Eocene birds montage # 3 (Patreon)

Here's that newest batched tidied and composited together, and here are some thoughts on the reconstruction process. As you'll have seen from some sketches shared here, I've been doing (low-fidelity but accurately proportioned) skeletal reconstructions first, then applying soft tissue and plumage based on (1) whatever fossil data is preserved and (2) inference based on the phylogenetic position of the taxon concerned.

At upper left, we have the stem-frogmouth Fluvioviridavis. Near-complete skeletons show that this was a deep-billed frogmouth relative, with proportions broadly like those of its extant relatives. Its rostrum looked pretty long as I was reconstructing it, but with substantial feathering added - as per extant species - about half the length of this is submerged. The plumage and patterning is all inferred from living frogmouths - one deliberate decision I made was to give the animal a smaller feathery crest than that present in living species, a speculation that may or may not be valid.

Beneath Fluvioviridavis we have the stem-rollers Primobucco and Eocoracias, both of which were clearly very roller-like albeit rather smaller and less predatory. Eocoracias is preserved with all of its feathers so what you see here is pretty accurate, the colour scheme being based on that of living rollers. Both taxa have less 'raptorial' bills than modern rollers (their stomach contents show that they were eating fruit), and their small size (they're finch-sized) led me to give them proportionally bigger eyes than their modern relatives.

At lower middle we have the tiny Gracilitarsus, a superficially sunbird-like bird that seems to be a stem-piciform of some sort. The skeletal proportions are based on the complete Messel specimens published by Mayr in 2005 but the feathering is speculative, albeit based on the wing proportions. The long, slender tarsometatarsus is obvious. The colour scheme is hypothetical - I wanted it to resemble a small, leaf-gleaning, tropical passerine-ish bird and based what you see on that of some tropical wrens.

At lower right we have the zygodactylid Primozygodactylus, reconstructed based on the complete skeletons (again, with full feathering) described by Mayr in 2017. Zygodactylids were passerine-like and seem to have resembled thrashers or babblers (though they aren't passerines); this determined the colour scheme I opted for. The proportionally short wings and two long tail feathers are evident in the fossils.

Finally... at upper right we have the cariamine Strigogyps: specifically, this is the 'Ameghinornis' holotype (which is complete and articulated, lacking only the skull and feathering). I always imagined Strigogyps to be guan- or chachalaca-like (and this view influenced aspects of my reconstruction), but it proved to be much leggier, shorter-winged and slimmer overall. The length of the tail is speculative but inferred from seriemas, and the form of the skull is also speculative but based on the approximate size of the skull's impression as preserved on the slab.

Ok, more Eocene birds next... I have a lot more to do yet. I hope you like.