An interesting article just appeared in Nature Ecology & Evolution. Here’s the short version. Researchers found a stem bird (a bird occupying an intermediate position in the phylogenetic tree between the oldest bird, Archaeopteryx, and the “true birds”) that helps bridge a large morphological gap in the fossil record. There’s a surface-level irony here given that Archaeopteryx is the OG intermediate form or “missing link.” But whenever you close a morphological gap you also create two new ones…
Anyway, the newly described bird, Cratonavis, is a mosaic of avian and non-avian characters, combining a relatively bird-like body with a more classically theropod-like skull. Don’t believe the news reports describing it as “bizarre”: I’m not even sure you could call it “unexpected.” Still, it is an interesting addition to a rapidly-filling aviary of stem birds. (Here’s a link to a non-technical write-up for anyone blocked by the paywall.)