NEWS&ANALYSIS PA L E O N T O LO G Y
bule. Nonburrowing terrestrial snakes had an intermediate anatomy. Snake fossils usually preserve the skull better than the sinuous body, so Yi looked at published scans of the inner ear of an 85million-year-old terrestwo legs, indicating it trial snake called Diniwas primitive. In another lysia. Its structure clusstrike against the aquatic tered tightly with that hypothesis, some genetic of modern burrowers. studies indicated that “This new inner ear snakes aren’t closely evidence adds support related to living mosato the hypothesis that saur relatives, such as the snakes have a terrestrial Komodo dragon. and burrowing origin,” Hong-yu Yi, a docsays evolutionary biolotoral student with palegist Olivier Rieppel of ontologist Mark Norell the Field Museum in at the American Museum Chicago, Illinois. of Natural History in By land not sea. New clues suggest that But Caldwell argues New York City, thought the earliest snakes, like 90-million-year-old that Dinilysia’s fosshe might find answers Najash, shown in an artist’s reconstruction, sil ear lacks soft tissue in an unexpected part of were terrestrial. and so can’t be directly snakes’ anatomy: their compared to that of livinner ears, which provide the sense of balance ing snakes; and that the 2-meter-long Diniand equilibrium. Because aquatic snakes can lysia was much too big to be a burrowing orient and rotate their bodies in all directions snake, which today are much smaller. He in the water, she suspected that their inner also argues that today’s burrowing snakes ears would differ from those of terrestrial may have different adaptations to life snakes. She CT-scanned 10 diverse modern underground—and different ear strucsnakes, aquatic and terrestrial, and, for com- tures—than ancient burrowers. parison, nine modern lizards, finding that in Rieppel suggests Yi extend her study to aquatic snakes and lizards, the inner ear’s include the smaller Najash. She might now semicircular canal projects relatively far from have more specimens to analyze: Also at a disk-shaped ear structure called the vesti- the meeting, Najash’s discoverer, Sebastián bule. In modern burrowing snakes and terres- Apesteguía of Maimónides University in trial lizards, the semicircular canal projects Buenos Aires, reported two new skulls of this much less and is partly fused with the vesti- ancestral snake. –MICHAEL BALTER
LOS ANGELES, CALIFORNIA—Did the first snakes crawl on the land or swim in the water? It’s one of paleontology’s sharpest debates, pitting those who think that four-legged snake ancestors lost their limbs to become more efficient swimmers against those who believe that the demands of burrowing were key. The final verdict has yet to come in, but a new study of snake inner ears, presented at a paleontology conference* here, bolsters the view that today’s snakes evolved from terrestrial, burrowing ancestors. “We keep finding new evidence that keeps [the debate] alive,” says paleontologist Thomas Holtz of the University of Maryland, College Park. Today, the majority of the world’s 3500 species of snakes are terrestrial. But in 1997, paleontologist Michael Caldwell of the University of Alberta in Edmonton, Canada, and his colleagues reported the discovery of Pachyrhachis, a marine fossil snake that still had hind legs. They argued that the 100-million-year-old fossil pointed to extinct aquatic lizards—agile swimmers called mosasaurs—as the ancestors of snakes. Other researchers demurred, and in 2006, some of those critics reported another transitional fossil: a 90-million-year-old burrowing snake named Najash—which retained * 73rd Annual Meeting of the Society of Vertebrate Paleontology, Los Angeles, California, 30 October to 2 November.
CREDIT: GEORGE GONZALEZ/WIKIMEDIA COMMONS
Has Program to Rotate Scientists At NSF Spun Out of Control? Anja Strømme still cries when she describes what happened to her this spring at the National Science Foundation (NSF). She hopes her story might help other scientists avoid the wrenching experience she went through. The ionospheric physicist was finishing up her first year at the agency under a program that allows scientists to work for the federal government for a few years without severing their ties to their home institution. So-called rotators like Strømme are a vital cog in NSF’s grantsmaking process. Roughly one in three NSF program officers is a rotator, as are a majority of the agency’s senior managers. Strømme managed the aeronomy program within NSF’s Division of Atmospheric and Geospace Sciences. But on 14 March, the division director summoned her to his office. There, Strømme was told that she had committed “several federal offenses” relating to an alleged conflict of interest involving a grant proposal and that she “would be going to jail.” Leaving the meeting in a state of shock, Strømme spent the next few days trying frantically to find out more about her alleged misbehavior. But
www.sciencemag.org
SCIENCE
Downloaded from www.sciencemag.org on November 9, 2013
The Ears Have It: First Snakes Were Burrowers, Not Swimmers
she was never given the opportunity to defend herself, and within a week she was told that she no longer worked at the foundation. Strømme is now back in California at her previous employer, SRI International, which she says has been very supportive during her ordeal. NSF officials credit rotators with keeping the agency on the cutting edge of science. But in recent years, some key members of Congress sciencemag.org have raised questions about how NSF manages See special online reports (http://scim. rotators, including their added cost and the loss of institutional memory. Those concerns have ag/NSFrotators). triggered three reports by NSF’s in-house watchdog, the Office of Inspector General, leading to recommendations that NSF needs to do a better job of monitoring the program. Strømme learned about another downside of the program in her last few days at NSF: Rotators aren’t entitled to the same workplace protections afforded permanent employees. There is no mechanism for a rotator to respond directly to any allegations made against them, for example, nor to file a grievance. Read more online about NSF’s reliance on rotators, and why they are so vulnerable if tensions arise in the workplace. –JEFFREY MERVIS
Online
VOL 342
Published by AAAS
8 NOVEMBER 2013
683
bule. Nonburrowing terrestrial snakes had an intermediate anatomy. Snake fossils usually preserve the skull better than the sinuous body, so Yi looked at published scans of the inner ear of an 85million-year-old terrestwo legs, indicating it trial snake called Diniwas primitive. In another lysia. Its structure clusstrike against the aquatic tered tightly with that hypothesis, some genetic of modern burrowers. studies indicated that “This new inner ear snakes aren’t closely evidence adds support related to living mosato the hypothesis that saur relatives, such as the snakes have a terrestrial Komodo dragon. and burrowing origin,” Hong-yu Yi, a docsays evolutionary biolotoral student with palegist Olivier Rieppel of ontologist Mark Norell the Field Museum in at the American Museum Chicago, Illinois. of Natural History in By land not sea. New clues suggest that But Caldwell argues New York City, thought the earliest snakes, like 90-million-year-old that Dinilysia’s fosshe might find answers Najash, shown in an artist’s reconstruction, sil ear lacks soft tissue in an unexpected part of were terrestrial. and so can’t be directly snakes’ anatomy: their compared to that of livinner ears, which provide the sense of balance ing snakes; and that the 2-meter-long Diniand equilibrium. Because aquatic snakes can lysia was much too big to be a burrowing orient and rotate their bodies in all directions snake, which today are much smaller. He in the water, she suspected that their inner also argues that today’s burrowing snakes ears would differ from those of terrestrial may have different adaptations to life snakes. She CT-scanned 10 diverse modern underground—and different ear strucsnakes, aquatic and terrestrial, and, for com- tures—than ancient burrowers. parison, nine modern lizards, finding that in Rieppel suggests Yi extend her study to aquatic snakes and lizards, the inner ear’s include the smaller Najash. She might now semicircular canal projects relatively far from have more specimens to analyze: Also at a disk-shaped ear structure called the vesti- the meeting, Najash’s discoverer, Sebastián bule. In modern burrowing snakes and terres- Apesteguía of Maimónides University in trial lizards, the semicircular canal projects Buenos Aires, reported two new skulls of this much less and is partly fused with the vesti- ancestral snake. –MICHAEL BALTER
LOS ANGELES, CALIFORNIA—Did the first snakes crawl on the land or swim in the water? It’s one of paleontology’s sharpest debates, pitting those who think that four-legged snake ancestors lost their limbs to become more efficient swimmers against those who believe that the demands of burrowing were key. The final verdict has yet to come in, but a new study of snake inner ears, presented at a paleontology conference* here, bolsters the view that today’s snakes evolved from terrestrial, burrowing ancestors. “We keep finding new evidence that keeps [the debate] alive,” says paleontologist Thomas Holtz of the University of Maryland, College Park. Today, the majority of the world’s 3500 species of snakes are terrestrial. But in 1997, paleontologist Michael Caldwell of the University of Alberta in Edmonton, Canada, and his colleagues reported the discovery of Pachyrhachis, a marine fossil snake that still had hind legs. They argued that the 100-million-year-old fossil pointed to extinct aquatic lizards—agile swimmers called mosasaurs—as the ancestors of snakes. Other researchers demurred, and in 2006, some of those critics reported another transitional fossil: a 90-million-year-old burrowing snake named Najash—which retained * 73rd Annual Meeting of the Society of Vertebrate Paleontology, Los Angeles, California, 30 October to 2 November.
CREDIT: GEORGE GONZALEZ/WIKIMEDIA COMMONS
Has Program to Rotate Scientists At NSF Spun Out of Control? Anja Strømme still cries when she describes what happened to her this spring at the National Science Foundation (NSF). She hopes her story might help other scientists avoid the wrenching experience she went through. The ionospheric physicist was finishing up her first year at the agency under a program that allows scientists to work for the federal government for a few years without severing their ties to their home institution. So-called rotators like Strømme are a vital cog in NSF’s grantsmaking process. Roughly one in three NSF program officers is a rotator, as are a majority of the agency’s senior managers. Strømme managed the aeronomy program within NSF’s Division of Atmospheric and Geospace Sciences. But on 14 March, the division director summoned her to his office. There, Strømme was told that she had committed “several federal offenses” relating to an alleged conflict of interest involving a grant proposal and that she “would be going to jail.” Leaving the meeting in a state of shock, Strømme spent the next few days trying frantically to find out more about her alleged misbehavior. But
www.sciencemag.org
SCIENCE
Downloaded from www.sciencemag.org on November 9, 2013
The Ears Have It: First Snakes Were Burrowers, Not Swimmers
she was never given the opportunity to defend herself, and within a week she was told that she no longer worked at the foundation. Strømme is now back in California at her previous employer, SRI International, which she says has been very supportive during her ordeal. NSF officials credit rotators with keeping the agency on the cutting edge of science. But in recent years, some key members of Congress sciencemag.org have raised questions about how NSF manages See special online reports (http://scim. rotators, including their added cost and the loss of institutional memory. Those concerns have ag/NSFrotators). triggered three reports by NSF’s in-house watchdog, the Office of Inspector General, leading to recommendations that NSF needs to do a better job of monitoring the program. Strømme learned about another downside of the program in her last few days at NSF: Rotators aren’t entitled to the same workplace protections afforded permanent employees. There is no mechanism for a rotator to respond directly to any allegations made against them, for example, nor to file a grievance. Read more online about NSF’s reliance on rotators, and why they are so vulnerable if tensions arise in the workplace. –JEFFREY MERVIS
Online
VOL 342
Published by AAAS
8 NOVEMBER 2013
683
