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Definitive fossil evidence for the extant avian radiation in the Cretaceous
A rare, partial skeleton from the Maastrichtian of Antarctica is identified as the first Cretaceous fossil definitively placed within the extant bird radiation, and phylogenetic analyses supported by independent histological data indicate that a new species, Vegavis iaai, is a part of Anseriformes (waterfowl) and is most closely related to Anatidae, which includes true ducks.
MORPHOLOGY, PHYLOGENETIC TAXONOMY, AND SYSTEMATICS OF ICHTHYORNIS AND APATORNIS (AVIALAE: ORNITHURAE)
- J. Clarke
This analysis provided a case study in the application of phylogenetic nomenclature at the species level and evaluated the relationships among Mesozoic ornithurines including Ichthyornis dispar and the newly identified taxa.
A Basal Dromaeosaurid and Size Evolution Preceding Avian Flight
Change in theropod body size leading to flight's origin was not unidirectional, and the two dinosaurian lineages most closely related to birds, dromaeosaurids and troodontids, underwent four independent events of gigantism, and in some lineages size increased by nearly three orders of magnitude.
Insight into diversity, body size and morphological evolution from the largest Early Cretaceous enantiornithine bird
The largest Early Cretaceous enantiornithine bird from north‐east China is reported, which provides evidence that basal members of Enantiornithes share more morphologies with ornithurine birds than previously recognized, and allows a re‐evaluation of a previously proposed hypothesis of competitive exclusion among EarlyCretaceous avian clades.
The deep divergences of neornithine birds: a phylogenetic analysis of morphological characters
A broad array of morphological characters (including both cranial and postcranial characters) are analyzed for an ingroup densely sampling Neornithes, with crown clade outgroups used to polarize these characters.
Insight into the evolution of avian flight from a new clade of Early Cretaceous ornithurines from China and the morphology of Yixianornis grabaui
The complete articulated holotype specimen of Yixianornis grabaui, from the Early Cretaceous Jiufotang Formation of Liaoning Province, in north‐eastern China, arguably the best‐preserved basal ornithurine specimen yet discovered, provides the earliest evidence consistent with the presence of extant avian tail feather fanning.
Paleogene equatorial penguins challenge the proposed relationship between biogeography, diversity, and Cenozoic climate change
- J. Clarke, D. Ksepka, +5 authors Clint A. Boyd
- Biology, MedicineProceedings of the National Academy of Sciences
- 10 July 2007
The most comprehensive phylogenetic analysis of Sphenisciformes to date, combining morphological and molecular data, places the new species outside the extant penguin radiation (crown clade: Speniscidae) and supports two separate dispersals to equatorial regions during greenhouse earth conditions.
Fossil Evidence for Evolution of the Shape and Color of Penguin Feathers
The fossil reveals that key feathering features, including undifferentiated primary wing feathers and broad body contour feather shafts, evolved early in the penguin lineage, and analyses of fossilized color-imparting melanosomes reveal that their dimensions were similar to those of non-penguin avian taxa and that the feathering may have been predominantly gray-brown.
Diffusible iodine‐based contrast‐enhanced computed tomography (diceCT): an emerging tool for rapid, high‐resolution, 3‐D imaging of metazoan soft tissues
A critical review of the recent contributions to iodine‐based, contrast‐enhanced CT research is provided to enable researchers just beginning to employ contrast enhancement to make sense of this complex new landscape of methodologies.
Plumage Color Patterns of an Extinct Dinosaur
This work has reconstructed the appearance of a theropod dinosaur by mapping features of its well-preserved feathers and comparing them with modern samples from birds, and indicates that the body was gray and dark and the face had rufous speckles.