Epidexipteryx

Epidexipteryx is a genus of small maniraptoran dinosaurs, known from one fossil specimen in the collection of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing.

[3] Due to a pre-publication error,[4] a manuscript of the Epidexipteryx hui description first appeared on a preprint Web portal in late September 2008.

However, unlike in modern-style rectrices (tail feathers), the vanes were not branched into individual filaments but made up of a single ribbon-like sheet.

[9] Turner, Makovicky and Norell (2012) included Epidexipteryx but not Scansoriopteryx/Epidendrosaurus in their primary phylogenetic analysis, as a full-grown specimen is known only of the former taxon; regarding Scansoriopteryx/Epidendrosaurus, the authors were worried that including it in the primary analysis would be problematic, because it is only known from juvenile specimens, which "do not necessarily preserve all the adult morphology needed to accurately place a taxon phylogenetically" (Turner, Makovicky and Norell 2012, p. 89).

[10] A separate exploratory analysis included Scansoriopteryx/Epidendrosaurus, which was recovered as a basal member of Avialae; the authors noted that it did not clade with Epidexipteryx, which stayed outside Eumaniraptora.

[11] A monophyletic Scansoriopterygidae was recovered by Godefroit et al. (2013); the authors found scansoriopterygids to be basalmost members of Paraves and the sister group to the clade containing Avialae and Deinonychosauria.

Replica of the holotype in Japan
The scansoriopterygid genera Epidexipteryx (orange), Yi (green), and Scansoriopteryx (red) compared to a human in size
Skeletal diagram showing known elements of the holotype
Life restoration showing the animal without arm membranes
Reconstructions of the skull