Named After A One-Winged Creature Of Chinese Mythology And The Fossil Bed Where It Was Found, Jian changmaensis Is The First Microraptor Ever Discovered Outside Northeastern China And The Missing Predator Behind 100 Broken Bird Skeletons Compressed Into Pellet-Like Fossils
According to the Pittsburgh Post-Gazette, EurekAlert, and a paper published June 4 in the Annals of Carnegie Museum, paleontologists co-led by Dr. Matt Lamanna of the Carnegie Museum of Natural History in Pittsburgh have formally named a new dinosaur species: Jian changmaensis based on a partial left shoulder and forelimb recovered from the Changma Basin in Gansu Province, northwestern China.
What is Jian changmaensis, and why is the name significant? The genus name Jian references a mythological one-winged bird from ancient Chinese folklore that must fly paired with another to survive; a deliberate nod to the species’ extraordinarily birdlike characteristics and its intimate ecological relationship with the actual birds it lived alongside and hunted.
The species name changmaensis refers to the Changma Basin, the fossil site in Gansu Province where the specimen was found. Together the name encodes the specimen’s geography, its mythology, and the moment in evolutionary time when the line between dinosaur and bird was at its most ambiguous.
Jian changmaensis belongs to Microraptorinae, a subgroup of small feathered dromaeosaurid dinosaurs; the same broader family as Velociraptor. Members of this lineage include Microraptor, the four-winged dinosaur widely regarded as capable of gliding and possibly powered flight.
Jian changmaensis is the first confirmed microraptor specimen discovered outside northeastern China, a finding that significantly extends the known geographic range of the entire Microraptorinae lineage and raises questions about how widely distributed these extraordinary animals were during the Early Cretaceous.
The fossil and its context. The specimen consists of intact left shoulder and forelimb bones, first referenced in a scientific abstract in 2010 but only now formally described and assigned to a new species. That description; just a partial limb might seem insufficient to justify a new species designation.
But bone morphology at the shoulder and forelimb is highly diagnostic in dromaeosaurids, and the combination of features present in Jian changmaensis is distinct enough from all previously known microraptors to support the new species identification. “Jian changmaensis is one of the biggest microraptor specimens that has ever been found,” said Dr. Jingmai O’Connor, a paleontologist with the Field Museum of Natural History and the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences.
The discovery comes from a site of extraordinary scientific significance. The Changma Basin is famous for its fossil birds; the research team has recovered more than one hundred bird fossils at Changma, but only this single non-avian dinosaur specimen. This concentration of bird fossils is itself an extraordinary circumstance.
The Changma Basin has yielded specimens of Gansus yumenensis; one of the most abundant Early Cretaceous birds known to science in extraordinary numbers, and the site represents one of the most productive Early Cretaceous bird localities on earth.
The mystery the discovery solves. For years, the Changma Basin’s bird fossil record included something anomalous: broken bird bones compressed into tight pellet-like masses, resembling the bone-fragment pellets regurgitated by modern owls after digesting prey. The presence of these pellet-like accumulations strongly suggested the existence of a larger predatory animal at the site that was consuming birds whole or in large fragments and later regurgitating the bones. But no predator had ever been found in the Changma Basin until now.
Jian changmaensis is the missing predator. Scientists had long guessed that a larger predatory animal must have hunted these ancient birds, but they never found direct fossil evidence of this predator. The discovery resolves a mystery that had been open in the scientific literature for over a decade and transforms the Changma Basin from a site that documented prey without predator into a more complete ecological picture of Early Cretaceous northwestern China.
What did Jian changmaensis actually look like? Like all microraptors, Jian changmaensis was feathered and small; though it was among the larger microraptors known. It had long feathers on both its arms and legs, giving it four flight-capable surfaces and the appearance of a small dragon or an anatomically improbable bird. “If you saw that thing sitting in a tree, you wouldn’t think Velociraptor from Jurassic Park,” Lamanna told CNN. “This is an extraordinarily birdlike dinosaur that could take to the air to some degree.”
The four-wing configuration is the most visually striking feature of the Microraptorinae lineage. It suggests these animals did not fly in the powered, full-wing-stroke manner of modern birds, but likely used a combination of gliding and controlled aerial maneuvering to move between trees and potentially to intercept prey in flight.
The wing geometry of a four-winged animal is fundamentally different from that of any modern bird, and the aerodynamic properties of this arrangement; how lift and drag were distributed across four feathered limb surfaces, remains an active area of research.
Why this matters for understanding the origin of flight. The evolution of powered flight in birds is one of the most actively debated questions in palaeontology. Two broad competing hypotheses have been debated for over a century: the “trees down” model, in which flight evolved from gliding ancestors that launched from elevated perches; and the “ground up” model, in which flight evolved from running, jumping animals. The Microraptorinae with their four-wing configuration, feathered hindlimbs, and apparent arboreal behaviour sit directly at the centre of this debate, and every new microraptor specimen has the potential to shift it.
The well-preserved fossil could help researchers understand better how microraptors used their wings to move between trees, offering new clues about the origins of avian flight, according to Lamanna.
The Changma Basin’s rich bird record makes this connection even more meaningful. “Jian changmaensis provides critical new insight into the biological history of the Changma region and the ecological context of the ancestors of today’s birds,” researchers noted. “Birds are arguably the most successful group of land-dwelling vertebrate animals on Earth today. Learning about early birds and their close non-bird dinosaur relatives gives us a better understanding of what made the group of birds that survived so special.”
The incomplete picture and the invitation. The fossil is, by its own description, a fragment. “We don’t have very much of Jian, just some bones from the shoulder and forelimb,” Lamanna said. “It’s enough to know that there was this interesting new microraptor living 120 million years ago in what’s now northwestern China, but not enough to be able to learn everything we’d like to learn about these dinosaurs. Maybe one of your readers will eventually become a paleontologist and be the one who finds the rest of Jian.”
The verdict. A partial left shoulder found in a basin packed with ancient bird bones has resolved a decade-old mystery about a missing predator, extended the known range of an entire dinosaur lineage by more than a thousand kilometres, and added a new branch to the already extraordinary family tree of feathered dinosaurs. Jian changmaensis is, for now, a partial silhouette of a creature; four-winged, birdlike, probably gliding between trees, hunting ancestors of every bird alive today. The rest of it is still out there in the Changma Basin.
To check out our previous coverage on palaeontology and prehistoric science, read our articles here.
