Pygostetus

Pygostetus is a genus of extinct bird that lived during the Early Cretaceous period. Fossils of Pygostetus have been found in the Jehol Biota of Liaoning Province, China. This ancient bird is known from a single, well-preserved specimen.

The most distinctive feature of Pygostetus is its elongated, fused tail vertebrae, which form a pygostyle. This characteristic, along with other skeletal features, places Pygostetus within the group of early birds. Its diet is believed to have consisted of small invertebrates and possibly plants, based on analyses of its fossilized remains and comparisons with related species.

The discovery of Pygostetus has contributed to our understanding of avian evolution, particularly the development of flight adaptations and the diversification of birds during the Mesozoic Era. It represents a transitional form, showcasing a mosaic of primitive and derived traits. Further research on its anatomy and phylogenetic relationships continues to shed light on the evolutionary pathways of birds.