Tuesday, May 20, 2014

[PaleoOrnithology • 2010] Longicrusavis houi • A New ornithuromorph (Aves: Ornithothoraces) Bird from the Jehol Group indicative of Higher-level Diversity

Life reconstruction of Longicrusavis houi in what was probably its favored habitat, shallow lake waters. A reconstruction of the fossil specimen itself is reflected in the water.
illustration: Stephanie Abramowicz,
Dinosaur Institute, Natural History Museum of Los Angeles County

Longicrusavis houi
O'Connor, Gao & Chiappe 2010

Basal Ornithuromorpha, until recently, was one of the most poorly documented segments of early avian evolution. The known species diversity of the ornithuromorph clade has increased rapidly with the addition of new discoveries from the Early Cretaceous deposits of northeastern China. Reported in this paper is the discovery of a new bird from the Lower Cretaceous Yixian Formation, Liaoning Province, China. The specimen represents a new species, Longicrusavis houi, but bears similarities to Hongshanornis longicresta from the same formation of Inner Mongolia. The two birds are comparable in size and share an unusual sigmoid mandible and elongate hindlimbs relative to their forelimbs. Together these taxa represent a clade (Hongshanornithidae, new taxon) of specialized ‘shorebirds’ whose elongate hindlimbs indicate ecological adaptations different from those of other Jehol ornithuromorphs. Phylogenetic relationships of Mesozoic birds are discussed based on the results of a comprehensive cladistic analysis. New morphological information on Ornithuromorpha is provided through the detailed description of the new taxon together with new information on Hongshanornis.

O'Connor, J.K.; Gao, K.-Q.; and Chiappe, L.M. 2010. A New ornithuromorph (Aves: Ornithothoraces) Bird from the Jehol Group indicative of Higher-level Diversity. Journal of Vertebrate Paleontology. 30 (2): 311–321. doi: dx.doi.org/10.1080/02724631003617498

New Bird Fossil Hints at More Undiscovered Chinese Treasures 
-- The study of Mesozoic birds and the dinosaur-bird transition is one of the most exciting and vigorous fields in vertebrate paleontology today. A newly described bird from the Jehol Biota of northeast China suggests that scientists have only tapped a small proportion of the birds and dinosaurs that were living at that time, and that the rocks still have many secrets to reveal. 
http://phy.so/188755666 via @physorg_com