Famous fossil is not an Archaeopteryx feather after all

Lasers solve the mystery of the missing quill.

  • The famous fossilized feather found in the 1860s is from some unknown animal.
  • The fossil's missing quill has long kept its identity unknown.
  • We're just at the beginning of our awareness of feathered dinosaurs.

Some time in the early 1860s, at the Solnhofen Community Quarry located about halfway between Munich and Nuremburg in Germany, a fossilized feather was discovered in shale deposits. The first mention of it appeared in 1861, in letters from paleontologist Christian Erich Hermann von Meyer — who described its appearance on two facing slabs of stone — to the editor of the German journal "Jahrbuch für Mineralogie". von Meyer proposed the feather be named Archaeopteryx lithographica. Six weeks later, von Meyer again wrote to announce a second discovery: A nearly complete skeleton of a feathered dinosaur found in the same deposits. The closeness of the timing and location caused the two finds to be linked together, with the feather considered the singular piece of evidence — the holotype — of a bird-like dinosaur to be called Archaeopteryx. Now, a new analysis of the fossil using Laser-Stimulated Fluorescence (LSF) has revealed, nearly 160 years later, that the two actually had nothing to do with each other other than proximity. Nature's Scientific Reports published the surprising result.

The case of the missing quill

One of the obstacles to a thorough understanding of the fossil has been that the feather it depicts has no quill, or calamus. Analysis of the calamus would have allowed scientists to ascertain the source of the feather on the animal from which it came. Was it a large primary wing feather, a secondary feather from the smaller secondary wing, or a tail feather called a primary covert?

When the discovery of the feather became public in 1862, the feather was described as having a calamus, and von Meyer drew it with one. However, there's nothing there to the naked eye or when the fossil is viewed under x-ray fluorescence or with UV imaging.

(Kaye, et al)

Original drawing by von Meyer, top. Fossil under white light today, bottom

Enter Laser-Stimulated Fluorescence

A microscopic examination of the fossil revealed to the authors of the new paper, led by Thomas G. Kaye, that there had originally been a quill present, but that "past preparation had engraved around the outline of the feather and inadvertently prepared away the calamus at some unknown point in the past."

The LSF uses a high-powered laser to expose geochemical differences between the fossil and the stone background. The chemicals fluoresce with different colors. In the end, LSF was able to recover the geochemical halo left behind by the missing materials. The halo perfectly matched von Meyer's drawing, as well, providing even more confidence of its accuracy.

The feather is, in fact, a primary covert. But there's something else.

(Kaye, et al)

LSF image of feather fossil with calamus halo

The Archaeopteryx lithographica is not from an Archaeopteryx

In the years since the 1860s, other specimens of feathered dinosaurs have been found, including 11 or 12 specimens of Archaeopteryx, notably one residing in a Berlin museum. While the newly identified primary covert somewhat resembles the Berlin specimen's secondary feathering — its closest match among all existing Archaeopteryx specimens — they're clearly not the same.

(Kay, et al)

Drawing of the 1860s feather superimposed over its closest match from the Berlin specimen

So, whose feather is it?

While it could be that the fossil is of an Archaeopteryx feather not yet catalogued, the greater likelihood is that it belonged to some other, thus far undiscovered feathered dinosaur. The inevitable implication? There were more bird-like dinosaurs in the Jurassic than we realized.

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Yale scientists restore brain function to 32 clinically dead pigs

Researchers hope the technology will further our understanding of the brain, but lawmakers may not be ready for the ethical challenges.

Still from John Stephenson's 1999 rendition of Animal Farm.
Surprising Science
  • Researchers at the Yale School of Medicine successfully restored some functions to pig brains that had been dead for hours.
  • They hope the technology will advance our understanding of the brain, potentially developing new treatments for debilitating diseases and disorders.
  • The research raises many ethical questions and puts to the test our current understanding of death.

The image of an undead brain coming back to live again is the stuff of science fiction. Not just any science fiction, specifically B-grade sci fi. What instantly springs to mind is the black-and-white horrors of films like Fiend Without a Face. Bad acting. Plastic monstrosities. Visible strings. And a spinal cord that, for some reason, is also a tentacle?

But like any good science fiction, it's only a matter of time before some manner of it seeps into our reality. This week's Nature published the findings of researchers who managed to restore function to pigs' brains that were clinically dead. At least, what we once thought of as dead.

What's dead may never die, it seems

The researchers did not hail from House Greyjoy — "What is dead may never die" — but came largely from the Yale School of Medicine. They connected 32 pig brains to a system called BrainEx. BrainEx is an artificial perfusion system — that is, a system that takes over the functions normally regulated by the organ. The pigs had been killed four hours earlier at a U.S. Department of Agriculture slaughterhouse; their brains completely removed from the skulls.

BrainEx pumped an experiment solution into the brain that essentially mimic blood flow. It brought oxygen and nutrients to the tissues, giving brain cells the resources to begin many normal functions. The cells began consuming and metabolizing sugars. The brains' immune systems kicked in. Neuron samples could carry an electrical signal. Some brain cells even responded to drugs.

The researchers have managed to keep some brains alive for up to 36 hours, and currently do not know if BrainEx can have sustained the brains longer. "It is conceivable we are just preventing the inevitable, and the brain won't be able to recover," said Nenad Sestan, Yale neuroscientist and the lead researcher.

As a control, other brains received either a fake solution or no solution at all. None revived brain activity and deteriorated as normal.

The researchers hope the technology can enhance our ability to study the brain and its cellular functions. One of the main avenues of such studies would be brain disorders and diseases. This could point the way to developing new of treatments for the likes of brain injuries, Alzheimer's, Huntington's, and neurodegenerative conditions.

"This is an extraordinary and very promising breakthrough for neuroscience. It immediately offers a much better model for studying the human brain, which is extraordinarily important, given the vast amount of human suffering from diseases of the mind [and] brain," Nita Farahany, the bioethicists at the Duke University School of Law who wrote the study's commentary, told National Geographic.

An ethical gray matter

Before anyone gets an Island of Dr. Moreau vibe, it's worth noting that the brains did not approach neural activity anywhere near consciousness.

The BrainEx solution contained chemicals that prevented neurons from firing. To be extra cautious, the researchers also monitored the brains for any such activity and were prepared to administer an anesthetic should they have seen signs of consciousness.

Even so, the research signals a massive debate to come regarding medical ethics and our definition of death.

Most countries define death, clinically speaking, as the irreversible loss of brain or circulatory function. This definition was already at odds with some folk- and value-centric understandings, but where do we go if it becomes possible to reverse clinical death with artificial perfusion?

"This is wild," Jonathan Moreno, a bioethicist at the University of Pennsylvania, told the New York Times. "If ever there was an issue that merited big public deliberation on the ethics of science and medicine, this is one."

One possible consequence involves organ donations. Some European countries require emergency responders to use a process that preserves organs when they cannot resuscitate a person. They continue to pump blood throughout the body, but use a "thoracic aortic occlusion balloon" to prevent that blood from reaching the brain.

The system is already controversial because it raises concerns about what caused the patient's death. But what happens when brain death becomes readily reversible? Stuart Younger, a bioethicist at Case Western Reserve University, told Nature that if BrainEx were to become widely available, it could shrink the pool of eligible donors.

"There's a potential conflict here between the interests of potential donors — who might not even be donors — and people who are waiting for organs," he said.

It will be a while before such experiments go anywhere near human subjects. A more immediate ethical question relates to how such experiments harm animal subjects.

Ethical review boards evaluate research protocols and can reject any that causes undue pain, suffering, or distress. Since dead animals feel no pain, suffer no trauma, they are typically approved as subjects. But how do such boards make a judgement regarding the suffering of a "cellularly active" brain? The distress of a partially alive brain?

The dilemma is unprecedented.

Setting new boundaries

Another science fiction story that comes to mind when discussing this story is, of course, Frankenstein. As Farahany told National Geographic: "It is definitely has [sic] a good science-fiction element to it, and it is restoring cellular function where we previously thought impossible. But to have Frankenstein, you need some degree of consciousness, some 'there' there. [The researchers] did not recover any form of consciousness in this study, and it is still unclear if we ever could. But we are one step closer to that possibility."

She's right. The researchers undertook their research for the betterment of humanity, and we may one day reap some unimaginable medical benefits from it. The ethical questions, however, remain as unsettling as the stories they remind us of.

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