NEWS IN FOCUS

PALAEONTOLOGY Rival species recast significance of ‘first bird’ Archaeopteryx’s status is changing, but the animal is still key to the dinosaur–bird transition.

BY EWEN CALLAWAY bird,” says Gareth Dyke, a vertebrate palaeon- brains of Archaeopteryx and a variety of dino- tologist at the University of Southampton, UK. saurs related to it were, like modern birds, all he iconic status of Archaeopteryx, the “They’d rather cut off one of their legs than relatively large for their body sizes. Because SCIENCE first animal discovered with both bird admit it has nothing to do with bird origins.” earlier dinosaurs did not fly as well as modern and dinosaur features, is under attack. New specimens of Archaeopteryx are birds, if they flew at all, the finding suggests that TMore-recently discovered rival species show also reinvigorating research. There are now the brain expansion occurred well before flight a similar mix of traits. But Archaeopteryx still 12 known fossils of the creature, and at the emerged. It is yet another clue that Archaeop-

hogged the opening symposium at the 2014 symposium Kundrat unveiled the first scien- teryx may not have been any more bird-like VLADIMIR NIKOLOV. SILHOUETTE: Society of Vertebrate Paleontology meeting tific description of the eighth to be discovered. than other suggested transitional species. “It’s in Berlin last month, and even festooned the Researchers lost track of the ‘phantom’ after it another piece of data that has taken away from official conference beer glasses. was found in Germany in the early 1990s, until the specialness of Archaeopteryx,” says Balanoff.

As the simplistic idea of a ‘first’ bird gives a collector purchased it in 2009. It is now on loan Balanoff is now investigating whether the ARCHAEOPTERYX ; SOURCES: BRAINS, REF.3/TREE, J. CLARKE BRAINS, REF.3/TREE, ; SOURCES: way to a messy evolutionary transition, newly to a Bavarian museum with an agreement that it Archaeopteryx brain shares finer anatomical

discovered fossils and improved analysis tech- will always be available for research. details — inferred from skull shape and small NATURE niques put Archaeopteryx in prime position Kundrat reported that the phantom lived impressions on it — with theropod dinosaurs, to unravel the details. “Research on Archae- more recently than other Archaeopteryx fos- the lineage that gave rise to birds. Her team also 3 E1001896 (2014)/ 12,

opteryx is really catching a new breath,” says sils, bolstering suggestions that there may been reported the discovery of a structure called a palaeobiologist Martin Kundrat of Uppsala more than one Archaeopteryx species. And in wulst in the Archaeopteryx brain, which was University in Sweden, who co-organized the July, an analysis1 of the eleventh fossil showed previously found only in living birds. The wulst, symposium at the November meeting. that the animals boasted feather-covered legs, involved in perception, might have helped the

The first Archaeopteryx fossil specimens suggesting that the feathers evolved for pur- creature to process visual information during BIOL. AL. PLOS ET turned up in limestone quarries in Bavaria, poses other than flight, such as display or insu- flight. But the question is whether it, too, is pre- ; GRAPHICS: JASIEK KRZYSZTOFIAK/ ; GRAPHICS: JASIEK southern Germany, in the early 1860s. Until lation. Kundrat says that the twelfth specimen sent in Archaeopteryx’s dinosaur kin. recently, they were the only fossil specimens might soon emerge from a private collection. Taken together, the findings suggest that found to mix bird- and dinosaur-like features. Scientists are also developing techniques there was no neat transition from dinosaur On the one hand, they are small — the fos- to analyse Archaeopteryx. Kundrat presented to bird, making the idea of a first bird seem

sils show juvenile creatures about the size of a a three-dimensional increasingly arbitrary and prone to the caprices WILLOUGHBY EMILY magpie, which as adults may have been raven- (3D) scan of the rock- “Archaeopteryx of an incomplete fossil record. “I love Archaeop- sized — and have broad feathered wings that embedded bones of is becoming teryx. I did a thesis on the animal,” says Nicholas 690–692 (2013)/R. B. J. BENSON look good for gliding; on the other, they have the phantom, which one more fossil Longrich, a palaeontologist at the University of 340,

a jaw with sharp teeth, dinosaur-like claws he made with help in this really Bath, UK. “But in some ways, we’re moving BY ILLUSTRATION and a bony tail. These features led to the idea from scientists at the diverse family beyond Archaeopteryx. It’s becoming one more of the first bird, and generations of scientists European Synchro- tree.” fossil in this really diverse family tree.” have treated the 145-million-year-old animal tron Radiation Facility Some think the debate over the transi- as a ‘transitional species’ — the key piece of in Grenoble, France. “Now we have the first tion will one day be moot. “The boundary evidence linking birds and dinosaurs (Archae- very detailed picture of the Archaeopteryx between dinosaurs and birds in the future will opteryx is Greek for ‘ancient feather’, whereas skull,” he says. completely disappear,” says Ulysse Lefevre, its German name, Urvogel, means ‘first bird’). Palaeontologist Ryan Carney of Brown Uni- a palaeontologist at the University of Liège But starting in the 1990s, the unique status of versity in Providence, Rhode Island, presented a in Belgium, who discussed new fossils from Archaeopteryx faced a challenge from the dis- 3D X-ray-tomography body scan of an Archae- China at the Berlin meeting that might further covery in China of other potential transitional opteryx fossil known as Thermopolis and a blur the line. species. Fossils of Anchiornis huxleyi and Micro- surface scan of another fossil. (Carney sports a What is clear is that Archaeopteryx research raptor gui reveal small-bodied creatures like black feather tattoo as a nod to his part in the is still key to understanding the dinosaur–bird Archaeopteryx, and they may have used their discovery2 of pigment structures in Archaeop- family tree. “There are some controversies over four wings to glide. Another, Aurornis xui, has teryx’s feathers that suggest the bird was black.) whether Archaeopteryx is the first bird or not. I legs, claws and a tail similar to those of Archae- Both analyses will help to model whether and don’t think it matters at the moment.”says Kun- opteryx, yet lived about 10 million years earlier, how Archaeopteryx flew and to determine its drat. “We are bringing Archaeopteryx back to leading some to propose it as a better candidate place in the transition from dinosaurs to birds. life through new quantifiable analysis.” ■ for first bird (see ‘The fight for first bird). Revelations about Archaeopteryx’s brain are Many scientists now believe that Archaeop- already informing its place in the evolution- 1. Foth, C., Tischlinger, H. & Rauhut, O. W. M. Nature 511, 79–82 (2014). teryx is just another dinosaur. Others find this ary tree. Last year, evolutionary biologist Amy 2. Carney, R. M. et al. Nature Commun. 3, 637 (2012). hard to swallow. “To some ornithologists this Balanoff of Stony Brook University in New York 3. Balanoff, A. M., Bever, G. S., Rowe, T. B. & is a really big deal — Archaeopteryx is the first and her colleagues reported3 in Nature that the Norell, M. A. Nature 501, 93–96 (2013).

18 | NATURE | VOL 516 | 4 DECEMBER 2014 | CORRECTED 4 DECEMBER 2014 © 2014 Macmillan Publishers Limited. All rights reserved Zanabazar e fight junior for first bird Zanabazar junior For more than a century, scientists looked to Archaeopteryx to understand the transition from dinosaurs to birds. But more-recently discovered fossils are threatening to strip Archaeopteryx of its ' rst bird' title. One by one, the features that once Archaeopteryx B    made Archaeopteryx stand out as a transitional Despite their reputation, bird brains are species are falling away. big relative to the size of their bodies owing to an expanded cerebrum (red). Archaeopteryx's brain was also large, but so were those of other theropod dinosaurs, Woodpecker such as Zanabazar junior, suggesting that this trait is not unique to birds. Archaeopteryx

Kulindadromeus zabaikalicus

Fossil of forelimb plates and bristles F   Feathers were once the sign of a bird. Things changed when feathered theropod dinosaurs — from the lineage that gave rise to modern birds — showed up in the 1990s. Now many researchers believe that all dinosaurs had feathers, thanks to Kulindadromeus zabaikalicus, which is from a completely dierent lineage. Its feathers — fossilized as structures that resemble ribbons, plates and bristles — may have A  been used for warmth or signalling. Aurornis xui is the latest creature to challenge Archaeopteryx's spot as rst bird. As well as being of similar size, it has limbs, claws and a tail like Aurornis xui Archaeopteryx, and it pre-dates its rival by about 10 million years.

Zanabazar

Kulindadromeus

Aurornis xui Archaeopteryx

F  Birds are the dinosaurs that didn't go Birds extinct. An incomplete fossil record for Avialae the transition means that each new Archaeopteryx fossil discovery can reshue the Exact positions evolutionary order. Watch Aurornis xui uncertain this space. Theropoda Troodontidae Zanabazar junior

Tyranosaurids

Sauropodomorpha Diplodocids

Kulindadromeus zabaikalicus Ornithischia Stegosaurs

Archosaurs Pterosauria Pterosaurs

Crocodylomorpha Crocodiles

4 DECEMBER 2014 | VOL 516 | NATURE | 19 © 2014 Macmillan Publishers Limited. All rights reserved