Pirkko Ukkonen ja Kristiina Mannermaa
Suomen lintujen ja nisäkkäiden varhainen historia
Museovirasto 2017, 240 s.
“Museoviraston uunituore Jääkauden jälkeläiset -julkaisu on kertomus Suomessa jääkauden aikana eläneistä eläimistä, niiden väistymisestä ilmaston muuttuessa ja nykyisten lintu- ja nisäkäslajien saapumisesta maahan sen vapautuessa lopullisesti jäästä ja jäätikön sulavesistä. Yleistajuinen kirja on suunnattu kaikille muinaisuudesta kiinnostuneille lukijoille, mutta se toimii myös tietolähteenä, oppikirjana ja hakuteoksena tutkijoille, opettajille, opiskelijoille ja medialle.”
Next week we’ll have a special lecture by Mark Norell (AMNH, Paleontology Professor), A dozen years of the theropod working group – New perspectives on bird origins
Dr. Norell works in several areas of specimen-based and theoretical research. He works on the description and relationships of coelurosaurs and studies elements of the Asian Mesozoic fauna. He analyzes important new “feathered” dinosaurs from Liaoning, China, and develops theoretical methods for better understanding phylogenetic relationships and pattern in the fossil record. Under his co-direction with Michael Novacek, a team of paleontologists working in the Gobi desert since 1990 has produced a wealth of great specimens. This has led to the development of a new phylogenetic hypothesis for coelurosaurian theropods. Similar studies have been carried out on fossil lizards and champsosaurs from this region. Work on these animals has led Dr. Norell’s team to discover some aspects of anguimorph phylogeny, to recognize new clades of lizards, to phylogenetically place problematic taxa, and to describe poorly known taxa based on new material. Dr. Norell’s theoretical work focuses on developing methodology for evaluating the effect of missing data on large data sets, sensitivity methods for character weighting, and using phylogeny to estimate patterns in the fossil record such as diversity and extinction. He also studies the relationship between stratigraphic position and phylogenetic topology.
We have a little larger room for this event, so come at 16.00 to D114 (1st floor, middle section, Physicum).
Your club hostess,
Scientists have discovered a freakish, birdlike species of dinosaur — 11 feet long, 500 pounds, with a beak, no teeth, a bony crest atop its head, murderous claws, prize-fighter arms, spindly legs, a thin tail and feathers sprouting all over the place. Officially, it’s a member of a group of dinosaurs called oviraptorosaurs.
Unofficially, it’s the Chicken From Hell.
A New Large-Bodied Oviraptorosaurian Theropod Dinosaur from the Latest Cretaceous of Western North America
Grooved enamel in the teeth of an Early Cretaceous bird:
Jingmai K. O’Connor , Yuguang Zhang , Luis M. Chiappe , Qingjin Meng , Li Quanguo & Liu Di (2013): A new enantiornithine from the Yixian Formation with the first recognized avian enamel specialization, Journal of Vertebrate Paleontology, 33:1, 1-12. http://dx.doi.org/10.1080/02724634.2012.719176
Footprints believed to have been made by the giant bird Diatryma indicate that it was a “gentle herbivore” and not a fierce carnivore.
P.S. Note, the title of the original paper (Giant Eocene bird footprints from Northwest Washington, USA) gives no indication of *what* is the significance of the footprints, a similar case that was discussed in Kurten club during Mikko’s last news flash…
Birds have paedomorphic dinosaur skulls
Bhart-Anjan S. Bhullar, Jesús Marugán-Lobón, Fernando Racimo, Gabe S. Bever, Timothy B. Rowe, Mark A. Norell & Arhat Abzhanov
The interplay of evolution and development has been at the heart of evolutionary theory for more than a century1. Heterochrony—change in the timing or rate of developmental events—has been implicated in the evolution of major vertebrate lineages such as mammals2, including humans1. Birds are the most speciose land vertebrates, with more than 10,000 living species3 representing a bewildering array of ecologies. Their anatomy is radically different from that of other vertebrates. The unique bird skull houses two highly specialized systems: the sophisticated visual and neuromuscular coordination system4, 5 allows flight coordination and exploitation of diverse visual landscapes, and the astonishing variations of the beak enable a wide range of avian lifestyles. Here we use a geometric morphometric approach integrating developmental, neontological and palaeontological data to show that the heterochronic process of paedomorphosis, by which descendants resemble the juveniles of their ancestors, is responsible for several major evolutionary transitions in the origin of birds. We analysed the variability of a series of landmarks on all known theropod dinosaur skull ontogenies as well as outgroups and birds. The first dimension of variability captured ontogeny, indicating a conserved ontogenetic trajectory. The second dimension accounted for phylogenetic change towards more bird-like dinosaurs. Basally branching eumaniraptorans and avialans clustered with embryos of other archosaurs, indicating paedomorphosis. Our results reveal at least four paedomorphic episodes in the history of birds combined with localized peramorphosis (development beyond the adult state of ancestors) in the beak. Paedomorphic enlargement of the eyes and associated brain regions parallels the enlargement of the nasal cavity and olfactory brain in mammals6. This study can be a model for investigations of heterochrony in evolutionary transitions, illuminating the origin of adaptive features and inspiring studies of developmental mechanisms.
Reconstruction of Microraptor and the Evolution of Iridescent Plumage
Quanguo Li, Ke-Qin Gao, Qingjin Meng, Julia A. Clarke, Matthew D. Shawkey, Liliana D’Alba, Rui Pei, Mick Ellison, Mark A. Norell, Jakob Vinther
You have to see the figures.
The Late Jurassic Pterosaur Rhamphorhynchus, a Frequent Victim of the Ganoid Fish Aspidorhynchus?
Eberhard Frey, Helmut Tischlinger
The Predatory Ecology of Deinonychus and the Origin of Flapping in Birds
Denver W. Fowler, Elizabeth A. Freedman, John B. Scannella, Robert E. Kambic
Most non-avian theropod dinosaurs are characterized by fearsome serrated teeth and sharp recurved claws. Interpretation of theropod predatory ecology is typically based on functional morphological analysis of these and other physical features. The notorious hypertrophied ‘killing claw’ on pedal digit (D) II of the maniraptoran theropod Deinonychus (Paraves: Dromaeosauridae) is hypothesized to have been a predatory adaptation for slashing or climbing, leading to the suggestion that Deinonychus and other dromaeosaurids were cursorial predators specialized for actively attacking and killing prey several times larger than themselves. However, this hypothesis is problematic as extant animals that possess similarly hypertrophied claws do not use them to slash or climb up prey. Here we offer an alternative interpretation: that the hypertrophied D-II claw of dromaeosaurids was functionally analogous to the enlarged talon also found on D-II of extant Accipitridae (hawks and eagles; one family of the birds commonly known as “raptors”). Here, the talon is used to maintain grip on prey of subequal body size to the predator, while the victim is pinned down by the body weight of the raptor and dismembered by the beak. The foot of Deinonychus exhibits morphology consistent with a grasping function, supportive of the prey immobilisation behavior model. Opposite morphological trends within Deinonychosauria (Dromaeosauridae + Troodontidae) are indicative of ecological separation. Placed in context of avian evolution, the grasping foot of Deinonychus and other terrestrial predatory paravians is hypothesized to have been an exaptation for the grasping foot of arboreal perching birds. Here we also describe “stability flapping”, a novel behaviour executed for positioning and stability during the initial stages of prey immobilisation, which may have been pivotal to the evolution of the flapping stroke. These findings overhaul our perception of predatory dinosaurs and highlight the role of exaptation in the evolution of novel structures and behaviours.
Additional specimen of Microraptor provides unique evidence of dinosaurs preying on birds
Jingmai O’Connor, Zhonghe Zhou, and Xing Xu
Preserved indicators of diet are extremely rare in the fossil record; even more so is unequivocal direct evidence for predator–prey relationships. Here, we report on a unique specimen of the small nonavian theropod Microraptor gui from the Early Cretaceous Jehol biota, China, which has the remains of an adult enantiornithine bird preserved in its abdomen, most likely not scavenged, but captured and consumed by the dinosaur. We provide direct evidence for the dietary preferences of Microraptor and a nonavian dinosaur feeding on a bird. Further, because Jehol enantiornithines were distinctly arboreal, in contrast to their cursorial ornithurine counterparts, this fossil suggests that Microraptor hunted in trees thereby supporting inferences that this taxon was also an arborealist, and provides further support for the arboreality of basal dromaeosaurids.