Latest Albian) Dinosaurs from Winton, Queensland, Australia
BAOTIANMANSAURUS HENANENSIS
A New Sauropod Dinosaur from the Late Cretaceous Gaogou Formation
of Nanyang, Henan Province
ZHANG Xingliao, LÜ Junchang, XU Li, LI Jinhua, YANG Li, HU Weiyong,
JIA Songhai, JI Qiang and ZHANG Chengjun
Abstract:
A new sauropod dinosaur Baotianmansaurus henanensis gen.
et sp. nov. from the Cretaceous Gaogou Formation of Neixiang,
Henan Province is erected. It is characterized by somphospondylous
presacral vertebrae; a highly-developed lamina system on the dorsal
vertebrae; transverse process supported by four laminae; and the
dorsal portion of the anterior centroparapophyseal lamina is bifurcated,
with a small branch extending to the ventral surface of the prezygapophysis.
It represents a new titanosauriform sauropod.
Paper: A New Sauropod Dinosaur from the Late Cretaceous Gaogou Formation of Nanyang, Henan Province (Subscription required)
BARROSASAURUS CASAMIQUELAI
A new titanosaur from the Anacleto Formation (Late Cretaceous: early Campanian) of Sierra Barrosa (Neuquén, Argentina)
Leonardo Salgado and Rodolfo A. Coria
Abstract:
A new Late Cretaceous titanosaurian sauropod from the Sierra Barrosa locality (Anacleto Formation, Late Cretaceous, early Campanian) of Neuquén Province, Argentina, Barrosasaurus casamiquelai gen. et sp. nov., is described. The
holotype of this species consists of three large and incomplete, although well-preserved, dorsal vertebrae (one probably the third, the next the seventh or eighth, and the last the ninth or tenth). The arrangement of neural arch laminae in the dorsal vertebrae of this titanosaur differs from that present in other genera in the following ways: the spinoprezygapophyseal laminae are well developed in the third vertebra, and relictual in the seventh or eighth vertebra; two spinodiapophyseal laminae are present in the seventh or eighth and in the ninth or tenth vertebrae, the anterior spinodiapophyseal lamina being more strongly developed than the posterior spinodiapophyseal lamina in the ninth or tenth vertebra. These characters, among others, allow the recognition of this individual as a new species of Titanosauria, which increases knowledge of the diversity of titanosaurs in the Late Cretaceous of Patagonia.
BEISHANLONG GRANDIS
A giant ornithomimosaur from the Early Cretaceous of China
Peter J. Makovicky, Daqing Li, Ke-Qin Gao, Matthew Lewin, Gregory M. Erickson and Mark A. Norell
Abstract:
Ornithomimosaurs (ostrich-mimic dinosaurs) are a common element
of some Cretaceous dinosaur assemblages of Asia and North America.
Here, we describe a new species of ornithomimosaur, Beishanlong
grandis, from an associated, partial postcranial skeleton
from the Aptian-Albian Xinminpu Group of northern Gansu, China. Beishanlong is similar to another Aptian-Albian ornithomimosaur, Harpymimus, with which it shares a phylogenetic position
as more derived than the Barremian Shenzhousaurus and
as sister to a Late Cretaceous clade composed of Garudimimus and the Ornithomimidae. Beishanlong is one of the largest
definitive ornithomimosaurs yet described, though histological
analysis shows that the holotype individual was still growing
at its death. Together with the co-eval and sympatric therizinosaur Suzhousaurus and the oviraptorosaur Gigantraptor, Beishanlong provides evidence for the parallel evolution
of gigantism in separate lineages of beaked and possibly herbivorous
coelurosaurs within a short time span in Central Asia.
Paper: A giant ornithomimosaur from the Early Cretaceous of China (Subscription required)
News Article: Field Museum palaeontologist leads study on two new dinosaurs from China (Science Centric)
BRACHYTRACHELOPAN MESAI
Discovery of a short-necked sauropod dinosaur from the Late Jurassic period of Patagonia. Nature Vol 435:670-672
Rauhut, O. W., 2005.
Sauropod dinosaurs are one of the most conspicuous groups of Mesozoic terrestrial vertebrates. They show general trends towards an overall increase in size and elongation of the neck, by means of considerable elongation of the length of individual vertebrae and a cervical vertebra count that, in some cases, increases to 19. The long neck is a particular hallmark of sauropod dinosaurs and is usually regarded as a key feeding adaptation. Here we describe a new dicraeosaurid sauropod, from the latest Jurassic period of Patagonia, that has a particularly short neck. With a neck that is about 40% shorter than in other known dicraeosaurs, this taxon demonstrates a trend opposite to that seen in most sauropods and indicates that the ecology of dicraeosaurids might have differed considerably from that of other sauropods. The new taxon indicates that there was a rapid radiation and dispersal of dicraeosaurids in the Late Jurassic of the Southern Hemisphere, after the separation of Gondwana from the northern continents by the late Middle Jurassic.
Paper: Discovery of a short-necked sauropod dinosaur from the Late Jurassic period of Patagonia (Subscription required)
Illustration: Nobumichi Tamura
CERATONYKUS OCULATUS
Ceratonykus oculatus gen. et sp. nov., a New Dinosaur (?Theropoda,
Alvarezsauria) from the Late Cretaceous of Mongolia
V. R. Alifanov and R. Barsbold, 2009.
Paper: Ceratonykus oculatus gen. et sp. nov., a new dinosaur (?Theropoda, Alvarezsauria) from the Late Cretaceous of Mongolia (Subscription required)
Illustration: gera_mirantsev (flickr alias)
DAXIATITAN BINGLINGI
Daxiatitan binglingi: a giant sauropod dinosaur from the Early Cretaceous of China. Gansu Geology 17(4):1-10.
You, H.-L., Li, D.-Q., Zhou, L.-Q., and Ji, Q. 2008.
.jpg)
Abstract:
A new sauropod dinosaur, Daxiatitan binglingi gen. et sp.
nov., discovered from the Lower Cretaceous Hekou Group of Lanzhou
Basin, Gansu Province, northwestern China, is unique in having
neomorphic structures in its femur, with the femoral distal condyles
beveled ~10° dorsolaterally with respect to femoral shaft
and the femoral distal condyles directed caudomedially-craniolaterally
in distal view, implying a strongly outwardly walking style. The
enormous cervical vertebrae of Daxiatitan mark it among
the largest dinosaurs in China. Cladistic analysis recovers Daxiatitan as a basal titanosaurian sauropod.
Illustration: Euhelophus (related genus) - Mitrchel Bogdanov
DIAMANTINASAURUS MATILDAE
New mid-Cretaceous (late Albian) dinosaurs from Winton, Queensland,
Australia. (2009)
Scott A. Hocknull, Mathew A. White, Travis R. Tischler, Alex G.
Cook, Naomi D. Calleja, Trish Sloan, David A. Elliott
Abstract:
Background
Australia's dinosaurian fossil record is exceptionally poor
compared to that of other similar-sized continents. Most taxa
are known from fragmentary isolated remains with uncertain taxonomic
and phylogenetic placement. A better understanding of the Australian
dinosaurian record is crucial to understanding the global palaeobiogeography
of dinosaurian groups, including groups previously considered
to have had Gondwanan origins, such as the titanosaurs and carcharodontosaurids.
Methodology/Principal Findings
We describe three new dinosaurs from the late Early Cretaceous
(latest Albian) Winton Formation of eastern Australia, including;
Wintonotitan wattsi gen. et sp. nov., a basal titanosauriform; Diamantinasaurus matildae gen. et sp. nov., a derived lithostrotian
titanosaur; and Australovenator wintonensis gen. et sp. nov.,
an allosauroid. We compare an isolated astragalus from the Early
Cretaceous of southern Australia; formerly identified as Allosaurus
sp., and conclude that it most-likely represents Australovenator sp.
Conclusion/Significance
The occurrence of Australovenator from the Aptian to latest
Albian confirms the presence in Australia of allosauroids basal
to the Carcharodontosauridae. These new taxa, along with the
fragmentary remains of other taxa, indicate a diverse Early
Cretaceous sauropod and theropod fauna in Australia, including
plesiomorphic forms (e.g. Wintonotitan and Australovenator)
and more derived forms (e.g. Diamantinasaurus).
Paper: A New Mid-Cretaceous (Latest Albian) Dinosaurs from Winton, Queensland, Australia
ELRHAZOSAURUS NIGERIENSIS
Notes on Neocomian (Lower Cretaceous) ornithopod dinosaurs from England
- Hypsilophodon, Valdosaurus, “Camptosaurus”, “Iguanodon” - and referred
specimens from Romania and elsewhere
Galton and Taquet
Abstract:
New age related individual variation for Hypsilophodon foxii, a basal euornithopod with no confirmed record outside of the Isle of Wight (late Barremian), includes an extensor groove on the distal femur that is absent and then shallow. The sequence of fusion of the neurocentral sutures follows the archosaurian caudal forwards pattern but fusion in the sacrum occurs in different sized individuals. Detailed figures are given of the form and wear patterns of the teeth. The “Iguanodon/Hypsilophodon/Polacanthus“ distal femur from Hastings (mid-Valanginian) is probably Euornithopoda indet. Large distal femora from the Isle of Wight (late Barremian) and Bedfordshire (Aptian), with an extensor groove of medium depth, are basal Iguanodontia indet. “Hypsilophodon” wielandi Galton & Jensen, 1978 (Barremian, Western USA) is basal Euornithopoda indet, not a dryosaurid ; it is not a junior synonym of probable dryosaurid “Camptosaurus” valdensis Lydekker, 1889a (late Barremian, Isle of Wight), and both taxa are nomina dubia. The record of the dryosaurid Valdosaurus, a femur of which was first described by Owen (1842) as Iguanodon, is restricted to England (Sussex, middle Valanginian ; Isle of Wight, late Barremian). Based on differences in horizon and form of the femur, Elrhazosaurus n. gen. is erected for the dryosaurid Valdosaurus nigeriensis Galton & Taquet, 1982 (Aptian, Niger). The holotype dentary of Iguanodon hoggii Owen, 1874 from Dorset (middle Berriasian) is made the type species of the new non-camptosaurid genus Owenodon ; a femur referred to “Camptosaurus” hoggii from Dorset is Iguanodontoidea indet. A small dentary from the Isle of Wight (late Barremian) is not Valdosaurus but basal Iguanodontoidea indet. An incomplete hindlimb (with tibia showing a very large callus from a healed fracture) of “Camptosaurus” hoggii from Yorkshire (mid-Berriasian) is very similar to that of “Iguanodon” hollingtoniensis Lydekker, 1889b, the femur of which is Camptosaurus-like except for the Iguanodon-like distal end. This species represents a new genus of basal Iguanodontoidea, but its diagnosis must await a review of all Sussex Wadhurst Clay (middle Valanginian) material. Dentary teeth of Owenodon sp. occur in the bauxite fissure fill (Berriasian-Valanginian) of Cornet, Romania. The bones more derived than those of Camptosaurus but not Styracosterna or Iguanodontea (which is represented by metacarpal II, ungual phalanges) are tentatively referred to Owenodon sp. These include a maxilla and teeth, cervical vertebra 6, fused medial carpals+metacarpal I, distal femora (and, tentatively, a frontal, a braincase, a dorso-sacral centrum, larger humerus). A smaller humerus is basal Euornithopoda indet, but most of the described bones are Euornithopoda indet. The possible stegosaurian pubis from the Isle of Wight (late Barremian) is basal
Iguanodontoidea indet.
HELIOCERATOPS
BRACHYGNATHUS
A New Basal Neoceratopsian Dinosaur from the Middle Cretaceous of
Jilin Province, China
JIN Liyong, CHEN Jun, ZAN Shuqin and Pascal GODEFROIT
Abstract:
A new basal neoceratopsian dinosaur, Helioceratops brachygnathus gen. et sp. nov., is described from the Quantou Formation (late
Early Cretaceous or early Late Cretaceous) in the Liufangzi locality
(Jilin province, China). Helioceratops differs from other
basal neoceratopsians with its deep dentary ramus, its steeply-inclined
ventral predentary facet, its heterogeneous dentary crowns, and
by the denticles and secondary ridges asymmetrically distributed
on either side of the primary ridge on its dentary teeth. Along
with Auroraceratops and Yamaceratops, Helioceratops represents one of the most derived non-coronosaurian neoceratopsians.
The palaeogeographical distribution of basal neoceratopsians appears
limited to northern China and southern Mongolia in the current
state of our knowledge. It is therefore probable that this region
constituted the birthplace for more advanced, Late Cretaceous
Coronosauria.
Paper: A New Basal Neoceratopsian Dinosaur from the Middle Cretaceous of Jilin Province, China (Subscription required)
HESPERONYCHUS ELIZABETHAE
A microraptorine (Dinosauria-Dromaeosauridae) from the Late Cretaceous
of North America
Nicholas R. Longricha and Philip J. Currie
Abstract:
The fossil assemblages of the Late Cretaceous of North America
are dominated by large-bodied dinosaur species. Associated skeletons
of small dinosaurs are exceedingly rare, and small (<10 kg) carnivorous
theropods have not previously been reported from these beds. Here,
we describe a small dromaeosaurid from the 75-million-year-old
Dinosaur Park Formation of Alberta, Canada. Hesperonychus
elizabethae gen. et sp. nov. is represented by a pelvic girdle
from an animal weighing 1,900 g. Despite its size, the pubes and
ilia are coossified, indicating that the animal was somatically
mature. This is the smallest carnivorous, nonavian dinosaur known
from North America. Phylogenetic analysis of Hesperonychus reveals that it is not closely related to previously described
North American dromaeosaurids. Instead, Hesperonychus is a member of the dromaeosaurid clade Microraptorinae, a group
containing the 4-winged Microraptor and the feathered Sinornithosaurus, both from the Lower Cretaceous Jehol
Group of China. Hesperonychus is the youngest known member
of this lineage, extending the temporal range of the clade by
45 million years, and it is the first microraptorine known from
North America, providing further evidence for an affinity between
the dinosaur faunas of North America and Asia. Study of fossil
collections from the Dinosaur Park and Oldman formations of Alberta
has revealed numerous isolated bones of small, basal dromaeosaurids,
which are tentatively referred to Hesperonychus. These
fossils suggest that small dromaeosaurids were a significant component
of the carnivore community in this Late Cretaceous biota.
University of Calgary press release: Velociraptor's little cousin
Full paper: A microraptorine (Dinosauria-Dromaeosauridae) from the Late Cretaceous of North America (Subscription required)
JINTASAURUS MENISCUS
A new basal hadrosauriform dinosaur (Ornithischia: Iguanodontia) from the Early Cretaceous of northwestern China
Hai-Lu You; and Da-Qing Li
Abstract:
A new hadrosauriform dinosaur, Jintasaurus meniscus gen. et sp. nov., is reported from the Lower Cretaceous Xinminpu Group of the Yujingzi Basin, Jiuquan area, Gansu Province, northwestern China. It is represented by an articulated posterior portion of the skull and is unique in having an extremely long, pendant and crescentic paroccipital process with its ventral tip projecting far beyond the ventral level of the occipital condyle. Phylogenetic analysis recovers Jintasaurus as the sister-taxon to Hadrosauroidea, more derived than other Early Cretaceous hadrosauriforms and Protohadros from the early Late Cretaceous of North America. This discovery adds one more close relative to Hadrosauroidea in Asia and supports an Asian origin for this group.
Paper: A new basal hadrosauriform dinosaur (Ornithischia: Iguanodontia) from the Early Cretaceous of northwestern China (Subscription required)
KEMKEMIA AUDITOREI
A new theropod dinosaur, represented by a single unusual caudal vertebra from the Kem Kem Beds (Cretaceous) of Morocco
Cau, Andrea; Maganuco, Simone (2009).
Abstract:
Abstract: We describe a near-complete distal caudal vertebra from an Upper Cretaceous theropod, discovered in the Kem Kem Beds (Cenomanian) of Tafi lalt, Morocco. The specimen exhibits an extremely unusual combination of features , and we herein erect a new species, Kemkemia auditorei gen. et sp. nov. The specimen differs from other theropod distal caudal vertebrae in the presence of a relatively inflated neural canal, strongly reduced zygapophyses, a low but very robust neural spine bearing shallow lateral fossae, a mediolaterally concave dorsal surface of the neural spine, and coalescence of the postzygapophyses in a position more proximal than the region where neural spines are absent. Although Kemkemia shares some derived features with neoceratosaurs, we provisionally refer it to Neotheropoda incertae sedis, pending the discovery of more complete material. Several distal caudal vertebrae from the Maastricthian of India are similar to Kemkemia, and may belong to a closely related taxon.
KINNAREEMIMUS KHONKAENENSIS
An early 'ostrich dinosaur' (Theropoda: Ornithomimosauria) from the Early Cretaceous Sao Khua Formation of NE Thailand
Buffetaut, E., V. Suteethorn & H. Tong. 2009.
Abstract:
Abstract: Postcranial remains of a small theropod dinosaur, including
vertebrae, incomplete pubes, tibiae, an incomplete fibula, metatarsals
and phalanges, from the Early Cretaceous Sao Khua Formation of
Phu Wiang, Khon Kaen Province, NE Thailand, are described as a
new taxon of ornithomimosaur, Kinnareemimus khonkaenensis, gen.
et sp. nov. This early 'ostrich dinosaur' is characterized by
a fairly advanced metatarsus, in which metatarsal III, although
still visible proximally between metatarsals II and IV in cranial
view, is markedly 'pinched' more distally and becomes triangular
in cross-section. The condition of its metatarsus shows that Kinnareemimus
khonkaenensis is more derived than the geologically younger primitive
ornithomimosaurs Harpymimus and Garudimimus, but less derived
than Archaeornithomimus. Its occurrence in the Early Cretaceous
of Thailand suggests that advanced ornithomimosaurs may have originated
in Asia.
Etymology: From Kinnaree, graceful beings of Thai mythology, with
the body of a woman and the legs of a bird, said to inhabit the
depths of the legendary Himmapan Forest, by allusion to the bird-like
feet of this dinosaur.
KOL GHUVA
A Large Alvarezsaurid from the Cretaceous of Mongolia
Alan H. Turner, Sterling J. Nesbitt, and Mark A. Norell (2009).
Abstract:
We report a new alvarezsaurid, Kol ghuva, from the Late Cretaceous
of Mongolia that demonstrates that the clade was not restricted to
small taxa (3–15 kg). The specimen was found at the Ukhaa Tolgod
locality, which has previously produced only a single diminutive
alvarezsaurid, Shuvuuia deserti. Although known only from a
well-preserved right foot, the new taxon is diagnosable by the
following combination of characters: extensor grooves on digit IV
phalanges; robust flexor tubercle on pedal unguals; MT III does
not reach ankle; accessory dorsomedial flange absent on the medial
side of the distal end of the MT II; MT II shorter than MT IV; and
MT III extends higher proximally than other alvarezsaurids (more than
½ total metatarsus length). The new taxon provides additional insight
into the diversity of this clade and the dinosaurian assemblage of Ukhaa Tolgod.
Paper: A Large Alvarezsaurid from the Cretaceous of Mongolia (Subscription required)
LESHANSAURUS QIANWEIENSIS
A new carnosaur from the Late Jurassic of Qianwei, Sichuan, China
F. Li; Peng G.; Ye Y.; Jiang S.; and Huang, D.
Abstract:
Based on new material from the top of the Late Jurassic Shangshaximiao Formation of Xiaogu,Qianwei County, southwestern Sichuan Basin, a new sinraptorid carnosaur Leshansaurus qianweiensis gen.et sp.nov. is erected. It is distinguished from other carnosaurs by supraoccipital with a sharp midline ridge;relatively longer frontal with a ratio of the maximum length to the maximum width about 2.4; basipterygoid processes of basisphenoid slender;atlantal intercentrum horseshoe-shaped; diapophyses of dorsal vertebrae relatively slender; neural spines of dorsal and sacral vertebrae very thin; ventral keel of sacral vertebrae distinctly defined; ilium with a conspicuous ridge medially along acetabular edge. This new dinosaur was the latest carnosaur presently known in Sichuan Basin. Its discovery extends the horizontal and geographical distributions of the carnosaurs in Sichuan Basin,and is significant in the evolution of the carnosaurs.
Paper: A New Carnosaur from the Late Jurassic of Qianwei, Sichuan, China (Subscription required)
LEVNESOVIA TRANSOXIANA
A new basal hadrosauroid dinosaur from the Late Cretaceous of Uzbekistan and the early radiation of duck-billed dinosaurs
Hans-Dieter Sues and Alexander Averianov
Abstract:
Levnesovia transoxiana gen. et sp. nov., from the Late
Cretaceous (Middle–Late Turonian) of Uzbekistan, is the oldest
well-documented taxon referable to Hadrosauroidea sensu Godefroit et al. It differs from a somewhat younger and
closely related Bactrosaurus from Inner Mongolia (China)
by a tall sagittal crest on the parietals and the absence of club-shaped
dorsal neural spines in adult specimens. Levnesovia, Bactrosaurus and possibly Gilmoreosaurus represent
the earliest radiation of Hadrosauroidea, which took place during
the Cenomanian–Turonian and possibly in North America. The second,
Santonian-age radiation of Hadrosauroidea included Aralosaurus,
Hadrosauridae and lineages leading to Tanius (Campanian)
and Telmatosaurus (Maastrichtian). Hadrosauridae appears
to be monophyletic, but Hadrosaurinae and Lambeosaurinae originated
in North America and Asia, respectively.
Paper: A new basal hadrosauroid dinosaur from the Late Cretaceous of Uzbekistan and the early radiation of duck-billed dinosaurs (Subscription required)
LIMUSAURUS INEXTRICABILIS
A Jurassic ceratosaur from China helps clarify avian digital homologies
Xu, X., Clark, J.M., Mo, J., Choiniere, J., Forster, C.A., Erickson, G.M., Hone, D.W.E., Sullivan, C., Eberth, D.A., Nesbitt, S., Zhao, Q., Hernandez, R., Jia, C.-K., Han, F.-L., and Guo, Y.
Abstract:
Theropods have traditionally been assumed to have lost manual digits from the lateral side inward, which differs from the bilateral reduction pattern seen in other tetrapod groups. This unusual reduction pattern is clearly present in basal theropods, and has also been inferred in non-avian tetanurans based on identification of their three digits as the medial ones of the hand (I-II-III). This contradicts the many developmental studies indicating II-III-IV identities for the three manual digits of the only extant tetanurans, the birds. Here we report a new basal ceratosaur from the Oxfordian stage of the Jurassic period of China (156–161 million years ago), representing the first known Asian ceratosaur and the only known beaked, herbivorous Jurassic theropod. Most significantly, this taxon possesses a strongly reduced manual digit I, documenting a complex pattern of digital reduction within the Theropoda. Comparisons among theropod hands show that the three manual digits of basal tetanurans are similar in many metacarpal features to digits II-III-IV, but in phalangeal features to digits I-II-III, of more basal theropods. Given II-III-IV identities in avians, the simplest interpretation is that these identities were shared by all tetanurans. The transition to tetanurans involved complex changes in the hand including a shift in digit identities, with ceratosaurs displaying an intermediate condition.
Paper: A Jurassic ceratosaur from China helps clarify avian digital homologies (Subscription required)
MALARGEUSAURUS FLORENCIAE
Malarguesaurus florenciae gen. et sp. nov., a new titanosauriform (Dinosauria, Sauropoda) from the Upper Cretaceous of Mendoza, Argentina
González Riga, Bernardo J.; Previtera, Elena; and Pirrone, Cecilia A.
Abstract:
Malarguesaurus florenciae gen. et sp. nov. is a new and robust somphospondylian titanosauriform (Dinosauria, Sauropoda) from the Neuquén basin, Mendoza Province, Argentina. The specimen comes from Upper Cretaceous strata assigned to the Portezuelo Formation (upper Turonian-lower Coniacian). It includes proximal, middle and distal caudal vertebrae, chevrons, dorsal ribs, and appendicular bones. Malarguesaurus is characterized by the following association of characters: (1) proximal caudal neural spines vertically directed, with a concave caudal border, and a caudodorsal corner forming a right angle; (2) procoelous-opisthoplatyan proximal and middle caudal vertebrae associated with procoelous distal caudal centra; and (3) distal caudal neural spines having a concave and depressed dorsal border. A preliminar cladistic analysis placed (Ligabuesaurus + (Malarguesaurus + Phuwiangosaurus)) as a sister taxon of Titanosauria. Unique among the titanosauriforms, Malarguesaurus has procoelous distal caudal centra associated with procoelous-opisthoplatyan proximal caudals. This discovery is a new evidence of the morphologic diversity of the South American sauropods.
Paper: Malarguesaurus florenciae gen. et sp. nov., a new titanosauriform (Dinosauria, Sauropoda) from the Upper Cretaceous of Mendoza, Argentina (Subscription required)
MINOTAURASAURUS RAMANCHANDRANI
Skull of Minotaurasaurus ramachandrani, a new Cretaceous ankylosaur from the Gobi Desert. Current Science 96 (1): 65-70.
Miles, C.A. & C.J. Miles, 2009.
Abstract:
A new genus and species of ankylosaurid, a dinosaur from the Upper
Cretaceous of the Gobi Desert has been described. It shows characters
typical of many Late Cretaceous ankylosaurs. The new specimen
is a virtually complete skull with both hemimandibles preserved
intact with the predentary. This skull has been subjected to almost
no crushing or shearing. It has an equilateral, triangular-shaped
skull when viewed dorsally and large, highly ornamented narial
osteoderms, which give the skull a bull-like appearance with flaring
nostrils. Braincase features are more primitive than those of
the other Gobi Desert ankylosaurs.
Paper: Skull of Minotaurasaurus ramachandrani, a new Cretaceous ankylosaur from the Gobi Desert (Direct to PDF)
Illustration: Wikipteryx (Wiki alias), Public Domain
MIRAGAIA LONGICOLLUM
A new long-necked 'sauropod-mimic' stegosaur and the evolution of the plated dinosaurs
Octávio Mateus, Susannah C.R Maidment and Nicolai A Christiansen
Abstract:
Stegosaurian dinosaurs have a quadrupedal stance, short forelimbs,
short necks, and are generally considered to be low browsers.
A new stegosaur, Miragaia longicollum gen. et sp. nov.,
from the Late Jurassic of Portugal, has a neck comprising at least
17 cervical vertebrae. This is eight additional cervical vertebrae
when compared with the ancestral condition seen in basal ornithischians
such as Scutellosaurus. Miragaia has a higher cervical
count than most of the iconically long-necked sauropod dinosaurs.
Long neck length has been achieved by 'cervicalization' of anterior
dorsal vertebrae and probable lengthening of centra. All these
anatomical features are evolutionarily convergent with those exhibited
in the necks of sauropod dinosaurs. Miragaia longicollum is based upon a partial articulated skeleton, and includes the
only known cranial remains from any European stegosaur. A well-resolved
phylogeny supports a new clade that unites Miragaia and Dacentrurus as the sister group to Stegosaurus;
this new topology challenges the common view of Dacentrurus as a basal stegosaur.
Full paper: A new long-necked 'sauropod-mimic' stegosaur and the evolution of the plated dinosaurs
Illustration: Octávio Mateus, Susannah C.R Maidment and Nicolai A Christiansen
OWENDEN HOGGII
Notes on Neocomian (Lower Cretaceous) ornithopod dinosaurs from England
- Hypsilophodon, Valdosaurus, “Camptosaurus”, “Iguanodon” - and referred
specimens from Romania and elsewhere
Galton and Taquet
Abstract:
New age related individual variation for Hypsilophodon foxii, a basal euornithopod with no confirmed record outside of the Isle of Wight (late Barremian), includes an extensor groove on the distal femur that is absent and then shallow. The sequence of fusion of the neurocentral sutures follows the archosaurian caudal forwards pattern but fusion in the sacrum occurs in different sized individuals. Detailed figures are given of the form and wear patterns of the teeth. The “Iguanodon/Hypsilophodon/Polacanthus“ distal femur from Hastings (mid-Valanginian) is probably Euornithopoda indet. Large distal femora from the Isle of Wight (late Barremian) and Bedfordshire (Aptian), with an extensor groove of medium depth, are basal Iguanodontia indet. “Hypsilophodon” wielandi Galton & Jensen, 1978 (Barremian, Western USA) is basal Euornithopoda indet, not a dryosaurid ; it is not a junior synonym of probable dryosaurid “Camptosaurus” valdensis Lydekker, 1889a (late Barremian, Isle of Wight), and both taxa are nomina dubia. The record of the dryosaurid Valdosaurus, a femur of which was first described by Owen (1842) as Iguanodon, is restricted to England (Sussex, middle Valanginian ; Isle of Wight, late Barremian). Based on differences in horizon and form of the femur, Elrhazosaurus n. gen. is erected for the dryosaurid Valdosaurus nigeriensis Galton & Taquet, 1982 (Aptian, Niger). The holotype dentary of Iguanodon hoggii Owen, 1874 from Dorset (middle Berriasian) is made the type species of the new non-camptosaurid genus Owenodon ; a femur referred to “Camptosaurus” hoggii from Dorset is Iguanodontoidea indet. A small dentary from the Isle of Wight (late Barremian) is not Valdosaurus but basal Iguanodontoidea indet. An incomplete hindlimb (with tibia showing a very large callus from a healed fracture) of “Camptosaurus” hoggii from Yorkshire (mid-Berriasian) is very similar to that of “Iguanodon” hollingtoniensis Lydekker, 1889b, the femur of which is Camptosaurus-like except for the Iguanodon-like distal end. This species represents a new genus of basal Iguanodontoidea, but its diagnosis must await a review of all Sussex Wadhurst Clay (middle Valanginian) material. Dentary teeth of Owenodon sp. occur in the bauxite fissure fill (Berriasian-Valanginian) of Cornet, Romania. The bones more derived than those of Camptosaurus but not Styracosterna or Iguanodontea (which is represented by metacarpal II, ungual phalanges) are tentatively referred to Owenodon sp. These include a maxilla and teeth, cervical vertebra 6, fused medial carpals+metacarpal I, distal femora (and, tentatively, a frontal, a braincase, a dorso-sacral centrum, larger humerus). A smaller humerus is basal Euornithopoda indet, but most of the described bones are Euornithopoda indet. The possible stegosaurian pubis from the Isle of Wight (late Barremian) is basal
Iguanodontoidea indet.
NOTHRONYCHUS GRAFFAMI
A new North American therizinosaurid and the role of herbivory in
‘predatory’ dinosaur evolution
Lindsay E. Zanno, David D. Gillette, L. Barry Albright and Alan
L. Titus
Abstract:
Historically, ecomorphological inferences regarding theropod (i.e.
‘predatory’) dinosaurs were guided by an assumption that they
were singularly hypercarnivorous. A recent plethora of maniraptoran
discoveries has produced evidence challenging this notion. Here,
we report on a new species of maniraptoran theropod, Nothronychus
graffami sp. nov. Relative completeness of this specimen permits
a phylogenetic reassessment of Therizinosauria—the theropod clade
exhibiting the most substantial anatomical evidence of herbivory.
In the most comprehensive phylogenetic study of the clade conducted
to date, we recover Therizinosauria as the basalmost maniraptoran
lineage. Using concentrated changes tests, we present evidence
for correlated character evolution among herbivorous and hypercarnivorous
taxa and propose ecomorphological indicators for future interpretations
of diet among maniraptoran clades. Maximum parsimony optimizations
of character evolution within our study indicate an ancestral
origin for dietary plasticity and facultative herbivory (omnivory)
within the clade. These findings suggest that hypercarnivory in
paravian dinosaurs is a secondarily derived dietary specialization
and provide a potential mechanism for the invasion of novel morpho-
and ecospace early in coelurosaurian evolution—the loss of obligate
carnivory and origin of dietary opportunism.
Paper: A new North American therizinosaurid and the role of herbivory in ‘predatory’ dinosaur evolution
PANPHAGIA PROTOS
A Basal Sauropodomorph (Dinosauria: Saurischia) from the Ischigualasto Formation (Triassic, Carnian) and the Early Evolution of Sauropodomorpha
Ricardo N. Martinez, Oscar A. Alcober
Museo de Ciencias Naturales, San Juan, Argentina
Background:
The earliest dinosaurs are from the early Late Triassic (Carnian)
of South America. By the Carnian the main clades Saurischia and
Ornithischia were already established, and the presence of the
most primitive known sauropodomorph Saturnalia suggests
also that Saurischia had already diverged into Theropoda and Sauropodomorpha.
Knowledge of Carnian sauropodomorphs has been restricted to this
single species.
Methodology/Principal Findings:
We describe a new small sauropodomorph dinosaur from the Ischigualsto
Formation (Carnian) in northwest Argentina, Panphagia protos gen. et sp. nov., on the basis of a partial skeleton. The genus
and species are characterized by an anteroposteriorly elongated
fossa on the base of the anteroventral process of the nasal; wide
lateral flange on the quadrate with a large foramen; deep groove
on the lateral surface of the lower jaw surrounded by prominent
dorsal and ventral ridges; bifurcated posteroventral process of
the dentary; long retroarticular process transversally wider than
the articular area for the quadrate; oval scars on the lateral
surface of the posterior border of the centra of cervical vertebrae;
distinct prominences on the neural arc of the anterior cervical
vertebra; distal end of the scapular blade nearly three times
wider than the neck; scapular blade with an expanded posterodistal
corner; and medial lamina of brevis fossa twice as wide as the
iliac spine.
Conclusions/Significance:
We regard Panphagia as the most basal sauropodomorph, which
shares the following apomorphies with Saturnalia and more
derived sauropodomorphs: basally constricted crowns; lanceolate
crowns; teeth of the anterior quarter of the dentary higher than
the others; and short posterolateral flange of distal tibia. The
presence of Panphagia at the base of the early Carnian
Ischigualasto Formation suggests an earlier origin of Sauropodomorpha
during the Middle Triassic.
Full paper: A Basal Sauropodomorph (Dinosauria: Saurischia) from the Ischigualasto Formation (Triassic, Carnian) and the Early Evolution of Sauropodomorpha (Public)
Illustration: Ricardo N. Martinez and Oscar A. Alcober
QIAOWANLONG KANGXII
The first well-preserved Early Cretaceous brachiosaurid dinosaur in Asia
You, H.-L. and Li, D.-Q.
Abstract:
A new genus and species of brachiosaurid sauropods, Qiaowanlong kangxii gen. et sp. nov., is reported, representing the first well-preserved Early Cretaceous brachiosaurid in Asia and expanding the distribution of brachiosaurids undoubtedly into the Asian continent. The new taxon was recovered from the late Early Cretaceous Xinminpu Group of Yujingzi Basin in northwestern Gansu Province, China, and is represented by a series of eight mid-cervical vertebrae, a right pelvic girdle and some unidentified bones. The existence of deeply excavated cervical neural spines and a rising transition in the neural spine height among mid-cervical vertebrae clearly show the affinity of Qiaowanlong as a member of brachiosaurids. Among brachiosaurids, Qiaowanlong shares a derived feature with the North American Early Cretaceous brachiosaurid Sauroposeidon: the lack of cranial centrodiapophyseal lamina. However, Qiaowanlong is unique in possessing a suite of features, such as a low central length/cotyle height ratio, bifurcated cervical neural spines and a much reduced ischium. The discovery of Qiaowanlong and other new material indicates a diverse and abundant sauropod assemblage in China during the Early Cretaceous.
Paper: The first well-preserved Early Cretaceous brachiosaurid dinosaur in Asia (Subscription required)
PSITTACOSAURUS GOBIENSIS
A new psittacosaur from Inner Mongolia and the parrot-like structure
and function of the psittacosaur skull. Proceedings of the Royal Society
B, June 17, 2009
You, H.-L., Li, D.-Q., Zhou, L.-Q., and Ji, Q. 2008.
Abstract:
We describe a new species of psittacosaur, Psittacosaurus gobiensis,
from the Lower Cretaceous of Inner Mongolia and outline a hypothesis
of chewing function in psittacosaurs that in many respects parallels
that in psittaciform birds. Cranial features that accommodate increased
bite force in psittacosaurs include an akinetic skull (both cranium
and lower jaws) and differentiation of adductor muscle attachments
comparable to that in psittaciform birds. These and other features,
along with the presence of numerous large gastroliths, suggest that
psittacosaurs may have had a high-fibre, nucivorous (nut-eating)
diet. Psittacosaurs, alone among ornithischians, generate oblique
wear facets from tooth-to-tooth occlusion without kinesis in either
the upper or lower jaws. This is accomplished with a novel isognathous
jaw mechanism that combines aspects of arcilineal (vertical) and
propalinal (horizontal) jaw movement. Here termed clinolineal (inclined)
jaw movement, the mechanism uses posteriorly divergent tooth rows,
rather than kinesis, to gain the added width for oblique occlusion.
As the lower tooth rows are drawn posterodorsally into occlusion,
the increasing width between the upper tooth rows accommodates oblique
shear. With this jaw mechanism, psittacosaurs were able to maintain
oblique shearing occlusion in an akinetic skull designed to resist
high bite forces.
Paper: A new psittacosaur from Inner Mongolia and the parrot-like structure and function of the psittacosaur skull (Subscription required)
Illustration: Todd Marshall
RAPTOREX KRIEGSTEINI
Tyrannosaurid skeletal design first evolved at small body size
Sereno, P.; Tan, L.; Brusatte, S. L.; Kriegstein, H. J.; Zhao, X. & Cloward, K.
Abstract:
Nearly all of the large-bodied predators (>2.5 tons) on northern continents during the Late Cretaceous were tyrannosaurid dinosaurs. We show that their most conspicuous functional specializations—a proportionately large skull, incisiform premaxillary teeth, expanded jaw-closing musculature, diminutive forelimbs, and hindlimbs with cursorial proportions—were present in a new, small-bodied, basal tyrannosauroid from Lower Cretaceous rocks in northeastern China. These specializations, which were later scaled up in Late Cretaceous tyrannosaurids with body masses approaching 100 times greater, drove the most dominant radiation of macropredators of the Mesozoic.
Paper: Tyrannosaurid Skeletal Design First Evolved at Small Body Size (Subscription required)
RUYANGOSAURUS GIGANTEUS
A new gigantic sauropod dinosaur from the Cretaceous of Ruyang, Henan, China.
Lu J, Xu L, Jia S, Zhang X, Zhang J, Yang L, You H, Ji Q. 2009.
Abstract:
The new gigantic sauropod dinosaur Ruyangosaurus giganteus gen. et sp. nov. from the early Late Cretaceous Mangchuan Formation
of Ruyang, Henan, China is described. It is characterized by a
lower neural spine, lack of centroprezygoapophyseal lamina, a
large, irregularly triangular deep fossa on the lateral surface
of the neural arch, the prezygodiapophyseal lamina oriented anteroposteriorly,
and a robust tibia, some 127 cm in length. The discovery of Ruyangosaurus
indicates that a higher diversity of sauropod dinosaurs occurred
during the early Late Cretaceous than previously thought.
SHAOCHILONG MAORTUENSIS
The first definitive carcharodontosaurid (Dinosauria: Theropoda) from Asia and the delayed ascent of tyrannosaurids
Brusatte, S., Benson, R., Chure, D., Xu, X., Sullivan, C., and Hone, D. (2009)
Abstract:
Little is known about the evolution of large-bodied theropod dinosaurs
during the Early to mid Cretaceous in Asia. Prior to this time,
Asia was home to an endemic fauna of basal tetanurans, whereas
terminal Cretaceous ecosystems were dominated by tyrannosaurids,
but the intervening 60 million years left a sparse fossil record.
Here, we redescribe the enigmatic large-bodied Chilantaisaurus
maortuensis from the Turonian of Inner Mongolia, China. We
refer this species to a new genus, Shaochilong, and analyze
its systematic affinities. Although Shaochilong has previously
been allied with several disparate theropod groups (Megalosauridae,
Allosauridae, Tyrannosauroidea, Maniraptora), we find strong support
for a derived carcharodontosaurid placement. As such, Shaochilong is the first unequivocal Asian member of Carcharodontosauridae,
which was once thought to be restricted to Gondwana. The discovery
of an Asian carcharodontosaurid indicates that this clade was
cosmopolitan in the Early to mid Cretaceous and that Asian large-bodied
theropod faunas were no longer endemic at this time. It may also
suggest that the ascent of tyrannosaurids into the large-bodied
dinosaurian predator niche was a late event that occurred towards
the end of the Cretaceous, between the Turonian and the Campanian.
SHIDAISAURUS JINAE
A New Theropod Dinosaur from the Middle Jurassic of Lufeng, Yunnan, China
Wu Xiao-chun, Philip J. Currie, Dong Zhiming, Pan Shigang and Wang Tao
Abstract:
A new theropod dinosaur, Shidaisaurus jinae gen. et sp.
nov., has been described on the basis of an incomplete skeleton.
The specimen was found near the base of the Upper Lufeng Formation
(early Middle Jurassic) in Yunnan, China. It is the first theropod
dinosaur from the Middle Jurassic of Yunnan. Shidaisaurus jinae is distinguishable from other Jurassic theropods by certain features
from the braincase, axis, and pelvic girdle. The absence of any
pleurocoels in the axis or in any anterior dorsal vertebrae suggests
that the new Lufeng theropod is relatively primitive and more
plesiomorphic than most of the Middle to Late Jurassic theropods
from China. Most Chinese taxa of Jurassic theropod dinosaurs have
not been well described; a further detailed study will be necessary
for us to determine their phylogenetic relationships with Shidaisaurus
jinae.
Full paper: A New Theropod Dinosaur from the Middle Jurassic of Lufeng, Yunnan, China
SKORPIOVENATOR BUSTINGORRYI
New carnivorous dinosaur from the Late Cretaceous of NW Patagonia and the evolution of abelisaurid theropods
Juan I. Canale, Carlos A. Scanferla, Federico L. Agnolin and Fernando E. Novas
Abstract:
A nearly complete skeleton of the new abelisaurid Skorpiovenator bustingorryi is reported here. The holotype was found in Late Cenomanian–Early Turonian outcrops of NW Patagonia, Argentina. This new taxon is deeply nested within a new clade of South American abelisaurids, named Brachyrostra. Within brachyrostrans, the skull shortening and hyperossification of the skull roof appear to be correlated with a progressive enclosure of the orbit, a set of features possibly related to shock-absorbing capabilities. Moreover, the development of horn-like structures and differential cranial thickening appear to be convergently acquired within Abelisauridae. Based on the similarities between Skorpiovenator and carcharodontosaurid tooth morphology, we suggest that isolated teeth originally referred as post-Cenomanian Carcharodontosauridae most probably belong to abelisaurids.
Paper: New carnivorous dinosaur from the Late Cretaceous of NW Patagonia and the evolution of abelisaurid theropods (Subscription required)
SPINOPHOROSAURUS NIGERENSIS
A new basal sauropod dinosaur from the Middle Jurassic of Niger and the early evolution of sauropoda
Kristian Remes, Francisco Ortega, Ignacio Fierro, Ulrich Joger, Ralf Kosma, José Manuel Marín Ferrer, for the Project PALDES, for the Niger Project SNHM, Oumarou Amadou Ide, Abdoulaye Maga
Abstract:
Background
The early evolution of sauropod dinosaurs is poorly understood because of a highly incomplete fossil record. New discoveries of Early and Middle Jurassic sauropods have a great potential to lead to a better understanding of early sauropod evolution and to reevaluate the patterns of sauropod diversification.
Principal Findings
A new sauropod from the Middle Jurassic of Niger, Spinophorosaurus nigerensis n. gen. et sp., is the most complete basal sauropod currently known. The taxon shares many anatomical characters with Middle Jurassic East Asian sauropods, while it is strongly dissimilar to Lower and Middle Jurassic South American and Indian forms. A possible explanation for this pattern is a separation of Laurasian and South Gondwanan Middle Jurassic sauropod faunas by geographic barriers. Integration of phylogenetic analyses and paleogeographic data reveals congruence between early sauropod evolution and hypotheses about Jurassic paleoclimate and phytogeography.
Conclusions
Spinophorosaurus demonstrates that many putatively derived characters of Middle Jurassic East Asian sauropods are plesiomorphic for eusauropods, while South Gondwanan eusauropods may represent a specialized line. The anatomy of Spinophorosaurus indicates that key innovations in Jurassic sauropod evolution might have taken place in North Africa, an area close to the equator with summer-wet climate at that time. Jurassic climatic zones and phytogeography possibly controlled early sauropod diversification.
Full paper: A New Basal Sauropod Dinosaur from the Middle Jurassic of Niger and the Early Evolution of Sauropoda (Full paper)
TATANKACEPHALUS COONEYORUM
A new ankylosaur from the Lower Cretaceous Cloverly Formation of central Montana
Parsons, W.L., and Parsons, K.M.
Abstract:
A cranium and other associated skeletal elements representing a new ankylosaurid dinosaur, Tatankacephalus cooneyorum gen. et sp. nov. possess several diagnostic features that indicate that this new taxon differs from the only other known ankylosaur from the Cloverly Formation, Sauropelta edwardsorum. These features include a frontoparietal dome, an enlarged nuchal ridge that obscures the occipital region, a circular orbit, ventral curvature in the posterolaterally directed paroccipital processes, a posteroventrally directed foramen magnum, and a number of features on the braincase. The phylogenetic analysis positions Tatankacephalus with Ankylosauridae based on its sharing of several characters with other members of this clade, including an enlarged nuchal segment that obscures the occiput in dorsal view, a ventrally curving lateral profile of the cranium anterior to the orbit, pyramidal postorbital boss, laterally projecting pyramidal quadratojugal boss, the presence of a postocular shelf, the presence of paranasal sinuses, and the lack of a cingulum on a maxillary (or dentary) tooth. It is considered a basal member of Ankylosauridae because it retains premaxillary teeth and a visible lateral temporal fenestra, in contrast to the absence of premaxillary teeth and an obscured lateral temporal fenestra in younger members of this clade.
Paper: A new ankylosaur from the Lower Cretaceous Cloverly Formation of central Montana (Subscription required)
TAWA HALLAE
A Complete Skeleton of a Late Triassic Saurischian and the Early Evolution of Dinosaurs
Sterling J. Nesbitt, Nathan D. Smith, Randall B. Irmis, Alan H. Turner, Alex Downs, Mark A. Norell
Abstract:
Characterizing the evolutionary history of early dinosaurs is central to understanding their rise and diversification in the Late Triassic. However, fossils from basal lineages are rare. A new theropod dinosaur from New Mexico is a representative of the early North American diversification. Known from several nearly complete skeletons, it reveals a mosaic of plesiomorphic and derived features that clarify early saurischian dinosaur evolution and provide evidence for the antiquity of novel avian character systems including skeletal pneumaticity. The taxon further reveals latitudinal differences among saurischian assemblages during the Late Triassic, demonstrates that the theropod fauna from the Late Triassic of North America was not endemic, and suggests that intercontinental dispersal was prevalent during this time.
Paper: A Complete Skeleton of a Late Triassic Saurischian and the Early Evolution of Dinosaurs (Subscription required)
TETHYSHADROS INSULARIS
Tethyshadros insularis, a new hadrosauroid dinosaur (Ornithischia) from the Upper Cretaceous of Italy
Dalla Vecchia, F. M.
Abstract:
An articulated skeleton of a hadrosauroid dinosaur, Tethyshadros insularis n. gen., n. sp., was recovered from the Liburnian Formation (uppermost Cretaceous) of Villaggio del Pescatore in the Trieste Province of northeastern Italy. One of the most complete dinosaur fossil ever found, it shows for the first time the entire morphology of a hadrosauroid phylogenetically close to, but outside the North American and Asiatic hadrosaurids. It lived on an island developed on a carbonate platform in the Tethys Ocean and the small size of the specimens suggests that it may be an insular dwarf. The skeleton has many peculiarities including cursorial adaptations, and a mix of derived and primitive features. European hadrosauroids probably did not evolve by vicariance nor did they colonize the European Archipelago from North America, but rather came from Asia by island hopping.
Paper: Tethyshadros insularis, a new hadrosauroid dinosaur (Ornithischia) from the Upper Cretaceous of Italy (Subscription required)
TIANYULONG CONFUCIUSI
Xiao-Ting Zheng, Hai-Lu You, Xing Xu & Zhi-Ming Dong
Abstract:
Ornithischia is one of the two major groups of dinosaurs, with
heterodontosauridae as one of its major clades. Heterodontosauridae
is characterized by small, gracile bodies and a problematic phylogenetic
position. Recent phylogenetic work indicates that it represents
the most basal group of all well-known ornithischians. Previous
heterodontosaurid records are mainly from the Early Jurassic period
(205-190 million years ago) of Africa. Here we report a new heterodontosaurid, Tianyulong confuciusi gen. et sp. nov., from the Early
Cretaceous period (144-99 million years ago) of western Liaoning
Province, China. Tianyulong extends the geographical
distribution of heterodontosaurids to Asia and confirms the clade's
previously questionable temporal range extension into the Early
Cretaceous period. More surprisingly, Tianyulong bears
long, singular and unbranched filamentous integumentary (outer
skin) structures. This represents the first confirmed report,
to our knowledge, of filamentous integumentary structures in an
ornithischian dinosaur.
Nature news: Earliest feathered dinosaur discovered (Subscription required)
Paper: An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures (Subscription required)
Illustration: Lida Xing
TIANYURAPTOR OSTROMI
A short-armed dromaeosaurid from the Jehol Group of China with implications for early dromaeosaurid evolution
Zheng, X., Xu, X., You, H., Zhao, Q. and Dong, Z. (2009)
Abstract:
Recent discoveries of basal dromaeosaurids from the Early Cretaceous Jiufotang and Yixian formations of Liaoning, China, add significant new information about the transition from non-avian dinosaurs to avians. Here we report on a new dromaeosaurid, Tianyuraptor ostromi gen. et sp. nov., from the Early Cretaceous Yixian Formation of western Liaoning, China, based on a nearly complete skeleton. Tianyuraptor possesses several features only seen in other Liaoning dromaeosaurids, although to a less developed degree, and it also exhibits features unknown in Laurasian dromaeosaurids but present in the Gondwanan dromaeosaurids and basal avialans, thus reducing the morphological gap between these groups. Tianyuraptor possesses a comparatively small furcula and proportionally short forelimbs. This lies in stark contrast to the possible capacity for flight in the microraptorines, which have proportionally long and robust forelimbs and large furculae. The presence of such striking differences between the Early Cretaceous Jehol dromaeosaurids reveals a great diversity in morphology, locomotion and ecology early in dromaeosaurid evolution.
WINTONOTITAN WATTSI
New mid-Cretaceous (late Albian) dinosaurs from Winton, Queensland, Australia. (2009)
Scott A. Hocknull, Mathew A. White, Travis R. Tischler, Alex G. Cook, Naomi D. Calleja, Trish Sloan, David A. Elliott
Abstract:
Background
Australia's dinosaurian fossil record is exceptionally poor compared
to that of other similar-sized continents. Most taxa are known
from fragmentary isolated remains with uncertain taxonomic and
phylogenetic placement. A better understanding of the Australian
dinosaurian record is crucial to understanding the global palaeobiogeography
of dinosaurian groups, including groups previously considered
to have had Gondwanan origins, such as the titanosaurs and carcharodontosaurids.
Methodology/Principal Findings
We describe three new dinosaurs from the late Early Cretaceous
(latest Albian) Winton Formation of eastern Australia, including; Wintonotitan wattsi gen. et sp. nov., a basal titanosauriform; Diamantinasaurus matildae gen. et sp. nov., a derived lithostrotian
titanosaur; and Australovenator wintonensis gen. et sp. nov.,
an allosauroid. We compare an isolated astragalus from the Early
Cretaceous of southern Australia; formerly identified as Allosaurus
sp., and conclude that it most-likely represents Australovenator sp.
Conclusion/Significance
The occurrence of Australovenator from the Aptian to latest Albian
confirms the presence in Australia of allosauroids basal to the
Carcharodontosauridae. These new taxa, along with the fragmentary
remains of other taxa, indicate a diverse Early Cretaceous sauropod
and theropod fauna in Australia, including plesiomorphic forms
(e.g. Wintonotitan and Australovenator) and more derived forms
(e.g. Diamantinasaurus).
Paper: A New Mid-Cretaceous (Latest Albian) Dinosaurs from Winton, Queensland, Australia
XIONGGUANOLONG BAIMONENSIS
A longirostrine tyrannosauroid from the Early Cretaceous of China
Daqing Li, Mark A. Norell, Ke-Qin Gao, Nathan D. Smith and Peter J. Makovicky
Abstract:
The fossil record of tyrannosauroid theropods is marked by a substantial
temporal and morphological gap between small-bodied, Barremian
taxa, and extremely large-bodied taxa from the latest Cretaceous.
Here we describe a new tyrannosauroid, Xiongguanlong baimoensis n. gen. et sp., from the Aptian–Albian Xinminpu Group of western
China that represents a phylogenetic, morphological, and temporal
link between these disjunct portions of tyrannosauroid evolutionary
history. Xiongguanlong is recovered in our phylogenetic
analysis as the sister taxon to Tyrannosauridae plus Appalachiosaurus,
and marks the appearance of several tyrannosaurid hallmark features,
including a sharp parietal sagittal crest, a boxy basicranium,
a quadratojugal with a flaring dorsal process and a flexed caudal
edge, premaxillary teeth bearing a median lingual ridge, and an
expanded axial neural spine surmounted by distinct processes at
its corners. Xiongguanlong is characterized by a narrow
and elongate muzzle resembling that of Alioramus. The
slender, unornamented nasals of Xiongguanlong are inconsistent
with recent hypotheses of correlated progression in tyrannosauroid
feeding mechanics, and suggest more complex patterns of character
evolution in the integration of feeding adaptations in tyrannosaurids.
Body mass estimates for the full-grown holotype specimen of Xiongguanlong fall between those of Late Cretaceous tyrannosaurids and Barremian
tyrannosauroids, suggesting that the trend of increasing body
size observed in North American Late Cretaceous Tyrannosauridae
may extend through the Cretaceous history of Tyrannosauroidea
though further phylogenetic work is required to corroborate this.
Paper: A longirostrine tyrannosauroid from the Early Cretaceous of China (Subscription required)
News Article: Ancestor of T rex found in China (BBC)
News Article: Fossil evidence for a Goldilocks tyrannosaur (ScienceNews)
ZANABAZAR JUNIOR
A Review of the Mongolian Cretaceous Dinosaur Saurornithoides (Troodontidae: Theropoda)
Norell, M.A.; Makovicky, P.J., Bever, G.S., Balanoff, A.M., Clark, J.M., Barsbold, R. and Rowe, T. (2009)
Abstract:
We review the morphology, taxonomy, and phylogenetic relationships of the Upper Cretaceous Mongolian troodontid Saurornithoides. Saurornithoides mongoliensis is known only by the holotype from Bayan Zag, Djadokhta Formation. This specimen includes a nearly complete, but weathered, skull and mandibles, a series of dorsal, sacral, and caudal vertebrae, and a partial pelvic girdle and hind limb. Saurornithoides junior, here referred to Zanabazar, also is known only by the holotype from Bugiin Tsav, Nemegt Formation. This specimen consists of a skull and partial mandible, a series of sacral and caudal vertebrae, a partial pelvic girdle, and the distal part of the right hind limb. Saurornithoides + Zanabazar is one of the few Mongolian taxa known from both the Djadokhta and Nemegt formations. The monophyly of Saurornithoides + Zanabazar has not been seriously questioned historically, yet empirical support for this clade is currently tenuous. A privileged phylogenetic relationship between Saurornithoides, Zanabazar, and the North American troodontid Troodon formosus is supported by numerous characters including the presence of a subotic recess, lateroventrally projecting and hollow basipterygoid processes, a lacrimal whose anterior process is significantly longer than its posterior process, a highly pneumatized parasphenoid rostrum, a constricted neck of the occipital condyle, a symphyseal region of the dentary that is slightly recurved medially, and an obturator process located near the middle of the ischiadic shaft. CT data for the skulls of both species facilitated a description of the endocranial anatomy of Saurornithoides mongoliensis and Zanabazar junior, including a reconstruction of the endocranial space of Zanabazar junior. Despite being the largest of the known troodontid species, the endocranial volume of Zanabazar junior is considerably smaller than that estimated for Troodon formosus, suggesting that the extremely high encephalization quotient of Troodon formosus may be autapomorphic among troodontids.
Paper: A Review of the Mongolian Cretaceous Dinosaur Saurornithoides (Troodontidae: Theropoda)
