Retro vs Modern #04: Archaeopteryx lithographica

Archaeopteryx lithographica was first discovered in the 1860s, still in the early days of our understanding of dinosaurs, and was a timely example of the sort of transitional form first proposed by Charles Darwin only a couple of years earlier. For over a century it was a famous icon of evolution, and has been part of a lot of weird drama over the years – it’s been central to arguments about bird origins, was accused of being a fake, and one specimen even vanished under mysterious circumstances.


At the time of its discovery Archaeopteryx was actually fairly quickly accepted as demonstrating an evolutionary link between dinosaurs and birds… but sadly this view wasn’t to last.

In the early 20th century opinion shifted towards birds not being dinosaurs but instead descended from “thecodont” reptiles (what we’d now call early archosaurs and pseudosuchians). And so for a long time Archaeopteryx ended up being depicted as simply the “first bird”, a half-reptile half-avian curiosity.

Reconstructions of it from this time period varied from very good to kind of awkward depending on how much the artist was trying to emphasize its reptilian ancestry, commonly featuring wonky-fingered wings and a scaly lizard-like face. It was also frequently depicted with bright gaudy parrot-like coloration, with a specific yellow-and-blue color scheme becoming a “paleoart meme” so prolific that it would eventually inspire the design of a Pokémon.


After decades of stagnation the dinosaur-bird link was resurrected in the early 1970s, with the discovery of the bird-like Deinonychus kicking off the Dinosaur Renaissance. Along with the explosion of spectacularly feathered dinosaur fossils from China in the mid-1990s, Archaeopteryx finally began to be properly presented as a feathered dinosaur again.

Continued study of the known Archaeopteryx specimens in the last couple of decades has vastly improved our knowledge of what this animal would have looked like, revealing previously unknown features like the exact plumage arrangement on its wings and legs, and even potentially some details about its coloration.

Living in southern Germany during the Late Jurassic, about 150-148 million years ago, Archaeopteryx inhabited what was then an island archipelago in a shallow tropical sea. It grew to around 50cm long (~1’8″) and was almost entirely covered with pennaceous feathers, externally probably just looking like a long-tailed bird.

It had broad wings, with asymmetrical flight feathers similar to those of modern birds but with more extensive coverts, some of which were probably a matte black color. Its legs also sported long “feather trousers” and a “raptor“-like hyperextensible second toe, and there was a slight forked shape to the tip of its tail.

Arguments have gone back and forth about how well it was actually able to fly, with current thinking being that it made short bursts of active flapping flight a little like a modern pheasant – but since its shoulder joints were less mobile than those of modern birds it must have used a different sort of flight stroke to generate lift.

It’s no longer always considered to have been the “first bird”, or even to have been the direct ancestor of any modern birds. Instead it represents an offshoot lineage of early birds (or very-bird-like dinosaurs) that was just one part of a still-expanding flock of feathery fossil discoveries.


66 million years ago, the end-Cretaceous mass extinction wiped out all dinosaurs except for the avian bird lineage.

…Or did it?

But I’m not talking about the dubious claims of non-avian dinosaur fossils found in places they shouldn’t be. This is about something else entirely: an unassuming little bird known as Qinornis paleocenica.

Living in Northwest China during the mid-Paleocene, about 61 million years ago, Qinornis was roughly pigeon-sized at around 30cm long (12″). It’s known only from a few bones from its legs and feet, but those bones are unusual enough to hint that it might have been something very special.

Uniquely for a Cenozoic bird, some of its foot bones weren’t fully fused together. This sort of incomplete fusion is seen in both juvenile modern birds and in adults of non-avian ornithurine birds from the Cretaceous – and the Qinornis specimen seems to have come from an adult animal.

If it was fully grown with unfused feet, then that would suggest it was actually part of a “relic” lineage living 5 million years after the mass extinction, surviving for quite some time longer than previously thought.

The last known non-avian dinosaur.

Island Weirdness #08 – Balaur bondoc

When Balaur was described in 2010 it was initially thought to be a dromaesaurid closely related to Asian forms like Velociraptor. With its particularly stocky legs built for strength rather than speed, two-fingered hands, and two large sickle claws on each foot, it was interpreted as a weird highly specialized predator terrorizing the other Hațeg Island species at the end of the Cretaceous. Although only 1.8m long (5’10”), it was hypothesized to have taken down prey much larger than itself with powerful slashing kicks.

But later analyses cast doubt on this interpretation.

A lot of the anatomical features of Balaur’s skeleton were odd for a dromaeosaurid, but matched those of avialans – a group of close evolutionary “cousins” to the dromaeosaurids, containing Archaeopteryx and the common ancestors of all modern birds. And, by 2015, multiple studies had confirmed Balaur wasn’t really a “raptor” but instead a little further along on the bird lineage.

So now our picture of this dinosaur is very different: a chunky-bodied island bird, grown large and secondarily flightless sort of like a Cretaceous equivalent to the dodo. Its double sickle claws were probably adaptations for climbing and perching in trees, and based on similar avialans it was likely a herbivore rather than a hypercarnivore.

Island Weirdness #04 – Gargantuavis philoinos

By far the biggest island in the Late Cretaceous European archipelago, the Ibero-Armorican island (sometimes also known as the Ibero-Occitan island) was made up of most of the Iberian Peninsula and France and was larger than modern-day Madagascar.

Around 73-71 million years ago one of the residents of this island was the aptly-named Gargantuavis – the largest known Mesozoic bird, and probably an example of island gigantism.

Although only known from a few isolated bones, it’s estimated to have been slightly larger than a modern cassowary, somewhere in the region of 2m tall (6′6″). At that size it would have also been secondarily flightless, which is surprising for a bird that was living alongside larger fast-moving theropods like abelisaurs.

Not much else is known about it due to the scarce remains, but it seems to have had a long slender neck and probably had a small head. Its hips were fairly broad, suggesting it wasn’t capable of running very fast, and it was likely a slow-moving herbivore that was a fairly rare member of its ecosystem.

Exactly where it belongs in the bird evolutionary tree is also unclear, with the best current guess being “some sort of euornithean”.


Enantiophoenix electrophyla, an enantiornithean bird from the Late Cretaceous of Lebanon (~95 mya).

It was similar in size to a modern starling, around 20cm (8″) long, and although only known from a fragmentary fossil it had fairly chunky leg bones with large claws. It was probably a strong percher like most other avisaurid enantiornitheans.

Several tiny pieces of amber were also found within the fossil, which have been suggested to be stomach contents. This could perhaps be evidence of Enantiophoenix feeding on tree sap like modern sapsuckers, but without a known skull it’s hard to tell for certain whether it was specialized for that sort of diet or not.


Longipteryx chaoyangensis, an enantiornithine from the Early Cretaceous of China, about 120 million years ago. With a body length of only around 15cm (6″), it had a long snout tipped with a few hooked teeth and feet capable of perching – features that indicate it may have lived very similarly to modern kingfishers, feeding on fish and small invertebrates in its swampy forest habitat.

The enantiornithines were a sort of “cousin” lineage to modern birds. Most had toothy jaws and clawed wings, and the wide variety in their skull shapes suggests that they were specialized for many different dietary niches. The entire group went extinct during the K-Pg mass extinction and left no living descendants, but during the Cretaceous they were the most widespread and diverse group of birds*, with fossils currently known from every continent except Antarctica.

* Depending on how you define “bird”.