Imparavis

Imparavis; Temporal range: Lower Cretaceous (Aptian), 120 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Clade:	Avialae
Clade:	†Enantiornithes
Genus:	†Imparavis
Species:	†I. attenboroughi
Binomial name
	†Imparavis attenboroughi; Wang et al., 2024

Imparavis (meaning "odd bird") is an extinct genus of enantiornithine birds from the Early Cretaceous (Aptian-aged) Jiufotang Formation of Liaoning Province, China. The genus contains a single species, I. attenboroughi, known from a well-preserved skeleton.^[1]

Discovery and naming

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Imparavis type locality in Jianchang County, Liaoning, China

The Imparavis holotype specimen, STM11-176, was discovered in sediments of the Jiufotang Formation near Toudaoyingzi village in Jianchang County, Liaoning Province, China. The holotype is preserved on a single slab, consisting of an articulated, nearly complete specimen, preserved in ventral view. It is missing part of the vertebral column and most of the gastralia. Faint feather traces are visible around parts of the skeleton.^[1]

In 2024, Wang et al. described Imparavis attenboroughi as a new genus and species of enantiornithine bird based on these fossil remains. The generic name, "Imparavis", combines the Latin words "impar", meaning "odd", and "avis", meaning "bird". The specific name, "attenboroughi", honors David Attenborough and his work with natural history presentation and wildlife preservation.^[1]

Classification

In their phylogenetic analyses, Wang et al. recovered Imparavis as a member of the Enantiornithes, as the sister taxon to Yuornis in a clade also containing Gobipteryx. The results of their analyses are shown in the cladogram below, with toothless taxa highlighted.^[1]