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Re: News from both congresses



Summaric response...

- *Hongshanornis* has a sister-group in the Jiufotang Fm.
No name was mentioned.

"Archaeorhychus" perhaps.

I didn't see anything spatula-shaped, though.

O'Connor Jingmai, Gao Keqin
A new fossil bird from the early Cretaceous
Jiufotang Formation, Liaoning province,
northeastern China [T13-19]

That's the one.

"We report on the discovery of an early [sic] Cretaceous bird from
northeastern China. The new bird is slightly larger than a sparrow,
represented by a nearly complete skeleton with feather impressions preserved
in a slab and counter slab [sic]. The new specimen was quarried from the
famous lacustrine deposits of the Jiufotang Formation (Jehol Group; ca. 120
mya.) near Chaoyang, in Liaoning Province. These deposits have previously
yielded numerous fossils ranging from avian taxa such as *Cathayornis*,
*Confuciusornis* and *Jeholornis* to a variety of nonavian dinosaurs, from
*Microraptor* to *Psittacosaurus*. The new fossil bird shares many
similarities to other Jiufotang avian taxa like *Yanornis* and *Yixiaornis*
[sic; this spelling, and pronunciation, was used throughout the talk], including a curved
scapula, the broad and robust nature of the first phalanx of the second
manual digit, and a slender U-shaped furcula lacking a hypocleideum, which
support its allocation within Ornithuromorpha. However, the new bird is most
similar to the older *Hongshanornis* from the Yixian Formation of Inner
Mongolia. The two birds are comparable in size and both birds share an
unusual elongation of the hindlimbs compared to the forelimbs. Yet, the new
specimen differs from *Hongshanornis* in the morphology of its pes, skull,
and sternum that support the erection of a new taxon."


IIRC it has two phalanges on its 3rd fingers, though I could be confusing
something here... The (newly named) clade formed by *H.* and its sister-group is not at the base of Euornithes, BTW.


Alan H. Turner, Sunny H. Hwang, Mark A.
Norell
New Theropod remains from the early
Cretaceous Öösh deposits of Mongolia
[G4-34]

Missed that one. :-( As you can expect from such a large (and not too well organized) congress, all interesting talks were at the same time.

"A new theropod dinosaur from the Early Cretaceous Öösh deposits of
Baykhangor, Mongolia comprises a well-preserved right maxilla, dentary and
partial splenial. The deposits at Öösh are considered to be Early Cretaceous
(Berriasian -- Barremian). This is roughly coeval with beds forming the
Jehol group of northeastern China (Zhou et al., 2003). The new specimen
exhibits a number of derived theropod features including a triangular
anteriorly tapering maxilla, a large antorbital fossa, and maxillary
participation in the caudally elongate external nares. These features
resemble the Early Cretaceous dromaeosaurids *Sinornithosaurus millenii*
[sic] (Xu et al., 1999) and *Microraptor zhaoianus* (Xu et al., 2000; Hwang
et al., 2002) from the Yixian, as well as the basal avialan *Archaeopteryx
lithographica*.
   Although, [sic] the taxon preserves an interesting mosaic of avialan
characteristics, numerous dromaeosaurid synapomorphies are preserved in IGM
100/1119. These include a straight, parallel-sided dentary and a dorsally
displaced maxillary fenestra that is itself recessed in a caudo-dorsally
directed depression. Relative to other dromaeosaurids, the new specimen is
autapomorphic in its lack of a promaxillary fenestra.
   A comprehensive phylogenetic analysis including 58 theropod taxa
unambiguously depicts the new Öösh theropod as a member of Dromaeosauridae.
IGM 100/1119 was found to be a member of a dromaeosaurid clade less
inclusive than Unenlagiinae (i.e., *Buitreraptor gonzolezorum* [sic],
*Unenlagia comahuensis*, and *Rahonavis ostromi*; see Makovicky et al.,
2005) in all of the most parsimonious reconstructions. This placement is
supported by four unambiguous synapomorphies (dentary with subparallel
dorsal and ventral edges [...]; large maxillary and dentary teeth, less than
25 in dentary [...]; teeth with confluent root and crown [...]; dorsal
displacement of maxillary fenestra [...]). Given the large percentage of
missing data for IGM 100/1119, it was recovered in all possible placements
within the large *Sinornithosaurus* + *Velociraptor* clade, resulting in an
unresolved strict consensus.
   Along with the discovery of this new theropod taxon, additional theropod
remains from the locality have been recovered and are being described. This
material pertains to a range of small[-] to large[-]sized taxa [IIRC someone
later mentioned they have a troodontid], and together with the dromaeosaurid
described above, expands our knowledge of the faunal similarity between the
Öösh and the Jehol biotas. It also suggests the presence of a wider
diversity of Early Cretaceous dromaeosaurids that show a broader
distribution of character states and avian-like cranial features."

Matt White
The subarctometatarsus: Further evidence
supporting the evolution of flight originated
from small arboreal theropod. [G4-35]

Matt makes a convincing argument that the subarctometatarsus (and then the even more derived conditions) is an adaptation for absorbing shocks. He thinks that the shock in question is landing, and then uses this to argue for trees-down. IMNSHO tyrannosaurs, ornithomimosaurs, and alvarezsaurs argue strongly for the whole affair being a purely cursorial adaptation, however.

"A diverse range of feathered dinosaurs, discovered from numerous localities
in China, have provided startling evidence for predicting the origin of
flight. Structures, such as primitive feathers, primitive wings and various
pedal structures have been discovered. The subarctometatarsus is just one of
these structures Xu et al. (1999) [...sic], a proposed intermediate form of
arctometatarsus. Five individual subarctometatarsalian specimens examined in
this study include *Microraptor gui* (Xu et al., 2003), *Sinornithosaurus
millenii* (Xu et al., 1999), *Sinovenator changii* (Xu et al., 2002),
*Sinovenator* sp. (Unregistered specimen), and *Sinornithoides youngi*
(Russell and Dong, 1993). The structure of the subarctometatarsus is
compared to the structure of the arctometatarsus formally described in Holtz
(1994, 2000) and theropods possessing the primitive metatarsus.
   Specimens possessing the subarctometatarsus possess similar hind limb
proportions to underived forms (eg. *Compsognathus*). *Microraptor gui* and
*Sinornithosaurus millinii* [sic] possess primitive feathers, fore and hind
limb structures capable of gliding. The strenghtened metatarsus
(subarctometatar[s]us) enabled small arboreal theropods to descend from
greater heights, supporting impact with the substrate. The
subarctometatar[s]us appears to have co-evolved with the evolution of avian
feathers.
   The subarctometatarsus was preadapted for advanced cursorial ability.
Following the descent from the trees small arboreal theropods evolved
primary terrestrial lifestyles, subsequently evolving longer hind limbs for
greater strides enabling greater cursorial speed. The strengthened
metatarsus supported forces inflicted on the limb resulting from a suspended
stride. Increased size, more elongated hind limbs and evolution of the
subarctometatarsus resulted in the evolution of the arctometatarsus."

David A. Burnham
Microraptor versus Bambiraptor and the
transition to terrestriality [T13-4]

This talk was at 8 in the morning, and I got lost on the large campus, so I missed the entire talk. :-( Burnham is, however, _absolutely certain_ that *Archaeopteryx* and *Microraptor* were arboreal; trying to argue with him is a rather boring exercise.

"*Microraptor* is a small, birdlike dinosaur from China recently described
as a four-winged, feathered glider and classified wihtin the
Dromaeosauridae. Previously, dromaeosaurid dinosaurs were considered
terrestrial cursors and the group included the larger, and better-known
forms, *Velociraptor* and *Deinonychus*. *Bambiraptor* is an important link
between arboreal and cursorial adaptations and it provides additional
information on the transition to terrestriality. Comparison of the anatomy
and functional morphology of the Early Cretaceous arboreal *Microraptor*, to
this Late Cretaceous terrestrial cursor demonstrates that the life habits of
birdlike dinosaurs was consistent with a transition to terrestriality.
Additionally, palaeoenvironments and palaeoecology spanning this time frame
shows that the initial radiation of dromaeosaurs in the Early Cretaceous
Jehol Biota [...what about the Kimmeridgian teeth from Guimarota?] was
primarily arboreal in warm, forested environments. Dromaeosaurs evolved into
cursors when the climate became cooler and open areas predominated [sic] the
landscape. These dromaeosaurs are represented by Late Cretaceous Lancian
forms. *Bambiraptor*'s skeletal anatomy shows that most changes took place
in the limbs including changes in the hip and leg structure coincident with
forelimb shortening. Proportions and morphology of the hindlimbs and pes
reflect locomotor differences as well, but the skull and axial skeleton
remained conservative. Throughout their evolution, certain features were
retained such as an avian-style arm and wrist as well as a sickle claw on a
flexible second pedal digit. More importantly, the function of these
characters changed from arboreal mechanisms to predatory. Palaeoclimate was
a significant factor for evolution of birds and birdlike dinosuars during
the Mesozoic. It is characterized by faunal and floral changes reflecting
climatic change. For instance, the first known birds such as *Archaeopteryx*
were arboreal and evolved during a warm period in the Late Jurassic. The
Solnhofen quarries where *Archaeopteryx* was discovered have a windblown
faunal and floral component from a forested area indicating a typical
Jurassic forest with large trees. [I just wonder if 10 Archies can be
windblown over two hundred kilometers?] During the Early Cretaceous, the
Jehol Biota climate was warm and forested providing a suitable arboreal
habitat for *Microraptor*. The cooling trend at end [sic] of the Cretaceous
opened up the environment making it difficult for poor fliers or gliders as
forested areas became less dense. Terrestrial forms and birds with full
flight capabilities could survive best in these new environments.
Furthermore, birds with specialized [???] manus claws for tree climbing were
common in the Early Cretaceous and are so far unknown in the Late
Cretaceous. This indicates a change in the avian community [...and/or the
complete lack of LK Konservatlagerstätten...] with fliers developing an
increased ability to take off from flat surfaces. Dromaeoaurs survived well
after their initial radiation during the Jehol Biota. Only terrestrial
forms, such as *Bambiraptor*, can be found during the Late Cretaceous. Birds
of modern aspect probably replaced the primitive dromaeosaurs, *Microraptor*
and its kin, since they were more efficient fliers. For the purposes of this
paper, the term dromaeosaur is used informally to include the taxons [sic]
Microraptoria and Dromaeosauridae since the complete resolution of
dromaeosaurid evolutionary relationships has been problematic and systematic
nomenclature differs depending on which cladogram is used [nope, it differs
depending on the authors]. A majority of these cladistic analyses show
*Microraptor* as the plesiomorphic sister group to the more terrestrial
dromaeosaurs. The geologically younger *Bambiraptor* provides examples of
the morphological changes necessary for the transition from arboreality to
ground dwelling and how this transition was accomplished."

Hailu You and Zhexi Luo
Dinosaurs from the lower Cretaceous
Mazongshan area in northwestern China
[T13-33]

Emilie Läng
New data on middle Jurassic Eusauropods
[G4-17]

I missed this one, too.

"Sauropod dinosaurs are mostly known by Late Jurassic and Cretaceous forms, Neosauropoda, which are usually divided into two monophyletic groups assembling most sauropods : [sic] Diplodocoidea (*Diplodocus* and close forms) and Macronaria (*Camarasaurus* and titanosauriforms) (Wilson, 2002). On the other hand, Early and Middle Jurassic forms, primitive Eusauropoda, remain poorly known. Because the fossil record of these primitive Eusauropoda is still rather poor and because they share both primitive and derived characters, their "intermediate" position within phylogenetic relationships of sauropods is unsolved (Upchurch, 1998; Upchurch et al., 2005; Wilson and Sereno, 1998; Wilson, 2002).
Now this position is better understood thanks to old unpublished materials and recently collected fossils from France (Läng a, in prep. ["A Bathonian eusauropod from Normandy (France)"]), Algeria (Mahammed et al., 2005 [*Chebsaurus*]; Läng et al., in prep. ["New data on the Bathonian eusauropod *Chebsaurus algeriensis* from Algeria"]), Morocco and Madagascar (Läng b, in prep. ["Revision of *Lapparentosaurus madagascariensis*, a sauropod [...] from the Middle Jurassic of Andranomamy, Madagascar"]). These new data improve significantly the fossil record of the Middle Jurassic sauropods on the one hand, and clarify our knowledge concerning their phylogenetic relationships on the other hand, with the bringing to the fore of a high degree of diversification of these forms. Moreover, monophyletic groups notably cetiosaurids are now better defined."


The psittacosaur talk didn't mention the bristle-tailed specimen.

Here is Jane:

Michael D. Henderson
A juvenile tyrannosaurid from the Hell Creek Formation (Uppermost Maastrichtian) of southeastern Montana and the status of Nanotyrannus
[G4-9]


"In the summer of 2002, field crews from the Burpee Museum of Natural History in Rockford, IL recovered the partially articulated skeleton of a seven meter long tyrannosaurid from the Hell Creek Formation (Uppermost Maastrichtian) of Carter County, MT. Nicknamed Jane; [sic] the specimen (BMR P2002.4.1) is represented by 145 skeletal elements including a nearly complete but disarticulated skull. Cranial bones of BMR P2002.4.1 (Jane) closely resemble those of CMNH 7541, a controversial tyrannosaurid skull regarded as a juvenile *T. rex* (Carr, 1999) or a separate taxon, *Nanotyrannus lancensis* [(]Bakker et al., 1988). The preorbital regions of both BMR P2002.4.1 and CMNH 7541 are long and transversely narrow while the postorbital regions of both skulls are laterally broad with rostralaterally [sic] facing orbits. In addition, both skulls possess a higher number of dentary and maxillary teeth than adult *T. rex* and an oval-shaped opening on the lateral surface of the quadratojugal. Based on the degree of skeletal fusion and on histological characters, Jane is a juvenile animal. Synapomorphies [that is, autapomorphies] of *Tyrannosaurus rex* are preserved in the skull of BMR P2002.4.1 which, combined with its undoubted juvenile status, support the position that boht it and CMNH 7541 are juvenile *Tyrannosaurus rex*. Postcranial skeletal elements of BMR P2002.4.1 are consistent with those of other juvenile tyrannosaurids and indicate that BMR P2002.4.1 possessed relatively longer hind limbs and a more abducted shoulder joint than adult *T. rex*. Continued study of Jane promises to yield further information on the ontogeny of *T. rex*."

There is no separate talk on the lonchodectid, it was only mentioned in David Unwin's general overview of Jehol pterosaurs.

A very impressive talk that I saw:

Romain Amiot, Christophe Lécuyer & Éric Buffetaut: Oxygen isotope
compositions of biogenic apatites: a tool to reconstruct Cretaceous
terrestrial climates, vertebrates' ecologies and metabolic status [T13-1]

"The temperature-dependent oxygen isotope fractionation between vertebrate
body water (delta ^18O(bw)) and phosphatic tissues (delta ^18O(p)) is used
to reconstruct metabolic status (1) and living environment (2) of fossil
vertebrates as well as mean air palaeotemperatures (3), on the following
basis:
1) Present-day oxygen isotope compositions of vertebrate apatites and
models show that ectotherms have higher delta ^18O(p) values than endotherms at high latitudes due to their lower body temperature, and conversely lower delta ^18O(p) values than endotherms at low latitudes. Using this method, it has been suggested that four groups of Cretaceous dinosaurs (theropods, sauropods, ornithopods and ceratopsians) possessed high metabolic rates similar to present[-]day endothermic vertebrates (Amiot et al. submitted-a; Fricke and Rogers 2000). 2) Drinking and food waters, both of which mainly derive from meteoric water [ = rain, snow...], are the main source of oxygen used to synthesise vertebrate phosphatic tissues. Due to the delta ^18O(w) value differences between marine, brackish and fresh waters, animals living in or drinking different waters will have delta ^18O(p) values reflecting the delta ^18O(w) value of these waters. Present[-]day phosphate-water oxygen isotopic fractionation equations established for turtles (Barrick et al., 1999) and crocodilians (Amiot et al., submitted-b) have been tested and used to discriminate the aquatic environment of some of their Mesozoic counterparts (Amiot et al., submitted-b, Billon-Bruyat et al. 2005). 3) Present[-]day fractionation equations between phosphate and drinking water of vertebrates are used to retrieve the delta ^18O(w) value of past meteoric waters from the delta ^18O(p) value of fossil vertebrates. Air palaeotemperatures are then calculated using the present-day relationships existing between Mean Annual Air Temperatures (MAAT) and meteoric water delta ^18O(mw) values (e.g. Dansgaard 1964). A latitudinal air temperature gradient less steep than the present-day one has been computed from the delta ^18O(p) values of continental vertebrate faunas from the Late Campanian -- Middle Maastrichtian interval (Amiot et al. 2004), and its validity has been confirmed with other proxies.
These methods that have proven their relevance when tested on Mesozoic vertebrate remains will be applied to the Early Cretaceous vertebrates from the Jehol Biota in order to retrieve the palaeoclimatic parameters of these environments and the relative abundance of taxa having elevated metabolic rates. As integumentary structures (hair, feathers) in non-avian vertebrates are assumed to be for insulation purpose[s], the hypothesis that environmental pressure was the main reason for the great abundance of feathered dinosaurs will be tested by this means."


Let me know if this is all :-)