Flightless Snapshots

Gastornis ate little horses like you eat Doritos.

When it comes to Terror Birds, not just Gastornis, we typically find illustrations that are, except for the archaic illustrations from when the birds were first discovered, of a uniform body plan and posturing but having one or another scheme of feathers. This is because no accurate fossilization of feathering patterns has been captured in the specimens to date. Therefore, we have two types of illustration: the ratite, hair like feathering, and the non-ratite, think of the feathers of every bird that does not look hairy. The lack of any Gastornis preserved feathering patterns makes all of the illustrations the artist's opinion, or the opinion of the scientist consulted, directly or indirectly, by the artist. Coloration is another thing which we lack on account of the fact that the feathers and their proteins have not been preserved.

He may look more like an Emu, but this Gastornis was still a
killer. From the paper of Matthew, Stein, and Granger, 1917.

Ratite feathering was the first conclusion that scientists came to and many still stick with this theory. Part of the reason for the adherence to this idea is that the largest living birds on our planet at this exact moment in time are ratites. Ostriches, Emus, etc.. They are not limited, however, to enormous birds; the kiwi is a ratite. The special thing about ratites is that they do not have the strong sternum required for the attachment of flight muscles. Gastornis does not help us come to a feathering conclusion in looking at its anatomy. The entire genus Gastornis is an anthropomorphic hodgepodge of descendant bird anatomies. Perhaps not descended directly or even indirectly from Gastornis but possessing a number of anatomical similarities with the Gastornis genus are ratites, ducks, cranes, geese, and even herons. This is a good reason that the ratite feathering has remained popular in illustrations of the giant Terror Bird since the discovery of the fossils. Thankfully we see these birds illustrated in a much more modern posturing, but for anyone that has grown up on Tim Haines' BBC creations, the ratite feathering looks rather ancient.

©Jaime Chirinos, courtesy of Science Photo Library

And this is the reason that the ratite version of feathering has become less popular with the "Walking with Dinosaurs" generation. In the series Gastornis was shown as a very colorful forest bird, even the females were bright blues, reds, and greens. Apparently, and we will get to this, giant birds were not afraid of anything at all and even the females were not worried about camouflage according to the documentary. Here, however, we have a nicely camouflaged bird which relates to the idea of Gastornis being an ambush predator. The ambushing quality of Gastornis seems evident in this illustration as well; it is believed that in order to be an active predator Gastornis would have had to have been an ambush predator or a pack (flock?) hunter on account of the limited agility and speed implied by the skeletal remains and their known diet of small horses, or in this case Leptictidium, which were notoriously quick and agile even before they became the big frightening beasts that they are today (some animals taller than me scare me, don't judge). Regardless, the most extraneous error we have in this illustration is neither the feathering or the coloration but the fact that its claws are back in prominence on the wing. The wing here is much more wing like and less KFC chicken wing than we see in many illustrations, which is very nice, considering it is a living bird. In some Terror Birds the evidence of a regrowth of claws is somewhat evident, though, in what I have found so far, there is no such evidence in Gastornis species.

UPDATE
Okay, I had this wonderful bit about what I meant to say yesterday, but let's just let it go at "oops, I made a mistake" rather than explaining where I meant to go with the topic before I cut off abruptly yesterday. I replaced the image above with a similarly modeled, as that was my point, the modelling of the figure, Gastornis and have crossed out text that does not figure in to the discussion now. Thank you for the correction though, I do appreciate it! I have also shifted some text around.