Epidexipteryx
From Greek 'epi' meaning 'upon' or 'over', 'deixi' meaning 'display', and 'pteryx' meaning 'wing' or 'feather', in reference to its ornamental display feathers.
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. Epidexipteryx represents the earliest known example of ornamental feathers in the fossil record.
Under dispute
Epidexipteryx hui is a scansoriopterygid; Cau (2024) considers it a junior synonym of Epidendrosaurus (and hence of Scansoriopteryx), arguing its distinguishing features are ontogenetic, though most workers retain it as a valid genus. It is placed at Scansoriopterygidae.
Diagnosis
- Four elongate ribbon-like tail feathers (ETFs) tightly attached to the last ten caudal segments.
- Highly procumbent and significantly enlarged anterior teeth, much larger than posterior teeth.
- Distally tapering pygostyle-like structure formed by ten unfused caudals at the end of the tail.
- Tail approximately 70% of trunk length, with only 16 caudal vertebrae and reduced caudal prezygapophyses.
- Pennaceous limb feathers absent despite well-preserved bones and integument, implying non-volant habit.
- Non-shafted feathers with free distal barbs arising from the edge of a membranous structure, an arrangement not previously reported.
Species
Epidexipteryx hui Zhang et al., 2008
Type species
Named in memory of paleomammalogist Hu Yaoming, using the Latinized genitive '-i' form of the surname.
- Holotype
- IVPP V15471 , Institute of Vertebrate Paleontology and Paleoanthropology
- Material
- Nearly complete skeleton with feather impressions
- Horizon
- Haifanggou Formation, Bathonian–Callovian, Middle Jurassic , 168.2–161.5 million years ago
- Locality
- Daohugou, Inner Mongolia, China
References
- Zhang, F.; Zhou, Z.; Xu, X.; Wang, X.; Sullivan, C. (2008). A bizarre Jurassic maniraptoran from China with elongate ribbon-like feathers. Nature 455(7216): 1105-1108. Springer Science and Business Media LLC. doi:10.1038/nature07447 zhang2008a
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Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.
Source of the hip height estimate, and the appearance features.
jones2026c -
Cau, A. (2024). A Unified Framework for Predatory Dinosaur Macroevolution. Bollettino della Società Paleontologica Italiana 63(1): 1-19. doi:10.4435/BSPI.2024.08
Considered Epidexipteryx a junior synonym of Epidendrosaurus.
cau2024a