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Nonavian feathers in a late Triassic archosaur.
T D Jones1, J A Ruben, L D Martin
1Department of Zoology, Oregon State University, Corvallis, OR 97331, USA. tdjones@sfasu.edu
Science (New York, N.Y.)
|June 24, 2000
Summary
Longisquama insignis, a Late Triassic archosaur, possessed feather-like structures that may be homologous to avian feathers. These findings suggest that feathers might predate the earliest known birds.
Area of Science:
- Paleontology
- Evolutionary Biology
- Vertebrate Zoology
Background:
- Longisquama insignis is an extinct archosaur from the Late Triassic of central Asia.
- This dinosaur possessed unique paired integumentary appendages along its dorsal side.
Purpose of the Study:
- To analyze the morphology of Longisquama's integumentary appendages.
- To determine the potential homology between these structures and avian feathers.
- To investigate the evolutionary origins of feathers.
Main Methods:
- Comparative anatomical analysis of Longisquama's appendages.
- Examination of the basal region's structure and comparison with modern avian feather anatomy.
Main Results:
- Longisquama's appendages share significant anatomical similarities with avian feathers, particularly at the base.
- The basal structures suggest similar developmental processes (morphogenesis) as avian feather calami.
- The exact phylogenetic position of Longisquama relative to birds remains uncertain.
Conclusions:
- The integumentary appendages of Longisquama are interpreted as non-avian feathers.
- These structures are likely homologous with avian feathers.
- If homologous, these feathers predate those of Archaeopteryx, the earliest known bird.
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