MAJOR RESEARCH AREAS
MESOZOIC AVIAN PHYLOGENY AND DINOSAUR-BIRD TRANSITION
The origin of birds has been the subject of debates since the advent of evolutionary theory. It is now widely accepted that birds are derived non-avian dinosaurs and deeply nested within the theropod phylogeny, and their closest relatives are small-sized, feathered dromaeosaurids and troodontids. It is curious to image how the modern birds evolved from the dinosaurs. To answer that question, we sure have to go back to the Mesozoic. The Early Cretaceous Jehol Biota (130.7–120 million years before present), distributed in northeast China, preserves thousands bird fossils, which provide unprecedented information regarding early avian evolution. Our research team have being working on birds from this biota for years, and have put forward some interesting hypotheses, including phylogeny, ontogeny, and the evolution of major avian biological features.
Moreover, because of the inclusion of birds within the Dinosauria, it is not possible to fully separate avian and dinosaurian evolution. We also focus some of our research on the evolution of non-avian dinosaurs an collaborate closely with dinosaur experts at the IVPP, such as Professor Xu Xing.
EVOLUTION OF MESOZOIC BIRDS
Mesozoic Avian Phylogeny (MAP) project: Our understanding about the early phase of avian evolution has been greatly advanced by continuously increased Mesozoic birds across the world, particularly the Lower Cretaceous Jehol Biota. A comprehensive data matrix targeting the phylogeny of Mesozoic birds, the Mesozoic Avian Phylogeny (MAP) project, has actively being maintained and expanded by our research team (e.g., Wang and Zhou, in press), which currently contains over 70 widely recognized Mesozoic birds and 280 morphological characters. This data matrix is publicly accessible, and is open for comments and suggestion. Only in that way, shall we progress.
EVOLUTION AND PALEOENVIRONMENT IN THE JEHOL BIOTA
Based on previous studies and findings, this project aims to conduct a systematic and comprehensive study of the Jehol Biota, in order to achieve a better understanding of the biodiversity of this biota and its evolutionary and geological implications, to complete and detail the geochronological framework of its evolution, and to further investigate the evolutionary processes of Mesozoic vertebrates and their relationships to the paleoenvironmental background. Some of the major purposes of the project include: 1) On the basis of extensive field investigations and excavations of vertebrates in areas such as northern Hebei–southern Inner Mongolia, western Liaoning and Xinjiang, the team will systematically study important vertebrate taxa and their phylogeny in order to obtain a better understanding of their origin and early evolution; 2) By studying the process of the origin and radiation of the Jehol Biota, the scientists hope to revise or improve the hypothesis about its origin area and age; 3) The team hopes to further study the division and correlation of the Jiufotang Formation and other horizons by combining comprehensive stratigraphic, sedimentological and taphonomic studies of the Jehol Biota, and provide new perspectives into the reconstruction of the paleolakes and sedimentological background of the Jehol Biota; and 4) the team will study the biological responses of the Jehol Biota to global and regional geological events in the Early Cretaceous by focusing on the multidiscipline (e.g., paleontology, sedimentology, taphonomy, paleogeochronology, paleomagnetism and geochemistry) in order to further current understanding of the Early Cretaceous terrestrial ecosystem.
EVOLUTION OF CENOZOIC BIRDS
This section will be updated shortly.
EVOLUTION OF AVIAN SOFT-TISSUE ANATOMY
Our understanding of the early evolution of birds has increased exponentially as a result of the recent discoveries of well-preserved fossils from the Jehol Biota of China. But despite these spectacular new insights on early avian biology and evolution, important questions still exist concerning their soft-tissue anatomy. Pairing morphological discoveries and with microscopic examinations can shed light on a whole new set of biological questions related to avian and paravian evolution. We are interested in sampling some preserved soft-tissues to shed light on the microstructure and the histochemical composition of the alimentary and reproductive systems of early birds. Such studies can elucidate unknown aspects of early avian evolution, but the new techniques employed also have the potential to be applied to other extinct groups, to bring new understanding to other important evolutionary transitions in vertebrate paleontology.
AVIAN MICROANATOMY, HISTOLOGY AND FUNCTION
We employ multiple microCT scanning methods and standard paleohistology (ground-sections) to investigate the growth patterns of Mesozoic birds, such as Jeholornis, enantiornithines (e.g., Avimaia) but also more derived ornithuromorphs such as Iteravis and Mirusavis. These studies aimed to shed light on the evolution of avian growth (in comparison with non-avian dinosaurs, and extant birds). There is still much to understand about the different patterns of avian growth during the Mesozoic.
We also use histology and CT scanning technologies to understand other aspects of bird evolution, such as dental and diet adaptations, or joint morphologies and functional interpretations about avian cranial kinesis in Mesozoic birds.
HISTOCHEMISTRY, CELLULAR & MOLECULAR PALEONTOLOGY
For centuries, most ground-breaking discoveries in vertebrate paleontology have come from gross morphological observations of fossils with skeletal examinations, sometimes accompanied with soft-tissue remains. Recently, the fairly new disciplines of histology and molecular paleontology have shown that fossils can also present original and relatively unaltered tissue morphology, cellular morphology, as well as partial original chemistry and biomolecules. We also investigate the molecular preservation of key hard tissue and soft-tissue structures preserved in fossil birds and non-avian dinosaurs to better understand processes of fossilization. Understanding preserved molecules can also give access to paleobiological information about the lives of these extinct Mesozoic dinosaurs. For this endeavor, we use various methods such as nanoCT scanning, standard histology, histochemistry, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), synchrotron-FTIR, or Transmission Electron Microscopy (TEM).
Our research also involves field work (mostly in the Summer time) in many localities across China.
This section will be further updated shortly.