Near-complete enantiornithean chick found in amber

[Dinoguy2]

So anyways... Very interesting specimen!  Lots of cool info to be gleaned from a paleoart perspective: scaly palms on the hands, feathers emerging from among the scute-like scales of the feet, a possible beak on the ends of the toothed jaws that otherwise show no correlations for a beak, peculiar ecological and ontogenic implications; good stuff!   

Where did it say or show it has scaly palms on the hands?  The paper mentions possible correlation for a beak, and that the ends of the jaws might not show teeth (a lack of teeth at the end of the jaws would suggest a beak was present instead):

The rostral ends of the facial margin of both the upper and lower jaws are jagged. This is most pronounced on the premaxilla and rostrally restricted on the dentary and could represent remnants of a horny beak or small teeth.

The rostral margin of the dentary displays the same jagged edge that was observed in the X-ray μCT data (Section 3.1.1) when viewed with strong incident light (Fig. 2c, e). However, this does not provide a clear indication of teeth. The dentary appears to be darkly pigmented, suggesting that a horny beak may have been present.

Sorry, should've just said bare rather than scaly palms, my memory slipped.  See Fig. 4.e, and from page 270:

The ventral surface of the manus lacks plumage, and the exposed skin has a mottled grey, tan, and black surface that may be related to partial carbonization or saponification of the soft tissues, or to a thin layer of milky amber produced by decay products, or moisture interacting with the surrounding resin (Martinez-Delclos et al., 2004)

I take this to be that they're describing possible reasons for the odd coloration, rather than the lack of plumage.

RE beak and teeth:  That's what I get for not double checking before posting!    Although, is this the first enantiornithe to preserve a beak and teeth?  I was under the impression that it always seemed to be a case of either/or in this family.

Im not convinced of the beak thing. They say there is evidence of keratin on the oral margins but that's not the same as a beak. Crocs have keratinized skin covering their mouths too. I think if we're going to talk about the evolution of bird beaks, we need to have a pretty strict definition of what a beak is that includes structures like the tomia etc.

That being said, there are prehistoric birds with both beak and teeth, just usually restricted to different sections of the jaws. Ichthyornis and Hesperornis are the most famous examples. But the same setup of beaked jaw tips and toothed posterior jaws is found in most early ornithuromorphs. Most enantiornithes though have teeth in the jaw tips, if not the whole mouth. There's not much difference between a generic enant skull and the skull of Archaeopteryx. So if these guys did have beak tissue around their teeth, we should probably be restoring other paravians the same way.

[ITdactyl]

I'm updating on a related thread, but this will likely deserve its own [thread].  We have a preserved enantiornithine foot (in amber) that has a combination of feathers and [foot]scales.*

*I'm aware there's a study contending that tarsal scutes are probably derived feathers, but I'm not knowledgeable enough to get into that argument.

Here's the related blog post from Theropoda.blogspot:
https://theropoda.blogspot.com/2019/01/piedino-piumato-nellambra-vs-lo.html

here's the picture and diagram used in the paper:


link the the full document:
https://www.nature.com/articles/s41598-018-37427-4.epdf?author_access_token=v5kWXq41EpDB036M5c8EKNRgN0jAjWel9jnR3ZoTv0PIiOg8wIiQcEvZMH5ELRjO81SqeeczFgZylappoP543gl-byzYytcWRMA4zNj6b4R9Ae3Rgb1WDk6UkY8nPgB2-xf5EG3yA8Lx_DExWz4GjA%3D%3D