A juvenile bird with possible crown-group affinities from a dinosaur-rich Cretaceous ecosystem in North America.

ABSTRACT:

Background

Living birds comprise the most speciose and anatomically diverse clade of flying vertebrates, but their poor early fossil record and the lack of resolution around the relationships of the major clades have greatly obscured extant avian origins.

Results

Here, I describe a Late Cretaceous bird from North America based on a fragmentary skeleton that includes cranial material and portions of the forelimb, hindlimb, and foot and is identified as a juvenile based on bone surface texture. Several features unite this specimen with crown Aves, but its juvenile status precludes the recognition of a distinct taxon. The North American provenance of the specimen supports a cosmopolitan distribution of early crown birds, clashes with the hypothesized southern hemisphere origins

SUBMITTER: Brownstein CD 

PROVIDER: S-EPMC10858573 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature