Nav: Home

The 100 million year-old piggyback

March 31, 2015

Scientists have uncovered the earliest fossilised evidence of an insect caring for its young.

The findings, published in the journal eLife, push back the earliest direct evidence of insect brood care by more than 50 million years, to at least 100 million years ago when dinosaurs dominated the earth.

The new fossil is the only record of an adult female insect from the Mesozoic, an era that spanned roughly 180 million years. The Mesozoic era was the age of the reptiles and saw both the rise and fall of the dinosaurs, as well as the breakup of the supercontinent Pangaea.

The female ensign scale insect is preserved in a piece of amber retrieved from a mine in northern Myanmar (Burma). The specimen was trapped while carrying around 60 eggs and her first freshly hatched nymphs. The eggs and nymphs are encased in a wax-coated egg sac on the abdomen. This primitive form of brood care protects young nymphs from wet and dry conditions and from natural enemies until they have acquired their own thin covering of wax.

The behaviour has been so successful for promoting the survival of offspring that it is still common in insects today. Young nymphs hatch inside the egg sac and remain there for a few days before emerging into the outside world.

The findings may even offer an explanation for the early diversification of scale insects. The emergence of flowering plants and ants are thought to have been crucial for the rapid evolution of many new insect species, but they were not yet present during the evolutionary history of the ensign scale insects.

"Brood care could have been an important driver for the early radiation of scale insects, which occurred during the end of the Jurassic or earliest Cretaceous period during the Mesozoic era," says lead author Bo Wang, an associate professor at the Chinese Academy of Sciences.

Fossilised evidence of animals caring for their young is extremely rare, especially in insects. Wingless females were largely immobile, so were less likely to be accidentally buried. A cockroach from a similar period was reported carrying a mass of eggs, but cockroaches often deposit their eggs rather than brooding them. The only other direct evidence of brood care is from Cenozoic ambers, the era that extends to the present and began about 65 million years ago with the extinction of the dinosaurs.

"Although analysis seemed to suggest that ancient insects evolved brood care, this is the first direct, unequivocal evidence for the fossil record," says Wang.

The team have named this new species Wathondara kotejai after the goddess of earth in Buddhist mythology and the late Polish entomologist Jan Koteja.
-end-
Professor Wang led the international team of scientists from the Chinese Academy of Sciences, the University of Bonn (Germany), the Natural History Museum (London), the University of Silesia, and the University of Gdansk (Poland).

Reference

The paper 'Brood care in a 100-million-year-old scale insect' can be freely accessed online at http://dx.doi.org/10.7554/eLife.05447. Contents, including text, figures, and data, are free to re-use under a CC BY 4.0 license.

About eLife Sciences Publications Ltd

eLife is a unique collaboration between the funders and practitioners of research to improve the way important research is selected, presented, and shared. eLife publishes outstanding works across the life sciences and biomedicine -- from basic biological research to applied, translational, and clinical studies. eLife is supported by the Howard Hughes Medical Institute, the Max Planck Society, and the Wellcome Trust. Learn more at elifesciences.org.

eLife

Related Dinosaurs Articles:

Volcanic eruptions triggered dawn of the dinosaurs
Huge pulses of volcanic activity are likely to have played a key role in triggering the end Triassic mass extinction, which set the scene for the rise and age of the dinosaurs, new Oxford University research has found.
Dinosaurs: Juvenile, adult or senior?
How old were the oldest dinosaurs? This question remains largely unanswered.
How the darkness and the cold killed the dinosaurs
66 million years ago, the sudden extinction of the dinosaurs started the ascent of the mammals, ultimately resulting in humankind's reign on Earth.
These dinosaurs lost their teeth as they grew up
By comparing the fossilized remains of 13 ceratosaurian theropod dinosaurs known as Limusaurus inextricabilis collected from the Upper Jurassic Shishugou Formation of northwestern China, researchers have been able to reconstruct the dinosaur's growth and development from a young hatchling of less than a year to the age of 10.
Dinosaurs' rise was 'more gradual,' new fossil evidence suggests
Researchers have discovered two small dinosaurs together with a lagerpetid, a group of animals that are recognized as precursors of dinosaurs.
More Dinosaurs News and Dinosaurs Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Teaching For Better Humans
More than test scores or good grades — what do kids need to prepare them for the future? This hour, guest host Manoush Zomorodi and TED speakers explore how to help children grow into better humans, in and out of the classroom. Guests include educators Olympia Della Flora and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#535 Superior
Apologies for the delay getting this week's episode out! A technical glitch slowed us down, but all is once again well. This week, we look at the often troubling intertwining of science and race: its long history, its ability to persist even during periods of disrepute, and the current forms it takes as it resurfaces, leveraging the internet and nationalism to buoy itself. We speak with Angela Saini, independent journalist and author of the new book "Superior: The Return of Race Science", about where race science went and how it's coming back.