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Updated: Nov 2, 2025

Visualization of the Superior Ocular Sulcus during Danio rerio Embryogenesis
Published on: March 27, 2019
Unusual morphology in the mid-Cretaceous lizard Oculudentavis
Arnau Bolet1, Edward L Stanley2, Juan D Daza3
1Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Barcelona, Spain; School of Earth Sciences, University of Bristol, Bristol, UK.
Abstract:
Oculudentavis khaungraae was described based on a tiny skull trapped in amber. The slender tapering rostrum with retracted narial openings, large eyes, and short vaulted braincase led to its identification as the smallest avian dinosaur on record, comparable to the smallest living hummingbirds. Despite its bird-like appearance, Oculudentavis showed several features inconsistent with its original phylogenetic placement. Here, we describe a more complete specimen that demonstrates Oculudentavis is actually a bizarre lizard of uncertain position. The new specimen is described as a new species within the genus Oculudentavis. The new interpretation and phylogenetic placement highlight a rare case of convergent evolution in skull proportions but apparently not in morphological characters. Our results re-affirm the importance of Myanmar amber in yielding unusual taxa from a forest ecosystem rarely represented in the fossil record.
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